The highly anticipated Diablo winds roared through Wine Country and parts of the Bay Area early Sunday, prompting Governor Gavin Newsom to declare a statewide emergency.
The strongest winds were recorded at 93 mph in the hills north of Healdsburg, one of the handful of towns now threatened by the Kincade fire.
Peak gusts overnight reached 87 mph at Mt. Saint Helena, 61 mph at Mount Diablo, 53 mph in Petaluma and 52 mph in the Santa Cruz mountains.
?️The winds definitely came in overnight with a peak gust of 93 mph at Healdsburg Hills North. Here is a complete list of gusts around the region https://t.co/5b76IpN6FB #cawx #cafire pic.twitter.com/lyS8EB9JTl— NWS Bay Area (@NWSBayArea) October 27, 2019
The powerful winds are part of the phenomena called the Diablo Winds. Instead of coming from the shore, these winds blow out to sea. The reversal in wind direction, which typically occurs in the fall, causes extremely dry air conditions.
In Sonoma County, the winds fueled the Kincade Fire to grow overnight by more than 4,000 acres, now spreading across a total of 30,000 acres.
A few hours ago, Governor Gavin Newsom declared a statewide emergency due to the effects of unprecedented high-wind events which have resulted in fires and evacuations across the state.
JUST IN: California Gov. Gavin Newsom declares statewide emergency due to fires: "Governor Gavin Newsom declared a statewide emergency due to the effects of unprecedented high-wind events which have resulted in fires and evacuations across the state." https://t.co/1NKWh5U8yg pic.twitter.com/fFC9i6ufkL— ABC News (@ABC) October 27, 2019
It’s All About Duration
Although the speeds are not unheard of, the duration is, according to Steve Anderson, a meteorologist with the weather service.
During California’s two deadliest wildfires in 2017, wind gusts reached 92 mph but only lasted four to six hours. By comparison, the high winds this time around are expected to last 24 to 30 hours.
“The critical fire weather will continue throughout that period, and with wind speeds that high, there’s really not a whole lot to be done other than to just get out of the way,” Anderson said Sunday morning.
Hurricane-force winds are defined as sustained winds of at least 74 mph lasting at least a minute. While the wind gusts in the North Bay are reaching those speeds, they are coming in smaller spurts.
Evacuation Zone and Power Shutoff
The high winds overnight caused the Sonoma County Sheriff’s Office to nearly double its evacuation zone. In the largest evacuation issued in the county’s history, more than 180,000 residents have been ordered to flee the area.
The winds also led PG&E to initiate its largest power shutdown up to this point. Overnight, the utility turned off power to more than 2 million Californians across 38 counties in northern and central California.
Paul Doherty, a spokesman for PG&E, said the company is advising customers in the shutdown zones to expect the widespread outage to last several days.
PG&E Has Begun De-energization of Electric Lines for Public Safety – Impacts Will Include Customers in Parts of 38 Counties in Northern and Central California, Historic Wind Event Will Affect 940,000 Customers and Last Through Monday https://t.co/XUqXZEo9k2 pic.twitter.com/nV4LlRdCDa— PG&E (@PGE4Me) October 27, 2019
But It’s Not The End Of It
A high wind advisory and red flag warning will remain in effect in Sonoma County and most of the higher elevations of the Bay Area until 11 a.m. Monday. But that won’t be the end of it.
Another round of offshore winds is expected to hit the region on Tuesday evening into Wednesday morning.
“It won’t be as strong, but any dry, offshore winds are not good news when you have an active fire,” Anderson said.
A fire in Vallejo, California, led to Interstate 80 being shut down. More than 185,000 people have been forced out of their homes in Northern California. Human remains were found in the scorched path left behind by the Tick Fire in Santa Clarita. Pacific Gas and Electric has shut off power in parts of 38 counties. Gov. Newsom declared a state of emergency because of the fires. This California fire is going to end up really bad! get out of the zone right now! [Mercury News]