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Hurricane Laura Intermediate Advisory Number 25A
NWS National Hurricane Center Miami FL AL132020
100 AM CDT Wed Aug 26 2020
...LAURA RAPIDLY INTENSIFYING...
...EXPECTED TO PRODUCE A LIFE-THREATENING STORM SURGE, EXTREME
WINDS, AND FLASH FLOODING OVER EASTERN TEXAS AND LOUISIANA LATER
SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION
ABOUT 360 MI...580 KM SSE OF LAKE CHARLES LOUISIANA
ABOUT 380 MI...610 KM SE OF GALVESTON TEXAS
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...978 MB...28.88 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
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
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
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
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
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 AM CDT (0600 UTC), the center of Hurricane Laura was located
near latitude 25.6 North, longitude 90.2 West. Laura is moving
toward the west-northwest near 17 mph (28 km/h), and this general
motion should continue overnight. A turn toward the northwest is
forecast later today, and a northwestward to north-northwestward
motion should continue through Wednesday night. On the forecast
track, Laura should approach the Upper Texas and southwest Louisiana
coasts on Wednesday evening and move inland near those areas
Wednesday night or Thursday morning.
Data from an Air Force Reserve Unit reconnaissance aircraft
indicate that maximum sustained winds have increased to near 105 mph
(165 km/h) with higher gusts. Significant strengthening is
forecast during the next 24 hours, and Laura is expected to be a
major hurricane at landfall. Rapid weakening is expected after
Laura makes landfall.
Hurricane-force winds extend outward up to 55 miles (90 km) from
the center and tropical-storm-force winds extend outward up to 175
miles (280 km). NOAA buoy 42001 in the central Gulf of Mexico
recently reported a sustained wind of 60 mph (97 km/h) and a gust to
78 mph (126 km/h).
The minimum central pressure estimated from Hurricane Hunter
observations is 978 mb (28.88 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...9-14 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
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. This storm surge could
penetrate up to 30 miles inland from the immediate coastline in
southwestern Louisiana and far southeastern Texas.
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: From this afternoon through Friday, Laura is expected to
produce rainfall totals of 5 to 10 inches, with isolated maximum
amounts of 15 inches across portions of the northwestern Gulf Coast
from western Louisiana to far eastern Texas, and northward into much
of Arkansas. Over the lower to middle Mississippi Valley from
central Louisiana into western Tennessee and Kentucky, and
southeastern Missouri, 2 to 4 inches of rainfall with isolated
totals of 6 inches are expected. This rainfall will cause
widespread flash and urban flooding, small streams to overflow their
banks, and minor to isolated moderate river flooding.
By late Friday into Saturday, portions of the Tennessee and Ohio
Valley could see 2 to 4 inches with locally higher amounts as
tropical moisture from Laura moves through the region. This
rainfall could lead to localized flash and urban flooding along
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
today or Wednesday night, and are expected in the tropical storm
warning area Wednesday night and Thursday.
Hurricane-force winds and damaging wind gusts are also expected to
spread well inland into portions of eastern Texas and western
Louisiana early Thursday.
TORNADOES: A few tornadoes are possible starting Wednesday evening
over Louisiana, far southeast Texas, and southwestern Mississippi.
The risk for a few tornadoes should continue into Thursday across
Louisiana, Arkansas, and western Mississippi.
SURF: Swells produced by Laura are affecting the U.S. Gulf coast
from the west coast of Florida to Louisiana and are expected to
reach the coast of Texas and northeastern Mexico today. 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 400 AM CDT.