BULLETIN Tropical Storm Isaias Intermediate Advisory Number 8A NWS National Hurricane Center Miami FL AL092020 800 AM AST Thu Jul 30 2020 ...ISAIAS CAUSING LIFE-THREATENING FLASH FLOODING AND HIGH WINDS OVER PUERTO RICO... SUMMARY OF 800 AM AST...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...17.6N 68.5W ABOUT 125 MI...205 KM W OF PONCE PUERTO RICO ABOUT 105 MI...175 KM ESE OF SANTO DOMINGO DOMINICAN REPUBLIC MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 20 MPH...31 KM/H MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Puerto Rico, Vieques, Culebra * U.S. Virgin Islands * British Virgin Islands * Dominican Republic entire southern and northern coastlines * North coast of Haiti from Le Mole St Nicholas eastward to the northern border with the Dominican Republic * Turks and Caicos Islands * Southeastern Bahamas including the Acklins, Crooked Island, Long Cay, the Inaguas, Mayaguana, and the Ragged Islands * Central Bahamas, including Cat Island, the Exumas, Long Island, Rum Cay, and San Salvador A Tropical Storm Watch is in effect for... * Northwestern Bahamas including Andros Island, New Providence, Eleuthera, Abacos Islands, Berry Islands, Grand Bahamas Island, and Bimini Interests in Cuba and the Florida peninsula should monitor the progress of this system. 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, generally within 48 hours. 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 800 AM AST (1200 UTC), the center of Tropical Storm Isaias was located near latitude 17.6 North, longitude 68.5 West. Isaias is moving toward the northwest near 20 mph (31 km/h), and a west-northwestward to northwestward motion with some decrease in forward speed is expected over the next couple of days. On the forecast track, the center of Isaias will move over Hispaniola later today and near the Southeastern Bahamas by tonight or early Friday. Isaias is forecast to be near the Central Bahamas Friday night and approach the Northwest Bahamas or southern Florida Friday night and Saturday. Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Little change in strength is anticipated until landfall in Dominican Republic later today, with re-strengthening forecast on Friday and Saturday. Tropical-storm-force winds extend outward up to 415 miles (665 km) from the center. Tropical-storm-force winds are occuring along the southern coast of Puerto Rico. A Weatherflow station in Yabucoa Tanque de Agua reported sustained winds of 46 mph (74 km/h) with a gust to 56 mph (91 km/h). A Weatherflow station at Las Mareas reported sustained winds of 43 mph (69 km/h) with a gust to 54 mph (87 km/h). The estimated minimum central pressure is 1003 mb (29.62 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Isaias can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT4.shtml. WIND: Tropical storm conditions will continue across portions of the U.S. and British Virgin Islands and Puerto Rico through this morning or early afternoon. These conditions are forecast to reach portions of the Dominican Republic and Haiti within the warning area later this morning, and the southeastern Bahamas and Turks and Caicos this afternoon. Tropical storm conditions are expected in the Central Bahamas beginning Friday morning and are possible in the northwestern Bahamas beginning late Friday. RAINFALL: Isaias is expected to produce the following rain accumulations: British and U.S. Virgin Islands and Turks and Caicos: 3 to 6 inches. Puerto Rico and northern Haiti: 3 to 6 inches, with isolated maximum totals of 8 inches. Dominican Republic: 4 to 8 inches, with isolated maximum totals of 10 inches. Bahamas: 4 to 8 inches. Cuba: 2 to 4 inches, with isolated maximum totals of 6 inches. These rainfall amounts will lead to life-threatening flash flooding and mudslides, as well as potential riverine flooding beginning today. Urban and small stream flooding is expected for the U.S. Virgin Islands, eastern Puerto Rico, and Hispaniola. SURF: Swells generated by Isaias are affecting portions of the Leeward Islands, the Virgin Islands, Puerto Rico, the Dominican Republic, the Turks and Caicos Islands and the southeastern Bahamas. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.