Going into this period of “critical” fire risk, Cal Fire, the state fire agency, counts 14 major wildfires as still burning across the state, with 12,600 firefighters assigned to battle these blazes. So far this year, more than 8,400 wildfires have burned well over 4.1 million acres in California, which is more than double the previous record. These fires have killed 31 people and destroyed more than 9,200 structures, including homes and businesses.
The heat and wind event this week stems from an expansive area of high pressure, or heat dome, that is building over the West. This weather feature is bringing temperatures in the 90s to Los Angeles from Tuesday through Friday, which is well above average for this time of year, and temperatures exceeding the century mark may be recorded in inland areas of Southern California.
The National Weather Service has issued heat advisories for parts of Southern California, including the L.A. metro area, through Friday.
In Northern California, including the Bay Area, a fire weather watch is in effect from early Wednesday until Friday morning for the North Bay Mountains, East Bay Hills and Santa Cruz Mountains. The watch also covers areas farther to the north, in the northern Sierras.
According to the Weather Service’s San Francisco office, winds are expected to peak Wednesday night into early Thursday. These winds that blow from land to sea, known as Diablo or devil winds, contain little moisture and are a recipe for spreading fires if any ignite.
Anticipating the potential for winds of up to 60 mph to damage some of its infrastructure, PG&E, the state’s largest utility, informed customers it may preemptively cut power to some areas to avoid causing a spark. The company’s equipment was blamed for igniting the Camp Fire in 2018, the deadliest blaze in state history.
It’s likely that the fire weather watch will be converted to Red Flag warnings later Tuesday or Wednesday morning.
Meanwhile, in Southern California, fire danger may peak a little later, on Friday, when offshore Santa Ana winds reach their maximum.
The heat dome across the West comes after many weather forecast models had shown encouraging prospects for rain in northern and central California, only to dash those hopes and switch to projections for more heat and critical fire weather conditions — the opposite of what the state needs right now.
The 2020 wildfire season has broken long-standing records, and with no end to the dry season in sight, it’s likely that even more fires will occur. October and November are typically when the state sees its strong offshore wind events, which Californians know to be wary of because of the high fire danger.
So far in 2020, California has recorded its largest wildfire on record, known as the August Complex. This is also the state’s first gigafire, one having burned more than 1 million acres. Five of the top six largest wildfires in state history (dating back to 1932) have burned between Aug. 1 and the end of September, along with six of the top 20 most destructive fires.
According to the National Oceanic and Atmospheric Administration (NOAA), the fires in California, Oregon and Washington have caused damage worth more than $1 billion.