More rain fell here in a few hours yesterday afternoon and last night than in the entire drought-stricken month of April, and forecasters said that they expected as much as an inch might be recorded in the metropolitan area before the skies go dry again today.

But the long-range signs are that yesterday's showers, which provided welcome precipitation to the moisture-starved middle Atlantic states, may be only an aberration. Little rain is in the forecast for the next 10 days.

By 10 o'clock last night, with the rain expected to continue for hours, the official measuring station at National Aiport had recorded .37 inches.

The total recorded rainfall for all of April was 0.05 inches.

It was too early last night to assess the effect of yesterday's showers on Washington's water-starved lawns. But glistening umbrellas quickly sprouted on the streets as pedestrians adjusted quickly to the unexpected -- rainfall.

Rain fell on only two days last month, and then in minuscule amounts.

But the rainfall, modest as it was, generated dangerous driving conditions in some parts of the metropolitan area.

Maryland state police said that during the long dry spell, oil and grime had soaked into the surfaces of streets and roadways, and yesterday's precipitation floated the oil to the surface, but did not fall in quantities that would wash it away, making for slickened driving surfaces.

Most motorists, aware of the phenomenon, drove more slowly than usual, according to police dispatchers in Montgomery and Prince George's counties.

But others ignored the danger and several were involved in traffic accidents, most of them of a minor nature.

National Weather Service forecaster Joe Bocchieri said the rain here resulted from a low pressure system that brought precipitation to the Midwest earlier in the week. Although the eastward movement of the storm was slow, it finally arrived to furnish the break in one of the area's record dry spells.