ZCZC MIATCPAT4 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Marco Advisory Number 10
NWS National Hurricane Center Miami FL AL142020
400 PM CDT Sat Aug 22 2020
...BIG CHANGES TO THIS AFTERNOON'S FORECAST FOR MARCO...
...STORM SURGE AND HURRICANE WATCHES ISSUED FOR THE NORTHERN GULF
SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
ABOUT 50 MI...80 KM W OF THE WESTERN TIP OF CUBA
ABOUT 540 MI...870 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
A Storm Surge Watch has been issued from Sabine Pass eastward to
the Alabama/Florida border, including Lake Pontchartrain, Lake
Maurepas, Lake Borgne, and Mobile Bay.
A Hurricane Watch has been issued from Intracoastal City Louisiana
eastward to the Mississippi/Alabama border, including Lake
Pontchartrain, Lake Maurepas, and Metropolitan New Orleans.
A Tropical Storm Watch has been issued from the Mississippi/Alabama
border eastward to the Alabama/Florida border.
The government of Mexico has discontinued the Tropical Storm Warning
for the northeastern Yucatan coast.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Watch is in effect for...
* Sabine Pass to the Alabama/Florida border
* Lake Pontchartrain, Lake Maurepas, Lake Borgne, and Mobile Bay
A Hurricane Watch is in effect for...
* Intracoastal City Louisiana to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
A Tropical Storm Warning is in effect for...
* Province of Pinar del Rio Cuba
A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Alabama/Florida border
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
A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
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, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
At 400 PM CDT (2100 UTC), the center of Tropical Storm Marco was
located near latitude 21.9 North, longitude 85.7 West. Marco is
moving toward the north-northwest near 13 mph (20 km/h). Marco is
expected to continue moving toward the north-northwest across the
central Gulf of Mexico on Sunday and is forecast to reach the
northern Gulf coast on Monday. After moving inland, Marco is
expected to slow down and turn toward the northwest and
west-northwest Monday night and Tuesday, moving across southern
Louisiana into east Texas.
Maximum sustained winds are near 65 mph (100 km/h) with higher
gusts. Strengthening is forecast during the next day or two, and
Marco is expected to become a hurricane tonight or on Sunday.
Marco is likely to still be at or near hurricane strength when it
reaches the northern Gulf coast on Monday. Weakening is forecast
to occur while the center moves farther inland Monday night and
Tropical-storm-force winds extend outward up to 90 miles (150 km)
from the center.
The estimated minimum central pressure is 992 mb (29.30 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...
Grand Isle LA to the AL/FL Border including Lake Borgne and Mobile
Lake Pontchartrain and Lake Maurepas...2-4 ft
Sabine Pass to Grand Isle LA...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
WIND: Hurricane conditions are possible within the hurricane watch
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.
Tropical storm conditions are expected to continue within the
warning area in Cuba through this evening.
RAINFALL: Marco is expected to produce the following rainfall
accumulations through Monday:
Far western Cuba: 2 to 4 inches of rain, with isolated maximum
amounts of 6 inches possible
Eastern portions of the Mexican states of Quintana Roo and Yucatan:
1 to 3 inches.
Central U.S. Gulf Coast: 1 to 3 inches, isolated maximum amounts of
This rainfall may result in areas of flash and urban flooding along
the Central U.S. Gulf Coast.
Next intermediate advisory at 700 PM CDT.
Next complete advisory at 1000 PM CDT.