Tropical Storm Helene is expected to unleash mudslides and flooding in Cuba before reaching major hurricane strength on Thursday as it hits Florida with life-threatening ocean surge, the U.S. National Weather Service said.

Tropical Storm Helene formed Tuesday in the Caribbean Sea and could strengthen into a major hurricane while moving north toward the U.S., forecasters said. Heavy rains and big waves already lashed the Cayman Islands, and some Florida residents began to evacuate or fill sandbags ahead of anticipated flooding.

Tropical Storm Helene continues to strengthen and is forecast to make landfall on the Big Bend Coast of Florida late Thursday night.

Forecasters say they expect Tropical Storm Helene in the Caribbean Sea to strengthen rapidly and become a hurricane as it moves north across the Gulf of Mexico on Wednesday toward the U.S. The Nationa

Gov. Ron DeSantis on Tuesday said Florida is preparing for a direct hit from a major hurricane that could intensify quickly before it makes landfall in the Panhandle later this week. The National Hurricane Center predicted a tropical storm currently in the Gulf of Mexico will become Hurricane Helene as it moves north toward Florida by Thursday.

Helene is expected to rapidly intensify into a major and massive hurricane with 115-mph winds by the time it makes landfall Thursday.

Helene officially developed into a named storm Tuesday and is expected to make landfall along Florida’s Gulf Coast as a Category 3 hurricane this week.

Tropical Storm Helene formed Tuesday in the Caribbean Sea and could strengthen into a major hurricane while moving north toward the U.S., forecasters said.