There are fears the first tropical storm of the hurricane season could hold up efforts to capture oil spewing into the Gulf of Mexico, for up to two weeks.
Experts say Tropical Storm Alex may also complicate efforts to clean up miles of coastline.
A tropical storm warning has already been issued for Belize, the Yucatan Peninsula and part of Honduras.
Currently miles off Chetumal in Mexico, Alex is moving in a west north-westerly direction, with winds of up to 65 kilometers an hour.
The National Hurricane Center says prediction models no longer show Alex going across the spill, but that could change.
High winds and seas could distribute the oil over a larger area, pushing it towards the coast of Florida.
It could cause a repeat of the scenes in Louisiana, where sun worshippers and pristine white sand are replaced by slicks, tar balls and hazard-suited clean-up crews.