Some 37 million people are on alert for flooding from Sacramento in Northern California to San Diego in Southern California.
The Santa Barbara Airport closed Monday morning due to flooding. More than 2.5 inches of rain fell in Santa Barbara before dawn and more is expected.
Flash flooding, mud and debris flows, as well as landslides and rockslides, are likely.
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Severe storms could hit the Sacramento region on Monday with a risk of brief tornadoes, damaging winds, large amounts of small hail, lightning and heavy rainfall rates. The greatest threat for storms in this area comes between noon and 8 p.m. PT.
Areas north of San Francisco reported 2 to 4 inches of rain from the weekend, and now there’s a slight risk for excessive rainfall from Los Angeles to the San Francisco Bay area to Sacramento on Monday.
Much of the areas under flood watches are also on alert for high winds. Gusts could reach 40 to 60 mph on Monday, especially in the morning.