Tropical Storm Isaac strengthened slightly as it spun toward the Dominican Republic and vulnerable Haiti on Friday, threatening to bring punishing rains but unlikely to gain enough steam to strike as a hurricane.
Forecasters now expect the storm to stay below hurricane force until it's in the Gulf of Mexico. It's expected to stay to the west of Tampa, Fla., where the Republican National Convention starts on Monday, though there is still an outside chance it could hit there.
The National Weather Service has discontinued a tropical storm warning for Louisiana after forecast models indicated that the state is under less of a threat from Tropical Storm Debby than initially thought.
Parts of Alabama and Florida remain under a tropical storm warning, however. Storm paths are generally hard to predict days in advance, and forecasters say they've been comparing several models to compile the official forecast. As of late Sunday, though, they believe the storm was less likely to make a westward turn toward Louisiana.
Forecasters dropped storm warnings for southeastern Louisiana Sunday afternoon and said the threat from Tropical Storm Debby had decreased.
National Hurricane Center forecasters backed away from an earlier projection that Debby might strike southeast Louisiana as a Category 1 hurricane. Instead they said they didn't expect it to turn west from its northward path that has it aimed at Florida and Alabama.