An estimated 16 million people in California are under flood watch ahead of an incoming storm that could dump five to six inches of rain over central and northern parts of the state, including the San Francisco Bay Area.
The impending system is expected to carry with it an atmospheric river (a long, narrow band of moisture carrying warm air and water vapor from tropical climates) into the heart of the state, compounding the already-increased threat of flooding due to recent snowstorms, according to CNN.
“Our reservoirs are all full from storms earlier this year. With reservoirs full, we expect our creeks will rise more rapidly with most of the rain becoming runoff,” Marin County Fire Chief Jason Weber told the outlet.
Emergency response teams across the state were already busy after several severe snowstorms impacted communities across California throughout 2023.
The Weather Prediction Center has placed parts of the state at a level 4 risk of excessive rain, the agency’s second most severe marking, CNN reported.
“It’s likely some of the (precipitation) will simply be absorbed into the many feet of snow at the highest elevations, but lower elevations, generally below 5,000 ft, appear most likely to not have the snowpack necessary to absorb the multiple inches of rainfall expected,” the center said, according to CNN.
Though California has seen atmospheric river events as recently as January 2023, the combination of back-to-back snowstorms and the incoming heavy downpours makes potential flooding a particularly concerning threat, the outlet reported.
Several counties and municipalities, including popular tourist destination Big Sur, have issued flood watches, and the state has opened seven congregate emergency shelters across six counties.