Florida and Cuba are bracing for Tropical Storm Idalia, which is expected to intensify into a dangerous Category 3 hurricane.
Forecasters say Idalia is expected to gain hurricane force before making landfall in Big Bend, Florida, on Wednesday.
The National Hurricane Center (NHC) said another storm, Franklin, could bring life-threatening storm surges to the US East Coast and Bermuda.
It comes as the Atlantic hurricane season nears its peak.
The BBC reports that Franklin is the first major hurricane of the season, which runs from June to November.
It is currently a Category 4 storm, packing 145mph (230km/h) winds, but is expected to weaken by midday Tuesday.
