SoCal fire weather threatens “particularly dangerous situation,” forecasters say

Los Angeles, Ventura counties and Santa Barbara counties will face especially high risks of wildfires as tens of thousands of residents face possible power shutoffs — with forecasters announcing a rare weather advisory that’s typically issued only once every few years, according to the National Weather Service (NWS). 
With extremely low humidity and strong winds, which can lead to fires sparking and quickly spreading, NWS has issued a Particularly Dangerous Situation (PDS) Red Flag Warning, which warns of the potential for “extreme fire behavior and rapid growth” as well as knocked down trees and power outages by utilities trying to prevent wildfires that the electrical system can cause.
“The NWS issues a PDS Red Flag Warning to alert emergency officials and the public to an ongoing or imminent fire weather pattern that is especially dangerous,” NWS said in a statement Tuesday, warning of potentially “extreme” and “volatile” conditions. 
Southern California Edison said more than 55,000 customers could have their power shut off while planned outages were already scheduled for 1,113 customers by 10 p.m., By that time, 2,230 customers had already had their power shut off.
The Los Angeles Department of Water and Power has also announced the possibility of outages, saying that planned shutoffs could be carried out and there could be also be accidental cuts to electricity with strong winds taking down power lines. 
The PDS warning is in effect from 9 a.m. Wednesday until 4 p.m. Wednesday in the San Fernando Valley, Santa Clarita Valley, the valleys of central and southeastern Ventura County and Ventura County’s inland coast all the way to the beaches from Malibu to Oxnard. Another PDS red flag warning is in effect from 9 a.m. Wednesday to 9 a.m. Thursday for the southern Ventura County mountains and the San Gabriel, Santa Susana and Santa Monica Mountains.
The south coast of Santa Barbara county is expected to see similar, but less severe, conditions while there are also red flag warnings being issued in other parts of Southern California, including areas of the Inland Empire and Orange and San Diego counties. 
“Any new fires in the Red Flag Warning area — and especially the PDS Red Flag Warning area — will have rapid fire spread, extreme fire behavior, and long range spotting,” the weather advisory states. 
Santa Ana winds will be especially strong and widespread in parts of LA and Ventura counties, with the most powerful and potentially damaging gusts expected to be up to 60 to 80 mph in the counties’ mountains and foothills from Wednesday morning to Wednesday evening, forecasters said. Some of the San Gabriel Mountains are expected to see isolated gusts of 80 to 100 mph.
Meanwhile, the Malibu coast and Ventura County coastal plain, among other coastal and valley areas of LA and Ventura counties, could see “damaging” gusts of between 50 and 70 mph, NWS said. Humidity levels in these areas is expected to decline to between 8 to 15 percent, conditions that forecasters say will likely continue into Thursday and Friday.
Southern California’s fire season usually runs from late spring, around May and June, through October and November. However, wildfires that break out later into the season can prove worse due to the differences in terrain and weather, according to the Western Fire Chiefs Association (WFCA).   
“While there may be fewer fires in September and October, the fires that do occur are far more destructive and burn through many more acres,” the WFCA website states. “This explosive effect is due to a combination of dry vegetation from hot summer weather, and intense dry winds that blow through the state during fall.”