Southland May Get Some Showers in Wake of Desert Thunderstorms

Isolated thundershowers struck Southern California deserts and a few sprinkles dotted Los Angeles on Wednesday afternoon ahead of a slow-moving storm system that is expected to bring the possibility of more general shower activity to the area today and Friday.

Patricia Cooper, a meteorologist for WeatherData Inc., which provides forecasts for The Times, said there’s about a 15% to 20% chance of showers in the Southland today, increasing to a 30% to 40% chance tonight and Friday.

Rainfall amounts, where measurable, are expected to range from about a quarter of an inch in some of the foothill communities to as much as half an inch at some mountain resorts.

WeatherData’s Mike Smith said Southern California’s weather is being provided by what the meteorologists call a “cut-off.” The winds that blow around the Northern Hemisphere are called the westerlies, Smith said, and nine times out of 10 a low-pressure system is carried along with them. But, every once in a while, one of those systems gets cut off from the so-called mother wind, the meteorologists said, and that is what has happened this week.

“It’s just spinning like a little top by itself,” Cooper said of the low-pressure system, “and it will pass over Southern California (today).”

Like a balloon without a string, Smith said, the unattached low-pressure system is expected to continue its south to southwesterly drift by weekend.

As it does so, Cooper said, the weather should be cooler, with highs in Orange County expected to reach the mid- to upper-60s today.

Wednesday’s high in Orange County was 75 degrees in Santa Ana, with a low of 56 degrees recorded in El Toro, according to the National Weather Service.

Sporadically heavy showers and lightning strikes were reported in Palm Springs, Daggett and Beaumont on Wednesday afternoon as the storm system started moving inland from the Pacific, but there were no reports of flooding.