ATL: GRACE - Advisories

[cycloneye]

BULLETIN
Tropical Depression Grace Advisory Number 13
NWS National Hurricane Center Miami FL AL072021
1100 AM EDT Mon Aug 16 2021

...CENTER OF GRACE JUST ABOUT TO CROSS THE BARAHONA PENINSULA OF
THE DOMINICAN REPUBLIC...
...FLASH FLOODING AND MUDSLIDES POSSIBLE ACROSS THE DOMINICAN
REPUBLIC AND HAITI TODAY...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.7N 71.4W
ABOUT 85 MI...140 KM SE OF PORT AU PRINCE HAITI
ABOUT 430 MI...690 KM E OF MONTEGO BAY JAMAICA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Cuba has issued a Tropical Storm Warning for the
southern coasts of the provinces of Santiago de Cuba, Granma, Las
Tunas, and Camaguey. A Tropical Storm Watch has been issued for
the southern coasts of the provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud.

The government of the Cayman Islands has issued a Tropical Storm
Warning for the Cayman Islands.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of the Dominican Republic
* Entire coast of Haiti
* Jamaica
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in Cuba and the Yucatan Peninsula of Mexico
should monitor the progress of Grace. Additional watches or
warnings are possible later today or tonight.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM EDT (1500 UTC), the center of Tropical Depression Grace
was located near latitude 17.7 North, longitude 71.4 West. Grace
is moving toward the west near 15 mph (24 km/h). A westward to
west-northwestward motion is expected over the next several days.
On the forecast track, the center of Grace will pass near the
southern coast of Hispaniola today and tonight, and then pass
between Jamaica, Cuba, and the Cayman Islands on Tuesday and
Wednesday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Some strengthening is forecast during the next few days, and Grace
is expected to become a tropical storm again by Tuesday.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are possible in the Dominican
Republic today, in Haiti today into tonight, and in Jamaica on
Tuesday. Tropical storm conditions are expected along the southern
coast of Cuba within the warning area on Tuesday, and over the
Cayman Islands beginning late Tuesday into early Wednesday.
Tropical storm conditions are possible along the southern coast of
Cuba within the watch area Tuesday night and Wednesday.

RAINFALL: Grace is expected to produce the following rainfall
amounts:

Over Haiti and the Dominican Republic...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected across the
southern terrain areas through Tuesday. This heavy rainfall may lead
to flash and urban flooding, and possible mudslides.

Over Cuba, Jamaica, and the Cayman Islands...2 to 4 inches of rain
with isolated maximum totals of 6 inches are expected through
Thursday.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola and Puerto Rico over the next day or so, and will spread
westward to Jamaica, the Cayman Islands, and the southern coast
of Cuba. These swells are likely to cause life-threatening surf
and rip current conditions. Please consult products from your local
weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 PM EDT.
Next complete advisory at 500 PM EDT.

$$
Forecaster Berg



Tropical Depression Grace Discussion Number 13
NWS National Hurricane Center Miami FL AL072021
1100 AM EDT Mon Aug 16 2021

Air Force Reserve and NOAA Hurricane Hunters were both able to
locate a center for Grace--probably the most well-defined center
observed over the past few days. That center now appears to be
moving onshore along the Barahona Peninsula of the Dominican
Republic as we speak. The planes measured several possible areas
of tropical-storm-force winds from the SFMR, however these
observations have not been supported by the more reliable 925-mb
flight-level winds for weaker systems, which were only as high as
38 kt, and warrant maintaining the 30-kt initial intensity.
Dropsonde data indicate that the central pressure has fallen to 1007
mb.

The aircraft fixes confirm that Grace is moving westward, or 280/13
kt. High pressure over the western Atlantic is forecast to slide
westward over the southeastern United States during the next
several days, which should keep Grace on a westward to west-
northwestward trajectory for the entire 5-day forecast period.
This scenario is agreed upon by all of the available track models,
and the new NHC track forecast has only been nudged slightly
southward from the previous forecast based on the latest consensus
aids.

Grace's intensity forecast remains complicated by interaction with
land and the possibility of some westerly shear during the forecast
period. However, the southern shift in the forecast track takes
the center of Grace more definitively over very warm 30 degrees
Celsius waters in the northwestern Caribbean Sea. Therefore,
gradual strengthening is anticipated while Grace approaches the
Yucatan coast of Mexico. Once the system reaches the Gulf of
Mexico, the shear appears to decrease, and conditions there will
likely be conducive for additional strengthening. In fact, many of
the models, including the consensus aids, bring Grace to hurricane
intensity, and the NHC intensity forecast has therefore been bumped
upward, bringing Grace very near hurricane strength by the end of
the forecast period.

Key Messages:

1. Heavy rainfall across the Dominican Republic, Haiti, Cuba,
Jamaica, and the Cayman Islands may lead to flash, urban, and small
stream flooding, with the potential for mudslides highest in Haiti
and the Dominican Republic.

2. Tropical storm conditions are possible over portions of
Hispaniola today and tonight, and over Jamaica on Tuesday.
Tropical storm conditions are expected over portions of the southern
coast of Cuba on Tuesday, spreading westward to the Cayman Islands
and other portions of the southern coast of Cuba Tuesday evening
through Wednesday morning.

3. There is a increasing risk of wind and rainfall impacts over
the Yucatan Peninsula of Mexico Wednesday night and Thursday.
Interests there areas should monitor the progress of Grace and
updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 16/1500Z 17.7N 71.4W 30 KT 35 MPH
12H 17/0000Z 18.2N 73.4W 30 KT 35 MPH...S COAST OF HAITI
24H 17/1200Z 18.8N 76.2W 35 KT 40 MPH
36H 18/0000Z 19.4N 79.0W 40 KT 45 MPH
48H 18/1200Z 20.1N 82.1W 45 KT 50 MPH
60H 19/0000Z 20.9N 85.2W 50 KT 60 MPH
72H 19/1200Z 21.6N 88.4W 50 KT 60 MPH...N COAST OF YUCATAN
96H 20/1200Z 22.5N 94.0W 60 KT 70 MPH
120H 21/1200Z 23.0N 98.0W 60 KT 70 MPH...INLAND

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Depression Grace Intermediate Advisory Number 13A
NWS National Hurricane Center Miami FL AL072021
200 PM EDT Mon Aug 16 2021

...HEAVY RAINS FROM GRACE SPREADING WESTWARD ACROSS SOUTHERN
HAITI...
...RISK OF FLASH FLOODING AND MUDSLIDES TO CONTINUE IN HISPANIOLA
THROUGH TUESDAY...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...17.8N 71.6W
ABOUT 70 MI...115 KM SE OF PORT AU PRINCE HAITI
ABOUT 415 MI...670 KM E OF MONTEGO BAY JAMAICA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Tropical Storm Watch for the Dominican Republic has been
discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Jamaica
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in Cuba and the Yucatan Peninsula of Mexico
should monitor the progress of Grace. Additional watches or
warnings are possible later today or tonight.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 200 PM EDT (1800 UTC), the center of Tropical Depression Grace
was located near latitude 17.8 North, longitude 71.6 West. Grace
is now moving toward the west-northwest near 12 mph (19 km/h), and
this general motion is expected to continue over the next several
days. On the forecast track, the center of Grace will move over or
near the Tiburon Peninsula of Haiti this afternoon and tonight, and
then pass between Jamaica, Cuba, and the Cayman Islands on Tuesday
and Wednesday.

Maximum sustained winds are near 35 mph (55 km/h) with higher
gusts. Some strengthening is forecast during the next few days, and
Grace is expected to become a tropical storm again by Tuesday.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are possible in Haiti this
afternoon into tonight, and in Jamaica on Tuesday. Tropical storm
conditions are expected along the southern coast of Cuba within the
warning area on Tuesday, and over the Cayman Islands beginning late
Tuesday into early Wednesday. Tropical storm conditions are
possible along the southern coast of Cuba within the watch area
Tuesday night and Wednesday.

RAINFALL: Grace is expected to produce the following rainfall
amounts:

Over Haiti and the Dominican Republic...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected across the
southern terrain areas through Tuesday. This heavy rainfall may lead
to flash and urban flooding, and possible mudslides.

Over Cuba, Jamaica, and the Cayman Islands...2 to 4 inches of rain
with isolated maximum totals of 6 inches are expected through
Thursday.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola and Puerto Rico over the next day or so, and will spread
westward to Jamaica, the Cayman Islands, and the southern coast
of Cuba. These swells are likely to cause life-threatening surf
and rip current conditions. Please consult products from your local
weather office.


NEXT ADVISORY
-------------
Next complete advisory at 500 PM EDT.

$$
Forecaster Berg

[Sciencerocks]

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM

Tropical Depression Grace Discussion Number 14
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Mon Aug 16 2021

Grace may have regained tropical storm status just before the
center moved across the Barahona Peninsula of the Dominican
Republic around midday. The Air Force Reserve Hurricane Hunters
measured peak 925-mb winds of 45 kt very near the coast, which
would equate to an intensity right at the threshold of tropical
storm. Since then, however, land interaction has likely weakened
these winds, and Grace is still estimated to be a 30-kt depression.
The center appears to have moved back over water just to the south
of the Haitian coast.

Grace has been moving a little slower today, possibly due to
interaction with the terrain of Hispaniola, and the initial motion
is estimated to be 285/11 kt. A mid-level high centered over the
western Atlantic is forecast to build westward over the
southeastern United States and northern Gulf of Mexico in the
coming days. This pattern should keep Grace on a westward to
west-northwestward trajectory for the entire 5-day forecast period,
moving across the northwestern Caribbean Sea, across the northern
Yucatan Peninsula, and into the southwestern Gulf of Mexico. The
most significant model trends are on days 4 and 5, when many of the
track models are indicating a slight west-southwest bend as the
cyclone approaches mainland Mexico. The NHC track forecast has
been nudged southward at most forecast times, but that may be
within the noise level of typical model run-to-run variability.

Once the center of Grace moves away from Hispaniola tomorrow, the
deep, warm waters of the northwestern Caribbean Sea and relatively
light deep-layer shear should be conducive for strengthening.
Model data suggest that some mid-level shear could come into play
at times, so it's not a sure bet that conditions will be ideal for
significant strengthening. Partly for that reason, the NHC
intensity forecast is near or just below the intensity consensus.
However, even this new forecast is a little higher than the
previous forecast, and many of the models indicate that Grace could
be near or at hurricane strength when it approaches the Yucatan
Peninsula in about 60 hours. After passing the Yucatan Peninsula,
additional strengthening is likely, and the new forecast now
explicitly shows Grace reaching hurricane intensity over the
southwestern Gulf of Mexico.


Key Messages:

1. Heavy rainfall across the Dominican Republic, Haiti, Cuba,
Jamaica, and the Cayman Islands may lead to flash, urban, and small
stream flooding, with the potential for mudslides highest in Haiti
and the Dominican Republic.

2. Tropical storm conditions are possible over portions of
Hispaniola this evening and tonight, and over Jamaica on Tuesday.
Tropical storm conditions are expected over portions of the southern
coast of Cuba on Tuesday, spreading westward to the Cayman Islands
and possibly other portions of the southern coast of Cuba Tuesday
evening through Wednesday morning.

3. There is a increasing risk of wind, rainfall, and storm surge
impacts on the Yucatan Peninsula of Mexico Wednesday night and
Thursday. Interests there areas should monitor the progress of
Grace and updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 17.9N 72.4W 30 KT 35 MPH
12H 17/0600Z 18.3N 74.4W 30 KT 35 MPH...NEAR SW TIP OF HAITI
24H 17/1800Z 18.9N 77.2W 35 KT 40 MPH
36H 18/0600Z 19.6N 80.4W 40 KT 45 MPH...NEAR CAYMAN ISLANDS
48H 18/1800Z 20.2N 83.5W 50 KT 60 MPH
60H 19/0600Z 20.9N 86.7W 60 KT 70 MPH...NEAR YUCATAN COAST
72H 19/1800Z 21.6N 89.9W 60 KT 70 MPH
96H 20/1800Z 22.4N 95.1W 65 KT 75 MPH
120H 21/1800Z 22.4N 98.8W 65 KT 75 MPH...INLAND

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Depression Grace Advisory Number 14
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Mon Aug 16 2021

...TORRENTIAL RAINS CONTINUE OVER PORTIONS OF HAITI AND THE
DOMINICAN REPUBLIC...
...GRACE FORECAST TO STRENGTHEN OVER THE NORTHWESTERN CARIBBEAN
SEA...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.9N 72.4W
ABOUT 50 MI...80 KM S OF PORT AU PRINCE HAITI
ABOUT 365 MI...585 KM E OF MONTEGO BAY JAMAICA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Jamaica
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in Cuba and the Yucatan Peninsula of Mexico
should monitor the progress of Grace. Additional watches or
warnings are possible tonight or on Tuesday.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Tropical Depression Grace
was located near latitude 17.9 North, longitude 72.4 West. Grace is
moving toward the west-northwest near 13 mph (20 km/h). A west to
west-northwest motion is expected during the next few days. On the
forecast track, the center of Grace will move near the Tiburon
Peninsula of Haiti through tonight, move between Jamaica and
southeastern Cuba on Tuesday, near the Cayman Islands Tuesday
night, and approach the Yucatan Peninsula of Mexico Wednesday and
Wednesday night.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Strengthening is forecast during the next few days, and Grace is
expected to regain tropical storm status on Tuesday. Grace could
be near hurricane strength when it approaches the Yucatan Peninsula
of Mexico Wednesday night.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are possible in Haiti this evening
into tonight, and in Jamaica on Tuesday. Tropical storm conditions
are expected along the southern coast of Cuba within the warning
area on Tuesday, and over the Cayman Islands beginning late Tuesday
into early Wednesday. Tropical storm conditions are possible along
the southern coast of Cuba within the watch area Tuesday night and
Wednesday.

RAINFALL: Grace is expected to produce the following rainfall
amounts:

Over Haiti and the Dominican Republic...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected across the
southern terrain areas through Tuesday. This heavy rainfall may lead
to flash and urban flooding, and possible mudslides.

Over far southern Cuba, Jamaica, and the Cayman Islands....2 to 4
inches of rain with isolated maximum totals of 6 inches are expected
through Thursday. This heavy rainfall may lead to flash and urban
flooding.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Berg



Tropical Depression Grace Discussion Number 14
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Mon Aug 16 2021

Grace may have regained tropical storm status just before the
center moved across the Barahona Peninsula of the Dominican
Republic around midday. The Air Force Reserve Hurricane Hunters
measured peak 925-mb winds of 45 kt very near the coast, which
would equate to an intensity right at the threshold of tropical
storm. Since then, however, land interaction has likely weakened
these winds, and Grace is still estimated to be a 30-kt depression.
The center appears to have moved back over water just to the south
of the Haitian coast.

Grace has been moving a little slower today, possibly due to
interaction with the terrain of Hispaniola, and the initial motion
is estimated to be 285/11 kt. A mid-level high centered over the
western Atlantic is forecast to build westward over the
southeastern United States and northern Gulf of Mexico in the
coming days. This pattern should keep Grace on a westward to
west-northwestward trajectory for the entire 5-day forecast period,
moving across the northwestern Caribbean Sea, across the northern
Yucatan Peninsula, and into the southwestern Gulf of Mexico. The
most significant model trends are on days 4 and 5, when many of the
track models are indicating a slight west-southwest bend as the
cyclone approaches mainland Mexico. The NHC track forecast has
been nudged southward at most forecast times, but that may be
within the noise level of typical model run-to-run variability.

Once the center of Grace moves away from Hispaniola tomorrow, the
deep, warm waters of the northwestern Caribbean Sea and relatively
light deep-layer shear should be conducive for strengthening.
Model data suggest that some mid-level shear could come into play
at times, so it's not a sure bet that conditions will be ideal for
significant strengthening. Partly for that reason, the NHC
intensity forecast is near or just below the intensity consensus.
However, even this new forecast is a little higher than the
previous forecast, and many of the models indicate that Grace could
be near or at hurricane strength when it approaches the Yucatan
Peninsula in about 60 hours. After passing the Yucatan Peninsula,
additional strengthening is likely, and the new forecast now
explicitly shows Grace reaching hurricane intensity over the
southwestern Gulf of Mexico.


Key Messages:

1. Heavy rainfall across the Dominican Republic, Haiti, Cuba,
Jamaica, and the Cayman Islands may lead to flash, urban, and small
stream flooding, with the potential for mudslides highest in Haiti
and the Dominican Republic.

2. Tropical storm conditions are possible over portions of
Hispaniola this evening and tonight, and over Jamaica on Tuesday.
Tropical storm conditions are expected over portions of the southern
coast of Cuba on Tuesday, spreading westward to the Cayman Islands
and possibly other portions of the southern coast of Cuba Tuesday
evening through Wednesday morning.

3. There is a increasing risk of wind, rainfall, and storm surge
impacts on the Yucatan Peninsula of Mexico Wednesday night and
Thursday. Interests there areas should monitor the progress of
Grace and updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 17.9N 72.4W 30 KT 35 MPH
12H 17/0600Z 18.3N 74.4W 30 KT 35 MPH...NEAR SW TIP OF HAITI
24H 17/1800Z 18.9N 77.2W 35 KT 40 MPH
36H 18/0600Z 19.6N 80.4W 40 KT 45 MPH...NEAR CAYMAN ISLANDS
48H 18/1800Z 20.2N 83.5W 50 KT 60 MPH
60H 19/0600Z 20.9N 86.7W 60 KT 70 MPH...NEAR YUCATAN COAST
72H 19/1800Z 21.6N 89.9W 60 KT 70 MPH
96H 20/1800Z 22.4N 95.1W 65 KT 75 MPH
120H 21/1800Z 22.4N 98.8W 65 KT 75 MPH...INLAND

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Depression Grace Intermediate Advisory Number 14A
NWS National Hurricane Center Miami FL AL072021
800 PM EDT Mon Aug 16 2021

...GRACE CONTINUES TO PRODUCE VERY HEAVY RAINFALL OVER PORTIONS OF
HAITI AND THE DOMINICAN REPUBLIC.
...THREAT OF FLOODING AND MUDSLIDES WILL CONTINUE THROUGH
TONIGHT...

SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...18.0N 73.0W
ABOUT 60 MI...95 KM SW OF PORT AU PRINCE HAITI
ABOUT 325 MI...525 KM E OF MONTEGO BAY JAMAICA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Jamaica
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in Cuba and the Yucatan Peninsula of Mexico
should monitor the progress of Grace. Additional watches or
warnings are possible tonight or on Tuesday.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 800 PM EDT (0000 UTC), the center of Tropical Depression Grace
was located near latitude 18.0 North, longitude 73.0 West. Grace is
moving toward the west-northwest near 13 mph (20 km/h). A west to
west-northwest motion is expected during the next few days. On the
forecast track, the center of Grace will continue to move near or
over the Tiburon Peninsula of Haiti tonight. It will then move
between Jamaica and southeastern Cuba on Tuesday, near the Cayman
Islands Tuesday night, and approach the Yucatan Peninsula of Mexico
Wednesday and Wednesday night.

Maximum sustained winds are near 35 mph (55 km/h) with higher
gusts. Strengthening is forecast during the next few days, and Grace
is expected to regain tropical storm status on Tuesday. Grace could
be near hurricane strength when it approaches the Yucatan Peninsula
of Mexico Wednesday night.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are possible in Haiti through
tonight, and in Jamaica on Tuesday. Tropical storm conditions are
expected along the southern coast of Cuba within the warning area on
Tuesday, and over the Cayman Islands beginning late Tuesday into
early Wednesday. Tropical storm conditions are possible along the
southern coast of Cuba within the watch area Tuesday night and
Wednesday.

RAINFALL: Grace is expected to produce the following rainfall
amounts:

Over Haiti and the Dominican Republic...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected across the
southern terrain areas through Tuesday. This heavy rainfall may lead
to flash and urban flooding, and possible mudslides.

Over far southern Cuba, Jamaica, and the Cayman Islands....2 to 4
inches of rain with isolated maximum totals of 6 inches are expected
through Thursday. This heavy rainfall may lead to flash and urban
flooding.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM EDT.

$$
Forecaster Zelinsky

[cycloneye]

BULLETIN
Tropical Depression Grace Advisory Number 15
NWS National Hurricane Center Miami FL AL072021
1100 PM EDT Mon Aug 16 2021

...EXTREME HEAVY RAIN CAUSING FLOODING ACROSS PORTIONS OF
HISPANIOLA...
...GRACE FORECAST TO BECOME A TROPICAL STORM ON TUESDAY...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.2N 73.8W
ABOUT 100 MI...165 KM WSW OF PORT AU PRINCE HAITI
ABOUT 270 MI...435 KM E OF MONTEGO BAY JAMAICA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Cuba has issued a Tropical Storm Watch for the
southern coast of the province of Pinar del Rio.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Jamaica
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests in the Yucatan Peninsula of Mexico should monitor the
progress of Grace. Watches may be required for portions of the
Yucatan coast early Tuesday.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM EDT (0300 UTC), the center of Tropical Depression Grace
was located near latitude 18.2 North, longitude 73.8 West. The
depression is moving toward the west near 14 mph (22 km/h). A
general westward to west-northwestward motion is expected for the
next several days. On the forecast track, the center of Grace will
continue to move near or over the Tiburon Peninsula of Haiti during
the next couple of hours, and then move between southeastern Cuba
and Jamaica on Tuesday. Grace is forecast to move near the Cayman
Islands Tuesday night and then approach the Yucatan peninsula of
Mexico late Wednesday or early Thursday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Strengthening is forecast during the next few days, and Grace is
forecast to become a tropical storm on Tuesday. Further
strengthening is anticipated before Grace approaches the coast of
Mexico in a few days.

The estimated minimum central pressure is 1006 mb (29.71 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are possible in Haiti overnight,
and in Jamaica on Tuesday. Tropical storm conditions are expected
along the southern coast of Cuba within the warning area on Tuesday,
and over the Cayman Islands beginning late Tuesday into early
Wednesday. Tropical storm conditions are possible along the
southern coast of Cuba within the watch area Tuesday night and
Wednesday.

RAINFALL: Grace is expected to produce the following rainfall
amounts:

Over Haiti and the Dominican Republic...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected across the
southern terrain areas through Tuesday. This heavy rainfall may lead
to flash and urban flooding, and possible mudslides.

Over far southern Cuba, Jamaica, and the Cayman Islands....2 to 4
inches of rain with isolated maximum totals of 6 inches are expected
through Thursday. This heavy rainfall may lead to flash and urban
flooding.

Over the northern Yucatan Peninsula...3 to 6 inches of rain with
isolated maximum totals of 10 inches are expected Wednesday into
Thursday, which may lead to areas of flash and urban flooding.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM EDT.
Next complete advisory at 500 AM EDT.

$$
Forecaster Zelinsky

Tropical Depression Grace Discussion Number 15
NWS National Hurricane Center Miami FL AL072021
1100 PM EDT Mon Aug 16 2021

IR and microwave imagery during the past few hours indicate that
Grace's convective organization has improved a little since this
afternoon. However, it is currently unknown if that has translated
to a better-defined surface wind field. Dvorak intensity estimates
from TAFB and SAB at 00Z supported tropical storm strength, and it
is possible Grace has redeveloped sustained winds of that magnitude.
A hurricane hunter aircraft is scheduled to investigate Grace in a
few hours, so it seems prudent to avoid making a big change before
the plane gets there. Grace is therefore conservatively maintained
as a 30 kt depression for this advisory. Regardless of Grace's exact
intensity right now, the immediate threat is still torrential
rainfall across Hispaniola overnight, which will likely cause severe
flooding in some locations.

The initial motion estimate is 280/12 kt. Confidence in the track
forecast has increased considerably during the past 24 h and the
track model spread is low. A mid-level ridge is forecast to build
over the Gulf of Mexico during the next several days, which should
keep Grace on a generally westward or west-northwestward track
through day 5. Once Grace moves away from Haiti, it should remain
over water until it reaches the Yucatan peninsula late Wednesday or
early Thursday. Very little change was made to the official track
forecast, which is based primarily on the multi-model consensus
TVCN.

Now that Grace is forecast to avoid all major land masses for the
next couple of days, all of the intensity guidance calls for some
strengthening to occur. That said, with the exception of the
COAMPS-TC model, the intensity guidance as a whole shows a slower
rate of strengthening than it did 6 h ago. The NHC forecast is now
very near the IVCN intensity consensus throughout the forecast,
including over the Gulf of Mexico where it continues to show Grace
reaching hurricane strength. Despite the slightly lower guidance for
this forecast, it still can not be ruled out that Grace will reach
hurricane strength over the western Caribbean. When the hurricane
hunter aircraft reaches Grace in a couple hours and provides more
information about the current organization of cyclone, we should
have a better feel for how quickly it could intensify prior to
reaching the coast of Mexico.

Key Messages:

1. Heavy rainfall across the Dominican Republic, Haiti, Cuba,
Jamaica, the Cayman Islands, and the northern Yucatan Peninsula may
lead to flash, urban, and small stream flooding, with the potential
for mudslides highest in Haiti and the Dominican Republic.

2. Tropical storm conditions are possible over portions of
Hispaniola overnight, and over Jamaica on Tuesday. Tropical storm
conditions are expected over portions of the southern coast of Cuba
on Tuesday, spreading westward to the Cayman Islands and possibly
other portions of the southern coast of Cuba Tuesday evening through
Wednesday morning.

3. There is a increasing risk of wind, rainfall, and storm surge
impacts on the Yucatan Peninsula of Mexico Wednesday night and
Thursday. Interests there areas should monitor the progress of
Grace and updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 17/0300Z 18.2N 73.8W 30 KT 35 MPH
12H 17/1200Z 18.6N 75.7W 35 KT 40 MPH
24H 18/0000Z 19.1N 78.8W 40 KT 45 MPH
36H 18/1200Z 19.7N 82.0W 45 KT 50 MPH
48H 19/0000Z 20.3N 85.1W 50 KT 60 MPH
60H 19/1200Z 21.0N 88.2W 50 KT 60 MPH...INLAND
72H 20/0000Z 21.6N 91.3W 55 KT 65 MPH...OVER WATER
96H 21/0000Z 22.2N 95.9W 65 KT 75 MPH
120H 22/0000Z 22.5N 100.0W 40 KT 45 MPH...INLAND

$$
Forecaster Zelinsky

[cycloneye]

BULLETIN
Tropical Storm Grace Advisory Number 16
NWS National Hurricane Center Miami FL AL072021
500 AM EDT Tue Aug 17 2021

...GRACE CONTINUING TO RE-ORGANIZE AS IT HEADS TOWARD JAMAICA...
...HEAVY RAINS CAUSING FLOODING ACROSS PORTIONS OF HISPANIOLA...


SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...18.2N 75.4W
ABOUT 165 MI...265 KM E OF MONTEGO BAY JAMAICA
ABOUT 385 MI...620 KM E OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Mexico has issued a Hurricane Watch for portions
of the Yucatan Peninsula from Cabo Catoche southward to Punta Allen.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Yucatan Peninsula of Mexico from Cabo Catoche to Punta Allen

A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Jamaica
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required for portions of the Yucatan coast later today.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 AM EDT (0900 UTC), the center of Tropical Storm Grace was
located near latitude 18.2 North, longitude 75.4 West. Grace is
moving toward the west near 16 mph (26 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will move near the northern
coast of Jamaica this afternoon. Grace is forecast to move near the
Cayman Islands tonight, and then approach the Yucatan peninsula of
Mexico late Wednesday or early Thursday.

Maximum sustained winds recently reported by an Air Force Reserve
reconnaissance aircraft were near 40 mph (65 km/h) with higher
gusts. Gradual strengthening is forecast during the next couple of
days, and Grace could be near hurricane strength when it approaches
the Yucatan coast of Mexico late Wednesday and early Thursday

Tropical-storm-force winds extend outward up to 45 miles (75 km)
from the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
http://www.hurricanes.gov/graphics_at2. ... y_messages.

WIND: Tropical storm conditions are possible in Haiti early this
morning, and in Jamaica this afternoon. Tropical storm conditions
are expected along the southern coast of Cuba within the warning
area this afternoon and evening, and over the Cayman Islands
beginning tonight into early Wednesday. Tropical storm conditions
are possible along the southern coast of Cuba within the watch area
tonight and Wednesday.

RAINFALL:
Grace is expected to produce the following rainfall amounts:

Over Haiti...5 to 10 inches of rain with isolated maximum totals of
15 inches are expected across the southern terrain areas today. This
heavy rainfall should lead to flash and urban flooding, and possible
mudslides.

Over far southern Cuba, Jamaica, the Cayman Islands, and portions of
the Yucatan Peninsula....3 to 6 inches of rain with isolated maximum
totals of 9 inches are expected through Thursday. This heavy
rainfall may lead to flash and urban flooding.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 AM EDT.
Next complete advisory at 1100 AM EDT.

$$
Forecaster Stewart


Tropical Storm Grace Discussion Number 16
NWS National Hurricane Center Miami FL AL072021
500 AM EDT Tue Aug 17 2021

An Air Force Reserve reconnaissance aircraft had difficulty locating
the center of Grace early this morning. The last few visible
satellite images along with 0200Z ASCAT wind data indicated that a
lee-side surface low had formed south of the western tip of Haiti.
That feature has gradually been pulling northward closer to the deep
convection that has developed near the well-defined mid-level
circulation center. The initial position is the midpoint between the
recon position in the latest vortex message and the mid-level
circulation noted in passive microwave imagery. The aircraft also
found some patches of 925-mb flight-level winds of 48-51 kt, which
equates to surface winds of 36-38 kt. Reliable SFMR surface winds
obtained by the aircraft were also in the 36-38-kt range. Based on
these data, Grace was upgraded back to a 35-kt tropical storm at
0600 UTC. Regardless of Grace's exact intensity right now, the
immediate threat is still torrential rainfall across western
Hispaniola today and over Jamaica this afternoon and tonight, which
will likely cause severe flooding in some locations.

The initial motion estimate is an uncertain 280/14 kt. A strong
mid-level ridge is forecast to build westward across Florida and the
Gulf of Mexico during the next several days, which should keep Grace
on a westward or west-northwestward track through the 120-h forecast
period. Only a very sight southward shift in the previous forecast
track was made, which was due primarily to the new estimated
southerly initial position, and the new NHC forecast track lies
along the northern edge of model guidance envelope.

Once Grace passes Jamaica in 12-18 hours, the cyclone will be
passing over water temperatures near 30 deg C and into a more
divergent upper-level wind flow pattern. These two favorable
conditions should allow for Grace to slowly intensify and possibly
be near hurricane strength by the time the cyclone reaches the
Yucatan peninsula in about 48 hours. Thereafter, Grace will weaken
as it pass over Yucatan, and then re-strengthen some over the Bay
of Campeche before reaching mainland Mexico in about 96 hours. The
NHC intensity forecast is close to a blend of the HCCA and IVCN
consensus models.

Key Messages:

1. Heavy rainfall across the Dominican Republic, Haiti, Cuba,
Jamaica, the Cayman Islands, and the northern Yucatan Peninsula may
lead to flash, urban, and small stream flooding, with the potential
for mudslides highest in Haiti and the Dominican Republic.

2. Tropical storm conditions are possible over portions of
Hispaniola and over Jamaica on today. Tropical storm conditions are
expected over portions of the southern coast of Cuba today,
spreading westward to the Cayman Islands and possibly other
portions of the southern coast of Cuba this evening through
Wednesday morning.

3. There is a increasing risk of wind, rainfall, and storm surge
impacts on the Yucatan Peninsula of Mexico Wednesday night and
Thursday. Interests there areas should monitor the progress of
Grace and updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 17/0900Z 18.2N 75.4W 35 KT 40 MPH
12H 17/1800Z 18.6N 77.6W 40 KT 45 MPH
24H 18/0600Z 19.1N 80.7W 45 KT 50 MPH
36H 18/1800Z 19.7N 83.9W 50 KT 60 MPH
48H 19/0600Z 20.4N 87.0W 60 KT 70 MPH
60H 19/1800Z 21.0N 90.0W 50 KT 60 MPH...INLAND
72H 20/0600Z 21.4N 92.7W 55 KT 65 MPH...OVER WATER
96H 21/0600Z 22.0N 97.2W 60 KT 70 MPH
120H 22/0600Z 22.3N 101.4W 30 KT 35 MPH...INLAND

$$
Forecaster Stewart

[cycloneye]

BULLETIN
Tropical Storm Grace Intermediate Advisory Number 16A
NWS National Hurricane Center Miami FL AL072021
800 AM EDT Tue Aug 17 2021

...GRACE NEARING JAMAICA...
...HEAVY RAINS CAUSING FLOODING ACROSS PORTIONS OF HISPANIOLA...


SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...18.2N 76.1W
ABOUT 120 MI...195 KM E OF MONTEGO BAY JAMAICA
ABOUT 340 MI...550 KM ESE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Jamaica has changed the Tropical Storm Watch for
Jamaica to a Tropical Storm Warning for Jamaica.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Yucatan Peninsula of Mexico from Cabo Catoche to Punta Allen

A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required for portions of the Yucatan coast later today.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 800 AM EDT (1200 UTC), the center of Tropical Storm Grace was
located near latitude 18.2 North, longitude 76.1 West. Grace is
moving toward the west near 16 mph (26 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will move near or over
Jamaica today. Grace is forecast to move near the Cayman Islands
tonight, and then approach the Yucatan peninsula of Mexico late
Wednesday or early Thursday.

Reports from an Air Force Hurricane Hunter aircraft indicate
that the maximum sustained winds are near 45 mph (75 km/h) with
higher gusts. Gradual strengthening is forecast during the next
couple of days, and Grace could be near hurricane strength when it
approaches the Yucatan coast of Mexico late Wednesday and early
Thursday

Tropical-storm-force winds extend outward up to 45 miles (75 km)
from the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected in portions of Jamaica
today. Tropical storm conditions are possible in Haiti early this
morning. Tropical storm conditions are expected along the southern
coast of Cuba within the warning area this afternoon and evening,
and over the Cayman Islands beginning tonight into early Wednesday.
Tropical storm conditions are possible along the southern coast of
Cuba within the watch area tonight and Wednesday.

RAINFALL:
Grace is expected to produce the following rainfall amounts:

Over Haiti...5 to 10 inches of rain with isolated maximum totals of
15 inches are expected across the southern terrain areas today. This
heavy rainfall should lead to flash and urban flooding, and possible
mudslides.

Over far southern Cuba, Jamaica, the Cayman Islands, and portions of
the Yucatan Peninsula....3 to 6 inches of rain with isolated maximum
totals of 9 inches are expected through Thursday. This heavy
rainfall may lead to flash and urban flooding.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 AM EDT.

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Tropical Storm Grace Advisory Number 17
NWS National Hurricane Center Miami FL AL072021
1100 AM EDT Tue Aug 17 2021

...TROPICAL STORM CONDITIONS SPREADING OVER JAMAICA...
...FLOODING RAINS CONTINUING OVER PORTIONS OF HAITI AND SPREADING
WESTWARD...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.3N 76.8W
ABOUT 75 MI...120 KM E OF MONTEGO BAY JAMAICA
ABOUT 295 MI...475 KM ESE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Yucatan Peninsula of Mexico from Cabo Catoche to Punta Allen

A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required for portions of the Yucatan coast later today.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM EDT (1500 UTC), the center of Tropical Storm Grace was
located near latitude 18.3 North, longitude 76.8 West. Grace is
moving toward the west near 15 mph (24 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will continue to move near
the northern coast of Jamaica this afternoon. Grace is forecast to
move near or over the Cayman Islands late tonight and early
Wednesday, and then approach the Yucatan peninsula of Mexico late
Wednesday or early Thursday.

Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Grace is forecast to strengthen into a hurricane on Wednesday, with
some additional strengthening possible prior to the center reaching
the Yucatan Peninsula.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
from the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected in Jamaica today.
Tropical storm conditions are possible in portions of Haiti for the
next several hours. Tropical storm conditions are expected along
the southern coast of Cuba within the warning area this afternoon
and evening, and over the Cayman Islands beginning tonight into
early Wednesday. Tropical storm conditions are possible along the
southern coast of Cuba within the watch area tonight and Wednesday.

RAINFALL: The system is expected to produce the following rainfall
amounts:

Over Haiti...an additional 2 to 4 inches of rain with isolated
maximum totals of 15 inches are expected across the southern terrain
areas today. This heavy rainfall should lead to flash and urban
flooding, and possible mudslides.

Over far southern Cuba, Jamaica, the Cayman Islands, and portions of
the Yucatan Peninsula....3 to 6 inches of rain with isolated maximum
totals of 10 inches are expected through Thursday. This heavy
rainfall may lead to flash and urban flooding.

STORM SURGE: A dangerous storm surge will raise water levels by as
much as 2-4 feet above normal tide levels along the immediate coast
near and to the north of where the center makes landfall in the
northeastern Yucatan Peninsula late Wednesday or early Thursday.
Near the coast,the surge will be accompanied by large and
destructive waves.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 PM EDT.
Next complete advisory at 500 PM EDT.

$$
Forecaster Pasch


Tropical Storm Grace Discussion Number 17
NWS National Hurricane Center Miami FL AL072021
1100 AM EDT Tue Aug 17 2021

The cloud pattern of Grace is gradually becoming better organized
on satellite images, but the system still lacks distinct banding
features over the eastern semicircle. Cirrus-level outflow from the
system appears to be well defined. Flight-level and SFMR-observed
surface winds, as well as dropsonde measurements, support an
intensity of 45 kt for this advisory.

Not much change in intensity is likely through this afternoon while
the circulation of Grace interacts with the island of Jamaica.
Thereafter, since the cyclone will be over the very high heat
content waters of the northwestern Caribbean Sea with modestly low
vertical shear tonight and Wednesday, strengthening is anticipated.
Grace will likely become a hurricane tomorrow and continue to
intensify before moving over the Yucatan Peninsula. The interaction
with that land mass is expected to temporarily interrupt
strengthening, with some reintensification over the Bay of Campeche
in 3-4 days. The official intensity forecast is near the model
consensus for the first half of the forecast period, but below the
consensus for the latter part of the period owing to the inherent
uncertainties for that extended time frame.

Grace continues to move just a little north of due west, or at
about 280/13 kt. A well-defined 500 mb ridge should remain
entrenched to the north of the tropical cyclone for the next several
days. Therefore, a continued west to west-northwestward track is
likely to continue for most, if not all, of the forecast period.
The official forecast is close to the previous one through 72 hours
and just slightly south of it at 4-5 days. This is very similar to
the latest multi-model consensus prediction.


Key Messages:

1. Heavy rainfall across Haiti, Cuba, Jamaica, the Cayman Islands,
and the northern Yucatan Peninsula may lead to flash, urban, and
small stream flooding, with the potential for mudslides highest in
Haiti and Jamaica.

2. Tropical storm conditions are expected over portions of Jamaica
today, and over the Cayman Islands later today and tonight.
Tropical storm conditions are expected over portions of the southern
coast of Cuba today in the warning area, spreading westward to
possibly other portions of the southern coast of Cuba this evening
through Wednesday morning.

3. There is an increasing risk of wind, rainfall, and storm surge
impacts on the Yucatan Peninsula of Mexico Wednesday night and
Thursday, and a Hurricane Warning will likely be needed for that
area later today.


FORECAST POSITIONS AND MAX WINDS

INIT 17/1500Z 18.3N 76.8W 45 KT 50 MPH
12H 18/0000Z 18.8N 79.0W 55 KT 65 MPH
24H 18/1200Z 19.2N 82.2W 65 KT 75 MPH
36H 19/0000Z 19.7N 85.3W 70 KT 80 MPH
48H 19/1200Z 20.4N 88.3W 65 KT 75 MPH...INLAND
60H 20/0000Z 20.9N 91.3W 60 KT 70 MPH...OVER WATER
72H 20/1200Z 21.1N 94.0W 65 KT 75 MPH
96H 21/1200Z 21.5N 98.5W 65 KT 75 MPH...INLAND
120H 22/1200Z 21.5N 103.0W 30 KT 35 MPH...POST-TROP/INLAND

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Tropical Storm Grace Intermediate Advisory Number 17A
NWS National Hurricane Center Miami FL AL072021
200 PM EDT Tue Aug 17 2021

...HEAVY RAINS SPREADING OVER JAMAICA AND BEGINNING TO
SPREAD OVER EASTERN CUBA...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...18.5N 77.5W
ABOUT 25 MI...40 KM E OF MONTEGO BAY JAMAICA
ABOUT 250 MI...400 KM ESE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Tropical Storm Watch for Haiti is discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Yucatan Peninsula of Mexico from Cabo Catoche to Punta Allen

A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands

A Tropical Storm Watch is in effect for...
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required for portions of the Yucatan coast later today.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 200 PM EDT (1800 UTC), the center of Tropical Storm Grace was
located near latitude 18.5 North, longitude 77.5 West. Grace is
moving toward the west near 15 mph (24 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will continue to move near
the northern coast of Jamaica this afternoon. Grace is forecast to
move near or over the Cayman Islands late tonight and early
Wednesday, and then approach the Yucatan peninsula of Mexico late
Wednesday or early Thursday.

Maximum sustained winds are near 50 mph (85 km/h) with higher
gusts. Grace is forecast to strengthen into a hurricane on
Wednesday, with some additional strengthening possible prior to the
center reaching the Yucatan Peninsula.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
from the center. Kingston, Jamaica recently reported a wind gust
to 46 mph (74 km/h).

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected to continue over
portions of Jamaica today. Tropical storm conditions are expected
along the southern coast of Cuba within the warning area later this
afternoon through this evening, and over the Cayman Islands
beginning tonight and into early Wednesday. Tropical storm
conditions are possible along the southern coast of Cuba within the
watch area tonight and Wednesday.

RAINFALL: The system is expected to produce the following rainfall
amounts:

Over Haiti...an additional 2 to 4 inches of rain with isolated
maximum totals of 15 inches are expected across the southern terrain
areas today. This heavy rainfall should lead to flash and urban
flooding, and possible mudslides.

Over far southern Cuba, Jamaica, the Cayman Islands, and portions of
the Yucatan Peninsula....3 to 6 inches of rain with isolated maximum
totals of 10 inches are expected through Thursday. This heavy
rainfall may lead to flash and urban flooding.

STORM SURGE: A dangerous storm surge will raise water levels by as
much as 2-4 feet above normal tide levels along the immediate coast
near and to the north of where the center makes landfall in the
northeastern Yucatan Peninsula late Wednesday or early Thursday.
Near the coast,the surge will be accompanied by large and
destructive waves.

SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 500 PM EDT.

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Tropical Storm Grace Advisory Number 18
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Tue Aug 17 2021

...HURRICANE WARNING ISSUED FOR THE EAST COAST OF THE YUCATAN
PENINSULA OF MEXICO...
...HURRICANE WATCH ISSUED FOR THE CAYMAN ISLANDS...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.4N 77.9W
ABOUT 5 MI...10 KM S OF MONTEGO BAY JAMAICA
ABOUT 225 MI...360 KM ESE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Mexico has issued a Hurricane Warning for the
eastern Yucatan Peninsula from Cancun to Punta Herrero including
Cozumel, a Tropical Storm Warning from north of Cancun to Cabo
Catoche, and a Tropical Storm Warning from south of Punta Herrero to
Puerto Costa Maya.

The government of the Cayman Islands has issued a Hurricane Watch
for the Cayman Islands.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Hurricane Watch is in effect for...
* Cayman Islands

A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Cabo Catoche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of
tropical-storm-force winds, conditions that make outside
preparations difficult or dangerous. Preparations to protect life
and property should be rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace.

Additional watches or warnings may be required tonight.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Tropical Storm Grace was
located near the northwest coast of Jamaica at latitude 18.4 North,
longitude 77.9 West. Grace is moving toward the west near 15 mph (24
km/h). A general westward to west-northwestward motion is expected
for the next several days. On the forecast track, the center of
Grace will continue to move near the northwestern coast of Jamaica
for the next few hours. Grace is forecast to move near or over the
Cayman Islands late tonight and early Wednesday, and then approach
the Yucatan peninsula of Mexico late Wednesday or early Thursday.

Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Grace is forecast to strengthen into a hurricane on Wednesday, with
some additional strengthening possible prior to the center reaching
the Yucatan Peninsula.

Tropical-storm-force winds extend outward up to 80 miles (130 km)
from the center. The official reporting station in Kingston,
Jamaica, has reported sustained winds of 47 mph (76 km/h) and a
gust to 54 mph (87 km/h) within the past few hours.

The estimated minimum central pressure is 1003 mb (29.62 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected to continue over
portions of Jamaica through this evening. Tropical storm
conditions are expected along the southern coast of Cuba within the
warning area through this evening, and over the Cayman Islands
beginning tonight and into early Wednesday. Hurricane conditions
are possible in the Cayman Islands by early Wednesday. Tropical
storm conditions are possible along the southern coast of Cuba
within the watch area tonight and Wednesday. Hurricane conditions
are expected for the warning area in the Yucatan Peninsula of
Mexico on Wednesday night, but tropical storm conditions could
begin as early as Wednesday evening.

RAINFALL: The system is expected to produce the following rainfall
amounts:

Over Haiti...an additional 1 to 2 inches of rain with isolated
maximum totals of 15 inches are expected across the southern terrain
areas today. This heavy rainfall will likely cause flash and
urban flooding, along with possible mudslides.

Over far southern Cuba...and additional 2 to 4 inches of rain.
Additional heavy rainfall could lead to flash and urban
flooding, along with possible mudslides.

Over Jamaica, the Cayman Islands, and portions of the Yucatan
Peninsula....3 to 6 inches of rain with isolated maximum totals of
10 inches are expected through Thursday. This heavy rainfall could
lead to flash and urban flooding.

STORM SURGE: A storm surge could raise water levels as high as 1 to
3 ft above normal tide levels in portions of the Cayman Islands.

A dangerous storm surge will raise water levels by as much as 3-5
feet above normal tide levels along the immediate coast near and to
the north of where the center makes landfall in the northeastern
Yucatan Peninsula late Wednesday or early Thursday. Near the
coast,the surge will be accompanied by large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
to the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Pasch




Tropical Storm Grace Discussion Number 18
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Tue Aug 17 2021

Radar imagery and earlier Hurricane Hunter aircraft and ASCAT
observations indicate that the center of Grace has been moving over
Jamaica. The aircraft and scatterometer data indicate that the
maximum winds are near 45 kt. Cirrus-level outflow from the
system remains quite pronounced, suggestive of weak vertical shear
at this time.

Grace will be moving over the waters of the northwestern Caribbean
Sea beginning later tonight. These waters are of very high oceanic
heat content. Although mid-level environmental humidities are
shown by the SHIPS diagnoses to be only marginally moist for the
next couple of days, other factors should be conducive for
strengthening. The official intensity forecast, which shows Grace
becoming a hurricane tomorrow, is in reasonable agreement with the
latest multi-model consensus. Some slight weakening should occur
due to passage over the Yucatan Peninsula, followed by
re-intensification over the Bay of Campeche. There is, however,
significant uncertainty in the intensity prediction for this latter
part of the forecast period.

The storm continues on a heading just north of west, or 280/13 kt.
A strong 500-mb ridge should be maintained to the north of Grace
for essentially the entire forecast period. There is good
agreement among the track models on a continued generally westward
to west-northwestward motion for the next 5 days. Little change
has been made to the official track forecast in comparison to the
previous one. The new NHC track is, again, very close to the
dynamical model consensus.


Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
over portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico late Wednesday night.

2. Heavy rainfall across Haiti, Cuba, Jamaica, the Cayman Islands,
and the Yucatan Peninsula is likely to cause to flash, urban, and
small stream flooding, with the potential for mudslides highest in
Haiti.

3. Tropical storm conditions are expected over portions of Jamaica
through this evening, and over the Cayman Islands tonight and
early Wednesday. Tropical storm conditions are expected to spread
westward from portions of the southern coast of Cuba in the warning
area to, possibly, other portions of the southern coast of Cuba in
the watch area tonight through Wednesday.


FORECAST POSITIONS AND MAX WINDS

INIT 17/2100Z 18.4N 77.9W 45 KT 50 MPH
12H 18/0600Z 18.9N 80.3W 60 KT 70 MPH
24H 18/1800Z 19.4N 83.4W 70 KT 80 MPH
36H 19/0600Z 20.0N 86.7W 75 KT 85 MPH
48H 19/1800Z 20.5N 89.7W 60 KT 70 MPH...INLAND
60H 20/0600Z 20.9N 92.2W 65 KT 75 MPH...OVER WATER
72H 20/1800Z 21.2N 94.8W 75 KT 85 MPH
96H 21/1800Z 21.0N 99.5W 40 KT 45 MPH...INLAND
120H 22/1800Z 21.0N 103.0W 20 KT 25 MPH...POST-TROP/INLAND

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Tropical Storm Grace Intermediate Advisory Number 18A
NWS National Hurricane Center Miami FL AL072021
800 PM EDT Tue Aug 17 2021

...NOAA AND AIR FORCE RECONNAISSANCE AIRCRAFT FIND THE CENTER OF
GRACE JUST WEST OF JAMAICA...
...HEAVY RAINFALL AND FLASH FLOOD THREAT CONTINUES IN JAMAICA...


SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...18.3N 78.6W
ABOUT 50 MI...80 KM W OF MONTEGO BAY JAMAICA
ABOUT 185 MI...295 KM ESE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Hurricane Watch is in effect for...
* Cayman Islands

A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Cabo Catoche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace.

Additional watches or warnings may be required tonight.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 800 PM EDT (0000 UTC), the center of Tropical Storm Grace was
located just west of the western tip of Jamaica near latitude
18.3 North, longitude 78.6 West. Grace is moving toward the west
near 15 mph (24 km/h). A general westward to west-northwestward
motion is expected for the next several days. On the forecast
track, the center of Grace will move away from the western coast
of Jamaica this evening. Grace is forecast to move near or over the
Cayman Islands late tonight and early Wednesday, and then approach
the Yucatan peninsula of Mexico late Wednesday or early Thursday.

Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft
indicate that the maximum sustained winds have increased to near
60 mph (95 km/h) with higher gusts. Grace is forecast to
strengthen into a hurricane on Wednesday, with some additional
strengthening possible prior to the center reaching the Yucatan
Peninsula.

Tropical-storm-force winds extend outward up to 80 miles (130 km)
from the center. A sustained wind of 40 mph (65 km/h) and a gust
to 52 mph (83 km/h) was recently reported at Kingston, Jamaica.

The latest minimum central pressure reported by an Air Force
Reserve Hurricane Hunter aircraft is 1002 mb (29.59 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected to continue over
portions of Jamaica through early tonight. Tropical storm
conditions are expected along a portion of the southern coast of
Cuba within the warning area through early tonight, and over the
Cayman Islands beginning tonight and into early Wednesday. Hurricane
conditions are possible in the Cayman Islands by early Wednesday.
Tropical storm conditions are possible along the southern coast of
Cuba within the watch area tonight and Wednesday. Hurricane
conditions are expected within the warning area in the Yucatan
Peninsula of Mexico on Wednesday night with tropical storm
conditions beginning as early as Wednesday evening.

RAINFALL: The system is expected to produce the following rainfall
amounts:

Over Haiti...an additional 1 to 2 inches of rain with isolated
maximum totals of 15 inches are expected across the southern terrain
areas today. This heavy rainfall will likely cause flash and
urban flooding, along with possible mudslides.

Over far southern Cuba...and additional 2 to 4 inches of rain.
Additional heavy rainfall could lead to flash and urban
flooding, along with possible mudslides.

Over Jamaica, the Cayman Islands, and portions of the Yucatan
Peninsula....3 to 6 inches of rain with isolated maximum totals of
10 inches are expected through Thursday. This heavy rainfall could
lead to flash and urban flooding.

STORM SURGE: A storm surge could raise water levels as high as 1 to
3 ft above normal tide levels in portions of the Cayman Islands.

A dangerous storm surge will raise water levels by as much as 3-5
feet above normal tide levels along the immediate coast near and to
the north of where the center makes landfall in the northeastern
Yucatan Peninsula late Wednesday or early Thursday. Near the
coast, the surge will be accompanied by large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
to the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM EDT.

$$
Forecaster Brown

[cycloneye]

BULLETIN
Tropical Storm Grace Advisory Number 19
NWS National Hurricane Center Miami FL AL072021
1100 PM EDT Tue Aug 17 2021

...GRACE FORECAST TO BECOME A HURRICANE ON WEDNESDAY...
...HEAVY RAINFALL AND FLASH FLOOD THREAT CONTINUES IN JAMAICA...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.4N 79.2W
ABOUT 145 MI...235 KM ESE OF GRAND CAYMAN
ABOUT 60 MI...95 KM W OF NEGRIL JAMAICA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Mexico has issued a Tropical Storm Warning along
the north coast of the Yucatan Peninsula from Cabo Catoche westward
to Dzilam. A Tropical Storm Watch has been issued for the north
and west coasts of the Yucatan Peninsula from west of Dzilam to
Campeche.

The government of Cuba has discontinued the Tropical Storm Warning
for the Cuban province of Santiago de Cuba.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Hurricane Watch is in effect for...
* Cayman Islands

A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Granma, Las Tunas, and
Camaguey
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Dzilam
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud
* North and west coasts of the Yucatan Peninsula from west of
Dzilam to Campeche

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required early Wednesday.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM EDT (0300 UTC), the center of Tropical Storm Grace was
located near latitude 18.4 North, longitude 79.2 West. Grace is
moving toward the west near 14 mph (22 km/h). A general westward
to west-northwestward motion is expected for the next several days.
On the forecast track, the center of Grace will continue to move
away from the western coast of Jamaica overnight. Grace is
forecast to move near or over the Cayman Islands early Wednesday,
and then approach the Yucatan peninsula of Mexico late Wednesday or
early Thursday.

Data from NOAA and Air Force Reserve reconnaissance aircraft
indicate that maximum sustained winds are near 60 mph (95 km/h)
with higher gusts. Grace is forecast to strengthen into a hurricane
on Wednesday, with some additional strengthening possible prior to
the center reaching the Yucatan Peninsula.

Tropical-storm-force winds extend outward up to 115 miles (185 km)
primarily to the east of the center.

The latest minimum central pressure estimated from reconnaissance
aircraft data is 1000 mb (29.53 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected to continue over
portions of Jamaica for a few more hours. Tropical storm conditions
are expected along a portion of the southern coast of Cuba within
the warning area through tonight, and over the Cayman Islands
beginning by early Wednesday. Hurricane conditions are possible in
the Cayman Islands by early Wednesday. Tropical storm conditions are
possible along the southern coast of Cuba within the watch area
tonight and Wednesday. Hurricane conditions are expected within the
warning area in the Yucatan Peninsula of Mexico on Wednesday night
with tropical storm conditions beginning as early as Wednesday
evening.

RAINFALL: The system is expected to produce the following rainfall
amounts:

Over Jamaica, the Cayman Islands, and portions of the Yucatan
Peninsula....3 to 6 inches of rain with isolated maximum totals of
10 inches are expected through Thursday. This heavy rainfall may
lead to flash and urban flooding, and across Jamaica, mudslides will
also be possible.

STORM SURGE: A storm surge could raise water levels as high as 1 to
3 ft above normal tide levels in portions of the Cayman Islands.

A dangerous storm surge will raise water levels by as much as 3 to 5
ft above normal tide levels along the immediate coast near and to
the north of where the center makes landfall in the northeastern
Yucatan Peninsula late Wednesday or early Thursday. Near the
coast, the surge will be accompanied by large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
to the Cayman Islands, the southern coast of Cuba, and the Yucatan
Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM EDT.
Next complete advisory at 500 AM EDT.

$$
Forecaster Brown


Tropical Storm Grace Discussion Number 19
NWS National Hurricane Center Miami FL AL072021
1100 PM EDT Tue Aug 17 2021

NOAA and Air Force Hurricane Hunter aircraft that have been
investigating Grace this evening have found that the center moved
off the western tip of Jamaica shortly before 0000 UTC. Radar and
conventional satellite imagery, as well as earlier microwave data,
show that convective banding has increased with a band that wraps
around the eastern and northern portions of the circulation. The
Air Force reconnaissance aircraft measured a peak 850-mb
flight-level wind of 64 kt, and both aircraft have measured
believable SFMR winds of 50-52 kt. Based on those data the maximum
winds were increased to 50 kt on the 0000 UTC intermediate advisory,
and the initial intensity remains unchanged for this advisory.

Grace will be moving over the high ocean heat content waters of the
northwestern Caribbean Sea during the next day or so. That, along
with generally low to moderate vertical wind shear conditions,
should allow for steady strengthening until Grace reaches the coast
of the Yucatan Peninsula in just under 36 hours. The NHC intensity
forecast call for Grace to become a hurricane on Wednesday, and the
storm could peak near category 2 intensity before it reaches the
coast of Mexico late Wednesday night or early Thursday. By the 36-
hour forecast, some weakening is likely to have occurred as that
point is now inland. Some weakening will likely occur while Grace
moves over land, but restrengthening is predicted when the storm
moves over the Bay of Campeche. The NHC intensity forecast is in
best agreement with the HCCA and IVCN consensus aids.

Grace has been moving slightly north of due west, or 280/12 kt. A
strong deep-layer ridge the extends from the western Atlantic across
the eastern and central Gulf of Mexico should continue to steer the
tropical storm westward to west-northwestward for the next several
days. While the dynamical models agree on this overall forecast
scenario, there remains some north-south spread with the HWRF, HMON,
and GFS along the northern side of the guidance envelope, taking
Grace near the northeastern portion of the Yucatan Peninsula. On
the other hand, the UKMET and its ensemble mean depict a more
westward track toward the southern portion of the Yucatan Peninsula
of Mexico. The NHC forecast splits these differences and lies near
the various consensus aids, which were just a tad farther south this
cycle.


Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
over portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico beginning late Wednesday night.

2. Heavy rainfall across Jamaica, the Cayman Islands, and the
Yucatan Peninsula is likely to lead to flash and urban flooding.
Mudslides are possible in Jamaica.

3. Tropical storm conditions are expected over portions of Jamaica
for a few more hours, and over the Cayman Islands later tonight
and Wednesday. Hurricane conditions are possible in the Cayman
Islands by Wednesday morning. Tropical storm conditions are
expected to spread westward from portions of the southern coast of
Cuba in the warning area to, possibly, other portions of the
southern coast of Cuba in the watch area tonight through Wednesday.


FORECAST POSITIONS AND MAX WINDS

INIT 18/0300Z 18.4N 79.2W 50 KT 60 MPH
12H 18/1200Z 18.9N 81.5W 60 KT 70 MPH
24H 19/0000Z 19.5N 84.7W 75 KT 85 MPH
36H 19/1200Z 20.0N 87.8W 80 KT 90 MPH...INLAND
48H 20/0000Z 20.4N 90.7W 50 KT 60 MPH...OVER WATER
60H 20/1200Z 20.7N 93.2W 65 KT 75 MPH
72H 21/0000Z 20.8N 95.6W 75 KT 85 MPH
96H 22/0000Z 20.7N 100.1W 35 KT 40 MPH...INLAND
120H 23/0000Z 20.5N 104.5W 20 KT 25 MPH...POST-TROP/INLAND

$$
Forecaster Brown

[cycloneye]

BULLETIN
Tropical Storm Grace Advisory Number 20
NWS National Hurricane Center Miami FL AL072021
500 AM EDT Wed Aug 18 2021

...OUTER BANDS WITH HEAVY RAINFALL AND GUSTY WINDS BEGINNING
TO SPREAD ACROSS THE CAYMAN ISLANDS...
...GRACE STILL FORECAST TO BECOME A HURRICANE LATER TODAY...


SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...18.8N 80.9W
ABOUT 40 MI...65 KM SSE OF GRAND CAYMAN
ABOUT 440 MI...710 KM ESE OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of Jamaica has discontinued the Tropical Storm
Warning for Jamaica.

The government of Cuba has discontinued the Tropical Storm Warning
for the southern coast Cuban provinces of Granma, Las Tunas, and
Camaguey. The Tropical Storm Watch for the southern coast of the
Cuban provinces of Ciego de Avila, Sancti Spiritus, Cienfuegos,
Matanzas have also been discontinued.

The government of Mexico has upgraded the Tropical Storm Watch to a
Tropical Storm Warning for the north and west coasts of the Yucatan
Peninsula from west of Dzilam to Campeche.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Hurricane Watch is in effect for...
* Cayman Islands

A Tropical Storm Warning is in effect for...
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required later this morning.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 AM EDT (0900 UTC), the center of Tropical Storm Grace was
located near latitude 18.8 North, longitude 80.9 West. Grace is
moving toward the west near 16 mph (26 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will continue to move near
or over the Cayman Islands later this morning. Grace will approach
the Yucatan peninsula of Mexico tonight or early Thursday.

Maximum sustained winds have increased to near 65 mph (100 km/h)
with higher gusts. Grace is forecast to strengthen into a hurricane
by tonight, with some additional strengthening possible prior to the
center reaching the eastern Yucatan Peninsula.

Tropical-storm-force winds extend outward up to 115 miles (185 km)
from the center. A reporting station near Rum Point Beach on the
north shore of Grand Cayman recently measured a sustained wind of
40 mph (64 km/h) and a gust to 47 mph (76 km/h).

The estimated minimum central pressure is 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected along a portion of the
southern coast of Cuba within the warning area and over the Cayman
Islands through this morning. Hurricane conditions are possible in
the Cayman Islands later this morning. Tropical storm conditions are
possible along the southern coast of Cuba within the watch area
through today. Hurricane conditions are expected within the warning
area in the Yucatan Peninsula of Mexico late tonight, with tropical
storm conditions beginning as early as this evening.

RAINFALL:
Grace is expected to produce the following rainfall amounts:

Over Jamaica, the Cayman Islands, portions of the Yucatan Peninsula
and Vera Cruz state....4 to 8 inches of rain with isolated maximum
totals of 12 inches are expected through Friday night. This heavy
rainfall could lead to flash and urban flooding, with mudslides
possible in Jamaica.

STORM SURGE: A storm surge could raise water levels as high as 1 to
3 ft above normal tide levels in portions of the Cayman Islands.

A dangerous storm surge will raise water levels by as much as 3 to 5
ft above normal tide levels along the immediate coast near and to
the north of where the center makes landfall in the northeastern
Yucatan Peninsula late tonight or early Thursday. Near the
coast, the surge will be accompanied by large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
to the Cayman Islands, the southern coast of Cuba, and the Yucatan
Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 AM EDT.
Next complete advisory at 1100 AM EDT.

$$
Forecaster Stewart


Tropical Storm Grace Discussion Number 20
NWS National Hurricane Center Miami FL AL072021
500 AM EDT Wed Aug 18 2021

An Air Force Reserve reconnaissance aircraft investigating Grace
earlier this morning observed a peak 850-mb flight-level wind of 61
kt in the northeastern quadrant along with reliable SFMR surface
wind speeds of 50-52 kt. The aircraft measured a central pressure of
about 1000 mb, a reading that had been steady for about 3 hours.
Those data were the basis for maintaining the 0600 UTC intensity at
50 kt. Since the last recon mission, however, deep convection has
increased markedly over the low-level center, with cloud tops
exceeding -75 deg C. Although the center is just inside the western
edge of convective cloud canopy due to modest west-northwesterly
vertical wind shear, Dvorak satellite intensity estimates from TAFB
and SAB are a consensus T3.5/55 kt. These intensity estimates, along
with the increase in convection over the center is the justification
for increasing the 0900 UTC advisory intensity to 55 kt.

Grace has been maintaining a steady course north of due west, or
280/14 kt for more than 18 hours. A strong deep-layer ridge to the
north of the cyclone is expected to keep Grace moving in direction
between west and west-northwest through the 96-hour forecast period.
The latest NHC model guidance remain in strong agreement on Grace
making landfall along the northeastern coast of the Yucatan
Peninsula of Mexico shortly after the 24-hour forecast period,
followed by a motion across the peninsula and emerging over the Bay
of Campeche around 36 hours. Thereafter, the model guidance begins
to diverge, with the HWRF, HMON, and COAMPS-TC regional models along
the northern side of the guidance envelope, the GFS and UKMET
global models down the middle, and the ECMWF model along the
southern edge of the guidance suite. The new NHC forecast lies close
to the previous advisory track and the consensus models TVCA and
HCCA, which are a little south of the FSSE consensus model.

Although the upper-level wind environment isn't ideal for rapid
strengthening, it is conducive enough for steady strengthening to
occur due to the flow forecast to be strongly diffluent. Sea-surface
temperatures are expected to be near 30 deg C and the water is also
deep and warm, which should prevent any cold upwelling from
occurring beneath the cyclone. As a result, a peak intensity of 75
kt just prior to landfall has been carried over from the previous
advisory, which is a little above all of the 0600 UTC intensity
guidance. Although Grace will weaken substantially after passing
over the Yucatan peninsula, restrengthening is expected over the
warm waters of thew Bay of Campeche in the 48-72- hour period where
the upper-level flow regime is forecast to be more conducive for
intensification. Dissipation is now expected over the mountains of
central Mexico by 120 hours. The NHC intensity forecast is in best
agreement with the HCCA and IVCN consensus aids at 36 hours and
beyond.

Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
over portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico beginning late tonight.

2. Over the next few days, heavy rainfall across the Cayman Islands
as well as portions of the Yucatan Peninsula and Vera Cruz State
should lead to flash and urban flooding. Mudslides will be possible
in Jamaica.

3. Tropical storm conditions are expected over the Cayman Islands
through this morning. Hurricane conditions are possible in the
Cayman Islands later this morning. Tropical storm conditions are
expected to spread westward from portions of the southern coast of
Cuba in the warning area to, possibly, other portions of the
southern coast of Cuba in the watch area today.


FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 18.8N 80.9W 55 KT 65 MPH
12H 18/1800Z 19.3N 83.2W 60 KT 70 MPH
24H 19/0600Z 19.9N 86.4W 75 KT 85 MPH
36H 19/1800Z 20.3N 89.4W 50 KT 60 MPH...INLAND
48H 20/0600Z 20.6N 92.1W 50 KT 60 MPH...OVER WATER
60H 20/1800Z 20.7N 94.4W 65 KT 75 MPH
72H 21/0600Z 20.7N 96.8W 75 KT 85 MPH
96H 22/0600Z 20.6N 101.4W 35 KT 40 MPH...INLAND
120H 23/0600Z...DISSIPATED

$$
Forecaster Stewart

[cycloneye]

BULLETIN
Tropical Storm Grace Intermediate Advisory Number 20A
NWS National Hurricane Center Miami FL AL072021
800 AM EDT Wed Aug 18 2021

...GRACE NEAR GRAND CAYMAN...
...HEAVY RAINS AND STRONG WINDS CONTINUING ACROSS THE CAYMAN
ISLANDS...


SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...19.1N 81.4W
ABOUT 20 MI...30 KM SW OF GRAND CAYMAN
ABOUT 405 MI...650 KM ESE OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...993 MB...29.32 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Hurricane Watch is in effect for...
* Cayman Islands

A Tropical Storm Warning is in effect for...
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required later this morning.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 800 AM EDT (1200 UTC), the center of Tropical Storm Grace was
located by an Air Force Reserve Hurricane Hunter aircraft near
latitude 18.8 North, longitude 80.9 West. Grace is moving toward
the west-northwest near 16 mph (26 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will continue to move near
or the Cayman Islands later this morning. Grace is expected to
make landfall in the Yucatan peninsula of Mexico early Thursday,
and move into the southwest Gulf of Mexico early Friday.

Maximum sustained winds are near 65 mph (100 km/h) with higher
gusts. Grace is forecast to strengthen into a hurricane later
today, with some additional strengthening possible prior to the
center reaching the eastern Yucatan Peninsula.

Tropical-storm-force winds extend outward up to 115 miles (185 km)
from the center. Wind gusts to hurricane force have been reported
on Grand Cayman.

The minimum central pressure estimated from Air Force Hurricane
Hunter observations is 993 mb (29.32 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are expected, and hurricane
conditions are possible, over the Cayman Islands through this
morning. Tropical storm conditions are possible along the southern
coast of Cuba within the watch area through today. Hurricane
conditions are expected within the warning area in the Yucatan
Peninsula of Mexico late tonight, with tropical storm conditions
beginning as early as this evening.

RAINFALL:
Grace is expected to produce the following rainfall amounts:

Over Jamaica, the Cayman Islands, portions of the Yucatan Peninsula
and Vera Cruz state....4 to 8 inches of rain with isolated maximum
totals of 12 inches are expected through Friday night. This heavy
rainfall could lead to flash and urban flooding, with mudslides
possible in Jamaica.

STORM SURGE: A storm surge could raise water levels as high as 1 to
3 ft above normal tide levels in portions of the Cayman Islands.

A dangerous storm surge will raise water levels by as much as 3 to 5
ft above normal tide levels along the immediate coast near and to
the north of where the center makes landfall in the northeastern
Yucatan Peninsula late tonight or early Thursday. Near the
coast, the surge will be accompanied by large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
to the Cayman Islands, the southern coast of Cuba, and the Yucatan
Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 AM EDT.

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Hurricane Grace Advisory Number 21
NWS National Hurricane Center Miami FL AL072021
1100 AM EDT Wed Aug 18 2021

...AIR FORCE RESERVE AND NOAA HURRICANE HUNTERS FIND THAT GRACE
BECOMES A HURRICANE JUST WEST OF GRAND CAYMAN...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.4N 82.2W
ABOUT 65 MI...105 KM W OF GRAND CAYMAN
ABOUT 350 MI...560 KM E OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Hurricane Watch is discontinued for the Cayman Islands.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Tropical Storm Warning is in effect for...
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in eastern mainland Mexico should monitor the
progress of Grace.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM EDT (1500 UTC), the center of Hurricane Grace was located
by Air Force Reserve and NOAA Hurricane Hunter aircraft near
latitude 19.4 North, longitude 82.2 West. Grace is moving toward
the west-northwest near 15 mph (24 km/h). A general
west-northwestward to westward motion is expected for the next
several days. On the forecast track, the center of Grace will
continue to move away from Grand Cayman today. Grace is expected to
make landfall in the Yucatan Peninsula Thursday morning, and move
over the southwest Gulf of Mexico early Friday.

Aircraft data indicate that maximum sustained winds are near 75 mph
(120 km/h) with higher gusts. Some additional strengthening is
forecast before the center of Grace reaches the eastern Yucatan
Peninsula. Weakening will occur while the center moves over the
Yucatan Peninsula on Thursday, with restrengthening expected when
Grace moves over the southwest Gulf of Mexico on Friday.

Hurricane-force winds extend outward up to 25 miles (35 km) from the
center and tropical-storm-force winds extend outward up to 115 miles
(185 km).

The estimated minimum central pressure is 992 mb (29.30 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
http://www.hurricanes.gov/graphics_at2. ... y_messages.

WIND: Tropical storm conditions are expected over portions of the
Cayman Islands for the next few hours. Tropical storm conditions
are possible along the southern coast of Cuba within the watch area
through today. Hurricane conditions are expected within the warning
area in the Yucatan Peninsula of Mexico late tonight or early
Thursday, with tropical storm conditions beginning as early as this
evening.

RAINFALL:
Grace is expected to produce the following rainfall amounts:

Over the Cayman Islands, portions of the Yucatan Peninsula and
Veracruz State of Mexico....4 to 8 inches with isolated maximum
totals of 12 inches are expected through Friday night. This
heavy rainfall could lead to flash and urban flooding, with
mudslides possible in Veracruz.

STORM SURGE: A dangerous storm surge will raise water levels by as
much as 3 to 5 ft above normal tide levels along the immediate
coast near and to the north of where the center makes landfall in
the northeastern Yucatan Peninsula late tonight or early Thursday.
Near the coast, the surge will be accompanied by large and
destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
and the Cayman Islands to the southern coast of Cuba and the Yucatan
Peninsula of Mexico. These swells are likely to cause life-
threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 PM EDT.
Next complete advisory at 500 PM EDT.

$$
Forecaster Pasch


Hurricane Grace Discussion Number 21
NWS National Hurricane Center Miami FL AL072021
1100 AM EDT Wed Aug 18 2021

Grace is becoming better organized on satellite images with a
comma-shaped cloud pattern, and the upper-level outflow remains
well defined. Wind gusts well into the hurricane-force range were
measured on Grand Cayman earlier this morning, along with some
damage on the island. Recent flight-level and SFMR observations
from both the Air Force and NOAA Hurricane Hunter aircraft support
sustained 65-kt surface winds, so the system is being upgraded to a
hurricane on this advisory.

Although Grace is situated over waters of very high oceanic heat
content, moderate northwesterly shear and only marginally moist
mid-level air could slightly impede intensification. However,
some additional strengthening is expected before landfall tonight
or early Thursday. Weakening will occur due to Grace's passage
over Yucatan, although that land mass has relatively low terrain.
Reintensification is anticipated over the Bay of Campeche on
Friday, and the system should regain hurricane strength before
reaching the east coast of mainland Mexico. The official intensity
forecast is similar to the numerical model consensus.

Grace has been moving west-northwestward near 13 kt. A prominent
mid-tropospheric ridge is likely to remain in place to the north of
the cyclone for the next several days. This pattern should keep
steering Grace on a west-northwestward to westward track for 72-96
hours. The track guidance models are in excellent agreement and
little change has been made to the NHC track forecast compared to
the previous few packages.

A Hurricane Watch will likely be required for a portion of the
coast of eastern mainland Mexico later today.

Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
in portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico beginning late tonight or early Thursday.
Preparations to protect life and property should be rushed to
completion.

2. There is an increasing risk of hurricane conditions and dangerous
storm surge in portions of eastern mainland Mexico beginning late
Friday, and a Hurricane Watch will likely be issued for part of this
area later today.

3. Over the next few days, heavy rainfall across the Cayman Islands
as well as portions of the Yucatan Peninsula and Veracruz State
should lead to flash and urban flooding, with mudslides possible in
the Mexican state of Veracruz.

FORECAST POSITIONS AND MAX WINDS

INIT 18/1500Z 19.4N 82.2W 65 KT 75 MPH
12H 19/0000Z 19.7N 84.5W 70 KT 80 MPH
24H 19/1200Z 20.3N 87.6W 75 KT 85 MPH...INLAND
36H 20/0000Z 20.6N 90.5W 50 KT 60 MPH...OVER WATER
48H 20/1200Z 20.7N 93.2W 65 KT 75 MPH...OVER WATER
60H 21/0000Z 20.7N 95.3W 75 KT 85 MPH
72H 21/1200Z 20.5N 97.7W 60 KT 70 MPH...INLAND
96H 22/1200Z 20.0N 103.0W 20 KT 25 MPH...POST-TROP/INLAND
120H 23/1200Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Hurricane Grace Intermediate Advisory Number 21A
NWS National Hurricane Center Miami FL AL072021
200 PM EDT Wed Aug 18 2021

...GRACE HEADED FOR THE YUCATAN PENINSULA OF MEXICO...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...19.6N 83.0W
ABOUT 295 MI...475 KM E OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Tropical Storm Warning is in effect for...
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in eastern mainland Mexico should monitor the
progress of Grace.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 200 PM EDT (1800 UTC), the center of Hurricane Grace was located
near latitude 19.6 North, longitude 83.0 West. Grace is moving
toward the west-northwest near 15 mph (24 km/h). A general
west-northwestward to westward motion is expected for the next
several days. On the forecast track, Grace is expected to make
landfall in the eastern Yucatan Peninsula Thursday morning, move
over the Yucatan Peninsula on Thursday, and move over the
southwest Gulf of Mexico Thursday night or early Friday.

Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts. Some strengthening is forecast before the center of Grace
reaches the Yucatan Peninsula. Weakening will occur while the
center moves over the Yucatan Peninsula on Thursday, with
restrengthening expected when Grace moves over the southwest Gulf of
Mexico on Friday.

Hurricane-force winds extend outward up to 25 miles (35 km) from
the center and tropical-storm-force winds extend outward up to 140
miles (220 km).

The minimum central pressure estimated from Air Force Hurricane
Hunter aircraft observations is 995 mb (29.38 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Tropical storm conditions are possible along the southern
coast of Cuba within the watch area through today. Hurricane
conditions are expected within the warning area in the Yucatan
Peninsula of Mexico late tonight or early Thursday, with tropical
storm conditions beginning as early as this evening.

RAINFALL:
Grace is expected to produce the following rainfall amounts:

Over the Cayman Islands, portions of the Yucatan Peninsula and
Veracruz State of Mexico....4 to 8 inches with isolated maximum
totals of 12 inches are expected through Friday night. This
heavy rainfall could lead to flash and urban flooding, with
mudslides possible in Veracruz.

STORM SURGE: A dangerous storm surge will raise water levels by as
much as 3 to 5 ft above normal tide levels along the immediate
coast near and to the north of where the center makes landfall in
the northeastern Yucatan Peninsula late tonight or early Thursday.
Near the coast, the surge will be accompanied by large and
destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
and the Cayman Islands to the southern coast of Cuba and the Yucatan
Peninsula of Mexico through Thursday. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 500 PM EDT.

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Hurricane Grace Advisory Number 22
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Wed Aug 18 2021

...GRACE EXPECTED TO BRING STRONG WINDS AND A DANGEROUS STORM
SURGE TO PORTIONS OF THE EASTERN YUCATAN PENINSULA OF MEXICO...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...19.7N 83.7W
ABOUT 250 MI...400 KM E OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Tropical Storm Warning is in effect for...
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in eastern mainland Mexico should monitor the
progress of Grace.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Hurricane Grace was located
near latitude 19.7 North, longitude 83.7 West. Grace is moving
toward the west-northwest near 16 mph (26 km/h). A general
west-northwestward to westward motion is expected for the next
several days. On the forecast track, Grace is expected to make
landfall in the eastern Yucatan Peninsula Thursday morning, move
over the Yucatan Peninsula on Thursday, and move over the
southwest Gulf of Mexico Thursday night or early Friday.

Maximum sustained winds are near 80 mph (130 km/h) with higher
gusts. Some strengthening is possible before the center of Grace
reaches the Yucatan Peninsula. Weakening will occur while the
center moves over the Yucatan Peninsula on Thursday, with
restrengthening expected when Grace moves over the southwest Gulf of
Mexico on Friday.

Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 140 miles
(220 km). Tropical-storm-force wind gusts were reported over
portions of western Cuba this afternoon.

The estimated minimum central pressure is 992 mb (29.30 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Strong gusty winds are likely over portions of the Cayman
Islands for the next few hours. Tropical storm conditions are
possible along the southern coast of Cuba within the watch area for
the next several hours. Hurricane conditions are expected within
the warning area in the Yucatan Peninsula of Mexico late tonight or
early Thursday, with tropical storm conditions beginning as early as
this evening.

RAINFALL:
The system is expected to produce the following rainfall amounts:

Over the Cayman Islands and central to northern portions of the
Yucatan Peninsula, 4 to 8 inches of rain with isolated maximum
totals of 12 inches are expected through Friday. Heavy rainfall
from Grace will likely result in areas of flash and urban flooding

Over the central to northern Veracruz state of Mexico, 5 to 10
inches of rain with isolated maximum totals of 15 inches are
expected from Friday through Sunday. Heavy rainfall from Grace will
likely result in areas of flash and urban flooding, and will also be
capable of producing mudslides.

STORM SURGE: A dangerous storm surge will raise water levels by as
much as 3 to 5 ft above normal tide levels along the immediate
coast near and to the north of where the center makes landfall in
the northeastern Yucatan Peninsula late tonight or early Thursday.
Near the coast, the surge will be accompanied by large and
destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
and the Cayman Islands to the southern coast of Cuba and the Yucatan
Peninsula of Mexico through Thursday. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Pasch



Hurricane Grace Discussion Number 22
NWS National Hurricane Center Miami FL AL072021
500 PM EDT Wed Aug 18 2021

A ragged eye appeared for a while on visible satellite imagery, but
it has recently been obscured by cumulonimbus tops. The overall
cloud pattern has been maintaining its organization with some
convective banding features and very cold cloud tops, mainly over
the eastern portion of the circulation. The current intensity
estimate is set at 70 kt, which is a blend of Dvorak estimates from
TAFB and SAB. Another Air Force Reserve Hurricane Hunter aircraft
is scheduled to investigate the hurricane in a few hours to provide
another intensity estimate.

Grace will continue to move over waters of very high oceanic heat
content prior to reaching the east coast of the Yucatan Peninsula,
which of course favors intensification. Aside from moderate
northwesterly shear, a possible impediment to strengthening is a
northeast to southwest-oriented shear axis located just to the
northwest of the hurricane. Nonetheless, some intensification is
anticipated before landfall in Yucatan, with restrengthening over
the Bay of Campeche. The official intensity forecast continues to
be in general agreement with the multi-model consensus predictions,
IVCN and HCCA.

Grace is moving west-northwestward, or about 285/14 kt. There has
been essentially no change to the track forecast philosophy. Grace
should maintain a west-northwestward to westward motion, on the
southern periphery of a strong subtropical ridge, for the next
several days. The official track forecast is very similar to the
previous one and about on top of the latest multi-model consensus,
TVCA.

A Hurricane Watch will likely be required for a portion of the
coast of eastern mainland Mexico tonight.

Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
in portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico beginning late tonight or early Thursday.
Preparations to protect life and property should be rushed to
completion.

2. There is an increasing risk of hurricane conditions and dangerous
storm surge in portions of eastern mainland Mexico beginning late
Friday, and a Hurricane Watch will likely be issued for part of this
area tonight.

3. Through the weekend, heavy rainfall across the Cayman Islands as
well as portions of the Yucatan Peninsula and Veracruz State should
lead to flash and urban flooding. In addition, the heavy rainfall
from Grace will be capable of producing mudslides in Veracruz.

FORECAST POSITIONS AND MAX WINDS

INIT 18/2100Z 19.7N 83.7W 70 KT 80 MPH
12H 19/0600Z 20.2N 86.1W 75 KT 85 MPH
24H 19/1800Z 20.7N 89.3W 55 KT 65 MPH...INLAND
36H 20/0600Z 20.9N 92.2W 60 KT 70 MPH...OVER WATER
48H 20/1800Z 20.8N 94.6W 70 KT 80 MPH...OVER WATER
60H 21/0600Z 20.4N 97.3W 75 KT 85 MPH...INLAND
72H 21/1800Z 20.0N 99.9W 30 KT 35 MPH...INLAND
96H 22/1800Z 19.5N 104.0W 20 KT 25 MPH...POST-TROP/INLAND
120H 23/1800Z...DISSIPATED

$$
Forecaster Pasch

[AlphaToOmega]

000
WTNT32 KNHC 182354
TCPAT2

BULLETIN
Hurricane Grace Intermediate Advisory Number 22A
NWS National Hurricane Center Miami FL AL072021
800 PM EDT Wed Aug 18 2021

...GRACE EXPECTED TO BRING STRONG WINDS AND A DANGEROUS STORM
SURGE TO PORTIONS OF THE EASTERN YUCATAN PENINSULA OF MEXICO...
...AIR FORCE RESERVE AND NOAA HURRICANE HUNTER AIRCRAFT CURRENTLY
INVESTIGATING THE HURRICANE...

SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...19.8N 84.9W
ABOUT 170 MI...275 KM E OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...989 MB...29.20 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Meteorological Service of the Cayman Islands has discontinued
the Tropical Storm Warning for the Cayman Islands.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Tropical Storm Warning is in effect for...
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in eastern mainland Mexico should monitor the
progress of Grace.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 800 PM EDT (0000 UTC), the center of Hurricane Grace was located
near latitude 19.8 North, longitude 84.9 West. Grace is moving
toward the west-northwest near 16 mph (26 km/h). A general
west-northwestward to westward motion is expected for the next
several days. On the forecast track, Grace is expected to make
landfall in the eastern Yucatan Peninsula Thursday morning, move
over the Yucatan Peninsula on Thursday, and move over the southwest
Gulf of Mexico Thursday night or early Friday.

Maximum sustained winds are near 80 mph (130 km/h) with higher
gusts. Some strengthening is possible before the center of Grace
reaches the Yucatan Peninsula. Weakening will occur while the
center moves over the Yucatan Peninsula on Thursday, with
restrengthening expected when Grace moves over the southwest Gulf of
Mexico on Friday.

Hurricane-force winds extend outward up to 15 miles (30 km) from
the center and tropical-storm-force winds extend outward up to 140
miles (220 km). NOAA buoy 40256, located west of the center,
recently reported sustained winds of 45 mph (72 km/h) and a wind
gust of 51 mph (83 km/h).

The minimum central pressure estimated from Air Force Reserve and
NOAA Hurricane Hunter aircraft data is 989 mb (29.32 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Strong gusty winds are likely over portions of the Cayman
Islands for the next few hours. Tropical storm conditions are
possible along the southern coast of Cuba within the watch area for
the next several hours. Hurricane conditions are expected within
the warning area in the Yucatan Peninsula of Mexico late tonight or
early Thursday, with tropical storm conditions beginning as early as
this evening.

RAINFALL:
The system is expected to produce the following rainfall amounts:

Over the Cayman Islands and central to northern portions of the
Yucatan Peninsula, 4 to 8 inches of rain with isolated maximum
totals of 12 inches are expected through Friday. Heavy rainfall
from Grace will likely result in areas of flash and urban flooding

Over the central to northern Veracruz state of Mexico, 5 to 10
inches of rain with isolated maximum totals of 15 inches are
expected from Friday through Sunday. Heavy rainfall from Grace will
likely result in areas of flash and urban flooding, and will also be
capable of producing mudslides.

STORM SURGE: A dangerous storm surge will raise water levels by as
much as 3 to 5 ft above normal tide levels along the immediate
coast near and to the north of where the center makes landfall in
the northeastern Yucatan Peninsula late tonight or early Thursday.
Near the coast, the surge will be accompanied by large and
destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
and the Cayman Islands to the southern coast of Cuba and the Yucatan
Peninsula of Mexico through Thursday. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM EDT.

$$
Forecaster Beven

[cycloneye]

BULLETIN
Hurricane Grace Advisory Number 23
NWS National Hurricane Center Miami FL AL072021
1000 PM CDT Wed Aug 18 2021

...GRACE EXPECTED TO MAKE LANDFALL ON THE EASTERN YUCATAN PENINSULA
OF MEXICO EARLY THURSDAY MORNING...
...EXPECTED TO BRING STRONG WINDS AND A DANGEROUS STORM
SURGE TO PORTIONS OF THAT AREA...


SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.8N 85.6W
ABOUT 125 MI...205 KM ESE OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...988 MB...29.18 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Meteorological Service of Mexico has issued a Hurricane Watch
for the coast of mainland Mexico from Puerto Veracruz to Cabo Rojo,
and a Tropical Storm Watch from the coast of mainland Mexico north
of Cabo Rojo to Puerto de Altamira.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel

A Hurricane Watch is in effect for...
* The coast of mainland Mexico from Puerto Veracruz to Cabo Rojo

A Tropical Storm Warning is in effect for...
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya

A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud
* The coast of mainland Mexico north of Cabo Rojo to Puerto de
Altamira

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in eastern mainland Mexico should monitor the
progress of Grace.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1000 PM CDT (0300 UTC), the center of Hurricane Grace was located
near latitude 19.8 North, longitude 85.6 West. Grace is moving
toward the west near 18 mph (30 km/h). A general west-
northwestward to westward motion is expected through Friday,
followed by a general westward to west-southwestward motion. On the
forecast track, Grace is expected to make landfall in the eastern
Yucatan Peninsula during the next six to twelve hours, move across
the Yucatan Peninsula on Thursday, and move over the southwest Gulf
of Mexico late Thursday through Friday.

Maximum sustained winds are near 80 mph (130 km/h) with higher
gusts. Some strengthening is expected before landfall on the
Yucatan peninsula. Grace is expected to weaken as it crosses
Yucatan, but re-intensification is expected when the center reaches
the Gulf of Mexico.

Hurricane-force winds extend outward up to 35 miles (55 km) from the
center and tropical-storm-force winds extend outward up to 140 miles
(220 km).

The latest minimum central pressure reported by an Air Force
Reserve Hurricane Hunter aircraft is 988 mb (29.18 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Hurricane conditions are expected within the warning area in
the Yucatan Peninsula of Mexico late tonight or early Thursday, with
tropical storm conditions beginning during the next few hours.
Hurricane and tropical storm conditions will spread inland the
Yucatan Peninsula during the day Thursday. Hurricane conditions
are possible in the hurricane watch area in mainland Mexico by by
late Friday, and tropical storm conditions are possible in the
tropical storm watch area in mainland Mexico by late Friday.
Tropical storm conditions are possible along the southern coast of
Cuba within the watch area for the next several hours.

RAINFALL:
The system is expected to produce the following rainfall amounts:

Over central and northern portions of the Yucatan Peninsula...4 to 8
inches of rain with isolated maximum totals of 12 inches are
expected through Friday. Heavy rainfall from Grace will likely
result in areas of flash and urban flooding.

Over central to northern Veracruz...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected from Friday
through Sunday. Heavy rainfall from Grace will likely result in
areas of flash and urban flooding, and will also be capable of
producing mudslides.

STORM SURGE: A dangerous storm surge will raise water levels by
as much as 3 to 5 ft above normal tide levels along the immediate
coast near and to the north of where the center makes landfall in
the northeastern Yucatan Peninsula late tonight or early Thursday
and along the eastern mainland coast of Mexico Friday night or
early Saturday. Near the coast, the surge will be accompanied by
large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica
and the Cayman Islands to the southern coast of Cuba and the Yucatan
Peninsula of Mexico through Thursday. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 100 AM CDT.
Next complete advisory at 400 AM CDT.

$$
Forecaster Beven

NNNN



Hurricane Grace Discussion Number 23
NWS National Hurricane Center Miami FL AL072021
1000 PM CDT Wed Aug 18 2021

Grace has become a bit better organized during the past several
hours. Cuban radar data indicates that the eye and eyewall have
become better defined, and reports from Air Force Reserve and NOAA
Hurricane Hunter aircraft show that the inner core circulation has
become better defined. There are also occasional attempts at eye
formation in satellite imagery. However, these changes have not
yet resulted in significant intensification, with the maximum winds
remaining near 70 kt and the central pressure hovering near 988 mb.
One possible restraint on development is a dry slot that is seen
wrapping around the central core in both satellite imagery and
Cuban radar data.

The center has jogged a little to the left during the past few
hours, and the initial motion is now 280/16. The hurricane should
continue to move generally westward to west-northwestward for the
next 24-36 h, followed by a westward to west-southwestward motion
from 36-48 h. This motion should bring the center over the
Yucatan Peninsula of Mexico during the next 12 h, followed by
passage across the southwestern Gulf of Mexico or the Bay of
Campeche to a second landfall in mainland Mexico between 48-60 h.
After that, the cyclone should continue moving into the mountains
of Mexico until it dissipates. The new forecast track is nudged a
little south of the previous forecast, and it lies near the various
consensus models.

Except for the aforementioned dry slot, conditions appear
favorable for intensification before landfall on the Yucatan
peninsula. While not explicitly show in the intensity forecast,
Grace could reach an intensity of 75-80 kt before it reaches
Yucatan. The cyclone should weaken some as it crosses the
peninsula, then re-intensify over the Gulf of Mexico until it
reaches mainland Mexico. After final landfall in Mexico, Grace is
expected to quickly weaken and dissipate over the mountains of
Mexico just after 72 h. The remnants of Grace are likely to emerge
in the Pacific and possibly re-develop there, but the uncertainty
of whether this will be the original center or a new center
precludes forecast points over the Pacific at this time.

A Hurricane Watch and a Tropical Storm Watch have been issued for
portions of mainland Mexico.

Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
in portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico beginning during the next several hours.
Preparations to protect life and property should be rushed to
completion.

2. There is an increasing risk of hurricane conditions and dangerous
storm surge in portions of eastern mainland Mexico beginning late
Friday, and a Hurricane Watch has been issued for part of this area.

3. Through the weekend, heavy rainfall across central and northern
portions of the Yucatan Peninsula and Veracruz State should lead to
flash and urban flooding. In addition, the heavy rainfall from Grace
will be capable of producing mudslides in Veracruz.


FORECAST POSITIONS AND MAX WINDS

INIT 19/0300Z 19.8N 85.6W 70 KT 80 MPH
12H 19/1200Z 20.3N 88.1W 70 KT 80 MPH...INLAND
24H 20/0000Z 20.6N 91.4W 60 KT 70 MPH...OVER WATER
36H 20/1200Z 20.7N 94.0W 65 KT 75 MPH
48H 21/0000Z 20.5N 96.1W 75 KT 85 MPH
60H 21/1200Z 20.0N 98.8W 35 KT 40 MPH...INLAND
72H 22/0000Z 19.7N 101.6W 20 KT 25 MPH...POST-TROP/INLAND
96H 23/0000Z...DISSIPATED

$$
Forecaster Beven