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| #1014142 (Received by flhurricane at: 4:48 AM 27.Aug.2020) TCPAT3 BULLETIN Hurricane Laura Advisory Number 30 NWS National Hurricane Center Miami FL AL132020 400 AM CDT Thu Aug 27 2020 ...LAURA MOVING NORTHWARD OVER SOUTHWESTERN LOUISIANA... ...CATASTROPHIC STORM SURGE, EXTREME WINDS, AND FLASH FLOODING CONTINUES IN PORTIONS OF LOUISIANA... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...30.5N 93.4W ABOUT 30 MI...50 KM NNW OF LAKE CHARLES LOUISIANA ABOUT 50 MI...80 KM NE OF PORT ARTHUR TEXAS MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H PRESENT MOVEMENT...N OR 355 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...948 MB...28.00 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Storm Surge Warning west of High Island, Texas has been discontinued. The Tropical Storm Warning from San Luis Pass to High Island, Texas has been discontinued. The Hurricane Watch from east of Intracoastal City to west of Morgan City Louisiana has been canceled. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * High Island Texas to the Mouth of the Mississippi River A Hurricane Warning is in effect for... * High Island Texas to Intracoastal City Louisiana A Tropical Storm Warning is in effect for... * East of Intracoastal City Louisiana to the Mouth of the Mississippi River 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 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 400 AM CDT (0900 UTC), the center of Hurricane Laura was located near latitude 30.5 North, longitude 93.4 West. Laura is moving toward the north near 15 mph (24 km/h) and this motion should continue through the day. A northeastward to east-northeastward motion is expected tonight and Friday. On the forecast track, Laura will move across southwestern Louisiana this morning, and then continue northward across the state through this afternoon. The center of Laura is forecast to move over Arkansas tonight, the mid-Mississippi Valley on Friday, and the mid-Atlantic states on Saturday. Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Laura is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Rapid weakening is forecast, and Laura is expected to become a tropical storm later today. Hurricane-force winds extend outward up to 60 miles (95 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). An observation in Chennault, Louisiana, recently reported sustained winds of 76 mph (122 km/h) and a wind gust of 93 mph (150 km/h). The estimated minimum central pressure is 948 mb (28.00 inches). An unofficial observation of 948 mb (28.00 inches) was recently measured in the eye of Laura. 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... Johnson Bayou to Rockefeller Wildlife Refuge including Calcasieu Lake...15-20 ft Rockefeller Wildlife Refuge to Intracoastal City...10-15 ft Intracoastal City to Morgan City including Vermilion Bay...8-12 ft Sea Rim State Park to Johnson Bayou including Sabine Lake...4-8 ft Morgan City to Mouth of the Mississippi River...4-7 ft High Island to Sea Rim State Park...2-4 ft Mouth of the Mississippi River to Ocean Springs including Lake Borgne...1-3 ft Lake Pontchartrain and Lake Maurepas...1-3 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. Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This surge could penetrate up to 40 miles inland from the immediate coastline, and flood waters will not fully recede for several days after the storm. 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 through the morning, with catastrophic wind damage expected near Laura`s eyewall. Tropical storm conditions will spread northward within the warning areas through the day. Hurricane-force winds and damaging wind gusts are also expected to spread well inland into portions of eastern Texas and western Louisiana this morning. RAINFALL: Through Friday, Laura is expected to produce the following rainfall totals: Across portions of Louisiana, Mississippi, across Arkansas: 6 to 12 inches with isolated totals of 18 inches. This rainfall will cause widespread flash and urban flooding, small streams and creeks to overflow their banks, and minor to moderate freshwater river flooding. Through Saturday, Laura is expected to produce 1 to 3 inches with isolated maximum amounts of 5 inches across the mid-Mississippi Valley and portions of the Tennessee and Lower Ohio Valley, the central Appalachians and the Mid-Atlantic States. This rainfall may lead to flash and urban flooding and rapid rises on small streams. TORNADOES: Tornadoes are possible today and tonight over parts of Louisiana, Arkansas, and western Mississippi. SURF: Swells produced by Laura are affecting the U.S. Gulf coast from the west coast of Florida to Texas and northeastern Mexico. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 700 AM CDT. Next complete advisory at 1000 AM CDT. $$ Forecaster Cangialosi/Zelinsky/Blake |