CNN

Evacuations are underway and time is running out for Floridians to prepare for Tropical Storm Helene, which threatens to hit as the strongest storm to make landfall in the United States in over a year.

Helene formed in the northwestern Caribbean Sea Tuesday morning and will set off on a breakneck pace of strengthening. It could take Helene just 48 hours to go from a 45 mph tropical storm to a Category 3 major hurricane as it rapidly intensifies over the extremely warm waters of the Gulf of Mexico.

A hurricane warning was issued for parts of Florida’s Gulf Coast, from Anclote River to Mexico Beach, according to the National Hurricane Center’s 11 p.m. ETadvisory. The Mexican government has also issued a hurricane warning from Cabo Catoche to Tulum.