NAPLES, Fla. (WWLP/AP Modified) – Hurricane Ian’s most damaging winds began hitting Florida’s southwest coast Wednesday, lashing the state with heavy rain and pushing a devastating storm surge after strengthening to the threshold of the most dangerous Category 5 status.

Fueled by warm waters in the Gulf of Mexico, Ian grew to a catastrophic Category 4 hurricane overnight with top winds of 155 mph (250 kph), according to the National Hurricane Center. The storm trudged on a track that would have it making landfall north of the heavily populated Fort Myers area, which forecasters said could be inundated by a storm surge of up to 18 feet (5.5 meters).

“This is going to be a nasty nasty day, two days,” Florida Gov. Ron DeSantis said, stressing that people in Ian’s path along the coast should rush to the safest possible shelter and stay there.

Ian’s center was about 25 miles (40 kilometers) west of Fort Myers at 2 p.m. Wednesday, as it churned toward toward the coast at 9 mph (15 kph). The storm was expected to spend a day or more crawling across the Florida peninsula, dumping flooding rains of 12 to 18 inches (30 to 45 centimeters) across a broad area, including Tampa, Orlando and Jacksonville.

Off the coast on Sanibel Island near Fort Myers, swirling water covered residential streets and was halfway up mailbox posts by mid-morning. Seawater rushed out of Tampa Bay, leaving parts of the muddy bottom exposed, and waves crashed over the end of a wooden pier at Naples.

22News viewers sent in videos from Naples on what it is like there right now. As seen in the videos, people’s homes and streets are flooded and there are very intense winds.

Florida residents rushed ahead of the impact to board up their homes, stash precious belongings on upper floors and join long lines of cars leaving the shore.

Parts of Georgia and South Carolina also could see flooding rains and some coastal surge into Saturday. Georgia Gov. Brian Kemp preemptively declared an emergency, ordering 500 National Guard troops onto standby.