Milton has rapidly strengthened to become a Category 5 hurricane as it heads towards population centres in the US state of Florida, including Tampa and Orlando.
The hurricane threatens a dangerous storm surge in Tampa Bay and sets the stage for potential mass evacuations less than two weeks after the catastrophic Hurricane Helene swamped the coastline.
Milton had maximum sustained winds of 160mph over the southern Gulf of Mexico, the US National Hurricane Centre in Miami said.
That path would largely spare other south-eastern US states ravaged by Helene, which caused widespread damage from northern Florida to the Appalachian Mountains and killed at least 230 people.
Forecasters warned of a possible eight to 12-foot storm surge (2.4 to 3.6 metres) in Tampa Bay and said flash and river flooding could result from five to 10 inches (13 to 25cm) of rain in mainland Florida and the Keys, with as much as 15 inches (38cm) in places.
The Tampa Bay area is still cleaning up extensive damage from Helene and its powerful surge. Twelve people died, with the worst damage along a 20-mile string of barrier islands from St Petersburg to Clearwater.
Florida governor Ron DeSantis said on Monday that it was imperative that messes from Helene be cleaned up ahead of Milton’s arrival so they do not become dangerous flying projectiles.
“We don’t have time for bureaucracy and red tape,” Mr DeSantis said. “We have to get the job done.”
“Yes, this stinks. We know that, and it comes on the heels of where a lot of us are still recovering from Hurricane Helene,” Sheriff Chad Chronister said. “But if you safeguard your families, you will be alive.”
“If you remain there, you could die and my men and women could die trying to rescue you,” Hillsborough Fire Rescue Chief Jason Dougherty said. “Help them by leaving.”
“This is the real deal here with Milton,” Tampa mayor Jane Castor said at a news conference. “If you want to take on Mother Nature, she wins 100% of the time.”
Milton’s centre was about 150 miles (240km) west of Progreso, Mexico, and about 735 miles (1,185km) southwest of Tampa on Monday morning, moving east-southeast at 8mph (13kph), according to the hurricane centre.
On beaches in the St Pete Beach area, where Helene’s storm surge flooded homes and businesses, lifeguards removed beach chairs and other items on Monday that could become projectiles in hurricane winds.
Schools including the University of Central Florida in Orlando announced they would close in the middle of the week, and Walt Disney World said it was monitoring the hurricane but operating normally for the time being.
All road tolls were suspended in western central Florida. The St Pete-Clearwater International Airport said it would close after the last flight Tuesday, and Tampa International Airport said it planned to halt airline and cargo flights starting on Tuesday morning.