(NewsNation) — Florida emergency personnel were standing at the ready Tuesday night to respond to a major hurricane that was expected to make landfall within the next 24 hours.

Hurricane Ian tore into western Cuba as a major hurricane Tuesday, knocking out power to the entire country and leaving 11 million people without electricity, before churning on a collision course with Florida over warm Gulf waters amid expectations it would strengthen into a catastrophic Category 4 storm.

Gov. Ron DeSantis and state emergency leaders spent Tuesday warning residents to evacuate and prepare for torrential rains and heavy winds. The storm was a Category 3 late Tuesday and centered less than 200 miles from the western coast, moving at about 10 mph, according to the National Hurricane Center.

Evacuation orders have been issued for people in coastal communities, mobile homes and low-lying areas in 12 counties. In some areas, police were seen driving through the neighborhood urging those still in their homes to leave and seek shelter.

Tropical storm-force winds were expected across the state’s southern peninsula late Tuesday, reaching hurricane-force Wednesday — when the eye was predicted to make landfall. With tropical storm-force winds extending 140 miles from Ian’s center, damage was expected across a wide area of Florida.

DeSantis held a media briefing at the State Emergency Operations Center in Tallahassee on Tuesday, saying the storm surges would “far eclipse” those produced by Hurricane Charley, a Category 4 hurricane that hit Florida in 2004.

“What we have here is really historic storm surge and flooding potential,” DeSantis said.

In a second news conference Tuesday, DeSantis said updated models of the hurricane now reflect the anticipated landfall of the storm over the Sarasota region, just south of Tampa.

“It’s still not set in stone,” DeSantis said. “I’d say anyone on the gulf coast (needs) to prepare for impact.”

He also said this storm is going to be different than storms in the past because forecasts have Ian slowing down when it hits land.

“Another factor that they are forecasting now, as it makes landfall … most of the forecasts have it slowing down to almost a crawl,” DeSantis explained. “What that means is that it’s going to dump an inordinate amount of rain.”

He said it is going to be a major water event in terms of the storm surge and flooding.

In a third news conference Tuesday night, DeSantis and other leaders from state emergency agencies said they stand at the ready to respond to residents’ needs and initiate recovery efforts once the storm passes.

Tolls have been suspended along interstates to allow for faster evacuations, and bridges will be closed when certain wind speeds are met, officials said.

DeSantis was expected to provide further updates early Wednesday morning.

After getting 67% stronger in less than 22 hours from Monday to Tuesday, Hurricane Ian was bearing down on Florida as a possible Category 4 hurricane that threatens to deliver a nightmare storm-surge to Tampa Bay.

Students have already been evacuated from the University of Tampa, and the residents of the Florida Keys were moving their cars to higher ground as they brace for possible floods, according to the Monroe County Emergency Management.

Walt Disney World will close all theme parks and water parks on Wednesday and Thursday, as well as some resorts. Universal Orlando Resort also announced it would close on Wednesday and Thursday.

White House press secretary Karine Jean-Pierre said Tuesday night President Joe Biden and DeSantis discussed ways the federal government is helping Florida prepare for the hurricane and later committed to continue providing a closely coordinated storm response.

As of Tuesday night, at least 5,000 Florida Guardsmen have been activated and pre-positioned at armories across the state.

Before heading for Florida, Ian made landfall at 4:30 a.m. Eastern time Tuesday in Cuba’s Pinar del Rio province, where officials set up 55 shelters, evacuated 50,000 people, rushed in emergency personnel and took steps to protect crops in Cuba’s main tobacco-growing region. The storm knocked out power to the entire country, leaving 11 million people without electricity.

The National Hurricane Center said “significant wind and storm surge impacts” were occurring Tuesday morning in western Cuba. Ian’s sustained top winds were 125 mph and as much as 14 feet of storm surge was predicted along Cuba’s coast.

A Hurricane Warning has been issued for parts of west central Florida including the following counties: Pinellas, Hillsborough, Manatee, Sarasota, Polk, Lake, Seminole, Orange, Osceola, Okeechobee, Hardee, Highlands, Desoto, Charlotte, Lee and Coastal Collier. Glades, Hendry and Inland Collier are under a Hurricane Watch.

The area where the storm comes ashore could see 12 to 16 inches of rain, with some areas seeing isolated amounts of up to 24 inches. The heavy rainfall could lead to considerable flash and urban flooding and prolonged river flooding. A few tornadoes will be possible across parts of Florida on Tuesday and Wednesday, the NHC said.

It’s been more than a century since a major storm like Hurricane Ian has struck the Tampa Bay area. Many residents live in low-lying neighborhoods that are highly susceptible to storm surges and flooding.

Tampa and St. Petersburg could get their first direct hit by a major hurricane since 1921.

Tampa Bay is also under a storm surge warning, meaning the storm could raise water levels above normal tides.

The storm is forcing people to evacuate, but also reducing some of their options. The Tampa Airport announced it would cease operations at 5 a.m. Tuesday to prepare the facility for the brutal storm. A statement from the airport did not include a potential reopening time — only a promise that damage assessments would begin as soon as it was safe.

So far, 26 school districts have been closed, and more are expected to close as the storm approaches.

DeSantis said that high-water vehicles, shallow boats and search and rescue aircraft are ready for deployment. The Coast Guard is also standing by.

The threat has also forced the Tampa Bay Buccaneers to pack up and head toward Miami to practice with the Dolphins. The Buccaneers Sunday night game at home against the Kansas City Chiefs was still scheduled as of Tuesday night, though the NFL is reviewing the possibility of moving the game to another stadium.

DeSantis declared a state of emergency for the entire state of Florida on Saturday, freeing up resources for all residents. He also urged residents to be ready for a storm that could lash large swaths of the state with heavy rains, high winds and rising seas.

Tampa Mayor Jane Castor was also preparing her city for the impact of the storm.

“No doubt we’re going to feel the effects. Just how severe the effects are remain to be seen. So what we are asking is everyone to be prepared,” Castor said.

On Monday, Hillsborough County activated 40 shelters for residents, one of them a local elementary school.

“Please treat this storm seriously. It’s the real deal. This is not a drill,” Hillsborough County Emergency Management Director Timothy Dudley said at a Monday news conference on storm preparations in Tampa.

Residents waited upward of four hours to fill sandbags at one of three locations. Grocery store lines reached down the streets as many prepared for the storm.

Biden also declared an emergency, authorizing the Department of Homeland Security and the Federal Emergency Management Agency, or FEMA, to coordinate disaster relief and provide assistance to protect lives and property.

The president postponed a scheduled Sept. 27 trip to Florida due to the storm and NASA decided to forgo a planned Tuesday launch opportunity for its new moon rocket.

The agency advised Floridians to have hurricane plans in place and monitor updates of the storm’s evolving path.

Georgia Gov. Brian Kemp on Sunday ordered the activation of the State Operations Center for Monday, to prepare for any potential impact from Hurricane Ian later in the week.

NewsNation affiliate WFLA and the Associated Press contributed to this report.