A Fire Weather Watch will be in effect from Thursday through Saturday evening for gusty winds and low humidity. Among the affected areas are the Northern San Joaquin Valley in San Joaquin and Stanislaus counties below 1,000 feet.
Before the strong winds will be a chance of rain and even a stray thunderstorm, according to the National Weather Service. The NWS is forecasting scattered light showers through today, with the heaviest precipitation expected in the foothills and mountains.
Starting late tonight, a “classic inside slider” — an upper level trough will dig south from the Gulf of Alaska — will cause critical fire conditions.
NWS forecasters in Sacramento indicated that in the Central Valley, there will be northerly winds from 15 to 25 mph, with gusts up to 40 mph. In the Delta, northerly winds of 20 to 30 mph, gusts 40 to 55 mph are forecast. In the foothills, northeasterly winds will be 15 to 25 mph, with gusts 35 to 45 mph. Strongest winds are expected Thursday night into Saturday morning.
Minimum daytime relative humidity of 10 to 25 percent is anticipated Friday and Saturday. The region will also see moderate to poor overnight relative humidity recoveries of 25 to 50 percent.
Highest threat during the fire watch period will be in the Sacramento Valley and adjacent foothills, and Delta, especially west of Interstate 5.
The combination of gusty winds and low humidity can cause new fire starts and ongoing wildfires to rapidly grow in size and intensity. Outdoor burning is not recommended.
A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly. A combination of strong winds, low relative humidity, and warm temperatures can contribute to extreme fire behavior.
The total acres burned in California this year surpassed 1 million as spiking temperatures on Oct. 1 added to the challenges facing firefighters struggling to contain a stubborn blaze in the mountains northeast of Los Angeles that flared up over the last weekend in September.
The risk of wildfires increased across California as an autumn heatwave scorched much of the state. Some inland areas saw temperatures up to 20 degrees above average for this time of year, according the National Weather Service.
Dry, hot winds in the northern part of the state prompted Pacific Gas & Electric to preemptively cut power to small clusters of customers in high-risk areas. The utility routinely stops electricity service in counties where weather conditions increase the probability of fires.
In Southern California, the Line Fire's surge pushed the total acres burned across the state in 2024 to 1,001,993 (405,492 hectares) as of Oct. 1, according to Cal Fire. The milestone surpasses the total scorched during the same time last year — 293,362 acres (118,719 hectares) — but is roughly on par with the five-year average for the period, the Los Angeles Times reported.
A 34-year-old man has pleaded not guilty to starting the Line Fire on Sept. 5. Justin Wayne Halstenberg of Norco, California, was charged with 11 arson-related crimes, according to court records.
At its height, the blaze threatened more than 65,000 homes in and around the Big Bear Lake area.
— The Associated Press contributed to this report.
