After dry spell, substantial storm expected by mid January

Champagne flowed on New Year’s Eve, but the liquid California truly longs for is expected soon.

Forecasters say two wet storms are on the way, breaking a two-week dry spell and offering more relief, albeit not an end, to California’s prolonged drought.

A breakdown in the high-pressure ridge that has shielded most of the state since before Christmas is expected to bring the Santa Rosa area a substantial storm in the third week of this month, followed by another one in late February or early March, said Jack Boston, a long-range forecaster with AccuWeather.com.

The Climate Prediction Center, a branch of the National Oceanographic and Atmospheric Administration, offered a similar prognosis, lumping all of California into a swath stretching all the way across Texas expected to see above average precipitation from January through March.

That forecast is based largely on the expectation of a weak El Niño system, which may have already formed but has not been officially declared, said David Miskus, a meteorologist with the climate center.

“Sometimes you don’t know you’re in it until you’re out of it,” he said.

El Niño, characterized by warming of water along the equator in the eastern Pacific Ocean, is commonly linked to soggy California winters. But a weak system amounts to “just about a coin toss” between wet and dry seasons, said Jan Null, a San Francisco meteorologist.

Of the 10 most costly flood years in the state, only four were El Niños, he said.

Null, a former National Weather Service meteorologist, said he is also skeptical of long-range forecasts, like the 45-day outlook presented on the AccuWeather website.

“I wouldn’t bet on a forecast past a week,” he said. “We’ve seen time and time again the patterns change.”

Santa Rosa enjoyed a gloriously wet December, with 14.49 inches of rain, bringing the seasonal total since July to 19.39 inches. But the city hasn’t had more than one-tenth of an inch on any day since Dec. 20, kindling fears of a repeat of last year’s bone-dry January, when just 0.1 inches fell the entire month.

AccuWeather’s forecast for January 2015 calls for rain on 13 days, starting Wednesday and totaling 6.99 inches for the month, virtually tying the 7.05-inch average for what is historically Santa Rosa’s wettest month.

“You guys did very well in December,” Boston said, noting that January could offer a repeat.

Breakup of the high-pressure system off the coast would allow the jet stream to sweep all the way across the Pacific Ocean straight into California, a precipitation phenomenon known as “the fire hose,” he said.

Slightly warmer weather also is on the way, with daytime high temperatures reaching into the 60s on Sunday and staying there for 10 of the following 11 days, according to AccuWeather.

The recent cold snap, with some nighttime lows below freezing in Santa Rosa, also is a product of the offshore high-pressure ridge, which has been channeling cold Arctic air into California, Boston said.

December’s rains made a dent in the drought, with Sonoma, Lake, Napa and Mendocino counties downgraded by the U.S. Drought Monitor to “extreme drought,” the fourth highest of five categories, covering 46 percent of the state.

Prior to the pre-Christmas deluge, the four counties were designated as in “exceptional drought,” the highest category, which covered 55 percent of the state on Dec. 9 and now has shrunk to 32 percent of California.

But even if AccuWeather’s storm forecasts come true, the prolonged drought won’t be over.

“It’s going to take a couple of wet seasons to really put the kibosh on it,” Boston said.

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