MIAMI Tropical Storm Sandy picked up speed and strength on its approach to the south coast of Jamaica on Wednesday and was forecast to make landfall as a hurricane later in the day, the U.S. National Hurricane Center said.
Emergency authorities on the Caribbean island closed schools and prepared shelters to take in residents of flood-prone areas.
The storm was centered about 120 miles south of the Jamaican capital, Kingston, on Wednesday morning and was moving north at 14 miles per hour (22 km per hour) with top sustained winds of 70 miles per hour.
A tropical storm watch has been issued for south Florida, but Sandy's expected path will not take it into the Gulf of Mexico, where U.S. oil and gas operations are clustered.
A hurricane warning was in effect for both Jamaica and Cuba, although forecasters said Sandy is expected to be only a weak Category One hurricane on the five-step Saffir-Simpson scale of hurricane intensity, with winds topping out at 80 mph.
Computer models showed Sandy was on a projected path that would cut across the middle of Jamaica near the capital, Kingston, and the popular north coast resort of Ocho Rios, before passing over eastern Cuba and losing hurricane strength as it reaches the Bahamas.
Sandy is expected to dump as much as 6 to 12 inches of rain across parts of Jamaica, Haiti, the Dominican Republic and eastern Cuba, with as much as 20 inches possible in some places, forecasters said.
"These rains may produce life-threatening flash floods and mud slides ... especially in areas of mountainous terrain," the hurricane center warned.
Storm surge could also raise water levels on Jamaica's south and east coasts by 1 to 3 feet (one-third to 1 meter) above normal tide levels, it added, and as much as 4 to 7 feet above normal in the Bahamas on Friday.
(Writing by David Adams; Editing by Jackie Frank)