A bomb cyclone occurs when a storm's pressure drops quickly, which intensifies the storm and ramps up wind gusts. Atmospheric rivers are a "long, narrow region in the atmosphere—like rivers in the sky—that transport most of the water vapor outside of the tropics," according to the National Oceanic and Atmospheric Administration.

An atmospheric river swept through Northern California, dumping record rain and deep snow in the region. In Santa Rosa, the rainfall shattered a three-day record of about 10 inches set in October 2021.