Vulnerable islands were evacuated and mainland schools were closed Tuesday as erratic Hurricane Ophelia strengthened and wobbled closer to land with a threat of flooding rain.

The National Hurricane Center upgraded the storm's status to a hurricane early Tuesday evening, saying maximum sustained winds had reached 75 mph, with higher gusts. The storm was graded a Category 1 hurricane, but the center said further strengthening was possible in the hours ahead.

A hurricane warning extended from the South Santee River in South Carolina northward to Oregon Inlet at Pamlico Sound in North Carolina, meaning hurricane conditions were expected within 24 hours. A hurricane watch and a tropical storm warning were in effect from the Oregon Inlet north to the North Carolina-Virginia border and southward from the South Santee River to Edisto Beach in South Carolina.

After taunting coastal residents for days, the storm appeared ready to move ashore, as heavy rain battered South Carolina's northern coast and the beaches of southeastern North Carolina.

Bobby Kane was forced to abandon his Waveland, Miss., house two weeks ago and has no hesitation about leaving his temporary home in Surfside Beach, S.C. Kane is one of hundreds of Hurricane Katrina evacuees who sought refuge along the Carolina coast and are watching another major weather system threaten their shelter -- and their peace of mind.

Kane, 65, and his wife, Judith Burke, 58, their two dogs and a cat, and seven other relatives have been staying south of Myrtle Beach for a week, sleeping on air mattresses.

"I don't think God would have spared us from Katrina to lose us to Ophelia," Burke said. But if Ophelia approaches, "I'll be out of here. I'm not taking any chances."

Unlike Hurricane Katrina's devastating charge at the Gulf Coast, the week-old Ophelia had been following a meandering path, making predictions of its landfall difficult. The hurricane center's latest forecasts showed it running along the coast, then veering through Pamlico Sound, crossing the Outer Banks and heading back out to sea.

Its slow movement -- 4 mph as of 5:30 p.m. -- meant heavy rain could linger over land, possibly causing serious flooding. The hurricane center said 15 inches of rain was possible in parts of eastern North Carolina.

At least six North Carolina counties ordered mandatory evacuations of some areas, and seven others had voluntary evacuations.

Along the exposed Outer Banks chain, all residents and visitors were ordered to evacuate Hatteras Island on Tuesday, visitors had been ordered off Ocracoke Island and the National Park Service closed the Cape Hatteras Lighthouse and the Wright Brothers National Memorial in Kill Devil Hills.

Schools were closed in several coastal counties in both North and South Carolina, while classes were canceled at the University of North Carolina at Wilmington and East Carolina University in Greenville.

With power outages expected, North Carolina utilities recalled workers they had sent to the Gulf Coast region after Hurricane Katrina. North Carolina Gov. Mike Easley (D) said coastal residents should be prepared to go without power for a few days.

"The beaches we expect to take a real beating," Easley said. "The bottom line is we're definitely going to get flooding, not just on the coast but in low-lying areas as the rivers swell from the storm surge itself."

South Carolina Gov. Mark Sanford (R) had called for a voluntary evacuation of oceanfront and riverside areas in the northeastern part of his state. Virginia Gov. Mark R. Warner (D) declared a state of emergency. National Guard troops were on duty in parts of North Carolina and Virginia.

A surfer was missing along the South Carolina coast, but the search had been suspended because of the rough sea.

Surf churned up by Ophelia smacks Johnnie Mercer's Pier at Wrightsville Beach, N.C. The storm was forecast to be near Wrightsville Beach on Wednesday.