The relentless winter of 1979 pounded the Washington area again yesterday -- this time with a treacherous mix of sleet, snow and freezing rain that sheathed roads in a new glaze of ice and slowed rush hour traffic in many places.

Though not as severe as the snowstorm that immobilized traffic on Monday, yesterday's sleet and stinging snow triggered scores of accidents during the evening rush hour, especially in the suburbs, and sent unsuspecting pedestrians tumbling on iceslick sidewalks.

"It's been a mess," said Fairfax County Cpl. Robert Howard, whose 80 incoming telephone lines were lit up with emergency calls for much of the afternoon.

There are "wrecks everywhere" on interstates 95, 66, 395 and the Capital Beltway, said a Virginia State Police dispatcher.

The sleet and freezing rain combined with continuing subnormal temperatures to make the first half of February one of the coldest and most miserable in recent years.

The temperature has not been above the freezing mark of 32 degrees in a week and has dipped below 10 degrees on four of the last six nights. Normal lows at this time of the year are in the upper 20s. Normal high temperatures in the daytime are in the 40s.

To make things worse, the National Weather Service says extreme cold and more snow are probably on the way this weekend. Frigid arctic air is expected to start pouring into the Washington area this afternoon, pushing temperatures into the low teens late tonight and shoving aside a weak warm front that had come close to bringing some relief here yesterday.

Forecasters say there is also a chance of more snow on Sunday and Monday.

As storm clouds darkened the city yesterday and the tiny wind-driven snow particles intensified, thousands of downtown workers left early and began the slippery exodus from the city.

The Chesapeake and Potomac Telephone Co.'s recorded weather forecast number was swamped with calls. The line was frequently busy -- it can take up to 1,900 simultaneous calls according to C&P officials -- as anxious commuters tried to figure out how to beat the storm.

The D.C. Transportation Department's emergency snow center said it put out scores of road crews spreading salt and other abrasives on major streets in the early afternoon and attempted to keep slippery streets to a minimum. An emergency center spokesman said most the rush hour traffic appeared to have cleared the city without serious accidents or pileups by 6:45 p.m.

"It was slow, but it moved," said Al Perkins of the emergency center.

The problems appeared to greater in the suburbs. Police reported minor accidents along most commuter routes. Many cars slid off the icy veneer of roadways and were seen abandoned in ditches. Several cars skidded down into the median strip of the Dulles International Airport access road and could not get out again.

"People are just wrecking everywhere," said a Virginia State Police dispatcher. "Every time a snowflake falls, it happens in this area. People just don't know how to drive in the snow. Instead of going slow, they take off."

The unrelenting cold has also created thick ice floes in the upper Chesapeake Bay and prompted the Coast Guard to require escorts for vessels hauling oil cargoes. Large ocean-going ships have been able to reach the port of Baltimore with no trouble so far, a Coast Guard spokesman said.

He said ice ranging from four to 24 inches thick covers much of the upper bay.

The sleety drizzle and continuing cold came as a warm front, which had promised some relief for the area, stalled 150 miles from Washington over southwestern Virginia and eastern West Virginia yesterday and refused to budge.

The stationary front produced some odd meteorological results: freezing temperatures north of the front and balmy, almost springlike temperatures south of it. The thermometer never rose above 23 degrees here during the day, but it was 55 degrees in Danville, Va., at midday, 63 degrees at Raleigh-Durham (N.C.) Airport, 47 degrees in Bristol, Tenn., and 57 degrees in London, Ky.

Also, some of that warm air spilled over the stationary front and was carried by southwest winds all the way to Washington -- but on top of the colder, heavier air at ground level where it could no good. Thus, at Dulles International Airport at 7 a.m. yesterday, when the ground temperature was 18 degrees, National Weather Service observers recorded temperatures of 35 to 36 degrees at 4,800 feet altitude.

Forecasters gave a bleak outlook for the weekend as well. Lingering snow flurries in the area this morning should give way to windy and much colder conditions this afternoon with temperatures falling into the teens late tonight.

Saturday should be clear and cold with the thermometer reaching only the mid-20s, according to the weather service. On Sunday, temperatures should moderate somewhat but with increasing cloudiness and a chance of snow late in the day. There is a chance of still more snow Monday with daytime temperatures in the 30s.