Atmospheric river: Bay Area residents brace for strong winds, floods, toppling trees, power outages

SAN FRANCISCO -- A powerful jet stream hurled a potent category 3 atmospheric river at the San Francisco Bay area early Thursday, triggering a flood watch for the region and warnings of mudslides, downed trees and power lines.

The National Weather Service said the plume of subtropical moisture would dumped several inches of rain over the next 24 hours.

"Inland regions expected to see 1-3 inches, inland hills 3 to 6 inches, Santa Cruz Mountains 4 to 6 inches with locally higher amounts up to 8 inches," forecasters said.

KPIX 5 First Alert Weather: Current Conditions, Forecasts, Alerts For Your Area

Late Wednesday night, Gov. Gavin Newsom declared a state of emergency in 21 counties in anticipation of the storm's wrath.

As Wednesday turned into Thursday, the jet stream intensified, speeding up the storm's arrival in Bay Area.

ALSO READ: Millions face atmospheric river flood threat; Evacuations warnings issued in Santa Cruz County

"The leading edge of the higher moisture plume is roughly 350 miles SW of San Francisco, but to deeper moisture core is still about 1,000 miles SW of San Francisco," the weather service said at around 11 p.m. "It's the deeper core that will be most concerning when it comes to rainfall and intensity."  

"As the the deeper moisture reaches the coast midday, rain will begin to increase in coverage and intensity and continue through the afternoon and evening."

The weather service has also issued a Bay Area-wide wind advisory for Thursday 1 p.m. through Friday at 4 p.m. as we expect gusts up to 50 mph.  

The combination of wind, saturated soil and weakened trees could be life-threatening across the region. Over the weekend, a woman who was hiking with her son and several other Boy Scouts and their parents on a popular trail in Cupertino's Rancho San Antonio Park died when a tree fell on her.

"I'm afraid of the wind mostly because the wind causes trees to just snap," said Felton resident Linda Glenn. "You heard about that lady who was killed. I like to walk, but I'm no walking under any trees right now. I'm walking in the park."

Felton is nestled in the midst of the Santa Cruz Mountains which will be ground zero for the storm's fury. Over  22-day stretch starting on Dec, 26, a series of atmospheric rivers flowed over the Bay Area. The San Lorenzo and Salinas Rivers and Pajaro Creek roared over their banks, flooding neighborhoods. 

"Rapid rise in rivers and streams is anticipated," the weather service said of the latest storm front. "Areas of particular concern include the San Lorenzo River at Big Trees, the Pajaro Creek near Dunneville and the Big Sur River near Big Sur. These areas are forecast to go into moderate flood stage early Friday morning."

Ramiro Murrieta's home and farm were overwhelmed by flood waters in Gilroy in January. He fears what the latest atmospheric river holds for his home and family.

"The water took away everything that was here. The tractors got flooded. We got about five feet of water in the house," Murrieta said.

As the area braces for the arrival yet another atmospheric river, Murrieta and Raul Vega, another Mexican farmworker from the area, said they are incredibly concerned about the impact of the coming storm on their livelihood.

"We don't know what will happen to the land or the plants. Right now, everything is unknown and stressful," explained Murrieta.

There will be brief break in the weather over the weekend, but another atmospheric river arrives next week.

"Still looking like another atmospheric river will arrive Monday to Tuesday timeframe," the weather service said. "Guidance still shows that this atmospheric river will not be as strong as the one we will see today/Friday with less rain anticipated."