Cooler Weather, Higher Humidity Aid Firefighters

Just as the Santa Ana winds, which had gusted up to 50 m.p.h., and bone-dry humidity exacerbated firefighting efforts in Southern California earlier this week, cooler temperatures and higher humidity have become a major ally in the battle against the blazes.

Readings dropped from highs in the 90s early in the week to the upper 70s on Thursday in the Los Angeles area. And the Los Angeles Civic Center recorded a peak humidity reading of 76% during the day--a virtual wet blanket, when compared to the 10% and lower humidity levels of Monday and Tuesday.

Today’s Civic Center high should reach 77 with an overnight low of 60.

And that temperature range should prevail throughout most of Southern California, with highs in the upper 70s and lows in the middle to upper 50s, the National Weather Service said.

The cooling trend is expected to continue through the weekend as a flow of moist marine air brings late-night and early-morning low clouds.

Deep Clouds

Circulating coastal air masses weakened a bit Thursday, but not before deepening the marine layer to nearly 3,000 feet, according to the weather service. A weak upper-level high-pressure system will provide mostly clear skies as the cloud cover burns off by late morning.

Warmer days are expected in the southern deserts, with highs in the 80s and lows in the 50s. Readings will be a few degrees cooler in the northern deserts.

Temperatures in the mountains will range from highs in the upper 60s to lows in the 30s.

Weekend beach temperatures will range from the upper 50s to the 70s, with a surf of one to three feet at 12-second intervals expected.

Coastal waters from Southern California to Ensenada will experience light, variable winds from 10 to 15 knots, with swells from one to two feet.

Low clouds and fog will line the San Francisco Bay Area over the weekend, with a possibility of drizzles at night. But clearing mid-afternoon skies will see temperatures reach the 60s along the coast, with inland highs in the 80s.

The Sacramento and San Joaquin valleys will have fair skies with high temperatures between the mid-70s and mid-80s, and some light winds, while the northern Sierra Nevada will be fair and sunny with clouds increasing in the north later today.

Southern Nevada will be sunny and warm with highs from the mid-70s to the upper 80s.

Western Arizona will have partly cloudy skies over the weekend with some chance of showers. Temperatures will range from the upper 50s in the mountains to the middle 80s in the deserts.