Updated

Residents up and down the East Coast boarded up windows Monday and the military ordered ships and planes out of harm's way as Hurricane Isabel (search) churned toward land with 120 mph winds.

Forecasters said Isabel could hit anywhere from North Carolina (search) to New Jersey late Thursday or early Friday.

Even though the storm was still at least three days away, coastal residents and military installations were already taking precautions.

• Map: Isabel's Path (NOAA)

Vice Adm. Gary Roughead (search), commander of the U.S. Second Fleet, ordered 40 ships and submarines based in the Norfolk, Va., area to head to sea Tuesday to avoid being battered against piers by high winds.

About 30 vessels, including two aircraft carriers, that cannot be moved were "being battened down as tight as possible, tightening all the hatches," said Lt. Scott McIlnay, a Navy spokesman.

Also Tuesday, the Air Force will fly about 60 planes from Langley Air Force Base in Hampton to Grissom Air Force Base in Indiana, said Capt. Jeff Glenn, spokesman for the 1st Fighter Wing at Langley.

Virginia Gov. Mark R. Warner declared a state of emergency, putting National Guardsmen, state police and transportation crews on full alert.

At Taylor's Do-It Center hardware store in Norfolk, Va., assistant manager George Wolf said he was swamped with customers as soon as the doors opened at 8 a.m., and large batteries and flashlights were sold out.

"You would have thought we were giving stuff away," Wolf said. "I just sold my last 30 sheets of plywood."

Stevens Hardware in Annapolis, Md., ran out of batteries, flashlights, lamp oil, tape, camping lamps, can openers, plastic sheeting and candles before noon Monday, said manager Mike Stevens.

"A lot of people are calling for generators. I don't think there's a generator in Annapolis to be bought," Stevens said.

Officials in Baltimore canceled leave for staffers in the police, fire, transportation and public works departments.

"Right now we are preparing ... as if the storm is coming right at us," Mayor Martin O'Malley said.

At 11 p.m. EDT, Isabel was centered about 710 miles southeast of Cape Hatteras, and was moving northwest at about 7 mph.

Isabel weakened Monday to a Category 3 storm with sustained wind blowing at 120 mph with higher gusts, the National Hurricane Center said. On Sunday, Isabel's top wind hit 160 mph, making it a Category 5 storm.

"It has been weakening," said Eric Blake, a meteorologist with the Miami-based center. "That's good for the people of the East Coast, but by no means should anyone let their guard down. Hurricanes are notorious for gaining strength as they cross the Gulfstream. Even if it weakens to a Category 2 hurricane, there's still a lot of potential for danger."

Isabel is the first major hurricane to threaten the mid-Atlantic since Floyd wreaked havoc on the East Coast in September 1999, leading to 56 deaths.

All 921 residents of Ocracoke Island in North Carolina's vulnerable Outer Banks were ordered to begin evacuating Monday afternoon. A line quickly formed at the ferry dock.

In other islands on the outer banks, residents started boarding windows, moving their vessels inland and checking up on their generators.

Kay Burros and Anne Troutman decided it was time to check their 5,000-watt home generator at Surf City.

"We've had it about 3 years, but haven't cranked it up in a while. It's been so long, we have to read the instructions," Burros said.

Up the coast in Dover, Del., B.J. Whittaker snapped up 10 sheets of plywood at a Lowe's home improvement store. "I can't do anything if the roof blows off, but I can keep my windows from getting broken," he said.

Emergency officials in central and eastern Pennsylvania started planning for the growing likelihood that Isabel or its remnants would bring high wind and heavy rain into the state by Friday morning.

Pennsylvania already has had a wetter than normal summer, and hundreds of people were evacuated Monday in West Chester, Pa., west of Philadelphia, because of extensive flooding caused by more than 8 inches of rain overnight.

In New Jersey, residents of Bound Brook remembered with dread the $70 million in damage caused by the remnants of Floyd as it swept through in September 1999.

Flood waters 10 feet high nearly put Phyllis Pournaras' diner out of business. But she and others rebuilt with the help of government disaster relief -- and the faith that they'd already been through the worst.

"If it floods again, we're done," Pournaras said. "You just don't have the heart to do that again."

Officials at the Miss America pageant were getting backup power generators and said Saturday's pageant in Atlantic City, N.J., which is to be telecast live, could be postponed if conditions become unsafe.

Meanwhile, a storm swirling over the Pacific Ocean south of Mexico's Baja California peninsula reached hurricane strength Monday afternoon, the National Hurricane Center in Miami reported.

Hurricane Linda's maximum sustained winds reached 75 mph, with the storm centered 290 miles southwest of the southern tip of Baja California. The hurricane was moving northwest at 12 mph and was expected to strengthen slightly overnight.