000 WTNT34 KWNH 280254 TCPAT4 BULLETIN Post-Tropical Cyclone Helene Advisory Number 19 NWS Weather Prediction Center College Park MD AL092024 1000 PM CDT Fri Sep 27 2024 ...CATASTROPHIC, HISTORIC FLOODING CONTINUES OVER PORTIONS OF THE SOUTHERN APPALACHIANS... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...38.0N 87.0W ABOUT 115 MI...185 KM ENE OF PADUCAH KENTUCKY MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...WSW OR 255 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. Several flood and flash flood warnings remain in effect across portions of the southern and central Appalachians. Flood watches continue through Saturday morning across portions of the Tennessee, Lower Ohio, and Mid Mississippi Valleys. High wind warnings and wind advisories continue this evening and overnight across parts of the Tennessee, Ohio, and Mid Mississippi Valleys. DISCUSSION AND OUTLOOK ---------------------- At 1000 PM CDT (0300 UTC), the center of Post-Tropical Cyclone Helene was located near latitude 38.0 North, longitude 87.0 West. The post-tropical cyclone is moving toward the west-southwest near 8 mph (13 km/h), as a slowdown in the forward speed has already begun. The system is forecast to stall over the Tennessee Valley late tonight and through the weekend. Maximum sustained winds are near 30 mph (45 km/h) with higher gusts. Continued weakening is expected during the next couple of days. The estimated minimum central pressure is 987 mb (29.15 inches). 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 RAINFALL: The remnant low of post tropical cyclone Helene is expected to produce an additional 1-2 inches of rainfall across portions of the Ohio Valley through early Sunday, with some isolated 3 inch totals possible. Most of the rainfall across the central and southern Appalachians has come to an end, although a few lingering showers are possible through tonight. 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: Isolated tornadoes are possible into the early overnight period over southern Virginia and northeast North Carolina. 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 complete advisory at 400 AM CDT. $$ Forecaster Hurley