000 WTNT34 KNHC 240858 TCPAT4 BULLETIN Potential Tropical Cyclone Nine Advisory Number 4 NWS National Hurricane Center Miami FL AL092024 500 AM EDT Tue Sep 24 2024 ...HURRICANE AND STORM SURGE WATCHES ISSUED FOR PORTIONS OF THE FLORIDA GULF COAST... SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...18.9N 83.0W ABOUT 120 MI...195 KM WSW OF GRAND CAYMAN ABOUT 240 MI...390 KM SSE OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...NW OR 315 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Storm Surge Watch has been issued from Indian Pass Florida southward to Bonita Beach Florida, including Tampa Bay and Charlotte Harbor. A Hurricane Watch has been issued for the Gulf Coast of Florida from Englewood northward and westward to Indian Pass, including Tampa Bay. A Tropical Storm Watch has been issued for the Gulf Coast of Florida from Indian Pass to the Walton/Bay County Line and from north of Bonita Beach to south of Englewood. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Watch is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Watch is in effect for... * Cabo Catoche to Tulum, Mexico * Cuban province of Pinar del Rio * Englewood to Indian Pass * Tampa Bay A Tropical Storm Warning is in effect for... * Grand Cayman * Rio Lagartos to Tulum, Mexico * Cuban provinces of Artemisa, and Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * Dry Tortugas * Lower Keys west of the Seven Mile Bridge * Flamingo to south of Englewood * West of Indian Pass to Walton Bay County line A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 24 to 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, generally within 48 hours. Interests elsewhere along the northeastern Gulf Coast, including the Florida Panhandle and the Florida west Gulf coast, should monitor the progress of this system. Additional watches or warnings will likely be required 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 500 AM EDT (0900 UTC), the disturbance was centered near latitude 18.9 North, longitude 83.0 West. The system is moving toward the northwest near 8 mph (13 km/h). This general motion is expected later today and tonight, followed by a faster northward to north-northeastward motion on Wednesday and Thursday. On the forecast track, the center of the system is forecast to move across the northwestern Caribbean Sea through tonight, and then over the eastern Gulf of Mexico on Wednesday and Thursday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is expected during the next few days, and the system is forecast to become a hurricane on Wednesday and continue strengthening on Thursday as it moves across the eastern Gulf of Mexico. * Formation chance through 48 hours...high...near 100 percent. * Formation chance through 7 days...high...near 100 percent. The estimated minimum central pressure is 1001 mb (29.56 inches) based on Air Force dropsonde data. HAZARDS AFFECTING LAND ---------------------- Key Messages for Potential Tropical Cyclone Nine 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: Potential Tropical Cyclone Nine is expected to produce total rain accumulations of 4 to 8 inches over western Cuba and the Cayman Islands with isolated totals around 12 inches. Over the eastern Yucatan Peninsula, 2 to 4 inches of rain is expected with isolated totals over 6 inches. This rainfall brings a risk of considerable flooding. Over the Southeastern U.S., Potential Tropical Cyclone Nine is expected to produce total rain accumulations of 3 to 6 inches with isolated totals around 10 inches. This rainfall will likely result in areas of locally considerable flash and urban flooding, with minor to isolated moderate river flooding also possible. For a complete depiction of forecast rainfall associated with Potential Tropical Cyclone Nine, 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 Bonita Beach, 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 possible within the watch areas in Cuba and Mexico by early Wednesday. Hurricane conditions are possible within the U.S. watch areas late Wednesday and early Thursday. Tropical storm conditions are expected in the warning areas in Cuba and Mexico beginning later today. Tropical storm conditions are possible in the watch area beginning on Wednesday in southern Florida and the Keys, and Thursday in the Florida Panhandle. SURF: Swells generated by the system 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 on Wednesday 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 800 AM EDT. Next complete advisory at 1100 AM EDT. $$ Forecaster Blake