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Hurricane Laura Intermediate Advisory Number 26A
NWS National Hurricane Center Miami FL AL132020
700 AM CDT Wed Aug 26 2020
...LAURA STRENGTHENS INTO A MAJOR HURRICANE...
...POTENTIALLY CATASTROPHIC STORM SURGE, EXTREME WINDS, AND FLASH
FLOODING EXPECTED ALONG THE NORTHWEST GULF COAST TONIGHT...
...STEPS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO
COMPLETION IN THE NEXT FEW HOURS...
SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION
ABOUT 280 MI...450 KM SSE OF LAKE CHARLES LOUISIANA
ABOUT 290 MI...465 KM SE OF GALVESTON TEXAS
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for...
* Freeport 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...
* 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 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. 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.
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.
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 eye of Hurricane Laura was located
near latitude 26.4 North, longitude 91.4 West. Laura is moving
toward the northwest near 15 mph (24 km/h) and this general motion
should continue today, followed by a north-northwestward motion
tonight. On the forecast track, Laura should approach the Upper
Texas and southwest Louisiana coasts this evening and move inland
near those areas tonight or Thursday morning.
Data from NOAA and Air Force Hurricane Hunter aircraft indicate
that maximum sustained winds have increased to near 115 mph (185
km/h) with higher gusts. Laura is a dangerous category 3 hurricane
on the Saffir-Simpson Hurricane Scale, and is forecast to continue
strengthening into a category 4 hurricane later today. Rapid
weakening is expected after Laura makes landfall.
Laura is a large hurricane. Hurricane-force winds extend outward
up to 70 miles (110 km) from the center and tropical-storm- force
winds extend outward up to 175 miles (280 km). Buoy 42395, located
just east of Laura's eye, recently reported a sustained wind of 74
mph (119 km/h) and a wind gust of 107 mph (172 km/h) and a wave
height of 37 feet (11 meters).
The latest minimum central pressure estimated from NOAA and Air
Force reconnaissance aircraft data is 963 mb (28.44 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 and tropical-storm-force winds will arrive within the
warning areas well in advance of Laura's center later today. All
preparations to protect life and property should be rushed to
completion in the next few hours.
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 to Intracoastal City including Sabine Lake and
Calcasieu Lake...10-15 ft
Intracoastal City to Morgan City including Vermilion Bay...8-12 ft
Port Bolivar to Sea Rim State Park...6-9 ft
Morgan City to Mouth of the Mississippi River...4-7 ft
San Luis Pass to Port Bolivar...3-5 ft
Galveston Bay...3-5 ft
Mouth of the Mississippi River to Ocean Springs including Lake
Lake Pontchartrain and Lake Maurepas...2-4 ft
Freeport to San Luis Pass...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.
WIND: Hurricane conditions are expected in the hurricane warning
area tonight and Thursday. Tropical storm conditions are
expected to reach the coast in the hurricane warning area late
today or tonight, and are expected in the tropical storm
warning area tonight 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.
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
TORNADOES: A few tornadoes are expected this evening through
tonight 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 1000 AM CDT.