Slanting down from low-hanging clouds, often in torrents too great for swollen streams and soaked ground to absorb, rain fell for much of the day here yesterday, sending high water surging onto streets and roads around the area.

As of 7 o'clock last night, 2.42 of rain had been recorded at the official measuring station at National Airport since the storm began Saturday night.

In many dry seasons, an entire month goes by with less rain recorded here.

The National Weather Service said last night that rain would continue to fall on and off through much of today, before ending about the time of the evening rush hour.

However, the heaviest downpours apparently had ended in the metropolitan area by 7 last night. "Most of the rain from here on should be light," said forecaster Charles Chilton.

A flash flood wraning that had been issued for the area in the day was canceled at 7 p.m. In the section of Maryland and Virginia west of the Blue Ridge the rain combined with cold air trapped in the mountain to form sheets of ice on trepe limbs and power lines.

Trees toppled and lines snapped, delaying traffic and cutting off electric power.

"Most of Warren County (Va.) is without electricity," the county sheriff's office there reported last night, and power was also reported interruted at higher elevations in Washington, Garrett and Allegany counties in Maryland.

In the Washington metropolitan area, the effects of the storm were often of brief duration as water rose, forcing the closing of roads and streets, and then subsided, permitting police to remove hastily erected barricades.

On some well-drained streets, the main effect of the daylong rain seemed to be the serpentine streaks of light produced by the reflection of automobile headlamps on damp and glistening pavements.

Elsewhere, autos threw up huge sprays of water as they rolled through puddles that quickly accumulated where drains were suddenly overtaxed by the downpour.

In Prince George's County, police reported the closing of at least eight roads or intersections, and in Fairfax County police reported the same number.

In Fairfax County a bridge on Collingwood Road near Karl Road was reported washed away, U.S. Park Police said Hains Point and many points on the George Washington Parkway were closed for a time.