The Weather : Clouds Will Stay Around for Weekend

Overcast skies that cooled and darkened much of Southern California through early afternoon Thursday are expected to return this morning and continue through much of the weekend.

Matt Sullivan, meteorologist-spokesman for Earth Environment Service, a private forecasting firm based in San Francisco, saw it as the beginning of a minor cooling trend.

“The trough of low pressure in the upper atmosphere that has been aligned along the coast,” he said, “is beginning to move inland, and that means a continued onshore flow of cool and moist marine air. The low clouds and fog that are morning staples of Southern California at this time of year will be thicker and will last longer.”

Civic Center High Was 76

The high temperature at Los Angeles Civic Center on Thursday was 76 degrees, with relative humidity ranging from 69% to 90%. And the National Weather Service predicted a high in the mid-70s again today, with clouds and some drizzle in the early morning hours.

Beach temperatures are expected to stay in the low 70s, with surf running two to three feet in most places, a sea breeze rising to 18 m.p.h. in the afternoon and water temperature in the upper 60s.

Weekend yachtsmen can expect calm mornings, but forecasters said the wind should increase west-southwest to 15 knots on a two-foot sea and three-foot southwest swell for inshore waters from Point Conception to the Mexican border, while those who venture farther from shore could find a 15-knot west-to-northwest wind on a three-foot sea and five-foot swell.

Southern California mountains are expecting fog, low clouds and drizzle on their coastal slopes, clearing in the afternoon with resort highs reaching the upper 70s. Forecasters said the Sierra should be mostly sunny, except for partial cloudiness with a chance of showers from Lake Tahoe northward.

Fair weather is predicted for the deserts, with west-to-southwest winds rising to 30 m.p.h. in the northern desert most afternoons. Northern desert temperatures are expected to reach 100 degrees or more, with the southern deserts about five degrees warmer.