BULLETIN Potential Tropical Cyclone Six Advisory Number 4 NWS National Hurricane Center Miami FL AL062021 1100 AM AST Tue Aug 10 2021 ...NOAA HURRICANE HUNTER AIRCRAFT REPORTS THE DISTURBANCE IS NOT YET A TROPICAL CYCLONE... ...LIKELY TO BECOME A TROPICAL STORM LATER TODAY OR TONIGHT... SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...16.3N 63.8W ABOUT 160 MI...255 KM W OF GUADELOUPE ABOUT 220 MI...350 KM ESE OF PONCE PUERTO RICO MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...1012 MB...29.89 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Government of France has discontinued the Tropical Storm Watch for Martinique and Guadeloupe. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Puerto Rico, including Culebra and Vieques * U.S. Virgin Islands * Dominican Republic on the south coast from Punta Palenque eastward and on the north coast from Cabo Frances Viejo eastward A Tropical Storm Watch is in effect for... * Saba and St. Eustatius * Dominican Republic on the north coast from Cabo Frances Viejo to the Dominican Republic/Haiti border * Haiti from the northern border with the Dominican Republic to Gonaives * Turks and Caicos Islands * Southeastern Bahamas A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Interests elsewhere in Haiti and the Bahamas, as well as in eastern and central Cuba, should monitor the progress of this system. 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 1100 AM AST (1500 UTC), the disturbance was centered near latitude 16.3 North, longitude 63.8 West. The system is moving toward the west-northwest near 18 mph (30 km/h) and this general motion is expected to continue during the next few days. On the forecast track, the disturbance is expected to pass near or over the U.S. Virgin Islands and Puerto Rico later today and tonight, be near or over Hispaniola on Wednesday, and be near the southeastern Bahamas and the Turks and Caicos Islands Thursday. Reports from a NOAA Hurricane Hunter aircraft indicate that maximum sustained winds are near 35 mph (55 km/h) with higher gusts. However, the aircraft did not find a well-defined closed circulation. Gradual strengthening is forecast during the next day or so and the disturbance is expected to become a tropical storm later today or tonight. Some weakening is likely while the system interacts with Hispaniola on Wednesday. * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent. The estimated minimum central pressure is 1012 mb (29.89 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Potential Tropical Cyclone Six can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1, WMO header WTNT41 KNHC and on the web at www.hurricanes.gov/graphics_at1.shtml?key_messages. RAINFALL: The potential tropical cyclone is expected to produce the following rainfall amounts: Over the Leeward Islands, Virgin Islands, and Puerto Rico...2 to 4 inches, with isolated amounts of 6 inches. Heavy rainfall could lead to flash, urban, and small stream flooding, along with possible rapid river rises and the potential for mudslides across the U.S. Virgin Islands and Puerto Rico. Over the northern Windward Islands...1 to 3 inches. Over the Dominican Republic...3 to 6 inches. WIND: Tropical storm conditions are possible within the watch area in the Lesser Antilles for the next few hours. Tropical storm conditions are expected in the warning areas in the U.S. Virgin Islands and Puerto Rico later today, and in the Dominican Republic by early Wednesday. Tropical storm conditions are possible elsewhere along the northern coasts of the Dominican Republic, northern Haiti, the Turks and Caicos, and the southeastern Bahamas beginning late Wednesday. SURF: Swells generated by the disturbance are affecting portions of the Leeward Islands. These swells are expected to spread across the U.S. Virgin Islands and Puerto Rico today and reach portions of Hispaniola on Wednesday, where they could cause life-threatening surf and rip current conditions. Please consult products from your local weather office.