By RONG-GONG LIN II in the Los Angeles Times – OCT. 26, 19 8:31 PM
SAN FRANCISCO — In 1991, flames swept into the Oakland and Berkeley hills, killing more than two dozen people and destroying more than 2,000 homes.
In 2017, the Tubbs fire devastated wine country, killing 22 people and eventually destroying more than 5,000 homes.
Last year, it was the Camp fire, the most destructive in California history, that left 86 dead and more than 13,900 homes destroyed, along with much of the town of Paradise.
Powerful downslope winds heading from the northeast to the southwest fanned all three firestorms. Forecasters now say these winds that will hit Northern California this weekend could bring one of the most potentially dangerous periods of fire weather experienced by the region in a generation.
That danger has prompted Pacific Gas & Electric Co. to plan to shut off power to millions, a relatively new and controversial strategy aimed at reducing the risk of fires triggered by electrical lines like the ones that caused the wine country and Paradise infernos. Also Saturday, about 90,000 more Sonoma County residents, from Healdsburg to Bodega Bay and the Pacific Coast, were ordered to evacuate.
The duration of the extreme wind event, known in the Bay Area as Diablo winds, is forecast to be roughly 36 hours, from Saturday evening around 8 p.m. into Monday morning, with isolated gusts of 65 mph to 80 mph in the highest peaks in the North Bay.
Weather forecasters hope that no sparks will ignite major destructive wildfires, but the potential for swift-moving wildfires is high.
“This is definitely an event that we’re calling historic and extreme,” said David King, meteorologist for the National Weather Service’s Monterey office, which manages forecasts for the Bay Area. “What really sets this apart from 1991 and 2017 is the time that these winds are going to continue gusting above 35 miles an hour…. The fact that this is going from Saturday night all the way to Monday morning, that’s what is really making this historic.”
Not only will winds be bad, but the air will be quite dry — relative humidity levels are forecast to fall between 15% and 30%; anything in the teens and 20s is really dry, King said.
_______________________________________________________________________
‘Potentially historic’ wind event could worsen California wildfires (Washington Post story and video)
_______________________________________________________________________
The Fire Weather Watch has been upgraded to a Red Flag Warning for the N/E Bay (8 PM Sat-11 AM Mon), SF Peninsula Coast and Santa Cruz Mountains (3 AM Sun-11 AM Mon). Confidence is high for dangerously strong offshore winds and critically low RH. #CAwx #CAfire
“It’s certainly going to be a potentially very dangerous situation,” said Jan Null, adjunct professor of meteorology at San Jose State. “We are at the driest time of the year — if a fire starts with this dry, very strong wind pattern, the spread is extremely rapid.”
Temperatures are forecast to drop from midweek levels, which reached the 90s as the Kincade fire burned out of control on the northern edge of Sonoma County, destroying dozens of structures; in the North Bay, highs were forecast to fall into the 80s on Saturday and the 70s on Sunday, said weather service meteorologist Anna Schneider. But the falling temperatures won’t make much difference; the hot weather this week just dried out vegetation even more.
The area of highest risk includes the San Francisco Bay Area and points north, among them the northern Sierra Nevada and California’s North Coast region, including such cities as Eureka, said Daniel Swain, a climate scientist with UCLA and the National Center for Atmospheric Research. It’s been particularly unusual that the North Coast has been so dry at this point in the fall, Swain said.
“This is the kind of event that makes me personally nervous, as somebody who has friends and family living in the fire zones in the Bay Area, and I don’t say that about all the events,” Swain said. “Hopefully, we get lucky and there are no major ignitions. But if they happen, it’s going to be really hairy Saturday night and Sunday. It’s looking really, really extreme.”
The winds are perhaps strong enough to cause some wind damage, perhaps even in some of the lower elevation regions, Swain said. Though it’s not unusual to see strong gusty winds in the hills and river canyons in Northern California in the autumn, this one is unusual for blowing strong winds in places where a lot more people live: in valleys and near the coast, Swain said.
- Healdsburg is a ghost town awaiting the Diablo winds and Kincade fire
- Thousands fleeing Kincade fire face heavy traffic and long gas station lines
- Dangerous winds expected in Northern California fire areas
- Calmer winds help fire crews fighting the Tick fire, now 55% contained
“These winds are going to be much more widespread, certainly than during previous events this autumn, but also more widespread than is typical during offshore wind events,” Swain said.
Related California wildfire stories
Up to 2.7 Million Will Lose Power (New York Times)
Lights begin going out in Californa (NBC News)
