December 17, 2017 – A quick weather system will move through northern California Tuesday night and Wednesday. Light rainfall is expected for the valley with low elevation mountain snow. Light accumulations possible around 2000 feet in the north to around 4000 feet in the south. Locally lower snow levels will be possible. Southwest wind gusts 50 mph or higher over higher terrain Tuesday night and Wednesday. Breezy southeast to southwest winds for valley as system passes becoming northerly after the system passes.


  • Slippery roads will increase travel times through mountains.
  • Possibly travel delays and chain controls.

Forecast Confidence

  • Medium for snow levels – chance they may be a little lower.
  • High for some precipitation.

Timing and Strength

  • Storm system begins Tuesday night; continuing into Wednesday afternoon.
  • Rain less than 0.25 for the valley.
  • 2-7 inches of snow for mountains above 4000 feet, highest totals above 5000 feet.
  • Snow levels lowering on late Tuesday night and Wednesday morning.
  • Wind gusts 50 mph or higher for ridges Tuesday night and Wednesday.