BULLETIN
Hurricane Laura Advisory Number 23
NWS National Hurricane Center Miami FL AL132020
1000 AM CDT Tue Aug 25 2020
…LAURA MOVING ACROSS THE SOUTHEASTERN GULF OF MEXICO…
…HURRICANE AND STORM SURGE WARNINGS ISSUED FOR THE NORTHWESTERN
GULF COAST…
SUMMARY OF 1000 AM CDT…1500 UTC…INFORMATION
———————————————–
LOCATION…23.7N 87.0W
ABOUT 585 MI…940 KM SE OF LAKE CHARLES LOUISIANA
ABOUT 620 MI…1000 KM SE OF GALVESTON TEXAS
MAXIMUM SUSTAINED WINDS…75 MPH…120 KM/H
PRESENT MOVEMENT…WNW OR 290 DEGREES AT 16 MPH…26 KM/H
MINIMUM CENTRAL PRESSURE…990 MB…29.24 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:
A Storm Surge Warning is in effect from San Luis Pass Texas to the
Mouth of the Mississippi River, including areas inside the Port
Arthur Hurricane Flood Protection system.
A Hurricane Warning is in effect from San Luis Pass Texas to
Intracoastal City Louisiana.
A Tropical Storm Warning is in effect from Sargent Texas to San Luis
Pass and from east of Intracoastal City to the Mouth of the
Mississippi River.
A Storm Surge Watch is in effect from Freeport Texas to San Luis
Pass.
The Tropical Storm Warning for the Dry Tortugas has been
discontinued.
The Tropical Storm Warning for Cuba has been discontinued.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for…
* San Luis Pass Texas to the Mouth of the Mississippi River
A Hurricane Warning is in effect for…
* San Luis Pass Texas to Intracoastal City Louisiana
A Tropical Storm Warning is in effect for…
* Sargent Texas to San Luis Pass
* East of Intracoastal City Louisiana to the Mouth of the
Mississippi River
A Storm Surge Watch is in effect for…
* Freeport Texas to San Luis Pass
* Mouth of the Mississippi River to Ocean Springs Mississippi
* Lake Pontchartrain, Lake Maurepas, and Lake Borgne
A Hurricane Watch is in effect for…
* East of Intracoastal City to west of Morgan City Louisiana
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.
A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
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 Hurricane Laura was located
near latitude 23.7 North, longitude 87.0 West. Laura is moving
toward the west-northwest near 16 mph (26 km/h), and this general
motion should continue today. 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 across the southeastern Gulf
of Mexico today. Laura is then forecast to move over the central
and northwestern Gulf of Mexico tonight and Wednesday, approach the
Upper Texas and Southwest Louisiana coasts on Wednesday night and
move inland near those area on Thursday.
Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft
indicate that maximum sustained winds are near 75 mph (120 km/h)
with higher gusts. Significant strengthening is forecast during
the next 36 hours, and Laura is expected to be a major hurricane at
landfall.
Hurricane-force winds extend outward up to 45 miles (75 km) from the
center and tropical-storm-force winds extend outward up to 175 miles
(280 km).
The estimated minimum central pressure based on the Hurricane
Hunter aircraft data is 990 mb (29.24 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…
Sea Rim State Park TX to Intracoastal City LA including Sabine Lake
and Calcasieu Lake…9-13 ft
Intracoastal City to Morgan City including Vermilion Bay…7-11 ft
Port Bolivar TX to Sea Rim State Park…6-9 ft
Morgan City LA to Mouth of the Mississippi River…4-6 ft
San Luis Pass TX to Port Bolivar…3-5 ft
Galveston Bay…3-5 ft
Freeport TX to San Luis Pass…2-4 ft
Mouth of the Mississippi River to Ocean Springs MS including Lake
Borgne…3-5 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
rainfall accumulations:
Western Cuba…Additional totals of 1 inch or less.
United States…From Wednesday night 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 from western Louisiana into east Texas, and northward into
portions of the lower to middle Mississippi Valley, lower Ohio
Valley, and Tennessee Valley. This rainfall will cause widespread
flash and urban flooding, small streams to overflow their banks, and
minor to isolated moderate river flooding.
WIND: Hurricane conditions are expected in the hurricane warning
area Wednesday night and Thursday. Tropical Storm conditions are
expected to reach the coast in the hurricane warning area late
Wednesday or Wednesday night, and are expected in the tropical
storm warning area Wednesday night and Thursday.
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.