000 WTNT34 KNHC 271436 TCPAT4 BULLETIN Tropical Storm Helene Advisory Number 17 NWS National Hurricane Center Miami FL AL092024 1100 AM EDT Fri Sep 27 2024 ...HELENE PRODUCING HISTORIC AND CATASTROPHIC FLOODING OVER PORTIONS OF THE SOUTHEAST AND SOUTHERN APPALACHIANS... ...FLASH FLOOD EMERGENCIES IN EFFECT FOR METROPOLITAN ATLANTA, AND MUCH OF UPSTATE SOUTH CAROLINA AND WESTERN NORTH CAROLINA... SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...35.1N 83.8W ABOUT 30 MI...50 KM SW OF BRYSON CITY NORTH CAROLINA ABOUT 105 MI...165 KM NNE OF ATLANTA GEORGIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...N OR 350 DEGREES AT 32 MPH...52 KM/H MINIMUM CENTRAL PRESSURE...975 MB...28.80 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning for the Georgia coast has been discontinued. All Storm Surge Warnings have been discontinued. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Savannah River northward to Little River Inlet 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 1100 AM EDT (1500 UTC), the center of Tropical Storm Helene was located near latitude 35.1 North, longitude 83.8 West. Helene is moving toward the north near 32 mph (52 km/h). A slowdown in forward speed is expected soon, and the storm is forecast to stall over the Tennessee Valley tonight and through the weekend. Maximum sustained winds have decreased to near 45 mph (75 km/h) with higher gusts. Continued weakening is expected, and Helene is forecast to become extratropical later today. Tropical-storm-force winds extend outward up to 345 miles (555 km) east of the center. The estimated minimum central pressure based on surface observations is 975 mb (28.80 inches). A weather station on Sassafras Mountain reported a sustained wind of 41 mph (67 km/h) with a gust of 61 mph (98 km/h). A coastal observation at Murrells Inlet recently reported a sustained wind of 38 mph (61 km/h) with a gust of 46 mph (74 km/h). HAZARDS AFFECTING LAND ---------------------- Key Messages for Helene can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC and on the web at hurricanes.gov/text/MIATCDAT4.shtml STORM SURGE: Water levels will continue to receed along the Florida Gulf Coast and portions of the southeast U.S. coast throughout the day. WIND: Tropical storm conditions are occurring along much of the South Carolina coast, and these conditions will continue for the next several hours. Strong, damaging winds, especially in gusts, will also continue as far inland as the higher terrain of the southern Appalachians. RAINFALL: Over portions of the Central and Southern Appalachians, Helene is expected to produce additional rainfall amounts of 3 to 6 inches leading to total rain accumulations of 6 to 12 inches, with isolated totals around 20 inches. This rainfall will result in catastrophic and potentially life-threatening flash and urban flooding, along with significant and record river flooding. Numerous significant landslides are expected in steep terrain across the Southern Appalachians. For a complete depiction of forecast rainfall associated with Tropical Storm Helene, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml?ero. For a list of rainfall observations (and wind reports) associated this storm, see the companion storm summary at WBCSCCNS4 with the WMO header ACUS44 KWBC or at the following link: www.wpc.ncep.noaa.gov/discussions/nfdscc4.html TORNADOES: Tornadoes are possible today across eastern South Carolina, central and eastern North Carolina, and southern Virginia. SURF: Swells generated by Helene will affect the coasts of Georgia and the Carolinas during the next day or so. 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 PM EDT. Next complete advisory at 500 PM EDT. $$ Forecaster Cangialosi/Rosado