A hurricane approaching the Bahamas and with the potential to strike the United States strengthened late Wednesday, forecasters said.
Hurricane Joaquin grew to a Category 3 hurricane Wednesday night, as maximum sustained winds increased to 115 mph from 85 mph over the course of the day, the National Weather Service said. Joaquin was about 90 miles east of San Salvador as of 11 p.m. ET and it was moving to the southwest at around 6 mph.
Hurricane warnings were expanded for parts of the Bahamas Wednesday as the storm approached the islands, and the governors of Virginia and North Carolina were urging residents to prepare for the possibility of flooding.
The hurricane was expected to pass near the islands of San Salvador, Cat Island, Eleuthera and Rum Cay on Thursday, close enough that it could bring tropical-storm-force winds, storm surges, coastal flooding and 5-10 inches of rain, said Geoffrey Greene, a senior forecaster with the Bahamas Meteorology Department.
"We would be very concerned about them," Greene said of the eastern islands.
The American forecast model predicts Joaquin will veer northwestward, ramming into Virginia, Maryland or North Carolina this weekend. But the European forecast model suggests Joaquin will avoid the East Coast entirely.
Disney Cruise Line rerouted a ship headed toward Nassau in anticipation of the hurricane, and said the vessel would go to Key West instead. Another Disney ship out of Port Canaveral will have its itinerary rerouted. Carnival Cruise Lines also modified the routes of two cruises, the company said.
Virginia was bracing for up to 10 inches of rain total Thursday and Friday. Virginia Gov. Terry McAuliffe on Wednesday declared a state of emergency, and North Carolina Gov. Pat McCrory ordered state agencies to prepare for floods.
"I cannot stress enough the imperative for Virginians to focus on the rainstorms that are headed our way tomorrow and Friday, well before Hurricane Joaquin could potentially impact Virginia," McAuliffe said. "The forecast of up to 10 inches of rain in areas across Virginia could result in floods, power outages and a serious threat to life and property."
The path of the potential hurricane into the U.S. depends in part on whether a separate storm system forming over the southeastern U.S. is close enough to Joaquin to pull it towards the East Coast, Kevin Roth, senior meteorologist at The Weather Channel, said.
If the southeastern storm is farther away, closer to Alabama, the storm system could instead push the hurricane away from the East Coast and out to sea, he said.
"Anybody from, I would say, Charleston, South Carolina, all the way up through the northern East Coast — you've got to really pay attention," Roth said.
Even if the hurricane misses the East Coast as the European model suggests, Joaquin is expected to inject tropical moisture into the area — and that could lead to more rain in parts of Virginia and North Carolina that have already been saturated, increasing the risk of floods.
In Kitty Hawk, North Carolina, officials were hoping sandbags protect the town if the hurricane strikes the Outer Banks. "It could be some resemblance of what Sandy offered us, and we've learned some lessons from that," Kitty Hawk Mayor Gary Perry told NBC station WAVY.
On Eleuthera, a narrow strip to the north of Cat Island in the Bahamas, people were removing stray coconuts and other debris from their yards and putting up storm shutters in blustery winds, Chris Gosling, who runs a volunteer ambulance service on the island, told The Associated Press.
"People don't panic too much. There's nothing you can do about it. If it comes, it comes and you do what you can," said Gosling, who has lived on Eleuthera for 27 years. "If the forecast is right we will get some wind and rain and it will go back out to sea."
This article originally appeared on NBCNews.com.