Another atmospheric river moved into San Jose and the greater Bay Area from the coast this morning, and forecasters say things will get worse through Friday night.
Heavy rain, strong wind, and thunderstorms are all expected.
A spokesman for the The National Weather Service said the region should experience “major to extreme impacts” today and tomorrow. “This is looking to be a big deal in terms of rain, wind and flooding,” he said, adding that the latest storms will cause “more problems with trees coming down with the gusty winds and wet soils.”
The weather service forecast for the greater San Francisco Bay Area calls for rain and strong winds Thursday that will get heavier and stronger overnight.
The atmospheric river will be most severe into Friday, with a flood watch already in effect today through Sunday -- as well as a wind advisory today and tomorrow – for the entire Bay Area and the Central Coast. Lingering but lighter rain will continue into the weekend with additional widespread rainfall expected next week.
Rainfall in San Jose and other lower elevations will be 1 to 4 inches, with 4 to 6 inches, perhaps as much as 10 inches of rainfall at higher elevations through Friday night. Another weather system is to arrive Monday.
The weather service said excessive rainfall could cause "considerable river flooding" from the Santa Cruz Mountains down through norther Monterey County. The San Lorenzo and Pajaro rivers are forecasted to approach flood levels Thursday and flooding is probable in low lying areas like Felton Grove.
With soils already saturated from winter storm after winter storm, residents can expect localized flooding to occur rapidly. The heavy rainfall and high winds are also expected to topple trees and trigger landslides in the area, possibly cutting power and blocking roads.
As California braces for another round of atmospheric rivers and storms, Gov. Gavin Newsom on Wednesday declared a state of emergency to support storm response and relief efforts in 21 counties, including five in the greater Bay Area.
Storms are forecast to pummel the state through mid-March, and many areas are already grappling with flooding, power outages and damage from recent record rainfall and snow storms.
The emergency proclamation issued Wednesday to provide disaster response and relief includes Santa Clara, San Francisco, San Mateo, Santa Cruz and Monterey counties.
Last week, a state of emergency was issued for 13 counties statewide that included Sonoma County, and the governor activated the California Guard and State Operations Center.
Bay Area communities are preparing for high winds and possible flooding.
“The state is working around the clock with local partners to deploy life-saving equipment and first responders to communities across California," Newsom said Wednesday. "With more dangerous storms on the horizon, we'll continue to mobilize every available resource to protect Californians."
Bay City News contributed to this report.