A man with an umbrella walks on a sidewalk in Union Square during heavy rain in San Francisco on February 13, 2025.

Don’t let the Sunday sunshine deceive you. A weak atmospheric river is brewing over California and is set to deliver two rounds of moderate to heavy rainfall, a chance of thunderstorms, small hail and high-elevation snow to the Bay Area this week.

A low pressure system moving out of the Gulf of Alaska is slated to produce initial showers Tuesday night into Wednesday morning. The first few drops of rain are expected in the North Bay as the storm follows a typical southerly trajectory down through the Bay Area and the Central Coast. “It will definitely be impacting morning rush hour,” Matt Mehle, a meteorologist for the National Weather Service’s Bay Area office, told SFGATE. “That’s the........

© SFGate