Elevated fire risk in the north
Forecasters in the Bay Area and Sacramento warn of low humidity, high winds this week.
Low humidity and gusty winds are significantly elevating the fire risk in Northern California this week, according to forecasters.
National Weather Service offices for the San Francisco Bay and Sacramento each issued warnings for Thursday and Friday.
“There is a risk for fire starts on Thursday into Friday given the combination of low humidity and gusty winds,” the Bay Area office said. “Remember to properly dispose of matches, ensure campfires are put out, and don’t let vehicle parts drag on the ground. One less spark, one less wildfire.”
Northerly wind gusts of at least 30 mph are expected to combine with humidity levels in the 15% to 25% range to create “near-critical fire conditions,” the forecasters said.
Inland areas including the hills of the North and East Bay are expected to be at the highest risk, forecasters said, with gusts up to 45 mph in the valleys and above 50 mph at the highest peaks.
Forecasters with the Sacramento office issued a red flag warning effective 11 a.m. Thursday to 8 p.m. Friday.
North winds of 15 to 30 mph with gusts of 35 to 45 mph are expected along with humidity levels from 5% to 12%, forecasters said.
The announcements came as a fire prompted an evacuation warning in Butte County north of Sacramento on Wednesday.
The Evita fire broke out in Palermo, a community south of Oroville, and grew to about 17 acres, according to the California Department of Forestry and Fire Protection.
Shortly before 4 p.m., the Butte County Sheriff’s Office warned residents in the area of Wyandotte Creek to evacuate.
The warning was lifted about 30 minutes later. Cal Fire reported one trailer and two small outbuildings were destroyed, and crews were mopping up the blaze Wednesday evening.
In Southern California, a brush fire that broke out Thursday east of the 5 Freeway near the Grapevine had grown to about 500 acres with 10% containment, according to the Kern County Fire Department.
Multiple helicopters and air tankers along with about 100 firefighters on the ground were battling the blaze, which was not threatening infrastructure or homes.
Authorities across California are bracing for the warmer months ahead.
The National Oceanic and Atmospheric Administration said recently that the temperature outlook for spring into summer calls for above-normal readings for most of the West.
The agency also reported that the climate phenomenon known as La Niña was hanging on, possibly into a third year. High temperatures and a lingering La Niña would have major consequences for urban and agricultural water use across the West, as well as for California’s increasingly extreme fire season.
The National Interagency Fire Center is predicting that much of the northern portion of the state will see an above-normal potential for significant fires through August, but meteorologists are calling for near- to belownormal fire activity in the southern reaches.
Some of the increased risk to Northern California may be tied to the amount of rain in the region earlier this year; La Niñas typically bring colder, stormier conditions in the northern U.S. and warmer, drier conditions in the southern part.
Northern California has received more rain than the southern portion of the state, particularly from the end of March through April, so there is a more robust grass crop, which helps spread fire by carrying it up into larger fuels such as trees, U.S. Forest Service meteorologist Matt Shameson said.
Last year, Southern California had fewer significant fires than average and saw less acreage burned, while Northern California shattered records, with the Dixie fire scorching nearly 1 million acres and burning across the Sierra Nevada — the first blaze to do so in recorded history.
“I can tell you: They’re expecting another big fire season up north,” Shameson said.
The effects of these repeated large, severe fires have the potential to be ecologically devastating and pose a real risk of compromising the state’s climate goals, experts say.
The Sierra Nevada and Southern Cascade ranges, which currently store close to half of California’s captured carbon, lost 1.1 million tons of stored carbon to wildfire, drought and invasive pests from 2018 to 2019 alone, according to recently published research by scientists at UC Berkeley.