By 11 a.m. yesterday Isabel's top winds were around 105 mph. That brought it down from a Category 3 to a Category 2 storm on the Saffir-Simpson scale of 1 to 5 that measures hurricanes' destructive power, the National Hurricane Center said.

The center issued a hurricane watch, alerting residents to expect hurricane conditions within 36 hours, for the coast from Little River Inlet in South Carolina north to Chincoteague, Virginia, including the Chesapeake Bay south of North Beach, Maryland.

The storm's predicted course had jogged slightly to the left, said Lt. Dave Roberts, a Navy meteorologist with the center. That path takes it further away from the Chesapeake Bay and would make it less of a threat to the Washington area.

A Category 2 storm can badly damage mobile homes, fell trees and damage roofs, doors and windows, as well as producing storm surges on the coast of up to 8 feet. While some further weakening was expected Yesterday, Isabel, once a rare Category 5 hurricane, could strengthen again before hitting land, forecasters said.

Homeland Security Secretary Tom Ridge warned that the hurricane could cause "significant damage and loss of life."

"We encourage families and communities who appear to be in the projected path of the hurricane to take the necessary precautions," he said on NBC's "Today" show.

Isabel's first encounter with land could take it over the Outer Banks, a low-lying island chain jutting out into the Atlantic that is a popular vacation spot and home to 55,000 permanent residents.

Officials in Dare County, which includes Hatteras Island, issued a mandatory evacuation order for the 75,000 people in the low-lying county. There were about 15,000 people on Hatteras Island.

Ocracoke Island, a tiny barrier island southwest of Cape Hatteras and reachable only by boat or plane, was also under a mandatory evacuation order.

STATE OF EMERGENCY

Virginia Gov. Mark Warner declared a state of emergency to enable the state to mobilize workers to prepare for the storm, which is expected to cause flooding in a region already saturated with months of above-normal ranifall.

Forecasters said the storm was already bringing large ocean swells and dangerous surf conditions along the mid-Atlantic coast.

"It is a large storm. Carolina residents will feel the effects as early as late Wednesday," said hurricane center meteorologist Krissy Williams.

The U.S. Navy began moving 40 ships and submarines based in Hampton Roads, Virginia, out to sea to avoid damage and warplanes at several bases were also being moved.

Residents of areas in the storm's possible track hurried to hardware stores and supermarkets to stock up on supplies from flashlights and batteries to plywood and bottled water.

At 11 a.m. EDT, Isabel's center was 600 miles south-southeast of Cape Hatteras, North Carolina, at latitude 27.4 north and longitude 71.2 west. It was heading northwest at 8 mph.