Strong Santa Ana winds are causing dangerous fire conditions to set up across Southern California during the first half of the week. The National Weather Service (NWS) office in Los Angeles has issued a rare Particularly Dangerous Situation (PDS) alert for the critical fire danger.
(MORE: What Are Santa Ana Winds?)
“Due to the expected long duration of dangerous fire weather conditions and critically dry fuels, there is the increasing potential for any new ignitions to have very rapid fire spread and extreme fire behavior,” The NWS office in Los Angeles said in their forecast discussion, adding, “As a result, there is the increasing threat for fire weather conditions to rival other historical fires in recent times including the Mountain and Thomas Fires.”
Areas in highest danger: The strongest winds and highest risk will extend from the mountains northeast of the Santa Clarita Valley to the eastern valleys of Ventura County and run south through the southern coastal section of Ventura County. The Calabasas, western Santa Monica and Malibu areas will also be greatly affected by these winds, according to the NWS.
Red flag warnings are in place from mid-morning Monday through Wednesday for areas just east of San Luis Obispo and stretch as far south as the Mexico border. The PDS is for Los Angeles and Ventura counties, where winds will be the strongest, until Tuesday afternoon.
Forecast Timing: Winds are expected to pick up by the afternoon Monday and continue at peak intensity through the overnight hours and into Tuesday. During the day on Tuesday, wind gusts could be as high as 60 to 80 mph, which could bring down trees and power lines, causing outages and dangerous travel conditions.
Humidity levels in the single digits will allow easy fire ignitions and rapidly spreading fires.
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What’s causing this: A strong area of high pressure is building across the Great Basin. This will bring an east-to-northeast wind through Southern California. As the winds are forced to squeeze through the mountain passes and canyons, they accelerate, bringing dangerously high winds.
When these winds are combined with dry conditions and low humidity levels, high fire danger will persist.
Most Santa Ana wind events begin in the morning, but this time, it will begin during the afternoon hours.
Forecasters urged residents to stay vigilant. Make sure you have a way to receive warnings and listen to instructions from officials regarding any fires that occur. Take quick action should evacuations be ordered because any wildfires that form will spread rapidly.
Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world’s biggest weather and climate stories for the last two decades.