ZCZC MIATCPAT3 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm Laura Advisory Number 21 NWS National Hurricane Center Miami FL AL132020 1100 PM EDT Mon Aug 24 2020 ...LAURA FORECAST TO BECOME A HURRICANE ON TUESDAY... ...HEAVY RAINS AND FLASH FLOODING CONTINUES OVER WESTERN CUBA... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...22.7N 84.0W ABOUT 80 MI...130 KM NE OF THE WESTERN TIP OF CUBA ABOUT 765 MI...1230 KM SE OF LAKE CHARLES LOUISIANA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...WNW OR 290 DEGREES AT 20 MPH...31 KM/H MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning for the Middle Florida Keys has been discontinued. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Watch is in effect for... * San Luis Pass Texas to Ocean Springs Mississippi * Lake Pontchartrain, Lake Maurepas, and Lake Borgne A Hurricane Watch is in effect for... * Port Bolivar Texas to west of Morgan City Louisiana A Tropical Storm Warning is in effect for... * Cuban provinces of Villa Clara, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar del Rio, and the Isle of Youth * Florida Keys from the Seven Mile Bridge to Key West * Dry Tortugas A Tropical Storm Watch is in effect for... * South of Port Bolivar to San Luis Pass Texas * Morgan City Louisiana to the Mouth of the Mississippi River 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. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. 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 dangerous. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM EDT (0300 UTC), the center of Tropical Storm Laura was located near latitude 22.7 North, longitude 84.0 West. Laura is moving toward the west-northwest near 20 mph (31 km/h) and this general motion with some decrease in forward speed is expected over the next day or so. A turn toward the northwest is forecast by Wednesday, and a northwestward to north-northwestward motion should continue through Wednesday night. On the forecast track, the center of Laura will move away from Cuba and over the southeastern Gulf of Mexico overnight. Laura is then forecast to move over the central and northwestern Gulf of Mexico Tuesday night and Wednesday, and approach the northwestern coast of the Gulf of Mexico Wednesday night. Maximum sustained winds are near 65 mph (105 km/h) with higher gusts. Strengthening is expected, and Laura is foreast to become a hurricane on Tuesday. Additional strengthening is forecast on Wednesday, and Laura could be near major hurricane strength when it approaches the coast. Tropical-storm-force winds extend outward up to 175 miles (280 km) from the center. The estimated minimum central pressure based on data from the NOAA and Air Force Hurricane Hunters is 996 mb (29.42 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... High Island TX to Morgan City LA including Sabine Lake, Calcasieu Lake, and Vermilion Bay...7-11 ft Port Bolivar TX to High Island TX...4-6 ft Morgan City LA to Mouth of the Mississippi River...4-6 ft Mouth of the Mississippi River to Ocean Springs MS including Lake Borgne...3-5 ft San Luis Pass TX to Port Bolivar TX...2-4 ft Galveston Bay...2-4 ft 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. 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: Laura is expected to produce the following storm total rainfall accumulations into tonight: Western Cuba: 4 to 6 inches, with maximum amounts of 10 inches. This heavy rainfall could lead to life-threatening flash and urban flooding, and the potential for mudslides. From Wednesday afternoon into Saturday, Laura is expected to produce rainfall of 4 to 8 inches, with isolated maximum amounts of 12 inches across portions of the west-central U.S. Gulf Coast near the Texas and Louisiana border north into portions of the lower Mississippi Valley. This rainfall could cause widespread flash and urban flooding, small streams to overflow their banks, and minor to isolated moderate river flooding. WIND: Tropical storm conditions are expected to spread westward within the warning area in western Cuba during the next few hours. Tropical storm conditions are also expected within the warning area in the middle and lower Florida Keys and the Dry Tortugas tonight. Hurricane conditions are possible in the hurricane watch area along the Gulf Coast by late Wednesday, with tropical storm conditions possible by Wednesday afternoon. SURF: Swells generated by Laura are affecting portions of Cuba, the central Bahamas, and the Florida Keys. Swells are expected to spread northward along portions of the west coast of Florida peninsula and the coast of the Florida panhandle on Tuesday and Tuesday night, and reach the northern and northwest Gulf coast by Wednesday. 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 200 AM EDT. Next complete advisory at 500 AM EDT. $$ Forecaster Cangialosi NNNN