Category 5 Hurricane Milton is expected to double its wind field by the time it makes landfall in the U.S. late Wednesday or early Thursday, bringing a storm surge of up to 15 feet along a low-lying stretch of the Florida coast, including the cities of Tampa, St. Petersburg and Sarasota.

Described as the “storm of a century,” with sustained winds still reaching 155 mph (257 km/h), Milton turned northeast about 300 miles (480 km) southwest of Tampa overnight, targeting densely populated and very vulnerable communities. It is expected to weaken slightly as it makes landfall in Category 4 with sustained winds of about 130 mph.

“Milton has the potential to be one of the most destructive hurricanes on record for west-central Florida,” the National Hurricane Center warned.

In an 8 a.m. update, Florida Governor Ron DeSantis said it was not clear exactly where the eye of the storm would make landfall, but that the impact would be “broader than that… absolutely every place on the West Coast of Florida could have major consequences. storm surge.”

“If you’re in a one-story house that gets hit by a 15-foot storm surge, which means water comes in immediately, you have nowhere to go,” said Tampa Mayor Jane Castor.

“So when you’re in it, that’s basically the coffin you’re in.”

Authorities have issued mandatory evacuation orders in 11 Florida counties, with a combined population of about 5.9 million people, saying anyone who chooses to stay behind should fend for themselves.

Before Helene struck, residents left behind were encouraged to write their names and social security numbers on their bodies so they could be more easily identified post-mortem.

Current forecasts say the wave is expected to hit Fort Myers Beach, an area still recovering from Hurricane Ian two years ago, which destroyed a causeway to remote islands.

The area was also hit by Hurricane Helene two weeks ago, raising concerns that discarded furniture, appliances and debris from that storm will become projectiles in the next storm. DeSantis said the state deployed more than 300 dump trucks that removed 1,300 loads of debris.

One resident said he saw bull sharks swimming behind Helene in the flooded streets.

Wherever exactly Milton makes landfall, damage is expected to be extensive, with seawater flowing inland through coastal channels. Cody Fritz of the National Hurricane Center’s storm surge team told NBC News: “The west coast of Florida is very susceptible to storm surge. It doesn’t take much to push water over dry land. It is extremely vulnerable.”

Kara Doran, a US geological survey scientist, said the risk of permanent shoreline change “cannot be overestimated as I believe communities are more vulnerable to the impacts of this storm due to the erosion that has recently occurred from Helene”.

Residents who tried to leave faced gas shortages and gridlocked roads. There are few hotels to shelter in and there are no flights out of the area. Ashley Khrais, a resident of Holiday, Florida, just inland from the coast, told NBC: “It seems very, very scary, but there is no way to leave.”

Mark Prompakdee, 71, a resident of a trailer park near St. Petersburg, said he planned to ride out the storm in a minivan parked higher up at a high school. “They say, ‘Get out of here,’” he said. “Where?”

But many people seemed to have heeded the warnings. “If there’s any good news here, we visited Fort Myers beach yesterday (and) it looks like people heeded those warnings,” NBC News’ Jay Gray said.

Efforts to protect property with sandbags and by boarding up windows were made “with the knowledge that this could be the most powerful storm that many in this area have ever seen, and they have seen plenty,” Gray said.

The National Weather Service warned that when Milton made landfall Wednesday, “conditions will be favorable for tornado development even well away from the expected landfall.”

With area airports closed, operators said they would not reopen until damage had been assessed. A spokesperson for Tampa International Airport told Scripps News that security was critical to their operations and that it could not serve as a shelter for travelers stuck there because it is in an evacuation zone.