In its 8 p.m. EDT Thursday advisory, the National Hurricane Center in Miami said the storm, with sustained top winds of 45 mph, was 190 miles southwest of San Juan, Puerto Rico, and 340 miles southeast of Santo Domingo, Dominican Republic, as it traveled west-northwest at 16 mph toward the coast of the Dominican Republic.
The government of the Dominican Republic changed a hurricane warning to a tropical storm warning for the south coast of the island nation from Isla Saona west to the Haiti-Dominican Republic southern border.
A hurricane warning was posted for Haiti and a tropical storm warning was in effect for the British Virgin Islands, Puerto Rico, Vieques, Culebra and the U.S. Virgin Islands, as well as southeastern Bahamas, Turks and Caicos Islands. A tropical storm watch was posted for the Cuban provinces of Camaguey, Las Tunas, Granma, Holguin, Santiago de Cuba and Guantanamo.
Isaac was forecast to follow on its current motion through Saturday and, on its current rack, is expected to approach the south coast of the Dominican Republic Thursday night, and then move near or over the south coast of Haiti-Dominican Republic Friday before approaching southeastern Cuba Friday night.
Isaac could become a hurricane Friday, forecasters said.
Tropical storm-force winds extended outward from Isaac's center 185 miles.
Isaac could generate 4- to 8 inches of rain over the northern Windward Islands and Leeward Island, the center said. Puerto Rico and the Virgin Islands could get 1-3 inches of rain with up to 6 inches possible.
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