Hurricane Ian continued to intensify Monday night, with maximum sustained winds now at 105 mph.

The hurricane is about 105 miles east-southeast of the western tip of Cuba, which is expected to see significant wind and storm surge impacts soon.

The storm is expected to become a major hurricane overnight or Tuesday morning.

-ABC News' Melissa Griffin

Tampa International Airport will stop all operations starting 5 p.m. Tuesday to secure its airfield and terminals ahead of Hurricane Ian's expected landfall later this week.

The U.S. Department of Health and Human Services has declared a public health emergency for the state of Florida.

HHS Secretary Xavier Becerra made the declaration Monday to address the possible health impacts for Florida residents once Hurricane Ian nears the state.

"We will do all we can to assist Florida officials with responding to the health impacts of Hurricane Ian," Becerra said in a statement. "We are working closely with state, local, and tribal health authorities, as well as our federal partners, and stand ready to provide additional public health and medical support."

HHS has pre-positioned two 15-person health and medical task force teams from its National Disaster Medical System, as well as a 13-person incident management team and two pharmacists to assist with the response in Florida.

"These teams are highly trained and ready to respond if, when, and where they may be needed following the storm," HHS Assistant Secretary for Preparedness and Response Dawn O’Connell said.

Florida Gov. Ron DeSantis declared a state of emergency on Saturday. That declaration was approved by President Joe Biden on Sunday.

The National Hurricane Center has issued a hurricane warning for the Tampa Bay area just after its 5 p.m. advisory for Hurricane Ian.

The hurricane, currently a Category 2, is forecast to strengthen before it slows down as it approaches land. It is then expected to hover off the coast of Tampa from Wednesday into Thursday before making landfall.

A hurricane watch has also been issued for Big Bend, Florida, near the panhandle, and tropical storm warnings are in effect for much of southwest Florida.

Tropical storm watches are in effect for Orlando toward the northeast portion of the state, from Fort Pierce to Jacksonville.

-ABC News' Melissa Griffin

Lee County Sheriff Carmine Marceno told ABC News' "Good Morning America" that Hurricane Ian was very unpredictable, with officials tracking the storm every minute and they didn't know where it would hit.

"This is a life-changing event for all of us. We tracked that storm up the coast of Florida, it was very unpredictable," Marceno said.

He added, "We didn't know where it would hit. I can tell you it came into Lee County strong and it was slow moving."

Marceno said there were fatalities, but he didn't yet know the exact number.

Marceno said they are already assessing the area, but the whole area is "crushed" and people are trapped. Marceno said they have thousands of 911 calls that they are currently answering.

"We still cannot access many of the people that are in need," Marceno said. "It's a real, real rough road ahead."

In Volusia County, on Florida's east coast, authorities said one person has been confirmed dead. A 72-year-old man who went outside to drain his pool was swept away and found dead in a canal behind the house.