BULLETIN Tropical Storm Isaac Advisory Number 23 NWS National Hurricane Center Miami FL AL092018 500 AM AST Thu Sep 13 2018 ...TROPICAL-STORM-FORCE WINDS NEARING THE LEEWARD ISLANDS... ...GUSTY CONDITIONS EXPECTED THROUGHOUT THE DAY... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...15.4N 59.7W ABOUT 105 MI...170 KM E OF DOMINICA ABOUT 130 MI...205 KM ESE OF GUADELOUPE MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...W OR 275 DEGREES AT 17 MPH...28 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Antigua has issued a Tropical Storm Watch for Barbuda. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Martinique * Dominica * Guadeloupe A Tropical Storm Watch is in effect for... * Antigua * Barbuda * Montserrat * St. Kitts and Nevis * Saba and St. Eustatius * St. Martin and St. Maarten A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next few hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within the next few hours. Interests elsewhere in the Leeward Islands should monitor the progress of Isaac. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 500 AM AST (0900 UTC), the center of Tropical Storm Isaac was located near latitude 15.4 North, longitude 59.7 West. Isaac is moving toward the west near 17 mph (28 km/h). This general motion is forecast to continue for the next several days. On the forecast track, Isaac is forecast to move across the central Lesser Antilles and into the eastern Caribbean Sea later today, and then move across the eastern and central Caribbean Sea through the weekend. Earlier data from a NOAA Hurricane Hunter aircraft indicate that maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Little change in strength is expected over the next several hours as Isaac moves through the Leeward Islands. Gradual weakening is forecast after that as Isaac moves through the eastern Caribbean. Tropical-storm-force winds extend outward up to 160 miles (260 km) from the center. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Tropical Storm Isaac is expected to produce total rainfall accumulations of 2 to 4 inches with isolated amounts up to 6 inches across Martinique, Dominica, and Guadeloupe, especially over elevated terrain. Rainfall of 0.5 to 1.5 inches with isolated amounts to 3 inches are forecast across Puerto Rico and the southern United States Virgin Islands, with up to an inch anticipated across the remaining Windward and Leeward Islands. This rainfall may cause dangerous flash flooding. WIND: Tropical storm conditions are expected within the tropical storm warning area beginning within the next few hours through the afternoon. Tropical storm conditions are possible within the tropical storm watch area, also beginning later this morning. STORM SURGE: Some coastal flooding is possible in areas of onshore winds. Near the coast, the surge will be accompanied by large waves. SURF: Swells generated by Isaac are affecting portions of the Lesser Antilles. 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 AST. Next complete advisory at 1100 AM AST. $$ Forecaster Zelinsky Source: NOAA https://www.nhc.noaa.gov/text/refresh/MIATCPAT4+shtml/130856.shtml?