Santa Ana winds knocking out power, adding to wildfire risk out west

The Santa Ana winds blew strong in California on Monday, knocking down power lines and trees, and killing one person.

Utility companies and firefighters have been on high alert as powerful winds combined with extremely dry vegetation and very dry air. Southern California has been in a severe drought almost all year, according to the U.S. Drought Monitor.

In Tustin, a woman was killed when a eucalyptus tree fell onto her car outside her apartment complex, crushing both the vehicle and a carport. Tustin Police Lt. Robert Wright said the woman was exiting the complex when it happened.

Wind speeds on Monday hit 82 mph in Fremont Canyon just east of the Orange County Zoo, and gusts topping 60 mph were reported in numerous Southern California locations. The National Weather Service (NWS) has had Red Flag warnings in place, effective until this evening, for the Los Angeles and San Diego metro areas, as well as portions of northern California.

Ryan Kittell, a meteorologist with the NWS Los Angeles/Oxnard office, told FreightWaves that Red Flag Warnings are reserved the most extreme conditions, when the environment (due to wind, humidity, and fuel conditions) is such that if a fire were to start it could grow very rapidly and behave erratically. From talking to fuel experts, Kittrell also said that a fire can spread at 10 mph under such conditions, with embers being blown three miles downstream. He added that the air dried out very quickly from a humidity of 60%-80% on Saturday to 10% or less Sunday and Monday.

 Fire risk outlook for Tuesday, October 16, 2018.  (Source: NOAA/NWS)
Fire risk outlook for Tuesday, October 16, 2018. (Source: NOAA/NWS)

Santa Anas develop when winds from the Nevada desert blow westward toward California. When the air flows over the mountains it compresses, warms up, and dries out. Then the air moves through canyons which act as wind tunnels, often increasing wind speeds to more than 50 mph. These winds can quickly spread fires across hundreds or thousand of acres. 

Crews are already fighting several small grass and brush fires across California, and a larger one in Mariposa County, just outside Yosemite National Park. 

“Winds don’t start fires, but if one ignites, the winds certainly are going to promote that fire and make it difficult to fight,” Bonnie Bartling, a weather specialist with the National Weather Service (NWS) told the L.A. Times

These are other wind gusts recorded on Monday:

• 67 mph at Malibu Hills
• 63 mph at Cal State-San Bernardino
• 48 mph at Bob Hope Airport in Burbank (BUR) 

Airport officials said planes at Los Angeles International (LAX) usually take off over the ocean, into the wind. On Monday pilots had to ascend toward the east instead. 

The winds also whipped through Dodger Stadium, where the Dodgers played the Milwaukee Brewers in Game 3 of the National League Championship Series. 

Southern California Edison crews were dealing with downed power lines across the coverage area of 50,000 square miles. About 61,000 customers were without power by late Monday morning, said Mary Ann Milbourn, a SoCal Edison spokeswoman. La Cañada High School and St. Francis High School both announced late Monday that they would be closed Tuesday due to power outages. 

The extreme fire-weather conditions prompted Pacific Gas & Electric to shut off power to tens of thousands of customers in Northern California ahead of the strong winds. It was done intentionally to reduce the risk of wildfires sparked by lines that break during extreme winds. Many of the state’s most destructive blazes,  including several last year, were attributed to power lines, according to this report

“It’s really a last resort for us,” said PG&E spokesman Paul Doherty. Other utility companies have shut off power in these situations, but this is the first time PG&E has elected to shut off power because of high winds. 

Winds aren’t expected to be as strong today as on Monday, according to Kittell – 30-50 mph – but are still a concern. Still, PG&E tweeted this morning “We will restore all customers today”, and this report shows power is back in all of southern California, but not in the northern part of the state.

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Nick Austin, Director of Weather Analytics and Senior Meteorologist

In his 17 years of weather forecasting experience, Nick worked on air at WBBJ-TV and WRCB-TV, including time spent doing weather analysis and field reporting. He received his Bachelor of Science in Meteorology from Florida State University as well as a Bachelor of Science in Management from Georgia Institute of Technology. Nick is also a member of the American Meteorological Society and National Weather Association. As a member of the weather team at WBBJ-TV in Jackson, Tennessee, Nick was nominated for a Mid-South Emmy for live coverage of a major tornado outbreak in 2008. As part of the weather team at WRCB-TV in Chattanooga, Tennessee, Nick shared the Chattanooga Times-Free Press Best of the Best award for “Best Weather Team” for eight consecutive years. Nick earned his National Weather Association Broadcasting Seal in 2005.