The National Hurricane Center says a tropical storm warning remains in effect and a hurricane watch is now in effect as Tropical Storm Issac approaches.
Hurricane Watch is also in effect for Puerto Rico, Vieques Culebra and the U.S. Virgin Islands.
A hurricane watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.
A tropical storm warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.
At 800 am, the center of Tropical Storm Isaac was located near latitude 15.7 north...longitude 58.4 west. Isaac is moving toward the west near 19 mph...31 km/h...and this general motion is expected to continue for the next couple of days. On the forecast track, the center of Isaac should move through the Leeward Islands this evening and move over the northeastern Caribbean Sea on Thursday.
Maximum sustained winds are near 45 mph with higher gusts. Strengthening is forecast during the next 48 hours and Isaac could become a hurricane by Thursday.
Tropical-storm-force winds extend outward up to 45 miles from the center.
Hazards Affecting Land
Tropical storm conditions are expected to reach the Leeward Islands by this afternoon or evening. Tropical storm conditions are expected over Puerto Rico and the U.S. and British Virgin Islands on Thursday.
Hurricane conditions are possible over Puerto Rico and the U.S. Virgin Islands on Thursday. As it relates to rainfall, officials estimate that total rain accumulations of 4 to 8 inches are possible over the northern Windward Islands and the Leeward Islands.
Total rain accumulations of 1 to 3 inches with maximum amounts of 6 inches are possible over Puerto Rico and the Virgin Islands. These rains could cause flash floods and mud slides.
A storm surge is expected to raise water levels by as much as 1 to 3 feet above normal tide levels in the northern Leeward Islands, Puerto Rico and the U.S. and British Virgin Islands. Near the coast, the surge will be accompanied by dangerous waves.