As winds picked up in the Dominican Republic, Tropical Storm Isaac continues to churn across the Caribbean on Thursday.
Winds of 45 miles an hour - forecasters said the storm - which had weakened slightly - could gain strength and become a hurricane within a day.
Hurricane warnings were in effect for the Dominican Republic and Haiti.
Computer models put the storm on track to hit off the coast of Florida by Monday - the first day of the Republican National Convention in Tampa.
Florida governor Rick Scott.
SOUNDBITE (English) FLORIDA GOVERNOR RICK SCOTT
"Isaac is a unique storm in this regard. It has the potential to threaten a major convention, designated a special national security event."
The governor was confident the state was prepared for the storm - but said the decision to move the four-day convention would lie with the Republican party.