SAN FRANCISCO (CBS SF) — For the second week in a row, a plume of unstable air from a dying tropical storm in the Pacific was streaming toward the San Francisco Bay Area Saturday, carrying with it a potent combination of gusty winds and dry lightning.
Thousands of firefighters were battling two of the state’s three largest outbreaks of wildfires in history that were ignited by dry lightning strikes during a round of unusual weather last week.
“The challenge we are facing, the fire concentration facing us here in the state, is now disproportionately impacting Northern California,” Gov. Gavin Newsom said morning news conference on Friday. “And that is because of close to 12,000 lightning strikes that we experience over a 72-hour period.”
That pulse of atmospheric energy last week from Tropic Storm Fausto created havoc with more than 600,000 acres now scorched, thousands of residents forced to evacuate, four deaths and several hundred homes and buildings razed. And that desperate battle by fire crews was continuing on Saturday.
Now, a plume from the remnants of Hurricane Genevieve was moving up the coast.
“Elevated moisture and instability from former Hurricane Genevieve will move over the region this weekend through early next week
and bring the threat of elevated thunderstorms across much of Northern California,” the National Weather Service warned Saturday. “A low pressure system off the coast may enhance and strengthen these thunderstorms allowing some to develop frequent lighting strikes and gusty erratic outflow winds.”
RED FLAG WARNING has been issued for the entire San Francisco Bay Area and Central Coast from 5 am Sunday to 5 pm MONDAY (updated) for Dry Lightning and Gusty Erratic Outflow Winds from Thunderstorms. #cawx #cafire pic.twitter.com/3qo57XlGMd
— NWS Bay Area (@NWSBayArea) August 22, 2020
Nothing strikes fear in the heart of a firefighter battling a wildfire that the words — lightning and erratic winds.
On Friday, the Weather Service issued a dry lightning warning. On Saturday, forecasters elevated it to a Red Flag Fire warning.
“These erratic gusty outflow winds can lead to potentially dangerous and unpredictable fire behavior on existing wildfires
while additional lightning strikes may result in new wildfire starts,” the Weather Service said.
The warning will go into effect at 5 a.m. Sunday and run until 5 p.m. Monday and cover the entire area where the current wildfires are raging from Lake Berryessa to Big Sur.
Marin County officials announced Saturday they were shutting down public access to the Marin Municipal Water District wildlands and Mount Tamalpais State Park during the Red Flag conditions.
“Lightning will likely spark new fires across the region, including remote areas,” the Marin County Fire Chiefs Association said in a news release. “Wildfires in remote regions may not become apparent until warmer and drier conditions allow them to grow. Erratic gusty outflow winds may result in dangerous and unpredictable fire behavior.”
Currently, Marin County firefighters are battling the Woodward Fire which erupted after a lightning strike in the Point Reyes National Seashore and had grown to more than 2,259 acres by early Saturday, threatening more than 1,600 structures. Fire officials said they had 5 percent containment of the blaze.