Already in the midst of the worst wildfire season on record, California faces the most favorable conditions for instigating large wildfires so far this year, beginning Sunday afternoon and lasting into Tuesday. The combination of hurricane force wind gusts and extremely dry conditions mean the potential of a fire starting, and spreading rapidly, is unusually high.

In the San Francisco Bay and areas from Sacramento northward, high winds of up to 80 mph are expected in higher elevations, with gusts to 50 mph possible even in downtown San Francisco.

The National Weather Service’s Storm Prediction Center has designated much of northern California’s fire risk as “extremely critical,” the most severe level on its scale.

Humidity levels Sunday night are expected to be in the single digits once the winds begin cranking out of the north and northeast, and the strongest winds will reach lower elevations than usual. The National Weather Service forecast office in Sacramento wrote a foreboding technical forecast discussion on its website Sunday morning, making clear that this event has the potential to be historic.

“This event is forecast to be the strongest event of the year so far for the region. Consequently, the potential fire weather impacts will be extreme,” the National Weather Service said. Forecasters referred to “desert-dry” humidity levels, and compared the setup to the conditions that led to some of the most notorious fire events of the past several years.

“The meteorological . . . setup is uncomfortably similar to recent past events in northern California such as [the] October 27-28, 2019 (Kincade Fire rapid growth), November 8, 2018 (Camp Fire rapid growth), and October 8-9, 2017 (2017 Wine Country Fires rapid growth),” forecasters stated.

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According to Brent Wachter, a meteorologist with the U.S. Forest Service in Redding, Calif., the peak winds will be somewhere between the deadly 2017 Wine Country firestorm and the near-historic late-October 2019 offshore wind. Though it’s not as hot as it was during the Wine Country event, low humidity levels are expected to make up for that difference to create similarly, if not even more dangerous conditions, Wachter said.

With the offshore movement of air, any moisture from coastal air will be blown out to the Pacific Ocean.

“Any new ignitions will be present in an environment that will promote rapid, explosive, and dangerous spread of fire,” the National Weather Service stated. “Have a plan in place if you need to evacuate will little/no notice. While Fire Season 2020 has already been historic from the countless lightning- based ignitions in August, remember that peak offshore wind season is right now for much of the Golden State.”

Wachter said he’s “highly confident” this event will rank as a greater than 97th percentile event that combines an ultra-dry and windy atmosphere with dry fuels.

In preparation for the winds and fire risk, the utility company Pacific Gas & Electric Co. plans to preemptively cut power to about 366,000 customers in 36 counties, or about 1 million residents, on Sunday.

During the past few years, the company’s infrastructure, including transmission lines, have been blamed for some of the state’s deadliest and most destructive blazes, including the 2018 Camp Fire that nearly destroyed the town of Paradise and killed dozens, as well as some of the wine country fires.

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On Friday, Berkeley took an extraordinary step in recommending that residents who live in the fire-prone hills of the city consider evacuating before Sunday. The National Weather Service has expressed concern about upcoming conditions in the East Bay hills, referencing the 1923 fire in Berkeley and the 1991 Tunnel Fire in the Oakland Hills.

It’s not just northern California facing high fire danger, either. Red flag warnings along with high wind warnings are also in effect for expected offshore winds in Southern California, where these winds are locally known as Santa Ana events. Any new fire ignitions here will spread quickly as well, the National Weather Service warns.

The abundance of recent burn scars may somewhat limit the potential for new blazes Sunday through Tuesday, but there are many more areas in the nation’s third-largest state that still have abundant dry vegetation that have been unaffected by flames so far this season or in recent fire seasons.

The high wind event, which is the result of a push of a record-setting Arctic air mass into the Rockies and Great Basin along with strong winds at the upper levels of the atmosphere. When low-pressure areas riding along the jet stream land in Colorado, high-pressure zones build in quickly to their north and west over northern Nevada and Utah, a region known as the Great Basin. The difference in pressure over this relatively short distance starts generating these winds.

The winds are then drawn westward toward California, where air pressure readings are lower (air flows from high to low pressure), and often, they gain speed passing through channels in the high terrain. As the air moves down mountain slopes, it dries out further.

This particular high wind event is shaping up to be what many meteorologists had feared the most for the Golden State this year: an extremely dry, land-to-sea (also known as offshore) wind event just when the region is at its most parched.

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The Bay Area’s National Weather Service office plans to send fire-related alerts to NOAA weather radios, if specific counties within their forecast area request such a move. It will also post “Civil Emergency” messages on the agency’s Bay Area website that contain evacuation orders and other county wildfire messages.

NOAA weather radios, which run by battery, can be an important source of emergency information when cellular service and electricity are disrupted by fires, wind damage or preemptive power shut-offs.

Although they are not yet in wide use in Western states when compared to tornado alley, for example, these radios may prove invaluable in an age of worsening wildfires and hasty evacuations and power outages.

California is already in the midst of its worst wildfire season on record, with more than 4.1 million acres burned, at least 9,200 structures destroyed and 31 people killed. A staggering 5 of the top 6 largest fires on record in the state have occurred this season, including the largest, which is the August Complex. That fire is also the state’s first “gigafire” on record, having burned over 1 million acres.

Over the longer term, 17 of the top 20 largest blazes in the state have taken place since the year 2000.

Scientific studies show that by increasing air temperatures and drying out soils and vegetation, climate change increases the frequency and severity of days with extreme fire risk. This is true in the West, but also in other parts of the world, according to a recent review of the scientific literature on this topic.

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California has seen its fire season lengthen, which pushes the driest time of year into the typical season for the state’s strongest fall offshore wind events, which is a combustible combination. The state saw its hottest August on record with sizzling temperature records. Then an even more severe heat wave struck in early September, leading to a firestorm of historic proportions.

Land management practices, along with the building of homes closer to forested areas that are susceptible to fires, are other significant factors driving wildfire trends in the West, but they don’t explain the major uptick in large fires in recent years.

One recent study found that climate change has doubled the days during the fall with extreme wildfire conditions in parts of California since the 1980s.

There is no sign of rain in California through at least the first week of November.

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The Washington Post’s Jason Samenow contributed to this report.