The wettest storm of the year, so far, is expected to bring showers and some snow to San Diego this week. The atmospheric river storm will bring significant rainfall to Northern California and break down as it approaches San Diego County as early as Tuesday night. Despite a weakening storm, San Diego County is still expected to get several inches of rain by the time the storm is through. Rain chances will be off-and-on through Friday with rounds of rain bringing anywhere from 2-3 inches of rain at the coast and in the valleys and up to 4 inches of rain — and possible snow — to the mountains.