Thunderstorms Are Possible as Moist Baja Air Arrives

An occasional thunderstorm and showers may add variety to San Diego County’s weather picture during the next few days as the remnants of tropical storm Hilda move northwest from the Baja California coast.

A flash flood watch for mountain areas was issued Sunday night, and gusty winds, hail, lightning, showers and thunderstorms are forecast for the mountains and deserts today and Tuesday, the National Weather Service said.

There also will be a 30% chance of thundershowers in San Diego’s coastal and beach areas today, increasing to 40% tonight, the weather service said.

The increased humidity and periodic storms, generally in the mountains, are typical of a summer monsoon pattern, said Steve Burback, a meteorologist with WeatherData Inc., which provides weather forecasts to The Times.

“Actually, this is quite normal” for Southern California in August, he said, particularly in the mountains and over some areas of the desert.

Trace amounts of rain fell Sunday at Lindbergh Field and the National Weather Service issued flash-flood warnings for Sunday evening in the mountain areas of San Diego and Imperial Counties.

Cuyamaca Park received .92 of an inch of rain Sunday, while Julian received .39; Borrego, .20, and and Mt. Laguna, .16 inches of rain, the weather service said.

“The coolness has been atypical. It really has been cloudy, and it looks like we are going to get more clouds,” said Richard Spitt, a forecaster with the National Weather Service.

Rains caused the closing of County Route S2 at three points near Borrego Springs, including at the 44-mile marker, where the road will be closed for at least two weeks because it washed out, the San Diego County Sheriff’s Department reported.

Other than occasional mudslides in the East County area, no damage was reported, deputies said.

“We’ll have higher humidity for the next couple of days, and the tropical remains of Hilda will be through here by Tuesday night, and we’ll get back to a sunnier pattern in the middle of the week,” Spitt said.

What Southern Californians traditionally think of as normal summer weather--including at least a week or so of 100-degree-plus heat--is nowhere in sight.

“The days are pretty much numbered for regular summer weather,” said Burback.

No 100-degree sizzlers are in sight for the next 30 days, he said, forecasting instead temperatures in the 70s along the coast and into the 90s inland.