Power might be shut off to tens of thousands of Southern California customers Tuesday due to warm temperatures and wind gusts as the region enters one of the most dangerous times of the year for wildfires.
Southern California Edison is considering Public Safety Power Shutoffs for parts of the utilities service area. The shutoffs could affect about 9,000 customers in Los Angeles County, 35,000 customers in Riverside County, 42,000 customers in San Bernardino County and 3,500 customers in Kern County. About 240 customers in Santa Barbara County are subject to potential shutoffs.
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No power shutoffs were in effect early Tuesday.
Utility companies consider power shutoffs when weather conditions like strong winds and warm temperatures increase the threat of a wildfire. Power lines can fall and spark, providing the ignition for a fast moving wildfire, especially when brush dries out during summer months.
Shutoffs are most likely for customers who live in high fire risk areas, determined by the California Public Utilities Commission. Customers outside the risk zones also can be affected due to how the electrical grid is connected.
High temperatures and high humidity are in Tuesday's forecast. Heat advisories are in effect for several communities. Some areas will sizzle in triple-digit heat with highs running about 10 degrees above normal.
Santa Ana winds, a key factor in the spread of California wildfires, are expected to develop. The winds will be weak to moderate with gusts up to 45 mph in LA County mountains.
"Santa Ana winds are coming back," said NBC4 forecaster Shanna Mendiola. "We have a pretty good wind starting up at 11 o'clock today and lasting through the afternoon. That wind dries out the air and heats us up."
The notorious winds, produced by surface high pressure over the Great Basin squeezing air down through canyons and passes in Southern California's mountain ranges, are common in the fall and have a long history of fanning destructive wildfires in the region.
Fall is historically one of the most dangerous times of the year for wildfires in California. Seven of the state's 10-most destructive wildfires occurred in October -- many fueled by monster winds, including Santa Ana gusts.
Through Sept. 15, more than 4,170 fires have burned about 38,600 acres in California. That's a dramatic decrease from the same period last year, when 4,500 fires burned an astounding 626,600 acres. California's five-year average through mid-September is 4,487 fires and 322,109 acres burned.