Warm, Humid Afternoons to Continue Through Weekend

Overcast mornings and warm, muggy afternoons that eased Southern California into summer this week will continue through the coming weekend, thanks to a high pressure system squatting offshore in the Pacific Ocean, forecasters said Thursday.

Matt Sullivan, meteorologist-spokesman for Earth Environment Service, a private forecasting firm based in San Francisco, said the only predictable change during the next few days might be an increase in thundershower activity over the Colorado River Valley.

The National Weather Service agreed, and explained that tropical air is moving in at upper levels from northwest Mexico, causing an unstable condition that can be expected to continue for several days.

The high temperature at Los Angeles Civic Center on Thursday was 82 degrees, with relative humidity ranging from 49% to 84%, and forecasters said it should be a degree or two warmer--and a little more humid--as the weekend continues.

Beachgoers can expect cool, overcast mornings with the clouds finally burning away after noon, and an afternoon sea breeze rising to 16 m.p.h. Surf is expected to run three to four feet on most beaches from Zuma Beach to San Diego, with water temperature reaching about 65 degrees each afternoon.

Yachtsmen who stay inshore can expect west to southwest winds rising to 15 knots each afternoon with two- to three-foot seas most afternoons from Point Conception to the Mexican border, while those venturing farther out can expect slightly less wind force--10 to 13 knots, with a southwest swell rising to seven feet.

Southern California mountain visitors can expect some afternoon cloudiness with a very small chance of thunderstorms at resort levels, forecasters said. Afternoon high temperatures will be in the upper 80s, while afternoon and evening thunderstorms are predicted for most parts of the Sierra through Sunday.

Northern desert temperatures are expected to range from the mid-90s to 106 degrees each afternoon, with the southern desert about five degrees warmer.