Washington shivered and shuddered through another spine-chilling slice of life below the freezing level yesterday, and weather forecasters predicted that today is likely to bring snow rather than relief.

Snow already on the ground is partially responsible for Washington's protracted period of subfreezing temperatures in which the mercury has risen above the 32-degree mark on only one day since Feb. 8, a Natioal Weather Service forecaster said.

With the city's blanket of snow reflecting heat away from the ground, significantly warmer temperatures are unlikely until the snow melts, forecaster Harold Hess said.

On the other hand, he added, little snow is likely to melt before the weather becomes warmer. "It's a chicken-and-egg kind of thing," Hess observed, referring to the old conundrum.

Meanwhile, by early today the temperature at Dulles Airport had fallen to 12 degrees below zero.

As of late last night, forecasters were still uncertain of the likely extent or precise arrival time of the snow. It might begain as soon as this evening and continue through tomorrow morning, Hess said.

He appeared more certain of tomorrow's high temperature -- about 28 degrees. That would be well above yesterday's high of only 22, recorded at 12:01 a.m.

In addition to the area's snow cover the consistently cold weather was attributed to the steady southward flow of Arctic air, which for days has clamped most of the eastern United States in the grip of subnormally low temperatures.

Boston recorded an overnight low temperature of zero yesterday. In Chicago, the reading was one degree, in Philadelphia three and in New York four. The overnight low for Pittsburgh was 10 degrees below zero.

In Washington, the overnight low was eight degrees, recorded at 6:20 a.m. at National Airport.

By 9 p.m. last night, the temperature was falling again to that level, after reaching an afternoon high of 18 at 2:45 p.m.

With winds that gusted to 29 miles an hour yesterday, the wind chill factor dropped under 20 degrees below zero, a figure as numbing to the imagination as it is to flesh.

Confronted with such conditions, fewer than the expected number of shoppers showed up for the first day of George Washington's Birthday sales. Firemen were kept busy turning off the flow of water to homes with frozen pipes. Mortality increased among birds deprived of their normal food supply.

Much of the Chesapeake Bay and substantial stretches of the Potomac River have frozen. The Coast Guard used tugs yesterday to break the ice for freighters pushing through the Chesapeake and Delaware canal toward Baltimore.

The Reflecting Pool at the foot of the Lincoln Memorial is safe for ice skating today, the National Park Service reported. The C&O canal also was approved for skating.

Zoo animals, particularly those that spend winter afternoons outdoors "are having a hard time," said William A. Xanten, curator of mammals at the National Zoological Park.

Animals such as elephants, rhinoceroses and hippopotamuses are confined to indoor quarters. There is no indication of fretfulness, Xanten said. "I think they know it's cold out."

Police departments reported fewer calls than usual. "Usually in weather like this, crime goes way down," said Prince Georgehs County police spokesman John Hoxie, who explained that "no one, including the criminal element, is outside."

Nevertheless indefatigable and heavily bundled, visitors continued to arrive at the Lincoln Memorial. They came despite the fact that yesterday was the 16th of the month's first 17 days on which daily temperature fell below normal.

In addition to standard inquiries about the city, the monument and the nation's 16th president, visitors asked park service technician Ellen Gloo, stationed at the memorial, to tell them the temperature.

They also asked, "Aren't you cold?" and "How can you stand to work here?"

Enduring or perhaps enjoying the rigors of a month in which the average high temperature has been 15.5 degrees below the normal 16, joggers continued to puff past the memorial on their windswept ways.

Car, pipe and furnace repairmen said they were getting fewer calls than might be expected. Weather forecaster Charles Chilton attributed that to Washingtonians' constantly increasing experience in coping with cold weather.

"People have learned how to protect their pipes," said a Washington Suburban Sanitary Commission spokesman. Such means, he said, include insulation, wind shielding, use of electric coils and supplementary heat.

He said hair dryers often can thaw frozen pipes, and he warned that use of an open flame is dangerous.

The ice itself foiled one Montgomery County couple's plan to flee it. Ready to leave for Florida, they found their car's locks frozen. After finally opening the doors, they began cleaning the windshield. That was when the man slipped and broke his collarbone.