An Early Taste of Winter: Storm Brings Bay Area Rain and Sierra Snow

Lightning. Erratic Winds. Hail. Waterspouts. Flooding. Forecasters suggest these environmental conditions are all possible through Tuesday in the Bay Area, and the Sierra Nevada will likely get its first significant snow of the season.

A low-pressure system moving into the region from Oregon and Washington “will quickly dive down the West Coast today,” first hitting the North Bay with rain midmorning Monday, according to the National Weather Service daily forecast discussion. But as the day lingers, the storm will move south, bringing potentially wet conditions across the region before likely dousing the Central Coast.

“Pretty much everywhere is going to be impacted,” said Roger Gass, a meteorologist with the weather service’s Bay Area office. “It’s an early storm system, but there’s no atmospheric river-type scenario associated with the system.”

Gass said the storm could bring a suite of environmental issues with it, including lightning, offshore water spouts and small hail. But he said the “biggest threat will be nuisance flooding,” where areas that typically pool water could flood.

As for rainfall totals, he said the larger amounts of rain will be on the Central Coast, with up to 2 inches of rain at the highest elevations. Meteorologists expect an inch of rain or less for the rest of the Bay Area.

“Don’t drive through flooded roadways,” Gass said. “The most deaths [in storms] are due to people driving through flooded roadways. And then for thunderstorms, if thunder roars, go indoors.”

Farther inland, forecasters said the storm could drop up to 3 feet of snow on the highest peaks of the Sierra Nevada, especially in the area south of Highway 50.

“This is our first time issuing winter products for the season and the first measurable snowfall event we’ve had in our area,” said Dakari Anderson, a meteorologist with the National Weather Service’s Sacramento office.

Anderson said travelers on mountain passes should expect chain controls, slippery conditions and inclement weather. The office has issued a winter storm warning through Wednesday at 5 a.m. for the Sierra Nevada and the Lassen National Park area above 6,500 feet.

Forecasters expect the heaviest snow totals on Monday afternoon and evening.

“Make sure you’re checking the forecast before heading out for the day,” Anderson said.