Thousands without power as 'Diablo winds' create fire threat in California
The position of a ridge of high pressure is expected to create what are known as the “Diablo winds," which blow out of the north and east. Farther south, the winds are known as “Santa Ana winds."
Dangerous Diablo Winds spark wildfire threat in northern California
Gusty winds and low humidity have triggered Fire Weather Warnings across central and northern California.
SACRAMENTO, Calif. – PG&E, the Golden State’s largest utility provider, preemptively shut off power to thousands of customers this week to help reduce the threat of wildfires.
A wind event began Thursday and is expected to last into the early weekend. Combined with power lines and dry vegetation, the winds present a fire threat.
PG&E began shutting power off to customers Thursday afternoon. As of Thursday evening, about 13,000 of their customers had their power shut off for safety, with about 7,000 more potentially having their power shut off, as well.
The company said they will continue to monitor the weather conditions to gauge the potential impact of the winds.
FILE: PG&E employee works to deactivate power lines in order to repair others knocked down by a trees due to high winds in Oakland, Calif.
(Jessica Christian/The San Francisco Chronicle / FOX Weather)
PG&E initially warned upwards of 32,000 customers in Northern and Central California could expect shutoffs this week.
The power outages are part of the company's Public Safety Power Shutoff program (PSPS), which is designed to reduce the risk of electrical equipment starting fires.
According to the FOX Forecast Center, the combination of northerly to easterly winds and low relative humidity values has caused local National Weather Service offices to issue fire weather alerts such as a Fire Weather Watch and Fire Weather Warning for millions of Californians.
Wind gusts reaching 45 mph are expected in the Valley and Foothills of California, while gusts reaching 55 mph are expected in the Delta, according to the NWS. They noted that the strongest winds are expected on Friday.
The winds are commonly referred to as "Diablo winds" and can gust to greater than 55 mph.
Diablo winds occur both during the spring and fall but are usually more impactful during the autumn months when vegetation is typically drier from the summer season.
Farther south, the phenomenon is known as "Santa Ana winds," which are also expected to impact parts of San Bernardino, Riverside, San Diego and Imperial counties by the end of the week.
This map illustrates the typical weather setup that causes Santa Ana winds in California during the fall.
(FOX Weather)
CALIFORNIA COMPANY USING ANIMALS TO REDUCE WILDFIRE DANGERS
A dry start to autumn has caused California to venture into drought conditions, with about 14% of the state officially in a drought and 75% considered to be unusually dry.
Drying vegetation increases the likelihood of wildfires because it essentially acts as fuel for fires to rapidly spread.
(FOX Weather)
According to the FOX Forecast Center, humidity levels are expected to increase, and winds will decrease throughout much of Northern California by the second half of the weekend, but the threat of increased wildfire activity will likely remain for Southern California into next week.
The height of Southern California’s fire season typically continues into November due in part to Santa Ana winds, whereas activity in the northern part of the state tends to decrease a bit earlier during the fall.