Inching along at a painstaking 1 mph, Hurricane Dorian tore through islands near the Bahamas Monday, causing massive devastation, as it continued to move slowly but unpredictably towards the Florida coastline.

The National Hurricane Center in Miami said Dorian, downgraded slightly to a Category 4 storm, was moving its way toward Palm Beach, Florida, as of Monday afternoon, packing wind gusts of up to 190 mph and prompting storm surges of between 18 and 23 feet above normal high-tide levels. 

"A slow westward to west-northwestward motion is forecast during the next day or so, followed by a gradual turn toward the northwest and north. On this track, the core of extremely dangerous Hurricane Dorian will continue to pound Grand Bahama Island through much of today and tonight," the NHC said in a statement on it website.

"The hurricane will move dangerously close to the Florida east coast tonight through Wednesday evening and then move dangerously close to the Georgia and South Carolina coasts on Wednesday night and Thursday."

"Catastrophic" Damage in Bahamas

The extent of the storm's destruction on the islands began to emerge on Monday, with the International Red Cross estimating some 13,000 homes may have been severely damaged or destroyed. In the Abaco Islands, where the storm first made landfall, extensive flooding likely contaminated wells with saltwater, the organization said.

The islands sustained "catastrophic damage," said Darren Henfield, the Bahamas minister of foreign affairs, in a video from the Abaco Islands posted on ZNS Bahamas, which is operated by a state-owned broadcasting company. He said there were reports of casualties, which search-and-rescue parties would seek to confirm once it was safe to venture out.

Florida Senator Rick Scott, the state's former Governor, said he was worried that the storm's unusual path would give residents a false sense of security.

"My biggest concern (is) that people are going to think we're off the hook," he told CNN on Sunday. "We are not off the hook.

"Plus, we're still going to get storm surge," he added. "We're going to get lots of rain the closer it gets to Florida. We're getting to get more rain which can cause flooding. So take it seriously. Overprepare, don't under-prepare."

Cancelled Flights, Closed Airports

Airports and airlines reacted on Monday to the latest storm forecasts, with flight-tracking website FlightAware saying 1,088 flights within, into, or out of the U.S. on Monday had been canceled. More than 500 of the flights were due to take off from airports in Florida. 

Fort Lauderdale-Hollywood International said it would close at noon until further notice, with Palm Beach International also shuttering, though Miami International planned to remain open.

Airlines expect knock-on delays and cancellations to continue through the week, with waivers on flight changes and caps on ticket prices expanded to more airports in Georgia and North and South Carolina.