Bay Area’s Rainless February
Would Be Historic

There’s two months left in California’s official “rainy season,” but it looks like a rainless February.  And fire officials are concerned.

A persistent high-pressure ridge over the Pacific is hindering any rainfall, just as it did during the state’s epic seven-year drought, from 2011 through 2017.

Much of Northern California is not likely to experience a drop of rain this month, meteorologists say. Sacramento has been 46 percent drier than normal, this winter; Fresno has been 45 percent drier.

And no rain has fallen in the Bay Area all month. Only one other time has San Francisco recorded no rainfall in February: Back in 1864, when Abraham Lincoln occupied the White House and the Civil War tore the country asunder.

California’s Rainy Season

The bulk of Northern California’s precipitation (90%) falls in the cool-season months, from October through April. And about half the annual precipitation total arrives in the three-month period from December through February.

During this time period, winter storms emerge off the Pacific Ocean, delivering rain and snow to the area. Some of these storms include moisture from atmospheric rivers and deliver heavy precipitation to the state, which can lead to flooding. (See infographic below.)

On average, five to seven larger storms contribute most of the precipitation that falls during the wet months.

Source: CA Dept. of Water Resources

Wildfires Waiting in the Wings

Below-average precipitation and tinder-dry hillsides would mean wildfires can’t be far behind.

Fire officials are carefully monitoring both the lack of precipitation and the vegetation-drying offshore winds.

Cal Fire spokesman Scott McLean said that, together with the U.S. Forest Service, they’ve battled 163 small wildland fires so far this year. That’s more than double the number fires fought last year at this time.

While waiting for rain, Cal Fire crews are busy thinning forests, creating firebreaks, and hiring additional staff. According to Fire Information Officer Stanton Florea, U.S. Forest Service fire crews are igniting dense forests that haven’t burned in many years, as part of a prescribed burn program.

And Cal Fire is introducing more and newer aircraft to increase its ability to dump water and fire retardant. It’s also urging residents of fire-prone areas to clear the vegetation around their homes, making them less susceptible to flying embers, and creating room for firefighters to maneuver.

“Now’s not the time to be complacent,” McLean said. “Those living in rural areas need to get out and get their defensible space done. If we have potential dryness continuing into summer, they’re not going to have time to do it.”

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No Time to Play Catch-up

During the last drought, which was declared over in 2017, tens of millions of trees died, significantly increasing wildfire risk. McLean says the forests still need several wet or at least average rain seasons to recover from that drought.

So even if it doesn’t result in a drought, a rainless February will leave the region needing far more rain than usual. Catching up to seasonal expectations would be nearly impossible.

For now, the immediate forecast remains bleak.


Featured Image: Pixabay

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