Florida Gov. Ron DeSantis urged people ordered to evacuate to leave now if they haven’t already.

“If you are in an evacuation zone and you’ve been directed to evacuate, particularly if you’re in a low-lying area or coastal area, in that Big Bend region, now’s the time to do it,” DeSantis said during a press briefing. “If you wait much longer, by the time we get in further into tonight, the weather is going to start getting nastier and nastier.”

Kevin Guthrie, director of the Florida Division of Emergency Management, said he is “greatly concerned about Cedar Key,” where he expects a storm surge of 12 to 13 feet.

DeSantis said that 28 counties in Florida now have some kind of evacuation order — including Alachua County, home to Gainesville. Over 50 shelters have been set up throughout the state, he said.

Idalia is expected to intensify to a Category 3 hurricane overnight, according to the National Hurricane Center, which warned in its latest advisory that “life-threatening” storm surge could reach 10 to 15 feet in some of the Big Bend area.

The impact of the eyewall is expected to arrive sometime Wednesday morning, DeSantis said.