The storm, which is not forecast to make landfall in Mexico, will travel across the Gulf of Mexico before reaching northwest Florida, the U.S. National Hurricane Center said.
Idalia will create “increasing risk of life-threatening storm surge and hurricane-force winds along portions of the west coast of Florida and the Florida Panhandle beginning as early as Tuesday,” the NHC warned.
“There is considerable spread in the model intensity guidance, ranging from minimal to major hurricane status before landfall on the northeast Gulf coast,” the NHC added.
At 2100 GMT Sunday, Idalia was swirling in the Caribbean, headed northeast with maximum sustained winds of 65 kilometers (40 miles) per hour, the NHC said.
In the Mexican state of Quintana Roo, home to Cancun and other coastal tourist resorts, Idalia dumped rain and put a damper on one of the last weekends of summer vacation.
Storm surge and hurricane watches have been issued for parts of Florida’s coast and scattered flash flooding can be expected, the NHC said.
Heavy rainfall is meanwhile expected across parts of the eastern Yucatan in Mexico and western Cuba.
Last weekend, Hilary, which at one point rose to a Category 4 hurricane on the five-point Saffir-Simpson scale, hit the state of Baja California on Mexico’s Pacific coast as a tropical storm, causing one death and damaging infrastructure.
Hurricanes hit Mexico every year on both its Pacific and Atlantic coasts.
Scientists have warned that storms are becoming more powerful as the world gets warmer with climate change.