Winter Storm Warning for a high impact snowstorm this afternoon through Monday – significant rainfall in the Foothills

November 30, 2019 – A significant winter storm arrives today with snow levels initially in the upper foothills then rising to pass levels by Sunday. Feet of snow are expected at and around the Sierra passes through the weekend. Windy conditions are expected in the Valley, mainly south of I-80 tonight through Sunday. Snow decreases Monday night, with lighter snow accumulations continuing into Tuesday. The wet pattern will continue into next week bring periods of rain and high mountain snow. Another very wet system could arrive late in the week.

Impacts

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  • Major mountain travel delays
  • Low visibility due to a combination of wind & heavy snow
  • Chain controls for mountain travel, highway closures
  • Difficult driving conditions down to the Valley for high profile vehicles from gusty winds (added)
  • Tree branches could blow down bringing local power outages (added)
  • Slick roads and minor roadway flooding 

Forecast Confidence

  • High for high elevation heavy snow 
  • High for wind (added)

Timing

  • Today – Monday 
  • Widespread precipitation spreads over the region Saturday
    • Snow levels 2500 feet, rising to near or above pass levels late Sunday
    • Heavy snow Coastal and northern mountains
      • Heaviest snow amounts expected late Saturday
      • Generally 6 to 12 inches, local amounts up to 2 feet 
      • Accumulations beginning in the foothills Saturday
    • Sierra Nevada
      • Heaviest snow amounts expected this evening into Sunday
      • Generally 3 to 5 feet of snow at pass levels (increased)
    • Valley
      • Moderate to heavy rain across the Valley
      • Winds gusting  to 45 mph for southern Sacramento & Northern San Joaquin valleys this afternoon into Sunday morning  (added)
      • Heaviest rain this evening into early Sunday
  • Lighter rain/snow showers persist into late Monday/Tuesday mainly in the Sierra Nevada with snow levels at or above pass levels
  • Additional storms could bring rain and mountain snow by midweek, and again by late next week