Tropical Storm Isaac weakened slightly as it dumped heavy rain off Puerto Rico and the Virgin Islands today, but it was expected to strengthen into a hurricane before tearing across the Dominican Republic and Haiti.
Isaac also continued to pose a major threat to Florida, where it is on track to make landfall Monday as the Republican National Convention is set to start in Tampa, according to a Reuters report.
Authorities have not ruled out postponing or relocating the RNC convention if the storm takes direct aim.
Most computer forecast models this morning had shifted west from Wednesday and showed Isaac brushing across the north coast of Cuba before cutting across the Keys and the southern tip of Florida on Monday. It was then likely to make landfall in the Florida Panhandle, in the northwest corner of the state, although one model puts it almost directly over Tampa en route to the Panhandle, Reuters reported.
The storm also has the potential to affect U.S. energy interests in the Gulf of Mexico.
Isaac was centered about 225 miles south-southeast of San Juan, Puerto Rico, on Thursday morning and moving westward at 13 mph, the U.S. National Hurricane Center said.
The storm's top sustained winds had dropped to 40 mph, but the Miami-based hurricane center said restrengthening was forecast during the next 48 hours.
The hurricane center said Isaac was expected to dump between 8 and 12 inches of rain over some parts of Hispaniola, an island shared by the Dominican Republic and Haiti, with total accumulations of as much as 20 inches in some areas, which could cause life-threatening flash floods and mudslides.
Haiti, the poorest country in the Americas, also still has hundreds of thousands of people living in tents or makeshift shelters more than 2-1/2 years after a devastating earthquake that took more than a quarter of a million lives.