Skip to content

Strong, dry winds hit California

Red Flag Warnings CaliforniaWith a forecast for strong Santa Ana winds that are predicted to gust above 65 mph in some areas firefighters and utility companies are making preparations — some to prevent fires and others to suppress them after they start.

Sunday night Pacific Gas and Electric turned off the power for 59,000 of their customers in areas of six Northern California counties — Amador, Calaveras, El Dorado, Lake, Napa, and Sonoma — reasoning  that their electricity infrastructure is vulnerable to the strong winds, which could ignite fires.

PG&E power shut off traffic signalsPG&E sent out a tweet asking residents of those areas to “Please be safe at intersections where traffic signals are out”.

In the south part of the state Southern California Edison warned 130,000 customers they may shut off power in parts of Ventura, Los Angeles, Orange and San Bernardino counties.

The National Weather Service has issued Red Flag Warnings for large areas of southern California through 10 p.m. Tuesday for 25 to 45 mph winds that could gust in some areas at 65 or 75 mph with humidities ranging from 4 to 12 percent.

Wind gusts at 9 a.m. PDT October 15, 2018 California
Wind gusts at 9 a.m. PDT October 15, 2018.

Several Red Flag Warnings are in effect in areas of Northern California until mid-day Monday or 1 a.m. Tuesday for 15 to 25 mph winds gusting at 35 to 45 mph along with very low humidities.

Many areas in Southern California from Los Angeles to San Diego received over half an inch of rain Friday which could have an effect on the spread of wildfires until the fine fuels are dried by the winds.

Red Flag Warnings precipitation california
Red Flag Warnings in California for October 15 with an overlay showing precipitation that occurred October 12-13, 2018.

On Sunday the moisture content of ten-hour time lag fuels in those areas was still relatively high, at 11 to 15 percent.  Ten-hour fuels include vegetation 0.25-inch to 1-inch in diameter.

10-hour time lag fuel moisture
Moisture content on October 14 of 10-hour time lag fuels (less than one-half inch in diameter).

But Northern California was a different story with 3 to 4 percent moisture content. These numbers will be lower at both ends of the state after a day or two of strong, dry winds.

Comments

More in Reports