November 17, 2021 – Locally breezy north to northeast winds into this afternoon. A chance of light showers late Thursday into Friday.
Discussion
Some high clouds are moving across the southern portion of the forecast area, through the short-wave ridge moving over NorCal. Otherwise, skies are clear except for areas of fog and low clouds over mainly the eastern half of the Central Valley south of Chico. The northerly surface pressure gradient (MFR-SAC) remains around 8.5-9 mbs while the northeast gradient (RNO-SAC) has tightened to around 4-4.5 mbs.
The result has been a continuation of the locally gusty north to east winds across the northern Sacramento Valley, foothills of the Coast Range, and northern Sierra. Most gusts have been in the 15-30 mph range, but local gusts over 40 mph have been observed at the usual spots near the mouth of the Feather River Canyon (Jarbo Gap RAWS).
Dry weather continues over the area today and most of Thursday as the ridge moves east. Temperatures today are expected to be similar to Tuesday’s with valley fog mixing out by late morning to early afternoon. Valley fog is forecast to redevelop tonight and spread further north up the valley as the north winds end.
A weak and rather disorganized southern stream trough moves through later Thursday into Friday and may bring some light precipitation mainly north of I-80. Amounts are expected to be very light with little or no snow impacts across the passes. Dry weather returns for Saturday with north wind limiting fog development.
Extended Discussion (Sunday through Wednesday)
No significant weather expected for the extended period. Ensemble guidance indicates ridging across the PacNW into northern CA Sunday through early next week. For mid-week, weak troughing is possible but for now it still looks like dry weather is favored. Have continued with the dry NBM forecast with near average highs and lows each day.