123 WTNT34 KNHC 131746 TCPAT4 BULLETIN Tropical Storm Isaac Intermediate Advisory Number 24A NWS National Hurricane Center Miami FL AL092018 200 PM AST Thu Sep 13 2018 ...ISAAC BECOMING LESS ORGANIZED OVER THE EASTERN CARIBBEAN SEA... SUMMARY OF 200 PM AST...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...14.9N 62.5W ABOUT 80 MI...130 KM WSW OF DOMINICA ABOUT 240 MI...385 KM SE OF ST. CROIX MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of the Netherlands has discontinued the Tropical Storm Watch for Saba and St. Eustatius. The government of France has discontinued the Tropical Storm Watch for St. Martin, and the government of St. Maarten has discontinued the Tropical Storm Watch for St. Maarten. 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 A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. 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 200 PM AST (1800 UTC), the center of Tropical Storm Isaac was located by satellite images near latitude 14.9 North, longitude 62.5 West. Isaac is moving toward the west near 18 mph (30 km/h). A westward track with a slower forward motion is forecast to continue for the next few days. On the forecast track, Isaac should move farther away from Lesser Antilles today, and then move across the eastern and central Caribbean Sea through the weekend. Maximum sustained winds remain near 45 mph (75 km/h) with higher gusts. Gradual weakening is forecast over the next few days as Isaac moves through the Caribbean Sea. 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 8 to 10 inches over Dominica. Rainfall amounts of 2 to 4 inches with isolated amounts up to 6 inches over elevated terrain are forecast across Martinique and Guadeloupe. Rainfall totals of 2 to 4 inches are forecast across southeastern Puerto Rico, while totals of 1 to 2 inches with maximum amounts of 3 inches are possible across the remainder of Puerto Rico and the U.S. Virgin Islands. This rainfall may cause dangerous flash flooding. WIND: Tropical storm conditions are occuring within portions of the warning area and should continue through the afternoon hours. Tropical storm conditions are possible within the watch area today. 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 complete advisory at 500 PM AST. $$ Forecaster Blake