Rain, Cool Weather Predicted for Area

A cold Pacific storm is expected to invade Southern California before dawn today, dropping up to an inch and a half of rain in the Los Angeles Basin and as much as a foot of snow in local mountains.

Forecasters said the snow level could dip as low as 4,000 feet in some areas, perhaps affecting holiday weekend traffic on Interstate 5 near Gorman and Interstate 15 in the Cajon Pass.

Scattered thundershowers are possible as the storm front passes through the metropolitan area this morning, according to Guy Pearson, a meteorologist with WeatherData Inc., a firm that provides forecasts for The Times.

The intensity of the storm will depend on how much moisture from a large pool of damp air to the south is swept into the Los Angeles Basin by winds circulating around the storm, forecasters said.

The heaviest showers are expected to fall in communities along the south-facing slopes of the Tehachapi, San Gabriel and San Bernardino mountains.

Snow amounts will vary widely, Pearson said, with 4 to 8 inches at most mountain resort levels and up to a foot on the tallest peaks.

Temperatures in metropolitan Los Angeles County should be generally on the cool side today, with highs in the mid-50s to mid-60s after overnight lows from the mid-40s to the mid-50s.

The rain and snow should start tapering off about nightfall. As skies begin to clear before dawn on Sunday, temperatures should get even colder, with overnight readings as low as the mid-30s in some of the coldest parts of the Los Angeles Basin.

Pearson said Sunday will be partly cloudy, with gusty winds below canyons and passes. A second storm will begin moving inland from the Pacific on Monday, but he said it probably will pass well to the north, with little or no rain expected in Los Angeles.

As of nightfall Friday, the total precipitation at the Civic Center for the season--which runs from July 1 through June 30--was .58 of an inch. The normal total by Nov. 27 is 2.61 inches.

Meteorologists say intensifying La Nina conditions, the counterpoint to last year’s drenching El Nino, mean that Southern California probably will have normal or below-normal precipitation this season.