20240925 SISE Hurricane Helene 5pm ET update All Hazards Consortium

...HELENE STRENGTHENING... ...PREPARATIONS TO PROTECT LIFE AND PROPERTY FROM STORM SURGE AND DAMAGING WINDS ALONG THE FLORIDA BIG BEND COAST SHOULD E RUSHED TO COMPLETION TODAY... KEY MESSAGES: 1. A catastrophic and deadly storm surge is likely along portions of the Florida Big Bend coast, where inundation could reach as high as 20 feet above ground level, along with destructive waves. There is also a danger of life-threatening storm surge along the remainder of the west coast of the Florida Peninsula. Residents in those areas should follow advice given by local officials and evacuate if told to do so. 2. Potentially catastrophic hurricane-force winds are expected within the eyewall of Helene when it makes landfall in the Florida Big Bend region late Thursday. Preparations to protect life and property should be completed by early Thursday before tropical storm conditions arrive. Damaging and life-threatening hurricane-force winds, especially in gusts, will penetrate well inland over portions of northern Florida and southern Georgia late Thursday and Thursday night where Hurricane Warnings are in effect. Strong wind gusts are also likely farther north across portions of northern Georgia and the Carolinas, particularly over the higher terrain of the southern Appalachians. 3. Catastrophic and life-threatening flash and urban flooding, including landslides, is expected across portions of the southern Appalachians through Friday. Considerable to locally catastrophic flash and urban flooding is likely for northwestern and northern Florida and the Southeast through Friday. Widespread minor to moderate river flooding is likely, and isolated major river flooding is possible. 4. Hurricane and tropical storm conditions are expected over northeastern portions of the Yucatan Peninsula of Mexico this evening where Tropical Storm and Hurricane Warnings are in effect. Tropical storm conditions are occurring over portions of western Cuba within the Tropical Storm Warning area, and hurricane conditions are possible this evening within the Hurricane Watch area. Helene will bring heavy rain to portions of the western Caribbean with potentially significant flooding across western Cuba and the northeastern Yucatan Peninsula into early Thursday. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 22.5N 86.6W 75 KT 85 MPH 12H 26/0600Z 24.1N 86.2W 95 KT 110 MPH 24H 26/1800Z 27.4N 85.2W 115 KT 130 MPH 36H 27/0600Z 32.1N 84.6W 70 KT 80 MPH...INLAND 48H 27/1800Z 36.1N 86.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 60H 28/0600Z 37.1N 88.1W 25 KT 30 MPH...POST-TROP/EXTRATROP 72H 28/1800Z 36.8N 88.7W 20 KT 25 MPH...POST-TROP/EXTRATROP 96H 29/1800Z 37.0N 88.0W 15 KT 15 MPH...POST-TROP/EXTRATROP