Will the Bay Area get a wet winter? Local forecasters weighs in. - SFGATE

"It has happened successful the past, but it’s not normal," said Brian Garcia, a meteorologist with the National Weather Service.

What does this mean for the water-starved San Francisco Bay Area? Last wintertime was abnormally adust amid a La Niña pattern. Could the portion spot the aforesaid this winter?

With La Niña persisting, NOAA's wintertime forecast favors wetter upwind successful the Pacific Northwest and drier conditions successful Southern California, for December 2022 to February 2023. Northern California and the Bay Area autumn successful an in-between area, wherever the likelihood of the wintertime going successful 1 absorption oregon the different aren't strong. The outlook map suggests the likelihood of a warmer wintertime are somewhat higher than a chillier 1 successful the Bay Area, portion determination are adjacent chances of supra average, beneath mean and mean precipitation.

The rainfall forecast is the effect of information from past winters marked by La Niña. While the Bay Area has seen much abnormally adust winters during La Niña years, it has besides mean years and unusually bedewed ones.

"The forecast of adjacent chances successful your country does successful information mean that existent clime signals and humanities forecast reliability successful your portion don't let for a assured oregon reliable forecast displacement successful climatological probabilities," Jon Gottschalk,  main of the NOAA Climate Prediction Center's forecasting branch, wrote successful an email. "So the likelihood astatine the existent clip for your country are 33% for each category. No wide displacement either mode unfortunately. Your country is notorious for precocious variability oregon outcomes during La Nina lawsuit winters and this is wherefore adjacent chances is forecast."

NOAA released its 2022-23 wintertime upwind outlook.

NOAA

La Niña is simply a upwind improvement that occurs erstwhile the equatorial waters successful the eastbound and cardinal Pacific Ocean chill to below-normal averages. The better-known El Niño, the inverse of La Niña, is erstwhile the waters warm. Both can interaction the atmospheric conditions worldwide, including the pitchy watercourse and tempest track.

Null said that portion La Niña influences wintertime weather, galore different factors are astatine play, including a smattering of oscillations, specified arsenic the Arctic and Magellan-Julian oscillations. 

"El Niño and La Niña, they are the superstars of the team," Null said. "They person the highest probability of having a large night. Some of these different seat players tin travel successful and inactive power the game."

A large twists successful this year's forecast is that NOAA predicts La Niña volition modulation into what's called ENSO neutral arsenic aboriginal arsenic February. In ENSO, the equatorial waters are astatine mean temperatures.

A akin signifier occurred successful 2016-17, erstwhile wintertime started adust but had a bedewed ending.

"We had 1 oregon 2 storms successful 2016 and past erstwhile we turned the caller twelvemonth and we popped retired of La Niña, the tempest wholly blew open," said Garcia, who works for the upwind service's Bay Area office. "We had 2 months of nonstop rain. It seemed similar nonstop rain. We had truthful galore atmospheric rivers travel done our area. That was the twelvemonth Coyote Creek flooded successful San Jose."

Garcia predicts that 2022-23 could unfold similarly.

"This winter, we volition get rain," helium said. "The question is, 'How overmuch rainfall volition we get?' From things that I've been looking at, it looks similar it's going to beryllium back-loaded. We'll get a fewer fronts travel done and springiness america a small spot of rainfall during the past portion of this calendar year, but I truly deliberation the adjacent calendar twelvemonth is going to beryllium the clip erstwhile we get hit; astir apt precocious February done April is going to beryllium our model this year. If we get thing successful March, we person 'Miracle March.' If we get thing successful April, we person our 'Amazing April.'"

Null isn't acceptable to marque a prediction and is sticking with NOAA's forecast that doesn't favour 1 script implicit another. 

"I deliberation we conscionable don’t know," helium said. "If idiosyncratic truly had the answer, they’d beryllium the richest idiosyncratic connected the planet."

This quality communicative has been updated.