Last Updated Jul 2, 2014 11:45 PM EDT
As one of the year's busiest travel weekends approaches, so does another visitor: Tropical Storm Arthur, expected to grow into a hurricane by the Fourth of July and hit most harshly at North Carolina's Outer Banks, a popular getaway spot of thin barrier islands along the shore.
The first named storm of the Atlantic hurricane season prompted a hurricane warning for a wide swath of the North Carolina coast and spurred authorities to order a mandatory evacuation for visitors to the Outer Banks' Hatteras Island as of 5 a.m. Thursday. Residents also were advised to leave the island. A voluntary evacuation was announced for the Outer Banks' Ocracoke Island, accessible only by ferry.
Officials, hotel owners and would-be vacationers as far north as New England were also carefully watching forecasts. The storm was enough of a concern that officials in Boston decided to move the annual Boston Pops July 4 concert and fireworks show up by a day because of potential heavy rain Friday night. And rip tides were a threat as far north as New Jersey.
The Outer Banks will be especially vulnerable, forecasters said. As word of the mandatory evacuation on Hatteras Island spread, a steady stream of cars, trailers and recreational vehicles began rolling north on North Carolina Highway 12, a two-lane road that is the only way to the mainland other than ferries to the south. Home to the famous Cape Hatteras Lighthouse, the island is just a narrow spit of land. Twice in recent years, storm-driven waves have sliced N.C. 12, rendering it impassable.
One of the visitors who planned to leave Thursday was Gary Reinhardt, 63, of Sarasota, Florida.
"I'm worried about the road. It took way too long to get here," he said, a reference to the 2 1/2 hours it took him and his wife, Lori Reinhardt, to get onto the island last Sunday in normal summertime traffic, when no storms were in sight.
Late Wednesday, the storm was about 160 miles southeast of Charleston, South Carolina, and about 380 miles southwest of Cape Hatteras, North Carolina. It was moving north about 8 mph with maximum sustained winds of 70 mph.
The National Hurricane Center predicted it would grow to a Category 1 hurricane with sustained winds of at least 74 mph sometime Thursday.
Astronaut Reid Wiseman aboard the International Space Station took a photo of the storm as he passed overhead, noting it "looks mean."
Forecasters said Arthur is likely to stay just offshore, passing northeastern Florida Wednesday night and moving parallel to the Southeastern U.S. coast on Thursday.
The worst of the storm should occur at Cape Hatteras about dawn Friday, with 3 to 5 inches of rain and sustained winds up to 85 mph, said Tony Saavedra, a meteorologist at the National Weather Service.
North Carolina Gov. Pat McCrory declared a state of emergency for 25 coastal and adjoining counties and advised residents and visitors alike to let caution be their guide.
"Don't put your stupid hat on," he said, as he urged surfers and swimmers not to get in the water regardless of how enticing the waves might be.
"Our major goal is to ensure that no lives are lost during this upcoming storm," including those of emergency workers, McCrory said.
In Boston, officials said the July 4 Boston Pops concert was being rescheduled to Thursday, what appears to be the best of two potential bad weather days - although it could also be canceled on that day if the weather is bad enough, said State Police Col. Timothy Alben.
The performance takes place in the Hatch Shell along the Charles River Esplanade. Fireworks are set off from barges on the river. Thousands of people usually attend.
Fireworks displays were also being postponed in several other Massachusetts and Rhode Island communities.
Arthur is expected to pass well east of New England over the weekend. Still, many Boston business owners feared that rainy weather could turn their biggest money-making weekend into a washout.
"You only have May through October, and once you lose a weekend it really kills you," Jeff Campanelli, manager of Bean Town Trolley, told CBS Boston.
Alison Nolan of Boston Harbor Cruises said she was afraid rain Friday would force the cancellation of popular whale-watching trips and many harbor boat rides.