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| #1199977 (Received by flhurricane at: 4:57 AM 25.Sep.2024) TCPAT4 BULLETIN Tropical Storm Helene Advisory Number 8 NWS National Hurricane Center Miami FL AL092024 400 AM CDT Wed Sep 25 2024 ...HELENE STRENGTHENING AS THE CENTER APPROACHES THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA... ...NEW TROPICAL STORM WATCHES AND WARNINGS FOR PORTIONS OF THE UNITED STATES... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...20.7N 86.2W ABOUT 45 MI...75 KM ENE OF COZUMEL MEXICO ABOUT 120 MI...190 KM SW OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Tropical Storm Warning is now in effect for the Upper Florida Keys from the Channel 5 Bridge to Ocean Reef and for the southern Florida Peninsula east of Flamingo to the Palm Beach/Martin County line. A Tropical Storm Warning is now in effect for the northeast coast of Florida north of the Flagler/Volusia line to the mouth of the St. Mary's River. A Tropical Storm Watch is now in effect for the South Carolina coast north of the Savannah River to the South Santee River. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach, Florida * Cabo Catoche to Tulum, Mexico including Cozumel A Hurricane Watch is in effect for... * Cuban province of Pinar del Rio * Englewood to Anclote River, including Tampa Bay A Tropical Storm Warning is in effect for... * Dry Tortugas * All of the Florida Keys * The Florida west coast from Flamingo to Anclote River, including Tampa Bay * West of Mexico Beach to the Walton/Bay County Line * The Florida east coast from Flamingo northward to the mouth of the St. Mary's River * Lake Okeechobee * Rio Lagartos to Cabo Catoche, Mexico * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * The Georgia and South Carolina coast north of the mouth of the St. Mary's River to the South Santee River A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within the next 36 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Additional watches or warnings may be required for portions of Florida and the southeastern United States later today. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 400 AM CDT (0900 UTC), the center of Tropical Storm Helene was located near latitude 20.7 North, longitude 86.2 West. Helene is moving toward the northwest near 9 mph (15 km/h). This motion should continue through this morning, followed by a general northward motion beginning later today and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula this morning, move across the eastern Gulf of Mexico on later today and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds are now near 65 mph (100 km/h) with higher gusts. Strengthening is forecast, and Helene is expected to become a hurricane later today. The storm is forecast to rapidly strengthen over the eastern Gulf of Mexico and become a major hurricane on Thursday. Tropical-storm-force winds extend outward up to 175 miles (280 km) from the center. A Mexican Navy weather station at Isla Contoy recently reported sustained winds of 38 mph (61 km/h) and a wind gust of 48 mph (78 km/h). The minimum central pressure recently reported by an Air Force Reserve Hurricane Hunter aircraft is 985 mb (29.09 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: Tropical Storm Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba, the Cayman Islands and the northeast Yucatan Peninsula, with isolated totals around 12 inches. This rainfall brings a risk of considerable flooding. Over the Southeastern U.S., Helene is expected to produce total rain accumulations of 5 to 10 inches with isolated totals around 15 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with areas of significant river flooding. Landslides are possible in areas of steep terrain in 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. STORM SURGE: The combination of a dangerous 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... Ochlockonee River, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...6-10 ft Indian Pass, FL to Ochlockonee River, FL...5-10 ft Anclote River, FL to Middle of Longboat Key, FL...5-8 ft Tampa Bay...5-8 ft Middle of Longboat Key, FL to Englewood, FL...4-7 ft Englewood, FL to Flamingo, FL...3-5 ft Charlotte Harbor...3-5 ft For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml?peakSurge. Storm surge could raise water levels by as much as 2 to 4 feet above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth. Storm surge could raise water levels by as much as 2 to 4 feet above ground level in areas of onshore winds within the warning area along the east coast of the Yucatan Peninsula. WIND: Hurricane conditions are expected in the hurricane warning area in Mexico during the next several hours, with tropical storm conditions already ongoing. Hurricane conditions are expected within the U.S. hurricane warning area late Thursday. Hurricane conditions are possible for the western portion of Cuba later today. Tropical storm conditions are expected to begin in the warning area in Cuba during the next several hours. Tropical storm conditions are expected in southern Florida later today and spreading northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday and Thursday night. TORNADOES: A tornado or two may occur tonight over parts of the western Florida peninsula and southern Alabama. The risk of tornadoes will increase on Thursday, expanding across Florida and into parts of Georgia and South Carolina. SURF: Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico during the next couple of days. Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast later today and Thursday. 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 700 AM CDT. Next complete advisory at 1000 AM CDT. $$ Forecaster Beven |
