December 27, 2016 – Dry weather with cool overnight temperatures and patchy morning valley fog this week. Chance of showers by the weekend.
Discussion
Quite a bit of high cloudiness has spread across the region early this morning as a weather system moves by to our north. Coupled with ridging building in, temperatures are considerably milder across most of interior NorCal compared to 24 hours ago. Current readings are in the teens and 20s in the mountain valleys with 30s elsewhere.
Dry weather will be prevalent this week, though a few light showers will be possible today over the northern mountains as the tail end of the system brushes NorCal. Overnight lows are expected to be a little milder the next few nights, though some upper 20s will be possible again in the Central Valley. Milder daytime temperatures are expected beginning mid-week.
Extended discussion (Saturday through Tuesday)
Models are in a bit better alignment on a low pressure system straddling the coastline and moving southward from NorCal to SoCal on Saturday. The associated moisture likely extending over to the Sierra for a chance of snow showers with rain in the valley.
As that low reaches SoCal, models show that a broader trough to over the Pacific NW will start to dig southward late Saturday or early Sunday bringing additional moisture Sunday into early next week. This trough will be fairly stationary and just linger over NorCal through midweek so expect much of the extended forecast to be in a wet, cold pattern with potentially low snow levels.