ATL: DANNY - Advisories

[cycloneye]

BULLETIN
TROPICAL STORM DANNY ADVISORY NUMBER 19
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 PM AST SAT AUG 22 2015

...DANNY WEAKENS A LITTLE MORE...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.6N 54.7W
ABOUT 480 MI...775 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Watch is in effect for...
* Antigua, Barbuda, Montserrat, St. Kitts, Nevis, and Anguilla
* Saba and St. Eustatius
* St. Maarten
* Guadeloupe, St. Barthelemy, and St. Martin

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, in this case within 36 to 48
hours.

Interests elsewhere in the U. S. and British Virgin Islands, Puerto
Rico, and the Dominican Republic should monitor the progress of
Danny. Additional watches or warnings could be required for
portions of these areas on Sunday.



TROPICAL STORM DANNY DISCUSSION NUMBER 19
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 PM AST SAT AUG 22 2015

Satellite imagery and data from an earlier NOAA Hurricane Hunter
aircraft mission indicate that Danny has continued to quickly
weaken. The center has become exposed to the southwest of the
remaining deep convection due to moderate southwesterly shear and
dry air. The earlier SFMR data supported an intensity of 50 to 55
kt around 0000 UTC, and since the organization of Danny has
continued to decrease the advisory intensity has been lowered to
50 kt. The next NOAA and U.S. Air Force Reserve reconnaissance
missions into Danny are scheduled for 0800 and 1200 UTC,
respectively.

Danny is expected to remain within a hostile environment consisting
of dry mid-level air and moderate to strong southwesterly shear.
This should result in additional weakening. Due to the fast rate of
weakening Danny experienced today, the new NHC intensity forecast
is significantly lower than the previous advisory, and is in best
agreement with the HWRF and LGEM guidance. The NHC forecast now
shows Danny weakening to a tropical depression within a couple of
days and dissipating by day 5. Both of these events could occur
sooner. In fact, the ECMWF, GFS, and UKMET all show Danny
degenerating into a trough of low pressure by the time it nears
Hispaniola in 2 to 3 days.

Danny appears to have turned westward as anticipated, with an
initial motion estimate of 275/13. The overall track forecast
philosophy remains unchanged from the previous advisory. The cyclone
should continue on a general westward motion during the next 24 to
36 hours. After that time, Danny is forecast to turn west-
northwestward to the south of a low-level ridge over the western
Atlantic. The dynamical models are in relatively good agreement on
this scenario, and the updated NHC track is similar to, but a little
south of, the previous advisory primarily due to the more southward
initial position and current westward motion.

Since Danny has rapidly weakened today and there is a reasonable
possibility that it will be below tropical storm strength while
moving through the Leeward Islands, the governments of the various
islands have elected to maintain tropical storm watches at this
time. Additional watches or warnings could still be required for
portions of the Leeward Islands, the Virgin Islands, and Puerto Rico
on Sunday if Danny does not weaken as quickly as forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 23/0300Z 15.6N 54.7W 50 KT 60 MPH
12H 23/1200Z 15.9N 56.7W 45 KT 50 MPH
24H 24/0000Z 16.4N 59.3W 40 KT 45 MPH
36H 24/1200Z 16.9N 61.9W 35 KT 40 MPH
48H 25/0000Z 17.7N 64.4W 30 KT 35 MPH
72H 26/0000Z 19.5N 69.3W 25 KT 30 MPH
96H 27/0000Z 21.7N 73.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 28/0000Z...DISSIPATED

$$
Forecaster Brown/Berg

[cycloneye]

BULLETIN
TROPICAL STORM DANNY INTERMEDIATE ADVISORY NUMBER 20A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
800 AM AST SUN AUG 23 2015

...TROPICAL STORM CONDITIONS EXPECTED OVER PORTIONS OF THE LEEWARD
ISLANDS TONIGHT...


SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...15.7N 56.7W
ABOUT 315 MI...510 KM E OF GUADELOUPE
ABOUT 350 MI...565 KM ESE OF ANTIGUA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Antigua, Barbuda, Montserrat, St. Kitts, Nevis, and Anguilla

A Tropical Storm Watch is in effect for...
* Saba and St. Eustatius
* St. Maarten
* Guadeloupe, St. Barthelemy, and St. Martin

A Tropical Storm Warning means that tropical storm conditions are
expected, in this case within the next 24 hours.

Interests elsewhere in the U. S. and British Virgin Islands, Puerto
Rico, and the Dominican Republic should monitor the progress of
Danny. Additional watches or warnings could be required for
portions of these areas later this morning.

[cycloneye]

BULLETIN
TROPICAL STORM DANNY ADVISORY NUMBER 23
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 PM AST SUN AUG 23 2015

...DANNY APPROACHING THE SOUTHERN LEEWARD ISLANDS...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.6N 59.8W
ABOUT 100 MI...160 KM E OF DOMINICA
ABOUT 115 MI...190 KM ESE OF GUADELOUPE
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1009 MB...29.80 INCHES


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

The Tropical Storm Watch for Puerto Rico, Vieques, Culebra, and the
U.S. Virgin Islands has been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Antigua, Barbuda, Montserrat, St. Kitts, and Nevis

A Tropical Storm Watch is in effect for...
* Saba and St. Eustatius
* St. Maarten

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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 1100 PM AST (0300 UTC), the center of Tropical Storm Danny was
located near latitude 15.6 North, longitude 59.8 West. Danny is
moving toward the west near 15 mph (24 km/h), and a westward to
west-northwestward motion is expected over the next 48 hours. On
the forecast track, the center will move near or over the southern
Leeward Islands late tonight or early Monday, and into the
northeastern Caribbean Sea on Monday.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Weakening is forecast during the next 48 hours, and Danny is
expected to become a tropical depression on Monday, and become a
remnant low Monday night or Tuesday.

Tropical storm force winds extend outward up to 105 miles (165 km)
to the northeast of the center.

The latest minimum central pressure reported by an Air Force
Reserve Hurricane Hunter aircraft is 1009 mb (29.80 inches).


HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are expected within portions of the
warning area overnight and early Monday. Tropical storm conditions
are possible elsewhere over the Leeward Islands from Guadeloupe
northward overnight.

RAINFALL: Danny is expected to produce 2 to 4 inches of rain over
the Leeward Islands, the U.S. and British Virgin Islands, and
Puerto Rico through Tuesday.


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

$$
Forecaster Brown



TROPICAL STORM DANNY DISCUSSION NUMBER 23
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 PM AST SUN AUG 23 2015

Danny remains a sheared tropical cyclone. The low-level center is
exposed well to the southwest of a small of area of deep convection
that has formed within the past couple of hours. An Air Force
Reserve Hurricane Hunter Aircraft that investigated Danny this
evening measured tropical-storm-force winds on the SFMR over a
small area close to the convection. Based on these data, Danny
remains a 35-kt tropical storm for this advisory. The environment
ahead of Danny is expected to remain unfavorable. Moderate
southwesterly shear and dry mid-tropospheric air should cause
weakening, and Danny is forecast to become a tropical depression
on Monday, and degenerate into a remnant low or dissipate in a
couple of days.

The tropical cyclone is moving westward or 270/13 kt. The track
forecast reasoning remains unchanged as Danny is expected to move
westward to west-northwestward to the south of a low- to mid-level
ridge over the western Atlantic. The new NHC track forecast is
essentially an update of the previous advisory and lies along the
southern edge of the guidance envelope.

Since the chance of tropical-storm-force winds has decreased in
Puerto Rico and the U.S. Virgin Islands, the tropical storm watch
for those areas has been discontinued.


FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 15.6N 59.8W 35 KT 40 MPH
12H 24/1200Z 15.9N 61.8W 30 KT 35 MPH
24H 25/0000Z 16.3N 64.4W 30 KT 35 MPH
36H 25/1200Z 16.8N 67.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 26/0000Z 17.5N 69.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 27/0000Z...DISSIPATED

$$
Forecaster Brown

[cycloneye]

BULLETIN
TROPICAL STORM DANNY ADVISORY NUMBER 24
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
500 AM AST MON AUG 24 2015

...DANNY SLOWS DOWN AS IT APPROACHES THE SOUTHERN LEEWARD ISLANDS...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...15.8N 60.5W
ABOUT 60 MI...95 KM ENE OF DOMINICA
ABOUT 70 MI...110 KM ESE OF GUADELOUPE
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


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

The Meteorological Service of Antigua has discontinued the Tropical
Storm Warning for Antigua, Barbuda, Montserrat, St. Kitts, and
Nevis.

The Meteorological Service of Curacao indicates that a Tropical
Storm Warning is in effect for Saba and St. Eustatius.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Saba and St. Eustatius

A Tropical Storm Watch is in effect for...
* St. Maarten


TROPICAL STORM DANNY DISCUSSION NUMBER 24
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
500 AM AST MON AUG 24 2015

Reports from a NOAA Hurricane Hunter aircraft investigating Danny
this morning indicate that Danny still has winds that support
keeping the cyclone as a tropical storm. However, due to a strong
burst of deep convection containing tops of -80 deg C and intense
lightning activity that has developed near the alleged center, the
aircraft has been unable to provide an exact center fix. This
avoidance is for aircrew and aircraft safety reasons. However,
satellite intensity estimates of T2.5/35 kt from TAFB and SAB also
support keeping Danny as a tropical storm.

The initial motion estimate is a slower 275/08 kt. UW-CIMSS shear
analyses indicate that Danny is now encountering west-northwesterly
mid-level shear of around 5 kt, which could explain the slow down
in forward speed since the previous advisory. That being said,
there is no significant change to the previous track forecast or
reasoning. The subtropical ridge to the north of the cyclone is
expected to remain strong for the next few days, which should force
Danny on a westward to west-northwestward track until the system
dissipates in about 72 hours. The official track forecast is
basically just an update and extension of the previous advisory,
and lies close to the GFEX and TVCN consensus models.

Danny is expected to remain a sheared tropical cyclone or low
until dissipation occurs. In the short term, however, there could be
some minor fluctuations in intensity today as the deep-layer
southwesterly vertical wind shear decreases some before increasing
again and becoming stronger by Tuesday morning. Mid-level dry air
with humidity values decreasing to less than 40 percent should also
enhance the weakening process. As result, Danny is expected to
become a tropical depression by this evening, degenerate into a
remnant low on Tuesday, and dissipate by Wednesday. The NHC
intensity forecast is similar to the previous advisory and the ICON
intensity consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT 24/0900Z 15.8N 60.5W 35 KT 40 MPH
12H 24/1800Z 16.1N 62.6W 30 KT 35 MPH
24H 25/0600Z 16.5N 65.2W 30 KT 35 MPH
36H 25/1800Z 17.0N 67.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 26/0600Z 17.4N 71.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 27/0600Z...DISSIPATED

$$
Forecaster Stewart

[cycloneye]

BULLETIN
REMNANTS OF DANNY ADVISORY NUMBER 25
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 AM AST MON AUG 24 2015

...DANNY DEGENERATES INTO A TROUGH OF LOW PRESSURE...
...THIS IS THE LAST ADVISORY..


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.0N 62.0W
ABOUT 45 MI...70 KM WSW OF GUADELOUPE
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1010 MB...29.83 INCHES