Hurricane Laura

 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

———————————————-

LOCATION…26.4N 91.4W

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:

None

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

Mississippi River

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

Borgne…2-4 ft

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

small streams.

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.