390 WTNT34 KWNH 281559 CCA TCPAT4 BULLETIN Post-Tropical Cyclone Helene Advisory Number 21...Corrected NWS Weather Prediction Center College Park MD AL092024 1000 AM CDT Sat Sep 28 2024 Corrected for typos in Discussion and Outlook Section. ...HELENE CONTINUES TO SLOWLY SPIN DOWN TODAY INTO TOMORROW ACROSS THE TENNESSEE VALLEY. WITH THE HEAVY RAIN LESSENING, THIS WILL BE THE LAST ADVISORY ON THE SYSTEM... SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...36.6N 87.4W ABOUT 145 MI...235 KM SW OF LOUISVILLE KENTUCKY ABOUT 50 MI...85 KM NW OF NASHVILLE TENNESSEE MAXIMUM SUSTAINED WINDS...15 MPH...30 KM/H PRESENT MOVEMENT...E OR 90 DEGREES AT 3 MPH...6 KM/H MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. Several flood warning and advisories remain in effect across portions of the southern and central Appalachians through Saturday. DISCUSSION AND OUTLOOK ---------------------- At 1000 AM CDT (1500 UTC), the center of Post-Tropical Cyclone Helene was located near latitude 36.6 North, longitude 87.4 West. The post-tropical cyclone is moving toward the east near 3 mph (6 km/h) and this slow motion is expected to continue before fully dissipating. Maximum sustained winds are near 15 mph (30 km/h) with higher gusts. Little change in strength is forecast during the next 48 hours. The estimated minimum central pressure is 998 mb (29.47 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 and central Appalachians through Sunday, with some isolated 3 inch totals possible. Additionally, 1-2 inches of rainfall is expected across the western Florida Peninsula. 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. SURF: Swells generated by Helene will affect much the Atlantic Seaboard from Florida to Long Island NY through Saturday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- This is the last public advisory issued by the Weather Prediction Center on this system. $$ Forecaster Gallina