Heat records eclipsed as waves pound Sonoma County coast

Monday brought the warmest day in more than a century in Santa Rosa along with bone-dry fields and forests, sneaker waves on the coast, and diminishing winds that led to the expiration of a rare red flag wildfire warning.

Such is the potpourri of weather as Sonoma County moves into December, typically the wettest month of the year with more than 6 inches of rain.

But now, in the wake of three straight months — October through November — that brought Santa Rosa about an inch and a half of rain and the prospect of a drier-than-average winter, there may be no end to fire season.

“That’s the scary part,“ Cal Fire Division Chief Ben Nicholls said Monday. The moisture level in dead and downed trees, a primary source of wildfire fuel, is critically low now and could sink to record levels, he said.

“Two inches (of rain) is what we’re looking for historically,” he said, noting that a long-range forecast of 2.7 inches in the last two weeks of December “might be enough.”

But even that would leave Sonoma County far below average for the final three months of the year, which typically deliver nearly a foot of rain.

Couple that with recollection of the Thomas fire, which erupted in December 2017 and scorched more than 280,000 acres in Ventura and Santa Barbara counties, Nicholls said, and “there’s a possibility that we may not transition out of fire season.”

Cal Fire’s nine Sonoma County stations have scaled back to one engine per station through Dec. 27, but won’t necessarily downsize operations after that, he said.

The Bay Area overall has received just 20% to 25% of normal precipitation for the rain year that began Oct. 1, said David King, a National Weather Service meteorologist based in Monterey.

Multiple indicators, including a strengthening La Niña, point to a drier than average winter, with storms generally shunted into the Pacific Northwest and British Columbia, he said.

The U.S. Drought Monitor last week showed nearly all of Sonoma County in severe drought, with a band of extreme drought immediately to the east. Three-fourths of the state was in moderate to extreme drought last week, compared with a year ago when only 0.01% of the state was in moderate drought, the monitor’s lowest level.

There’s a chance of showers in the Bay Area on Sunday and Monday, amounting to at most half an inch, said Max Gawryla, a meteorologist with AccuWeather, a Pennsylvania-based private weather service.

The federal weather service sees only a 10% chance for “a couple hundredths of an inch” in Sonoma County, King said.

AccuWeather, which does long-term forecasting, expects nearly 2.7 inches of rain here on six days between Dec. 21 and 29, Gawryla said.

“It looks pretty wet toward the end of the month,” he said.

But AccuWeather previously forecast five straight days of rain, starting Tuesday and totaling 2.8 inches. “We have toned down what we were saying early on,” Gawryla said.

Drier than average doesn’t mean a “total shutout” in precipitation, said weather blogger Daniel Swain, a UCLA climate scientist. More rain and snow should fall this winter, he said, “but when all is said and done, the odds that the seasonal total will be below average looks pretty high — and increases with each passing dry week.”

Meanwhile, Santa Rosa hit 75 degrees on Monday, measured at the Sonoma County airport and shattering the 72-degree record set in 1917. The record for Tuesday is 75 degrees, set in 1943, and the weather service is expecting 72.

The red flag warning posted Sunday with strong offshore winds expected in Sonoma County and much of the Bay Area expired on schedule at 5 p.m. Monday. No serious hazards were reported overnight, a Sonoma County emergency dispatcher said Monday morning, calling it “a really uneventful day so far.”

The last wintertime red flags were posted in December of 2013 and 2017, along with three issued in January 2014 at the peak of the drought years, the weather service said.

A beach hazard statement issued by the weather service for a high sneaker wave threat on the Sonoma coast Monday was scheduled to change to a high surf warning Monday night through 5 p.m. Tuesday.

Breaking waves of 25 feet or more were expected, especially on northwest facing beaches, King said.

For beachgoers other than surfers, his advice was to stay off coastal jetties and rocks and to “never turn your back on the ocean.”

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.