A red flag warning is putting gutters, decks, doormats, firewood, garbage bins, dry grass, and patio items back on the checklist for homeowners in parts of Northern California.
The National Weather Service San Francisco office issued a red flag warning for the East Bay Hills and North Bay interior mountains from 11 p.m. Wednesday, June 10, through 9 a.m. Thursday, June 11.
The Sacramento office issued a separate warning for the Sacramento Valley, Yolo-Solano hills, and nearby fire-weather zones from 11 a.m. Wednesday through 5 p.m. Thursday.
Both warnings point to the same fire-weather problem: dry air, gusty north winds, and vegetation that can carry a new fire quickly if embers, equipment, vehicles, or outdoor burning create an ignition.
CAL FIRE is urging residents to do an “Ember Check” before the wind arrives by closing openings, clearing debris, moving flammable items away from the home, and avoiding work that can throw sparks during dangerous fire weather.
The Warning Covers Bay Area Hills and the Sacramento Valley
The Bay Area warning covers the East Bay Hills and North Bay interior mountains. Forecasters expect northwest winds of 10 to 20 mph with gusts up to 45 mph, with ridge-top gusts possibly exceeding 60 mph.
Relative humidity in those warning areas is forecast between 12% and 18%. The weather service said hot, dry, and windy conditions combined with mixed vegetation, including grass, will create critical fire-weather conditions Wednesday night into Thursday morning.
The Sacramento warning includes parts of the Sacramento Valley and nearby hills. Forecasters expect north winds of 15 to 25 mph, gusts of 30 to 40 mph, and daytime minimum humidity between 9% and 15%.
The Sacramento office said the highest threat is along and west of the Interstate 5 corridor in the Sacramento Valley. The warning says gusty winds and low humidity can cause fire to rapidly grow in size and intensity.
CAL FIRE Says the First Five Feet Around a Home Need Work
CAL FIRE says the first five feet around buildings, structures, and decks is the most important defensible-space zone because keeping that area clear can stop embers from igniting materials that spread fire to a home.
That area can include bark mulch, dry leaves, pine needles, doormats, planters, deck furniture, cardboard boxes, firewood, lumber, trash bins, recycling containers, and items stored under stairs, porches, or decks.
CAL FIRE recommends hardscape such as gravel, pavers, or concrete in that closest zone instead of combustible bark or mulch. The agency also says homeowners should remove dead and dying plants, weeds, leaves, needles, and debris from roofs, gutters, decks, porches, stairways, and areas under the home.
Before red flag winds arrive, residents can clear roof and gutter debris, move combustible patio items away from the house, relocate firewood and lumber, close windows and exterior doors, close garage and pet doors, and make sure vents are protected with proper mesh.
Mowing Dry Grass Can Start the Fire Homeowners Are Trying To Avoid
Red flag conditions make some yard work riskier than leaving it unfinished for another day.
Sonoma County emergency officials say mowing or trimming dry grass during a red flag warning is strongly discouraged because a power tool can spark on a rock and start a grass fire.
The county also warns against dragging trailer chains, pulling vehicles into grass, welding or blowtorch work, burning plant cuttings, and careless use of spark-producing equipment during high fire danger.
The Bay Area warning from the National Weather Service also tells residents to avoid equipment or machinery that could create sparks, secure tow chains, avoid throwing cigarette butts from vehicles, and fully extinguish campfires or burning debris.
The safer pre-wind work is fuel removal that does not create sparks: hand-clearing leaves, moving patio furniture, checking doors and vents, clearing gutters, and postponing mowing, trimming, welding, grinding, or other power-tool work until conditions improve.
Power Shutoffs Could Affect Garage Doors, Phones, and Medical Devices
PG&E warned that Public Safety Power Shutoffs could affect parts of Colusa, Glenn, Lake, Napa, Sonoma, Sutter, Tehama, and Yolo counties during the wind event.
CBS Sacramento reported that just under 5,000 customers could be affected, with shutoffs possible from June 10 to June 11 because of elevated fire danger.
A shutoff can affect garage doors, medical devices, well pumps, refrigerators, phones, internet routers, and battery-powered tools used during emergency preparation.
Residents in possible shutoff areas should charge phones, backup batteries, medical equipment, and essential devices, test flashlights, check outage alerts, and know how to manually open the garage door.
The Putah Fire Shows Why Officials Are Watching New Starts
The warning is arriving while crews are already managing fire activity in Northern California.
The San Francisco Chronicle reported that the Putah Fire along the Yolo-Solano County border had burned 869 acres by Tuesday afternoon as the red flag conditions approached.
New fires during red flag weather can start from equipment, vehicles, outdoor burning, smoking materials, power lines, or wind-blown embers, then spread through dry grass and brush.
Before the strongest winds reach affected areas, homeowners still have specific work they can do without throwing sparks: clear roofs and gutters, move items that can burn, close exterior openings, check vents, secure tow chains, charge devices, and keep vehicles out of dry grass.