November 14, 2016 – Dry weather through early Tuesday and patchy morning valley fog. A system will bring light rain and mountain snow to the area later Tuesday into Wednesday. Mainly dry Thursday-Friday. Wet weather may develop next weekend.
Mostly clear skies across interior NorCal early this morning with patches of valley fog. Current temperatures are in the upper 20s and lower 30s in the mountain valleys with mid 40s to lower 50s elsewhere.
Warm and dry weather will continue across the region today as high pressure remains in place. Temperatures will remain above average for mid-November.
The large trough over the Gulf of Alaska will move closer to NorCal tonight and Tuesday bringing a return of precipitation to areas mainly north of I-80. QPF is not looking overly impressive with a few tenths possible in the Valley with a half inch or so across much of the higher terrain. The trough is forecast to deepen over the region on Wednesday with lots of showers likely continuing over the mountains along with lowering snow levels.
Snow levels will rapidly drop Tuesday night, and could drop to around 4000-5000 feet by Wednesday. Forecast models suggests only light accumulations of snow, but mountain travel could still be impacted. Gusty winds could develop over higher terrain as the system moves through. Cooler temperatures are expected across interior NorCal with readings lowering to slightly below average.
Extended discussion (Friday through Monday)
Confidence is improving for a general wet pattern with a moist southwest flow late this week into early next week, along with below normal high temperatures. The exact details and timing continue to be uncertain.
Overall, the frontal passage looks a little slower on Friday, with the afternoon remaining dry and onset of precipitation expected to wait until night. The GFS continues to have a stronger/wetter system than the ECMWF or GEM. Have blended QPF, leaning more towards the more conservation ECMWF for now.
While there could be some snow accumulating at pass levels, winter travel impacts are not expected to be high at this point. Stay tuned to see how this system develops.