Not a drop in sight for the next 2 weeks
Forecasters unsure if dry spell will last through winter
The same weather pattern that fostered years of drought in California has set up house again over the Northern Hemisphere, blocking nearly all chances of rain in the Bay Area for at least two weeks, according to weather forecasters — who hope the dry spell won’t last all winter.
The National Weather Service’s official forecast through Dec. 12 calls for “dryer than normal conditions” in the Bay Area, said Charles Bell, a meteorologist with the weather service.
December and January tend to be the wettest months of the year in the region. In San Francisco, the city typically averages 2 inches of rainfall in the first half of December.
“We’re not forecasting any rainfall at all for the area in the next seven days,” Bell said. “It looks like it will be much drier than normal.”
But, Bell added, there’s a
“very slight chance” the North Bay could receive sprinkles this weekend.
The Climate Prediction Center, a parent agency of the weather service, has a forecast through Dec. 22 predicting there could be four weeks of drier than normal weather, Bell said.
A strong ridge of high pressure is pushing the jet stream — the main storm track — to the north away from California, Bell said. Instead of getting a storm coming directly off the Pacific into the Bay Area, storms are being pushed to regions such as Washington state.
In previous drought years, the ridge was “strong like a dome” and stayed in the area for weeks on end. Meteorologists will be closely monitoring the dome to see whether it’s shrinking or endures for long periods like years past.
“The big question mark and the potential big difference is, just how long does this persist?” said Daniel Swain, a climate scientist at UCLA. “Unless it persists really though the winter, it’s not quite as remarkable or dramatic.”
If it persists, California could be in “ridiculously resilient-ridge territory,” Swain said. Such a strong ridge is believed to have formed the weather phenomenon termed “the Blob,” a patch of warm water in the North Pacific that had existed in tandem during the drought.