The emergency response from Florida Power & Light is “well underway” as Hurricane Ian approaches, the utility company announced Monday.

FP&L has mobilized 13,000 workers, as well as supplies, to ensure the response is conducted as safely and quickly as possible after the storm hits, according to a press release.

As the hurricane begins to bear down on the region, FP&L will use remote grid technology to restore power remotely during the storm, as long as it is safe to do so, the company said. After the storm passes and winds drop below 35 mph, FP&L will continue restoration and conduct damage assessments with field crews.

The utility company also urged customers to make preparations and take safety precautions.

"As this storm approaches Florida, we know our customers are counting on us and we are determined to meet this challenge," said Eric Silagy, chairman and CEO of FP&L in a statement. "We are mobilizing and pre-positioning our restoration workforce, so these brave men and women can quickly start working as soon as it is safe to do so."

-ABC News' Matt Foster

Florida State University has canceled classes Tuesday through Friday as Hurricane Ian approaches.

"The cancellation of classes on Tuesday is to allow students to travel safely out of the area if they so choose," the university said. "Students who choose to stay in Tallahassee will be advised via the FSU Alert system to follow a 'shelter in place' protocol during the storm."

The St. Pete-Clearwater International Airport will close at 1 p.m. Tuesday due to the mandatory evacuation orders in Pinellas County. The airport will stay closed until the evacuation order is lifted.

Mandatory evacuation orders are in place for coastal parts of Hillsborough County, Florida. Over 300,000 people are expected to evacuate, officials announced Monday, with emergency shelters opening at 2 p.m. Monday.

Hillsborough County could face up to 15 feet of storm surge and 30 straight hours of tropical storm force winds, Florida Emergency Management Director Tim Dudley said.

County Administrator Bonnie Wise added, “We did not make this decision easily, but the storm poses a serious threat, and we must do everything we can protect our residents.”

Some residents of Sarasota County and Manatee County are also under mandatory evacuation orders.

-ABC News’ Alex Faul

Tropical Storm Ian has weakened slightly, but it is expected to not only strengthen but rapidly intensify overnight as it travels over warm waters in the Caribbean.

As of 5 p.m. ET, the storm system had maximum sustained winds of 45 mph and was moving west-northwest at 12 mph, with the center located about 220 miles away from Grand Cayman.

Dry air ahead of the storm has delayed the strengthening trend so far. But the rapid intensification is expected to occur Monday into Tuesday as the system continues across the northwestern Caribbean and closes in on western Cuba.

Over the next 24 hours, the outer bands will impact Jamaica and the Cayman Islands, bringing rounds of heavy rain, possible flash flooding and storm surge. Later Monday and into Monday night, Ian will be closing in on western Cuba and will likely bring significant wind and storm surge impacts to the region.

A hurricane warning is in effect for Grand Cayman and portions of western Cuba. A tropical storm watch has been issued for portions of western Cuba, as well as the lower Florida Keys, including Key West.

As of 5 p.m., the forecast track was nudged slightly eastward. Overall, the forecast guidance variability and uncertainty will remain high, and the track for where the storm will be from the middle to the end of the week will continue to shift over the next 24 to 48 hours.

-ABC News' Dan Peck