The storm became a Cat 1 hurricane early Monday morning and is expected to continue to strengthen until it reaches the US coast.

HAVANA, Cuba – Cuban authorities have suspended classes in Pinar del Río province and said they will begin evacuations on Monday as Hurricane Yan is forecast to reach the western part of the island on its way to Florida.

A hurricane warning was in effect for Grand Cayman and the Cuban provinces of Isla de Juventud, Pinar del Río and Artemisa. The U.S. National Hurricane Center said Ian should reach far western Cuba late Monday or early Tuesday, hitting near the country’s most famous tobacco fields. It could become a strong hurricane on Tuesday.

Cuban state media Granma reported that authorities will begin evacuating people from vulnerable areas early Monday in the far western province of Pinar del Río. Classes there are suspended.

At 2 a.m. EDT Monday, Yang was moving northwest at 13 mph (20 kph), about 115 miles (185 kilometers) south-southwest of Grand Cayman, according to the center. The maximum sustained wind reached 110 kilometers per hour.

Meanwhile, Florida residents kept a close eye on Ian as it thundered ominously across the Caribbean en route to the state.

Governor Ron DeSantis declared a state of emergency throughout Florida and urged residents to prepare for a thunderstorm to hit large parts of the state with heavy rains, strong winds and rising seas.

Forecasters still aren’t sure exactly where Ian might make landfall, and current models are targeting it toward the west coast of Florida or the melee regions, he said.

“We will continue to monitor the progress of this storm. But it’s really important to highlight the degree of uncertainty that’s still there,” DeSantis said at a news conference Sunday, warning that “even if you’re not necessarily in the center of the storm’s path, there’s going to be a pretty broad impact across the state.”

Flash and urban flooding is possible in the Florida Keys and peninsular Florida through midweek, and heavy rainfall is possible in northern Florida, southeast Florida, and the southeastern United States later this week.

The agency placed a tropical storm watch over the lower Florida Keys on Sunday night and advised Floridians to have hurricane plans and monitoring updates path of storm development.

President Joe Biden, too declared a state of emergency allowing the Department of Homeland Security and the Federal Emergency Management Agency (FEMA) to coordinate disaster relief and provide assistance to protect lives and property. The president postponed a trip to Florida planned for September 27 because of the storm.

John Congialosi, the center’s senior hurricane specialist in Miami, said in an interview Sunday that it was unclear exactly where in Florida Ian would hit the hardest. Residents should start preparing, including stocking up for potential power outages, he said.

“It’s hard to say, stay tuned, but it’s the right message right now,” Cangialosi said. “But for those in Florida, there’s still time to prepare. I’m not telling you to close the shutters or anything like that, but it’s still time to get your supplies.

Local media in Florida are reporting a rush for water, generators and other supplies in some areas where residents have moved to stock up on supplies ahead of the storm.

Associated Press writer Julie Walker contributed to this report from New York.