Washington area residents taped windows, bought candles and stocked up on canned goods last night as they prepared for Hurricane Gloria and the wind and rainstorms it is expected to bring to the metropolitan area.

The National Weather Service predicted that the Washington area could be pelted today by heavy rains and lashed by winds of up to 50 mph, with gusts reaching higher as the center of the storm draws abreast of the area on its northward track.

Householders "should tie down everything they can," and morning rush hour motorists should be "very, very careful," said weather service specialist Joseph Cefaratti.

Winds were expected to reach their peak between daybreak and noon. Forecaster Charlie Chilton said he expected about two to three inches of rain here.

Most of it was expected to fall in sudden heavy downpours that raised the possibility of flooding in low-lying areas.

A hurricane warning was issued for bay and coastal areas of Virginia, Maryland and Delaware, although forecasters said late last night that the northward track of the storm could not yet be predicted accurately.

Yesterday afternoon, under a blanket of gray clouds that appeared to heighten anticipation of the storm's arrival and to minimize the fact that Gloria's center was then about 200 miles south of Cape Hatteras, N.C., area residents went with varying degrees of urgency about their preparations.

In St. Mary's, Calvert and Anne Arundel counties, residents left homes in low-lying areas and went to emergency shelters.

Prince George's County schools will be closed today. Officials of other school systems in the immediate area said they would decide this morning whether to open. A liberal leave policy was put into effect for Prince George's County government workers.

In anticipation of streets littered with fallen tree limbs and branches, Fairfax County police officers were told to come to work today armed with chain saws. Workers tied down planking on a wall of scaffolding on the West Front of the Capitol.

Customers had "fear in their eyes," said Mike Rowe, a manager at the Safeway store at 10350 Willard Way in Fairfax City. And in Giant Food stores, they had "candles in their hands," said a spokeswoman for the chain.

Flashlights, bottled water, batteries and bread all proved to be in demand at stores throughout the metropolitan area. Polyethylene sheets were big sellers at Quince Orchard Hardware in Gaithersburg.

At the Hechinger Store on Wisconsin Avenue NW, customers buying flashlights and candles also got advice from cashier Sidney Smith, who is studying environmental science at the University of the District of Columbia. Basically, he said he advised closing windows and "tying down everything that needs to be tied down."

At Brandywine Auto Parts in Prince George's County, employes were tying down automobile front ends, which were stacked on an outdoor rack. In many places around the area, people searched their property for loose items that might be hurled about by high winds.

"Right now we're out looking for trash cans or anything loose," said Jim Gordon of Herb Gordon's Auto World on Rte. 29 near White Oak.

The Metro authority, which said last night it planned to provide service as usual today, said through a spokeswoman that it was stockpiling sandbags to protect some transit facilities from flooding and securing "everything that could possibly be moved by the wind."

Airplanes were being tied down at the Butler Aviation terminal at National Airport. Sump pumps also sold briskly, and in the District, public works crews cleaned out catch basins as a flood prevention measure at 13 flood-prone intersections.

The Potomac Electric Power Co. went on the alert, placing employes on 12-hour shifts and taking the standard precautions for a severe storm, a spokeswoman said.

Sailors were warned by the Boat Owners Association of the United States that boats should be carefully moored, with all seacocks closed and all vents and hatches sealed.

Most important, association Vice President Bill Oakerson said, "Don't stay aboard during the storm."

Local jurisdictions monitored weather reports and began opening emergency command centers.

Some Washingtonians, however, maintained a wait-and-see posture. At one Channel Home Center, store assistant manager Alan Pavik said business had increased only slightly.

Storm preparations in coastal regions had an air of greater immediacy. By 8 p.m. almost every shop, hotel and restaurant along Ocean City's seaside strip was shut down and boarded up. The voluntary evacuation of most of the resort's residents was described by police as quick and orderly. In Virginia Beach, Va., 3,000 people were in emergency shelters by 9 o'clock last night.

Weather service forecaster Chilton indicated last night that the strength of the winds and amounts of rainfall recorded here today would depend on the northward track taken by the storm.

The closer the storm's center comes to Washington, he said, the higher the winds and the heavier the rain, which could possibly amount to as much as six inches.

The farther east the storm remained, he said, the more moderate would be the wind and rain. Late last night, he said there was a growing likelihood that the storm would remain east of the Chesapeake.