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Tropical Storm Laura Intermediate Advisory Number 21A
NWS National Hurricane Center Miami FL AL132020
200 AM EDT Tue Aug 25 2020
...LAURA BECOMING BETTER ORGANIZED OVER THE SOUTHEASTERN GULF OF
...EXPECTED TO BECOME A HURRICANE LATER TODAY...
SUMMARY OF 200 AM EDT...0600 UTC...INFORMATION
ABOUT 50 MI...85 KM N OF THE WESTERN TIP OF CUBA
ABOUT 765 MI...1165 KM SE OF LAKE CHARLES LOUISIANA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Watch is in effect for...
* San Luis Pass Texas to Ocean Springs Mississippi
* Lake Pontchartrain, Lake Maurepas, and Lake Borgne
A Hurricane Watch is in effect for...
* Port Bolivar Texas to west of Morgan City Louisiana
A Tropical Storm Warning is in effect for...
* Cuban provinces of Villa Clara, Cienfuegos, Matanzas, Mayabeque,
La Habana, Artemisa, Pinar del Rio, and the Isle of Youth
* Florida Keys from the Seven Mile Bridge to Key West
* Dry Tortugas
A Tropical Storm Watch is in effect for...
* South of Port Bolivar to San Luis Pass Texas
* Morgan City Louisiana to the Mouth of the Mississippi River
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 Warning means that tropical storm conditions are
expected somewhere within the warning area.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
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 200 AM EDT (0600 UTC), the center of Tropical Storm Laura was
located near latitude 22.6 North, longitude 85.0 West. While Laura
has recently taken a jog to the west, it is expected to move toward
the west-northwest near 20 mph (31 km/h) today with some decrease in
forward speed likely by this evening. A turn toward the northwest
is forecast by Wednesday, and a northwestward to north-northwestward
motion should continue through Wednesday night. On the forecast
track, the center of Laura will move away from Cuba and over the
southeastern Gulf of Mexico this morning. Laura is then forecast to
move over the central and northwestern Gulf of Mexico tonight and
Wednesday, and approach the coasts of Texas and Louisiana on
Maximum sustained winds are near 65 mph (100 km/h) with higher
gusts. Strengthening is expected, and Laura is forecast to become a
hurricane later today. Additional strengthening is forecast on
Wednesday, and Laura could be near major hurricane strength when it
approaches the coast.
Tropical-storm-force winds extend outward up to 175 miles (280 km)
from the center.
The estimated minimum central pressure based on data from an Air
Force Hurricane Hunter aircraft is 995 mb (29.38 inches).
HAZARDS AFFECTING LAND
Key messages for Laura can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC.
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...
High Island TX to Morgan City LA including Sabine Lake, Calcasieu
Lake, and Vermilion Bay...7-11 ft
Port Bolivar TX to High Island TX...4-6 ft
Morgan City LA to Mouth of the Mississippi River...4-6 ft
Mouth of the Mississippi River to Ocean Springs MS including Lake
San Luis Pass TX to Port Bolivar TX...2-4 ft
Galveston Bay...2-4 ft
Lake Pontchartrain and Lake Maurepas...2-4 ft
The deepest water will occur along the immediate coast near and to
the right of the landfall location, 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.
RAINFALL: Laura is expected to produce the following storm total
Western Cuba: 4 to 6 inches, with maximum amounts of 10 inches.
This heavy rainfall could lead to life-threatening flash and urban
flooding, and the potential for mudslides.
From Wednesday afternoon into Saturday, Laura is expected to produce
rainfall of 4 to 8 inches, with isolated maximum amounts of 12
inches across portions of the west-central U.S. Gulf Coast near the
Texas and Louisiana border north into portions of the lower
Mississippi Valley. This rainfall could cause widespread flash and
urban flooding, small streams to overflow their banks, and minor to
isolated moderate river flooding.
WIND: Tropical storm conditions are expected to spread westward
within the warning area in western Cuba during the next few hours.
Tropical storm conditions are also expected within the warning area
in the lower Florida Keys and the Dry Tortugas for a few more hours.
Hurricane conditions are possible in the hurricane watch area along
the Gulf Coast by late Wednesday, with tropical storm conditions
possible by Wednesday afternoon.
SURF: Swells generated by Laura are affecting portions of Cuba, the
central Bahamas, and the Florida Keys. Swells are expected to
spread northward along portions of the west coast of Florida
peninsula and the coast of the Florida panhandle later today and
tonight, and reach the northern and northwest Gulf coast by
Wednesday. These swells are likely to cause life-threatening surf
and rip current conditions. Please consult products from your
local weather office.
Next complete advisory at 500 AM EDT.