Cold and rainy weather will continue today, mainly in the mountains and south of Sacramento in the Central Valley. Dry weather will return on Tuesday, then another weather system will bring a quick display of rain and wind late Wednesday and Wednesday night, with the rain ending on Thursday. A long period of dry weather is then expected later this week into next week.
A cold upper trough is burrowing south of the area today. Radar is currently showing extensive light to moderate rain south of Sacramento as a strong vortex moves ashore south of the Bay Area.
Some light snow continues in the northern Sierra, mainly from around I-80 south, but snow will increase again early this morning as the vortex swings inland.
By this afternoon, most of the remaining rain is expected to occur in the Sierra, while the next pair of upstream gyres will slide further south ashore. About 36 hours of dry weather is expected through Wednesday afternoon as some rain lingers across the northern Sierra this evening, then a short wave moves across NorCal.
The next system late Wednesday into early Thursday will bring a quick shower of rain to the area, mainly Wednesday night.
As cold, dry northerly flow filters through before Tuesday, snow levels will remain low in this system, and some light snow will accumulate in the base.
The system’s rapid movement expects overall QPF to be less than 1/2 an inch in the Valley, with 1/2 to 1 inch possible in the northern Sierra. Travel impacts over the Sierra are expected mainly from Wednesday night through Thursday morning with 6-8 inches of snow accumulation.
Behind that system, a strong ridge over the eastern Pacific is forecast to move closer to the coast, with northerly flow and a prolonged period of dry weather beginning this weekend.
Extended Discussion (Friday to Monday)
It looks like we will finally retire from the wet model. An upper level trough will push south and east early Thursday morning. Some rain may linger over the mountains but drier weather will begin quickly in the afternoon as the upper ridge builds.
The mound will remain in place until the end of the week. An upper-level trough will dig into the Great Basin early next week and increase northward flow.