ATL: MARCO - Advisories

[cycloneye]

BULLETIN
Tropical Storm Marco Intermediate Advisory Number 12A
NWS National Hurricane Center Miami FL AL142020
700 AM CDT Sun Aug 23 2020

...MARCO NEARING HURRICANE STRENGTH AS IT CROSSES THE SOUTHEASTERN
GULF OF MEXICO...


SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...24.2N 87.1W
ABOUT 210 MI...340 KM NW OF THE WESTERN TIP OF CUBA
ABOUT 360 MI...580 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 13 MPH...20 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 Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Hurricane Warning is in effect for...
* Morgan City Louisiana to the Mouth of the Pearl River

A Storm Surge Watch is in effect for...
* Sabine Pass to Morgan City Louisiana
* Ocean Springs to the Alabama/Florida border
* Lake Pontchartrain, Lake Maurepas, and Mobile Bay

A Hurricane Watch is in effect for...
* Intracoastal City Louisiana to west of Morgan City
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

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 Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

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, generally within 48 hours.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 700 AM CDT (1200 UTC), the center of Tropical Storm Marco was
located near latitude 24.2 North, longitude 87.1 West. Marco is
moving toward the north-northwest near 13 mph (20 km/h). Marco is
forecast to continue moving north-northwestward across the central
Gulf of Mexico today and will approach southeastern Louisiana on
Monday. A gradual turn toward the west with a decrease in forward
speed is expected after Marco moves inland on Monday and on Tuesday.

Maximum sustained winds are near 70 mph (110 km/h) with higher
gusts. Some strengthening is anticipated and Marco is forecast to
become a hurricane later today and be at hurricane strength when it
approaches the northern Gulf Coast on Monday. Rapid weakening is
expected after Marco moves inland.

Tropical-storm-force winds extend outward up to 60 miles (95 km)
from the center.

The estimated minimum central pressure based on data from the Air
Force Reserve Hurricane Hunter aircraft is 994 mb (29.36 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Sabine Pass to Morgan City LA...2-4 ft
Morgan City LA to Ocean Springs MS including Lake Borgne...4-6 ft
Ocean Springs MS to the AL/FL Border including Mobile Bay...2-4 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
destructive waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Hurricane conditions are expected within the hurricane
warning area by midday Monday, with tropical storm conditions
possible by early Monday. Tropical storm conditions are possible
within the tropical storm watch area on Monday, and hurricane
conditions are possible within the hurricane watch areas late
Monday.

RAINFALL: Marco is expected to produce rainfall accumulations of 2
to 4 inches with isolated maximum amounts of 6 inches across the
Central U.S. Gulf coast through Tuesday.

This rainfall may result in isolated areas of flash and urban
flooding along the Central U.S. Gulf Coast.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast later today. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.

TORNADOES: An isolated tornado will be possible early Monday morning
near the southeast Louisiana coast.


NEXT ADVISORY
-------------
Next complete advisory at 1000 AM CDT.

$$
Forecaster Latto

[cycloneye]

BULLETIN
Tropical Storm Marco Advisory Number 13
NWS National Hurricane Center Miami FL AL142020
1000 AM CDT Sun Aug 23 2020

...MARCO EXPECTED TO BECOME A HURRICANE TODAY AS IT ENTERS
THE CENTRAL GULF OF MEXICO...
...LIFE-THREATENING STORM SURGE AND HURRICANE-FORCE WINDS EXPECTED
ALONG PORTIONS OF THE U.S. GULF COAST...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...24.7N 87.3W
ABOUT 325 MI...520 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 475 MI...765 KM SE OF LAFAYETTE LOUISIANA
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...993 MB...29.33 INCHES


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

The Storm Surge Watch has been discontinued from the
Mississippi/Alabama border to the Alabama/Florida border, including
Mobile Bay.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Hurricane Warning is in effect for...
* Morgan City Louisiana to the Mouth of the Pearl River

A Storm Surge Watch is in effect for...
* Sabine Pass to Morgan City Louisiana
* Ocean Springs Mississippi to the Mississippi/Alabama border
* Lake Pontchartrain and Lake Maurepas

A Hurricane Watch is in effect for...
* Intracoastal City Louisiana to west of Morgan City
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

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 Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

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, generally within 48 hours.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1000 AM CDT (1500 UTC), the center of Tropical Storm Marco was
located near latitude 24.7 North, longitude 87.3 West. Marco is
moving toward the north-northwest near 14 mph (22 km/h), and this
motion is expected to continue through tonight, followed by a turn
to the northwest by Monday. On the forecast track, Marco will cross
the central Gulf of Mexico today and will approach southeastern
Louisiana on Monday. A gradual turn toward the west-northwest with
a decrease in forward speed is expected after Marco moves inland.

Maximum sustained winds are near 70 mph (110 km/h) with higher
gusts. Some strengthening is anticipated and Marco is forecast to
become a hurricane later today and be at hurricane strength when it
approaches the northern Gulf Coast on Monday. Rapid weakening is
expected after Marco moves inland.

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

The estimated minimum central pressure is 993 mb (29.33 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Ocean Springs MS including Lake Borgne...4-6 ft
Sabine Pass to Morgan City LA...2-4 ft
Ocean Springs MS to the MS/AL Border...2-4 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft
MS/AL Border to AL/FL Border including Mobile Bay...1-3 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Hurricane conditions are expected within the hurricane
warning area by midday Monday, with tropical storm conditions
possible by early Monday. Tropical storm conditions are possible
within the tropical storm watch area on Monday, and hurricane
conditions are possible within the hurricane watch areas late
Monday.

RAINFALL: Marco is expected to produce rainfall accumulations of 2
to 4 inches with isolated maximum amounts of 6 inches across the
Central U.S. Gulf coast through Tuesday.

This rainfall may result in isolated areas of flash and urban
flooding along the Central U.S. Gulf Coast.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast later today. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.

TORNADOES: An isolated tornado will be possible early Monday morning
near the southeast Louisiana coast.


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

$$
Forecaster Latto

[cycloneye]

BULLETIN
Hurricane Marco Intermediate Advisory Number 13A
NWS National Hurricane Center Miami FL AL142020
100 PM CDT Sun Aug 23 2020

...HURRICANE MARCO CROSSING THE CENTRAL GULF...
...LIFE-THREATENING STORM SURGE AND HURRICANE-FORCE WINDS EXPECTED
ALONG PORTIONS OF THE U.S. GULF COAST MONDAY...


SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...25.3N 87.4W
ABOUT 280 MI...450 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 440 MI...710 KM SE OF LAFAYETTE LOUISIANA
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...992 MB...29.29 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Hurricane Warning is in effect for...
* Morgan City Louisiana to the Mouth of the Pearl River

A Storm Surge Watch is in effect for...
* Sabine Pass to Morgan City Louisiana
* Ocean Springs Mississippi to the Mississippi/Alabama border
* Lake Pontchartrain and Lake Maurepas

A Hurricane Watch is in effect for...
* Intracoastal City Louisiana to west of Morgan City
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

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 Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

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, generally within 48 hours.

For storm information specific to your area in the United States,
including possible inland watches and warnings, please monitor
products issued by your local National Weather Service forecast
office. For storm information specific to your area outside of the
United States, please monitor products issued by your national
meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 100 PM CDT (1800 UTC), the center of Hurricane Marco was located
near latitude 25.3 North, longitude 87.4 West. Marco is moving
toward the north-northwest near 14 mph (22 km/h), and this motion is
expected to continue through tonight, followed by a turn toward the
northwest by Monday. On the forecast track, Marco will cross the
central Gulf of Mexico today and will approach southeastern
Louisiana on Monday. A gradual turn toward the west-northwest with a
decrease in forward speed is expected after Marco moves inland.

Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts. Marco is expected to be a hurricane when it approaches the
northern Gulf Coast on Monday. Rapid weakening is expected after
Marco moves inland.

Hurricane-force winds extend outward up to 20 miles (30 km) from
the center and tropical-storm-force winds extend outward up to 100
miles (160 km) from the center.

The estimated minimum central pressure is 992 mb (29.29 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Ocean Springs MS including Lake Borgne...4-6 ft
Sabine Pass to Morgan City LA...2-4 ft
Ocean Springs MS to the MS/AL Border...2-4 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft
MS/AL Border to AL/FL Border including Mobile Bay...1-3 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Hurricane conditions are expected within the hurricane
warning area by midday Monday, with tropical storm conditions
possible by early Monday. Tropical storm conditions are possible
within the tropical storm watch area on Monday, and hurricane
conditions are possible within the hurricane watch areas late
Monday.

RAINFALL: Marco is expected to produce rainfall accumulations of 2
to 4 inches with isolated maximum amounts of 6 inches across the
Central U.S. Gulf coast through Tuesday.

This rainfall may result in isolated areas of flash and urban
flooding along the Central U.S. Gulf Coast.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast later today. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.

TORNADOES: An isolated tornado will be possible early Monday
morning near the southeast Louisiana coast.


NEXT ADVISORY
-------------
Next complete advisory at 400 PM CDT.

$$
Forecaster Latto

[cycloneye]

BULLETIN
Hurricane Marco Advisory Number 14
NWS National Hurricane Center Miami FL AL142020
400 PM CDT Sun Aug 23 2020

...MARCO EXPECTED TO BRING LIFE-THREATENING STORM SURGE AND
HURRICANE-FORCE WINDS ALONG PORTIONS OF THE U.S. GULF COAST
MONDAY...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...25.8N 87.8W
ABOUT 240 MI...390 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 395 MI...640 KM SE OF LAFAYETTE LOUISIANA
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES


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

A Tropical Storm Warning has been issued from Cameron to
west of Morgan City, Louisiana.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Hurricane Warning is in effect for...
* Morgan City Louisiana to the Mouth of the Pearl River

A Storm Surge Watch is in effect for...
* Sabine Pass to Morgan City Louisiana
* Ocean Springs Mississippi to the Mississippi/Alabama border
* Lake Pontchartrain and Lake Maurepas

A Hurricane Watch is in effect for...
* Intracoastal City to west of Morgan City
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
* Cameron to west of Morgan City

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

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 Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

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, generally within 48 hours.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 400 PM CDT (2100 UTC), the center of Hurricane Marco was located
near latitude 25.8 North, longitude 87.8 West. Marco is moving
toward the north-northwest near 13 mph (20 km/h), a turn to the
northwest is expected later tonight followed by a turn to the
west-northwest by Monday night. On the forecast track, Marco will
be near the Louisiana coast Monday afternoon, and move near or
over the coast through Tuesday.

Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts. Little change is strength is expected over the next 24 h.
Gradual weakening is expected thereafter, and Marco could become a
remnant low by Tuesday night.

Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 105 miles
(165 km).

The estimated minimum central pressure is 991 mb (29.27 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Mouth of the Mississippi River...4-6 ft
Mouth of the Mississippi River to Ocean Springs MS including Lake
Borgne...3-5 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft
Intracoastal City LA to Morgan City LA...2-4 ft
Sabine Pass to Intracoastal City...1-3 ft
Ocean Springs MS to the AL/FL Border including Mobile Bay...1-3 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Hurricane conditions are expected within the hurricane
warning area by midday Monday, with tropical storm conditions
possible by early Monday. Tropical storm conditions are possible
within the tropical storm watch area on Monday, and hurricane
conditions are possible within the hurricane watch areas late
Monday.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 5 inches with isolated maximum amounts of 7 inches across
the Central U.S. Gulf coast through Tuesday.

This rainfall may result in scattered areas of flash and urban
flooding along the Central U.S. Gulf Coast.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next couple of days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: An isolated tornado is possible early Monday morning
near the southeast Louisiana coast. Isolated tornadoes are possible
across southeast Louisiana, southern Mississippi, southern Alabama,
and the Florida Panhandle Monday and Monday night.


NEXT ADVISORY
-------------
Next intermediate advisory at 700 PM CDT.
Next complete advisory at 1000 PM CDT.

$$
Forecaster Latto


Hurricane Marco Discussion Number 14
NWS National Hurricane Center Miami FL AL142020
400 PM CDT Sun Aug 23 2020

Shortly after the 10 AM CDT advisory was issued, the Air Force
Reserve Hurricane Hunter aircraft investigating Marco measured SFMR
winds of 65 to 69 kt for several minutes. A dropsonde around the
same time also measured winds equivalent to 64 kt at the surface.
Based on these data, it was evident that Marco had strengthened
into a hurricane. Since that time, the convective pattern has
changed little, and the final leg of the aircraft mission did
not reveal any notable changes to the cyclone's intensity.
Therefore, the initial intensity has been set to 65 kt, which is
also in agreement with the latest Dvorak intensity estimate from
SAB.

Marco continues to move north-northwest at around 11 kt. Model
guidance is in good agreement on a north-northwest and then
northwest motion into Monday morning as Marco nears the northern
Gulf coast. However, there has been a major shift in the track
guidance beyond Monday morning, and the majority of the forecast
models now keep Marco offshore of the northern Gulf coast for the
next few days rather than moving it inland over Louisiana Monday
afternoon. Since this shift was so abrupt, I would rather split the
difference between the previous official forecast track and the
latest consensus tracks until another round of model runs can
confirm this new suggested track is higher confidence. Based on this
shift in track, tropical storm conditions are expected farther west
along the Louisiana coast, and a Tropical Storm Warning has been
issued from Morgan City to Cameron, Louisiana. It should be noted
that if the trend in the models are correct, some of the impacts
over portions of the north-central Gulf coast could be lessened.

The current shear analysis from UW-CIMSS shows that Marco is
experiencing about 20-25 kt of southwesterly shear, yet Marco has
been able to slowly strengthen in this environment today, likely
due to the presence of very warm waters and plenty of atmospheric
moisture. By late tonight and through Monday, the SHIPS guidance
suggests this shear will increase to over 30 kt. This should limit
any further intensification, and could cause Marco to weaken before
it nears the northern Gulf coast Monday afternoon. By Monday night,
the shear is forecast to increase to close to 40 kt, which should
strip the convection away from the center of the cyclone, causing it
to weaken. After 48 h, Marco is now expected to become a remnant low
devoid of deep convection. The official NHC intensity forecast is
similar to the previous one, but is at the high end of the guidance
through 24 h.

Key Messages:

1. Hurricane conditions, life-threatening storm surge, and heavy
rainfall are expected from Marco along portions of the Gulf Coast
beginning on Monday. Interests in these areas should follow any
advice given by local government officials.

2. Tropical Storm Laura could bring additional storm surge,
rainfall, and wind impacts to portions of the U.S. Gulf Coast by the
middle of the week. This could result in a prolonged period of
hazardous weather for areas that may also be affected by Marco.
Interests there should monitor the progress of Marco and Laura and
updates to the forecast during the next few days.

FORECAST POSITIONS AND MAX WINDS

INIT 23/2100Z 25.8N 87.8W 65 KT 75 MPH
12H 24/0600Z 27.1N 88.6W 65 KT 75 MPH
24H 24/1800Z 28.5N 89.7W 65 KT 75 MPH
36H 25/0600Z 29.3N 91.4W 50 KT 60 MPH...INLAND
48H 25/1800Z 29.8N 93.2W 35 KT 40 MPH...INLAND
60H 26/0600Z 29.9N 95.1W 30 KT 35 MPH...POST-TROP/INLAND
72H 26/1800Z 29.7N 96.8W 25 KT 30 MPH...POST-TROP/INLAND
96H 27/1800Z...DISSIPATED

$$
Forecaster Latto

[cycloneye]

BULLETIN
Hurricane Marco Intermediate Advisory Number 14A
NWS National Hurricane Center Miami FL AL142020
700 PM CDT Sun Aug 23 2020

...MARCO EXPECTED TO MOVE NEAR THE LOUISIANA COAST ON MONDAY...


SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...26.4N 87.6W
ABOUT 180 MI...290 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Hurricane Warning is in effect for...
* Morgan City Louisiana to the Mouth of the Pearl River

A Storm Surge Watch is in effect for...
* Sabine Pass to Morgan City Louisiana
* Ocean Springs Mississippi to the Mississippi/Alabama border
* Lake Pontchartrain and Lake Maurepas

A Hurricane Watch is in effect for...
* Intracoastal City to west of Morgan City
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
* Cameron to west of Morgan City

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

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 Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

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, generally within 48 hours.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 700 PM CDT (0000 UTC), the center of Hurricane Marco was located
by an Air Force Reserve Hurricane Hunter Aircraft near latitude 26.4
North, longitude 87.6 West. Marco is moving toward the
north-northwest near 13 mph (20 km/h). Marco is forecast to move
generally north-northwestward to northwestward tonight and approach
the Louisiana coast Monday afternoon. It is then forecast to turn
westward and move near or over the coast through Tuesday.

Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts. Small fluctuations in strength are possible tonight. Gradual
weakening is expected to begin on Monday, and Marco could become a
remnant low by Tuesday night.

Hurricane-force winds extend outward up to 15 miles (30 km) from
the center and tropical-storm-force winds extend outward up to 105
miles (165 km).

The estimated minimum central pressure is 991 mb (29.27 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Mouth of the Mississippi River...4-6 ft
Mouth of the Mississippi River to Ocean Springs MS including Lake
Borgne...3-5 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft
Intracoastal City LA to Morgan City LA...2-4 ft
Sabine Pass to Intracoastal City...1-3 ft
Ocean Springs MS to the AL/FL Border including Mobile Bay...1-3 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Hurricane conditions are expected within the hurricane
warning area by midday Monday, with tropical storm conditions
possible by early Monday. Tropical storm conditions are possible
within the tropical storm watch area on Monday, and hurricane
conditions are possible within the hurricane watch areas late
Monday.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 5 inches with isolated maximum amounts of 7 inches across
the Central U.S. Gulf coast through Tuesday.

This rainfall may result in scattered areas of flash and urban
flooding along the Central U.S. Gulf Coast.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next couple of days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: An isolated tornado is possible early Monday morning
near the southeast Louisiana coast. Isolated tornadoes are possible
across southeast Louisiana, southern Mississippi, southern Alabama,
and the Florida Panhandle Monday and Monday night.


NEXT ADVISORY
-------------
Next complete advisory at 1000 PM CDT.

$$
Forecaster Zelinsky

[cycloneye]

BULLETIN
Tropical Storm Marco Advisory Number 15
NWS National Hurricane Center Miami FL AL142020
1000 PM CDT Sun Aug 23 2020

...HURRICANE HUNTERS FIND MARCO HAS WEAKENED...
...HURRICANE AND STORM SURGE WARNINGS REMAIN IN EFFECT FOR
PORTIONS OF THE NORTHERN GULF COAST...


SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...26.8N 87.6W
ABOUT 185 MI...295 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NNW OR 345 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES


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

The Hurricane Watch from Intracoastal City to west of Morgan City
has been canceled.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Hurricane Warning is in effect for...
* Morgan City Louisiana to the Mouth of the Pearl River

A Storm Surge Watch is in effect for...
* Sabine Pass to Morgan City Louisiana
* Ocean Springs Mississippi to the Mississippi/Alabama border
* Lake Pontchartrain and Lake Maurepas

A Hurricane Watch is in effect for...
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning is in effect for...
* Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
* Cameron to west of Morgan City

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

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 Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

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, generally within 48 hours.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1000 PM CDT (0300 UTC), the center of Tropical Storm Marco was
located by an Air Force Reserve Hurricane Hunter plane near latitude
26.8 North, longitude 87.6 West. Marco is moving toward the
north-northwest near 12 mph (19 km/h). A continued
north-northwestward motion is possible tonight, but a turn toward
the northwest is expected by Monday morning. Marco is forecast to
approach the coast of Louisiana by Monday afternoon, and then turn
westward and move near or over the coast through Tuesday.

Data from the Hurricane Hunter plane indicate that maximum sustained
winds have decreased to near 70 mph (110 km/h) with higher gusts.
Fluctuations in intensity are possible during the next 24 hours, but
Marco is forecast to weaken rapidly by early Tuesday.

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

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


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Mouth of the Mississippi River...4-6 ft
Mouth of the Mississippi River to Ocean Springs MS including Lake
Borgne...3-5 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft
Intracoastal City LA to Morgan City LA...2-4 ft
Sabine Pass to Intracoastal City...1-3 ft
Ocean Springs MS to the AL/FL Border including Mobile Bay...1-3 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Hurricane conditions are still possible within the hurricane
warning area by midday Monday, with tropical storm conditions
likely by midday Monday. Tropical storm conditions are possible
within the tropical storm watch area on Monday, and hurricane
conditions are possible within the hurricane watch areas late
Monday.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 5 inches with isolated maximum amounts of 10 inches across
portions of the northeast and north-central Gulf coast through
Tuesday.

This rainfall may result in areas of flash, urban and
small stream flooding along the central U.S. Gulf Coast.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next couple of days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: Isolated tornadoes are possible across southeast
Louisiana, southern Mississippi, southern Alabama, and the Florida
Panhandle Monday and Monday night.


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

$$
Forecaster Zelinsky


Tropical Storm Marco Discussion Number 15
NWS National Hurricane Center Miami FL AL142020
1000 PM CDT Sun Aug 23 2020

Marco is feeling the effect of strong southwesterly shear. The
center, as identified by an Air Force Reserve Hurricane Hunter
aircraft, is displaced to the southwest edge of the convective
canopy. That said, Marco has not quite fully decoupled yet and has
moved well right of the previous forecast. Data from the plane
indicates that Marco has weakened; the highest flight-level winds
were only 58 kt with unflagged SFMR winds just above 50 kt.
Marco's intensity has been lowered slightly to 60 kt, but this is
probably generous.

The intensity guidance remains maddeningly inconsistent. The most
recent runs of the HWRF and HMON show that there is still a chance
that Marco could reach the Gulf Coast as a hurricane, despite the
shear. While this seems unlikely given the current structure of the
cyclone, it also seems slightly premature to rule it out entirely.
After all, the shear lessened enough to allow Marco to briefly
strengthen after it was strongly sheared for a time last night. The
rest of the guidance shows Marco weakening further as it approaches
the coast, and this seems like a more likely solution. The NHC
forecast just holds Marco at 60 kt for the next 24 h, but its
certainly possible it could already be weaker than that. Rapid
weakening is likely by 36 h if it hasn't happened sooner and Marco
is forecast to become a remnant low by early Wednesday.

Marco's track is tied entirely to its intensity and structure. Once
Marco becomes fully decoupled it will slow and turn westward. It is
not out of the question that this could happen before Marco reaches
the coast and the system never makes landfall. However, as long as
the strong southwesterly upper-level flow contributes to the
steering, Marco will continue to move more northward to
north-northwestward. Due to the recent northward movement of Marco's
center, the NHC track forecast has been adjusted in that direction,
but it is blended to the previous forecast by about 36 h and
onward. Confidence in this forecast unfortunately remains low since
the model spread remains usually high.

It is worth noting that Marco is a small tropical cyclone. The large
area of Tropical Storm and Hurricane watches and warnings along the
northern Gulf Coast is a reflection of the unusually high
uncertainty in the forecast, and it is unlikely that all of those
regions will experience tropical-storm-force winds or
life-threatening storm surge associated with Marco. However, impacts
will likely occur in some portions of the watch/warning area
beginning on Monday, and heavy rain is likely across most of the
region during the next couple of days. Changes to the watches and
warnings are likely on Monday and users should consult products from
their local weather forecast office for more information about
potential hazards in their area.

Key Messages:

1. Strong winds, life-threatening storm surge, and heavy rainfall
are expected from Marco along portions of the Gulf Coast beginning
on Monday. Interests in these areas should follow any advice given
by local government officials.

2. Tropical Storm Laura could bring additional storm surge,
rainfall, and wind impacts to portions of the U.S. Gulf Coast by the
middle of the week. This could result in a prolonged period of
hazardous weather for areas that may also be affected by Marco.
Interests there should monitor the progress of Marco and Laura and
updates to the forecast during the next few days.


FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 26.8N 87.6W 60 KT 70 MPH
12H 24/1200Z 28.0N 88.7W 60 KT 70 MPH
24H 25/0000Z 29.0N 90.2W 60 KT 70 MPH
36H 25/1200Z 29.6N 92.0W 40 KT 45 MPH...INLAND
48H 26/0000Z 29.8N 93.6W 30 KT 35 MPH...INLAND
60H 26/1200Z 29.7N 94.9W 25 KT 30 MPH...POST-TROP/INLAND
72H 27/0000Z...DISSIPATED

$$
Forecaster Zelinsky

[cycloneye]

TCPAT4

BULLETIN
Tropical Storm Marco Advisory Number 16
NWS National Hurricane Center Miami FL AL142020
400 AM CDT Mon Aug 24 2020

...HURRICANE WARNINGS DISCONTINUED FOR MARCO BUT DANGEROUS STORM
SURGE STILL ANTICIPATED...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...27.6N 88.2W
ABOUT 115 MI...190 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


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

The Hurricane Warning from Morgan City Louisiana to the Mouth of the
Pearl River has been changed to a Tropical Storm Warning.

The Hurricane Watch for Lake Pontchartrain, Lake Maurepas, and
Metropolitan New Orleans has been discontinued.

The Tropical Storm Watches west of Intracoastal City Louisiana and
from the Mississippi/Alabama border to the Alabama/Florida
border have been discontinued.

All Storm Surge Watches have been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Tropical Storm Warning is in effect for...
* Intracoastal City to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within 12
to 24 hours.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 400 AM CDT (0900 UTC), the center of Tropical Storm Marco was
located near latitude 27.6 North, longitude 88.2 West. Marco is
moving toward the northwest near 10 mph (17 km/h). Marco is
forecast to approach the coast of Louisiana this afternoon, and
then turn westward and move very close to the coast of Louisiana
through Tuesday night.

Data from the Hurricane Hunter plane indicate that maximum
sustained winds have decreased to near 60 mph (95 km/h) with higher
gusts. Further weakening is expected, and Marco is forecast to
become a tropical depression late on Tuesday and dissipate on
Wednesday.

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

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


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Ocean Springs MS, including Lake Borgne...2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Tropical storm conditions are expected to start by this
afternoon in portions of the warning area.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 5 inches with isolated maximum amounts of 10 inches across
portions of the northeast and north-central Gulf coast through
Tuesday. This rainfall may result in areas of flash, urban and
small stream flooding along the area.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next couple of days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: A couple of tornadoes will be possible today from
southeast Louisiana to the western Florida Panhandle.


NEXT ADVISORY
-------------
Next intermediate advisory at 700 AM CDT.
Next complete advisory at 1000 AM CDT.

$$
Forecaster Blake



Tropical Storm Marco Discussion Number 16
NWS National Hurricane Center Miami FL AL142020
400 AM CDT Mon Aug 24 2020

Marco is clearly weakening tonight. Data from an Air Force Reserve
Hurricane Hunter mission showed that flight-level and SFMR had
decreased along with a substantial rise in central pressure. In
addition, GOES-16 1-min satellite data show the surface center well
displaced from the deep convection, and it appears that Marco is
decoupling from its mid-level circulation to the northeast. The
initial wind speed is set to 50 kt, and that could be generous.

Some large changes have been required on this forecast. Considering
the shear is only forecast to increase, there is no significant
chance that Marco re-intensifies to a hurricane, and the hurricane
warnings have been replaced with tropical storm warnings.
Furthermore, now that the storm is losing vertical coherence, the
intensity forecast has been decreased as well, and is fairly
consistent with the model consensus and almost every model.

Marco has turned northwestward this morning at about 9 kt. The
storm should gradually turn westward as it approaches southeastern
Louisiana due to the shallower cyclone feeling the low-level ridge.
Marco will likely dissipate in a couple of days near the
Texas/Louisiana border due to continued strong shear. Guidance has
come into better agreement on the track going slightly inland or
just brushing the Louisiana coast, and the track has been nudged
southward on this advisory. It should be noted that the heaviest
rain and strongest winds will likely be northeast of the center, so
users should not focus on the exact track of the cyclone.


Key Messages:

1. Gusty winds, dangerous storm surge, and heavy rainfall are
expected from Marco along portions of the Gulf Coast beginning
later today. Interests in these areas should follow any advice given
by local government officials.

2. Tropical Storm Laura could bring additional storm surge,
rainfall, and wind impacts to portions of the U.S. Gulf Coast by the
middle of the week. This could result in a prolonged period of
hazardous weather for areas that may also be affected by Marco.
Interests there should monitor the progress of Marco and Laura and
updates to the forecast during the next few days.


FORECAST POSITIONS AND MAX WINDS

INIT 24/0900Z 27.6N 88.2W 50 KT 60 MPH
12H 24/1800Z 28.6N 89.2W 45 KT 50 MPH
24H 25/0600Z 29.2N 90.8W 35 KT 40 MPH...INLAND
36H 25/1800Z 29.5N 92.7W 30 KT 35 MPH...OVER WATER
48H 26/0600Z 29.4N 94.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 26/1800Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

BULLETIN
Tropical Storm Marco Intermediate Advisory Number 16A
NWS National Hurricane Center Miami FL AL142020
700 AM CDT Mon Aug 24 2020

...MARCO PRODUCING HEAVY RAINFALL AND GUSTY WINDS ALONG PORTIONS OF
THE NORTHERN GULF COAST...


SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...28.1N 88.4W
ABOUT 85 MI...135 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...50 MPH...80 KM/H
PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 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 Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Tropical Storm Warning is in effect for...
* Intracoastal City to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within 12
to 24 hours.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 700 AM CDT (1200 UTC), the center of Tropical Storm Marco was
located near latitude 28.1 North, longitude 88.4 West. Marco is
moving toward the northwest near 10 mph (17 km/h). Marco is
forecast to approach the coast of Louisiana this afternoon, and then
turn westward and move very close to the coast of Louisiana through
Tuesday night.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate
that maximum sustained winds have decreased to near 50 mph (80 km/h)
with higher gusts. Further weakening is expected, and Marco is
forecast to become a tropical depression late on Tuesday and
dissipate on Wednesday.

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

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


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Ocean Springs MS, including Lake Borgne...2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Tropical storm conditions are expected to start by this
afternoon in portions of the warning area.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 5 inches with isolated maximum amounts of 10 inches across
portions of the northeast and north-central Gulf coast through
Tuesday. This rainfall may result in areas of flash, urban and
small stream flooding in the area.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next couple of days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: A couple of tornadoes will be possible today from
southeast Louisiana to the western Florida Panhandle.


NEXT ADVISORY
-------------
Next complete advisory at 1000 AM CDT.

$$
Forecaster Latto

NNNN

[cycloneye]

BULLETIN
Tropical Storm Marco Advisory Number 17
NWS National Hurricane Center Miami FL AL142020
1000 AM CDT Mon Aug 24 2020

...MARCO CONTINUES TO PRODUCE HEAVY RAINFALL AND GUSTY
WINDS ALONG PORTIONS OF THE NORTHERN GULF COAST...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...28.5N 88.5W
ABOUT 55 MI...90 KM SE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


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

The Tropical Storm Warning from west of Morgan City to Intracoastal
City, Louisiana, has been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for....
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne

A Tropical Storm Warning is in effect for...
* Morgan City to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a depiction
of areas at risk, please see the National Weather Service Storm
Surge Watch/Warning Graphic, available at hurricanes.gov. This is a
life-threatening situation. Persons located within these areas
should take all necessary actions to protect life and property from
rising water and the potential for other dangerous conditions.
Promptly follow evacuation and other instructions from local
officials.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within
the next 6 to 18 hours.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 1000 AM CDT (1500 UTC), the center of Tropical Storm Marco was
located near latitude 28.5 North, longitude 88.5 West. Marco is
moving toward the north-northwest near 8 mph (13 km/h). A turn to
the west-northwest is expected to occur by Tuesday, and this
motion should continue until the system dissipates in a couple of
days.

Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Steady weakening is forecast, and Marco is expected to weaken to a
tropical depression tonight, and degenerate to a remnant low on
Tuesday.

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

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


HAZARDS AFFECTING LAND
----------------------
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Morgan City LA to Ocean Springs MS, including Lake Borgne...2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

WIND: Tropical storm conditions are expected to start by this
afternoon in portions of the warning area.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 6 inches with isolated maximum amounts of 10 inches across
portions of the northeast and north-central Gulf coast through
Tuesday. This rainfall may result in areas of flash, urban and
small stream flooding along the same area.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next couple of days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: A couple of tornadoes are possible today into tonight
across the Florida Panhandle, southern Georgia, southern Alabama,
and southern Mississippi.


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

$$
Forecaster Latto


Tropical Storm Marco Discussion Number 17
NWS National Hurricane Center Miami FL AL142020
1000 AM CDT Mon Aug 24 2020

Strong southwesterly shear is taking its toll on Marco, with the
edge of the nearest deep convection now displaced 50 n mi northeast
of the exposed circulation center. Data from an Air Force Reserve
Hurricane Hunter aircraft that investigated the system this morning
measured 45-kt surface winds with the onboard SFMR instrument in
that convection, but winds of only 20 to 30 kt were measured
between this thunderstorm activity and the cyclone's center.
Sampling by the aircraft has also revealed that winds of tropical
storm force are likely no longer occurring in any portion of the
circulation except in that convection. Based on the SFMR data, the
initial intensity is initialized at 45 kt.

The shear is not forecast to abate in the foreseeable future, and
the simulated satellite imagery in the GFS and ECMWF suggests that
Marco will degenerate into a remnant low on Tuesday. The latest NHC
forecast is near the various consensus aids, which shows the cyclone
weakening to a tropical depression late tonight. Based on the
updated intensity forecast, tropical storm conditions are no longer
expected to be produced by Marco over the central portions of the
Louisiana coast, and the Tropical Storm Warnings for those
locations have been discontinued.

Marco has slowed down and has moved a little to the right of the
forecast track over the past few hours, with an initial motion of
NNW/7 kt. The track guidance for the entire forecast period has
shifted back northward, and is just south of where it was this time
yesterday. The official forecast track was adjusted eastward in the
near term to accommodate the recent right-of-track bias. After 12
h, the track forecast lies between the previous one and most of the
consensus track guidance. On this track, Marco is expected to move
inland tonight, and remain inland when the system turns
west-northwestward in the low-level flow by Tuesday morning.


Key Messages:

1. Gusty winds, dangerous storm surge, and heavy rainfall are
expected from Marco along portions of the Gulf Coast beginning
later today. Interests in these areas should follow any advice given
by local government officials.

2. Tropical Storm Laura could bring additional storm surge,
rainfall, and wind impacts to portions of the U.S. Gulf Coast by the
middle of the week. This could result in a prolonged period of
hazardous weather for areas that may also be affected by Marco.
Interests there should monitor the progress of Marco and Laura and
updates to the forecast during the next few days.


FORECAST POSITIONS AND MAX WINDS

INIT 24/1500Z 28.5N 88.5W 45 KT 50 MPH
12H 25/0000Z 29.2N 89.3W 35 KT 40 MPH...INLAND
24H 25/1200Z 30.0N 91.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 26/0000Z 30.5N 93.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 26/1200Z 30.9N 95.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 27/0000Z...DISSIPATED

$$
Forecaster Latto

[cycloneye]

BULLETIN
Tropical Storm Marco Special Advisory Number 18
NWS National Hurricane Center Miami FL AL142020
100 PM CDT Mon Aug 24 2020

...MARCO WEAKENS...
...GUSTY WINDS AND HEAVY RAINFALL STILL POSSIBLE OVER PORTIONS OF
THE NORTHERN GULF COAST THROUGH TONIGHT...


SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...28.7N 88.6W
ABOUT 40 MI...65 KM SE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES


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

The Tropical Storm Warning and Storm Surge Warning for the U.S.
Gulf Coast have been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

There are no coastal watches or warnings in effect.

Gusty winds, heavy rainfall, and lingering coastal flooding are
expected from Marco along portions of the Gulf Coast through this
evening. For information on these hazards see products from your
local National Weather Service office.

Tropical cyclone wind and surge watches or warnings are likely to
be issued for portions of the U.S. Gulf Coast later today for
Tropical Storm Laura.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 100 PM CDT (1800 UTC), the center of Tropical Storm Marco was
located near latitude 28.7 North, longitude 88.6 West. Marco is
moving toward the northwest near 6 mph (9 km/h). A turn to the
west-northwest is expected to occur by Tuesday, and this motion
should continue until the system dissipates in a couple of days.

Aircraft and satellite derived wind data indicate that maximum
sustained winds are near 40 mph (65 km/h) with higher gusts.
Further weakening is expected, and Marco is forecast to become a
tropical depression tonight and degenerate to a remnant low on
Tuesday.

Tropical-storm-force winds extend outward up to 80 miles (130 km)
to the northeast of the center over water. A National Ocean
Service weather station located on Petit Bois Island, Mississippi
recently reported a wind gust to 35 mph (58 km/h).

The latest minimum central pressure reported by aircraft
reconnaissance is 1008 mb (29.77 inches).


HAZARDS AFFECTING LAND
----------------------
WIND: Wind gusts to tropical storm force are possible over the
coastal sections of southeastern Louisiana and Mississippi through
this evening.

RAINFALL: Marco is expected to produce total rainfall accumulations
of 2 to 4 inches with isolated maximum amounts of 7 inches across
portions of the northeast and north-central Gulf coast through
Tuesday. This rainfall may result in areas of flash, urban and
small stream flooding along the same area.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next day or so. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: A couple of tornadoes are possible today into tonight
across the Florida Panhandle, southern Georgia, southern Alabama,
and southern Mississippi.


NEXT ADVISORY
-------------
Next complete advisory at 400 PM CDT.

$$
Forecaster Latto

[cycloneye]

BULLETIN
Tropical Storm Marco Advisory Number 19
NWS National Hurricane Center Miami FL AL142020
400 PM CDT Mon Aug 24 2020

...MARCO EXPECTED TO CONTINUE TO PRODUCE GUSTY WINDS AND HEAVY
RAINFALL OVER PORTIONS OF THE NORTHERN GULF COAST THROUGH THIS
EVENING...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...29.0N 88.9W
ABOUT 15 MI...20 KM ESE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

There are no coastal watches or warnings in effect.

Gusty winds, heavy rainfall, and lingering coastal flooding are
expected from Marco along portions of the Gulf Coast through this
evening. For information on these hazards see products from your
local National Weather Service office.

Tropical cyclone wind and surge watches have been issued for
portions of the U.S. Gulf Coast for Tropical Storm Laura.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 400 PM CDT (2100 UTC), the center of Tropical Storm Marco was
located near latitude 29.0 North, longitude 88.9 West. Marco is
moving toward the northwest near 7 mph (11 km/h), a turn to the
west-northwest and a slight increase in forward speed is expected
to occur tonight. On the forecast track, Marco will move inland
over southeastern Louisiana tonight, and across southern Louisiana
on Tuesday.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Weakening is expected, and Marco is forecast to become a
tropical depression tonight and degenerate to a remnant low on
Tuesday.

Tropical-storm-force winds extend outward up to 80 miles (130 km)
from the center. A National Ocean Service weather station located
on Petit Bois Island, Mississippi recently reported a wind gust to
38 mph (61 km/h).

The estimated minimum central pressure is 1008 mb (29.77 inches).


HAZARDS AFFECTING LAND
----------------------
WIND: Wind gusts to tropical storm force are possible over the
coastal sections of southeastern Louisiana and Mississippi through
this evening.

RAINFALL: Marco is expected to produce additional rainfall
accumulations of 2 to 4 inches with additional isolated totals of 7
inches across portions of the north-central Gulf coast and
southeastern United States through Wednesday. Rain totals related
to Marco near Apalachicola, Florida reached as high as 11.81 inches
on Sunday per a CoCoRaHS report. The additional rainfall may result
in areas of flash, urban and small stream flooding along the same
area.

SURF: Swells generated by Marco are likely to affect portions of
the northern Gulf Coast for the next day or so. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.

TORNADOES: A couple of tornadoes are possible late this afternoon
through tonight across the Florida Panhandle, southern Georgia, far
southern Alabama, and far southern Mississippi.


NEXT ADVISORY
-------------
Next complete advisory at 1000 PM CDT.

$$
Forecaster Latto



Tropical Storm Marco Discussion Number 19
NWS National Hurricane Center Miami FL AL142020
400 PM CDT Mon Aug 24 2020

There has been little change to the structure of Marco over the past
few hours, with the deep convection and associated heavy rainfall
being sheared well to the northeast of the exposed center of
circulation. Based on earlier Hurricane Hunter aircraft and
scatterometer data, there was a small area of tropical-storm-force
winds in the strongest convection located about 50-75 n
mi offshore of the northern Gulf coast. Since the shower and
thunderstorm activity is persisting, it is assumed that these winds
are still occurring in that offshore area and the initial intensity
is being held at 35 kt.

The exposed vortex should continue to spin down as the center of the
cyclone reaches the southeastern Louisiana coast late this evening,
which would result in the coastal areas being spared from
experiencing sustained tropical-storm-force winds. The
official NHC forecast shows Marco weakening to a tropical
depression tonight, which is in agreement with the model guidance.
Strong vertical wind shear should strip away any remaining
convection associated with Marco at some point tonight, as indicated
by GFS and ECMWF simulated satellite imagery. When the convection
does diminish, most of the model guidance does not show any
significant new convection developing thereafter. So it is
anticipated that Marco will degenerate to a remnant low by Tuesday.

Marco's initial motion is northwest at 6 kt. As the cyclone
continues to weaken and degenerate to a remnant low, a turn to the
west-northwest is expected as the system becomes steered in the
low-level flow. The latest NHC track forecast is little changed from
the previous one, and is near the TVCN consensus track guidance.

Key Messages:

1. Gusty winds, heavy rainfall, and lingering coastal flooding are
expected from Marco along portions of the Gulf Coast through this
evening. For information on these hazards see products from your
local National Weather Service office.

2. Tropical Storm Laura could bring dangerous storm surge, rainfall,
and wind impacts to portions of the U.S. Gulf Coast by the middle of
the week, and tropical cyclone wind and surge watches have been
issued for portions of the U.S. Gulf Coast.


FORECAST POSITIONS AND MAX WINDS

INIT 24/2100Z 29.0N 88.9W 35 KT 40 MPH
12H 25/0600Z 29.7N 89.9W 30 KT 35 MPH...INLAND
24H 25/1800Z 30.3N 91.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 26/0600Z 30.8N 94.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 26/1800Z...DISSIPATED

$$
Forecaster Latto

[cycloneye]

Tropical Storm Marco Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL142020
600 PM CDT Mon Aug 24 2020

...MARCO MAKES LANDFALL NEAR THE MOUTH OF THE MISSISSIPPI...
...EXPECTED TO BECOME A TROPICAL DEPRESSION LATER TONIGHT...

Visible satellite imagery and surface observations indicate that
Marco made landfall near the mouth of the Mississippi River around
600 PM CDT. Data from an Air Force Reserve Hurricane Hunter Aircraft
indicate that Marco is producing a small area of
tropical-storm-force winds over water to the northeast of the
center. These winds will likely subside during the next few hours as
Marco moves along the coast of Louisiana. Heavy rain will continue
along portions of the north-central Gulf Coast through tonight.

The estimated minimum pressure at the time of landfall was 1006 mb
(29.71 inches).


SUMMARY OF 600 PM CDT...2300 UTC...INFORMATION
----------------------------------------------
LOCATION...29.0N 89.2W
ABOUT 0 MI...0 KM N OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

$$
Forecaster Zelinsky

[cycloneye]

Tropical Depression Marco Discussion Number 20
NWS National Hurricane Center Miami FL AL142020
1000 PM CDT Mon Aug 24 2020

Visible imagery and surface observations indicated that Marco made
landfall around 6 pm CDT near the mouth of the Mississippi River.
Shortly before landfall, reports from an Air Force Reserve Hurricane
Hunter plane indicated that Marco was still producing a small area
of tropical-storm-force winds over water to the northeast of its
center. Since then, the system has moved almost due west along the
southeast coast of Louisiana while its deep convection has become
farther displaced from the low-level center. Between the lack of
central convection and Marco's proximity to land, it is likely that
the winds have decreased since earlier this evening and the
intensity has been lowered to 30 kt.

If deep convection does not redevelop overnight, Marco will become a
remnant low as soon as Tuesday morning. Regardless of its status,
Marco should move generally westward near the coast of Louisiana
while it weakens for the next day or so and could continue to
produce heavy rain for portions of the north-central Gulf Coast
tonight. The system is then forecast to dissipate by early
Wednesday, if not sooner.


FORECAST POSITIONS AND MAX WINDS

INIT 25/0300Z 29.0N 89.8W 30 KT 35 MPH
12H 25/1200Z 29.0N 91.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 26/0000Z 29.0N 93.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 26/1200Z...DISSIPATED

$$
Forecaster Zelinsky

[cycloneye]

BULLETIN
Post-Tropical Cyclone Marco Advisory Number 21
NWS National Hurricane Center Miami FL AL142020
400 AM CDT Tue Aug 25 2020

...MARCO BECOMES A REMNANT LOW JUST SOUTH OF LOUISIANA...
...THIS IS THE LAST ADVISORY...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...28.8N 91.2W
ABOUT 60 MI...100 KM S OF MORGAN CITY LOUISIANA
ABOUT 110 MI...175 KM SSE OF LAFAYETTE LOUISIANA
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 400 AM CDT (0900 UTC), the center of Post-Tropical Cyclone Marco
was located near latitude 28.8 North, longitude 91.2 West. The
post-tropical cyclone is moving toward the west near 10 mph (17
km/h), and this general motion is expected to continue for the
next day or so. On the forecast track, Marco should continue moving
westward just offshore the coast of Louisiana until the system
dissipates.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.
Additional weakening is expected, and Post-Tropical Cyclone Marco
is forecast to dissipate by early Wednesday, if not sooner.

The estimated minimum central pressure is 1008 mb (29.77 inches).


HAZARDS AFFECTING LAND
----------------------
SURF: Swells and rip currents affecting the north-central Gulf
coast will gradually subside today. Please consult products from
your local weather service office.


NEXT ADVISORY
-------------
This is the last public advisory issued by the National Hurricane
Center on Marco. Additional information on this system can be found
in High Seas Forecasts issued by the National Weather Service, under
AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at
ocean.weather.gov/shtml/NFDHSFAT1.php

$$
Forecaster Stewart