WTNT33 KNHC 182032 TCPAT3 BULLETIN Potential Tropical Cyclone Three Advisory Number 5 NWS National Hurricane Center Miami FL AL032021 400 PM CDT Fri Jun 18 2021 ...HEAVY RAINFALL AND TROPICAL-STORM-FORCE WINDS SPREADING ACROSS PORTIONS OF THE NORTHERN GULF COAST... SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...27.9N 91.2W ABOUT 125 MI...200 KM S OF MORGAN CITY LOUISIANA ABOUT 270 MI...430 KM SW OF MOBILE ALABAMA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...N OR 5 DEGREES AT 16 MPH...26 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * East of Morgan City, Louisiana to the Okaloosa/Walton County line Florida. * Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 6-12 hours. Interests elsewhere along the northern Gulf Coast should monitor the progress of this system. 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 PM CDT (2100 UTC), the disturbance was centered near latitude 27.9 North, longitude 91.2 West. The system is moving toward the north near 16 mph (26 km/h) and a north to north-northeast motion is expected during the next day or so. On the forecast track, the system will make landfall along the north-central Gulf Coast tonight or early Saturday. A northeastward or east-northeastward motion across the southeastern United States is forecast after landfall through the weekend. Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Satellite images and surface observations indicate that the circulation is gradually becoming better defined, and the system still is likely to become a tropical or subtropical storm before landfall. Regardless of its status, little change in strength is expected through landfall. Weakening is forecast to begin after the system crosses the coast. * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent. Tropical-storm-force winds extend outward up to 205 miles (335 km) from the center. The estimated minimum central pressure based on surface observations and Air Force Hurricane Hunter data is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Potential Tropical Cyclone Three can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3, WMO header WTNT43 KNHC, and on the web at www.hurricanes.gov/graphics_at3.shtml?key_messages. RAINFALL: The potential tropical cyclone is expected to produce rainfall totals of 4 to 8 inches with isolated maximum amounts of 12 inches across portions of the Central Gulf Coast. Considerable flash, urban and small stream flooding impacts as well as new and renewed minor to isolated moderate river flooding are likely. As the system continues to lift northeast through the weekend, heavy rain will expand across southeastern Mississippi, southern and central Alabama, central to northern Georgia, far western North Carolina and western South Carolina, resulting in rainfall totals of 3 to 5 inches with isolated maximum amounts of 7 inches. Flash, urban, small stream and isolated minor river flooding impacts are possible. STORM SURGE: The combination of 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... Morgan City, LA to Okaloosa/Walton County Line, FL...2-3 ft Lake Borgne and Mobile Bay...2-3 ft Lake Pontchartrain and Lake Maurepas...1-2 ft Okaloosa/Walton County Line, FL to Panama City, FL...1-2 ft Pensacola Bay, Choctawhatchee Bay, and Saint Andrew Bay...1-2 ft Cameron, LA to Morgan City, LA...1-2 ft Vermilion Bay...1-2 ft 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: Tropical storm conditions are beginning to reach the coast within the warning area, and these winds will continue into Saturday. TORNADOES: There is a threat for a tornado or two tonight across coastal Louisiana. A few tornadoes are possible on Saturday across southern portions of Louisiana, Mississippi, Alabama, and the western Florida Panhandle.