Tropical Storm Idalia is forecast to become a major hurricane before it hits Florida

Tropical Storm Idalia is now expected to grow into a "major hurricane" by the time it reaches Florida late Tuesday, and forecasters are warning residents to prepare for severe weather, including potentially deadly storm surge.

The tropical storm system churning in the waters off the western tip of Cuba is expected to batter parts of that country late Monday and early Tuesday, according to the National Hurricane Center.

Forecasters say Idalia will then move north through the Gulf of Mexico, where it will strengthen into a powerful hurricane before coming ashore in Florida midweek.

"The risk continues to increase for life-threatening storm surge and dangerous hurricane-force winds along portions of the west coast of Florida and the Florida Panhandle beginning as early as late Tuesday," the National Weather Service said in a tweet.

A chief concern with Idalia is storm surge, which occurs when a storm's strong winds push seawater above normal levels and onto coastal land. The Tampa Bay area could see 4 to 7 feet of storm surge from Idalia, according to forecasters.

With maximum sustained winds near 70 mph, Idalia remained a tropical storm Monday evening, but it was expected to become a hurricane at any time.

By the time it reaches Florida's coast, Idalia is predicted to be a "major" hurricane — meaning it will be a Category 3 hurricane or higher.

How Florida is preparing for its first hurricane of the season

Hurricane and storm surge warnings were in effect for parts of Florida on Monday.

Gov. Ron DeSantis has put 46 counties under a state of emergency and announced a raft of other storm preparedness measures, including the mobilization of 1,100 Florida National Guard personnel.

"This is gonna be a major hurricane. This is gonna be a powerful hurricane, and this is absolutely gonna impact the state of Florida in many, many different ways," DeSantis said during a Monday morning press conference.

The White House said President Biden and DeSantis spoke Monday about preparations for Idalia. Biden said he approved an emergency declaration for Florida and added that the Federal Emergency Management Agency had deployed personnel and supplies to the region ahead of the storm.

During his press conference, DeSantis warned residents to prepare for power outages and said there would likely be evacuation orders in counties along the Gulf Coast.

"All the barrier islands, places that are low-lying along the coast, you are going to be told to evacuate," DeSantis said, adding that that could mean relocating as few as tens of miles inland.

By early afternoon, parts of Hernando, Pasco and Citrus counties were already under evacuation orders, member station WUSF reported.

"We can't emphasize enough that you need to take this storm seriously," said David DeCarlo, director of Hernando County Emergency Management, according to the station.

Tampa International Airport announced that it would suspend commercial operations starting at 12:01 a.m. ET on Tuesday and anticipated reopening Thursday morning after the storm passed.

"Some cargo and private aircraft operations could continue overnight, but all air traffic will cease by 7 a.m. Tuesday morning," a post on its website read. "The Airport, including the Main Terminal and Airsides will be closed to all visitors and is not equipped to function as a shelter."

A number of Florida school districts had already announced closures on Tuesday, and the state's Department of Health was working to ensure residents could fill their prescriptions early.

According to WUSF, several cities and towns including Tampa were providing residents with free sandbags to prepare for the incoming storm.

Idalia forecast to become a hurricane as it passes near or over Cuba

Before Idalia reaches Florida, the storm will pass over or near western Cuba.

The National Hurricane Center said it expects Idalia to cross the island nation late Monday. The Cuban province of Pinar del Río was under a hurricane warning, and the Isla de la Juventud was under a tropical storm warning.

Forecasters said parts of Cuba could see as much as 4 to 6 feet of storm surge and between 4 and 10 inches of rain, which could produce flash flooding and landslides.

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