563 WTNT34 KNHC 112032 TCPAT4 BULLETIN Tropical Storm Isaac Advisory Number 17 NWS National Hurricane Center Miami FL AL092018 500 PM AST Tue Sep 11 2018 ...WARNINGS LIKELY TO BE ISSUED TONIGHT FOR ISAAC... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...14.6N 51.3W ABOUT 670 MI...1075 KM E OF THE LESSER ANTILLES MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 17 MPH...28 KM/H MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... * Guadeloupe * Martinique * Dominica A Tropical Storm Watch is in effect for... * Antigua * Montserrat * St. Kitts and Nevis A Hurricane Watch means that hurricane conditions are possible within the watch 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 as additional watches or warnings will likely be issued tonight. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 500 PM AST (2100 UTC), the center of Tropical Storm Isaac was located near latitude 14.6 North, longitude 51.3 West. Isaac is moving toward the west near 17 mph (28 km/h), and this general motion is expected to continue for the next few days. On the forecast track, Isaac is anticipated to move near or over the central Lesser Antilles on Thursday, move into the eastern Caribbean Sea Thursday night, and move into the central Caribbean Sea by the weekend. Maximum sustained winds remain near 70 mph (110 km/h) with higher gusts. Isaac is expected to be near hurricane strength when it moves through the central Lesser Antilles, with some weakening forecast afterward on Friday and Saturday. Tropical-storm-force winds extend outward up to 105 miles (165 km) from the center. The estimated minimum central pressure is 996 mb (29.42 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Isaac is expected to produce total rainfall accumulations of 3 to 5 inches with isolated amounts near 10 inches across Martinique, Dominica, and Guadeloupe, with 1 to 2 inches anticipated across the remaining Windward and Leeward Islands. STORM SURGE: A storm surge of 2 to 4 feet above normal tide levels is possible near and to the north of where the center moves through the Lesser Antilles. Near the coast, the surge will be accompanied by large and destructive waves. WIND: Hurricane conditions are possible within the hurricane watch area by Thursday morning, with tropical storm conditions possible overnight Wednesday in both the hurricane and tropical storm watch areas. SURF: Swells generated by Isaac will begin to affect portions of the Lesser Antilles on Wednesday afternoon. 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 PM AST. Next complete advisory at 1100 PM AST. $$ Forecaster Blake