Hundreds of airline passengers were stranded or delayed for hours at National Airport last night and electricity was cut off to thousands of Washington area homes as turbulent thunderstorms swept across much of the Eastern seaboard in advance of a cool front.

A number of flights scheduled to leave the airport last night were canceled after they could not get clearance to take off before the imposition of National's 10 p.m. antinoise curfew.

Stranded passengers, attempting to book other flights or alternate transportation, as well as retrieve their baggage and find overnight accommodations, filled the airport terminal for hours after activity there normally subsides.

"It is one of our worst nights," said a harried employe at an airline ticket counter.

"It was a colossal mess," an Eastern Airlines spokesman said of the weather-snarled air traffic situation that he said forced many Washington-bound flights to land at other airports.

The spokesman said flights scheduled to leave National last night for Syracuse, Atlanta and the Tampa-Fort Myers area, carrying a total of 300 passengers, were all canceled by the curfew. He said at least one of the planes had left the boarding gate and had to be brought back.

In addition, the spokesman said, the 8 p.m. and 9 p.m. shuttle flights to New York were canceled earlier. Newark Airport was reported closed for part of the night, and delays of up to three hours were reported there and at the other airports in the New York area.

A United Airlines reservation agent said three United flights scheduled to leave National last night were canceled, and a US Air employe said at least three of that line's flights also were canceled.

All eight TWA flights finally left, an airline spokesman said, but one was delayed almost four hours.

Most of the homes that lost electricity were in the southern part of Alexandria and the adjoining section of Fairfax County where 12,700 Virginia Electric & Power Co. customers were affected when lightning struck a substation, a Vepco spokesman said. Power was also knocked out for a time to about 2,200 homes in Maryland and the District of Columbia. About 1,000 of them were in the Gaithersburg area, according to Potomac Electric Power Co.

By 11 p.m. the storm had brought .83 inches of rain to the official measuring station at National Airport the National Weather Service said.