January 15, 2020 – A Winter Storm arrives tonight continuing through Friday morning bringing periods of rain, snow, and gusty winds to the area. Wet weather continues over the weekend into next week.
Discussion
Clear to partly cloudy skies cover the region early this morning as we’re in a brief interlude before the next storm system moves in later today. With a relative lack of cloud cover compared to yesterday, current temperatures are running much cooler compared to 24 hours ago and range from the single digits and teens in the mountain valleys to mainly the 30s across the Central Valley.
Little change to current forecasts as satellite imagery shows the well-advertised upcoming system taking shape off the coast of the PacNW. The system will move ashore later today, moving across interior NorCal tonight and Thursday with showers lingering into Friday. Heavy snow is likely for the upper foothills and mountains with major travel impacts likely. Moderate amounts of rain are likely for the valley. Post-frontal thunderstorms are also possible Thursday afternoon.

Precipitation chances taper and retreat to the northern mountains on Friday as broad ridging returns. Another weaker system moves into the area on Sunday, but precipitation chances will be mainly limited to areas north of I-80.
Extended Discussion (Sunday through Wednesday)
Lingering post-frontal showers are possible early Sunday, mainly over the mountains, otherwise drier weather for the second half of the weekend under short wave ridging.
Models have come into better agreement for the early part of next week as far as several systems bringing wet weather into midweek. Pacific frontal system progged to move into interior NorCal during the Monday to Tuesday time frame. GFS continues to be more progressive than the EC, spreading precip into the Central Valley by Monday afternoon. The EC delays onset of precip until Tuesday morning. Another front follows later Tuesday into Wednesday for more widespread light to moderate precip.