January 1, 2020 – A few showers are possible today across the northern mountains as a weak weather system passes to the north, otherwise dry weather is expected across the region through the remainder of the week. Chances for precipitation return this weekend.
Discussion
Plenty of mid and high level clouds indicated by satellite imagery moving across NorCal early this morning associated with a short- wave moving through the PacNW. Radar shows some light precip occurring across the far northern portion of the state. With all the cloud cover, current temperatures are rather mild ranging from the upper 20s to mid 30s in the mountain valleys to mainly the 40s elsewhere.
Once the system moves east this morning, dry weather is expected the next several days as the eastern Pacific ridge amplifies and moves onto the West Coast. Temps are expected to be rather mild for this time of the year with widespread 60s highs possible in the valley on Thursday as light northerly flow returns for a day.
The next chance of precipitation will be late Friday night into Saturday, primarily well north of I-80. Snow levels appear to be between 5,000 and 6,000 feet with minor accumulations down to pass level. Models have remained in decent agreement with this system but will continue to monitor for any southward shifts.
Extended Discussion (Sunday through Wednesday)
A weak trough looks to clip the northern part of California which could bring some showers to the coastal and Cascade mountains on Sunday. The rest of NorCal looks to remain dry, with ridging returning behind this fast moving system. The ensembles appear to differ from each other with how strong and long this ridge holds. The GEFS keeps the ridge over us through the week while the EPS slides a trough over the PacNW midweek. NBM guidance appears to be a blend of the two, thus kept PoP chances to a minimum and mainly over the mountains for the time being.