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Laura Strengthens Into a Major Hurricane; Potentially Catastrophic Storm Surge, Extreme Winds, & Flash Flooding Expected Along the Northwest Gulf Coast Tonight

| August 26, 2020 @ 7:17 am

NHC UPDATE SUMMARY OF XX CDT INFORMATION

LOCATION: 290 miles southeast of Galveston, Texas
MAXIMUM WINDS: 115 mph
MOVEMENT: northwest at 15 MPH
MINIMUM PRESSURE: 963 MB or 28.44 in


WATCHES AND WARNINGS

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 the west of Morgan City Louisiana


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

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
The 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.

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.


Category: ALL POSTS, Severe Weather, Tropical

About the Author ()

Scott Martin is an operational meteorologist, professional graphic artist, musician, husband, and father. Not only is Scott a member of the National Weather Association, but he is also the Central Alabama Chapter of the NWA president. Scott is also the co-founder of Racecast Weather, which provides forecasts for many racing series across the USA. He also supplies forecasts for the BassMaster Elite Series events including the BassMaster Classic.

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