National Weather Service United States Department of Commerce

Slow Moving Storm to Impact California and Dampen Western States

A slow moving system off the California coastline will bring rain, mountain snow, and coastal impacts. Locally heavy rain may cause flash flooding, especially, on burn scars in from central California to southwestern Oregon. Snow up to 3 feet will be possible in the Sierra-Nevada Mountains. Rain with mountain snow can be expected from the Northwest to the Northern Rockies and into the Plains. Read More >

Snow Amount Potential
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Expected Snowfall - Official NWS Forecast
Point Range
Expected Snowfall - Official NWS Forecast
What's this?
High End Amount
1 in 10 Chance (10%) of Higher Snowfall

Maximum Potential Snow Accumulation
What's this?
Low End Amount
9 in 10 Chance (90%) of Higher Snowfall

Minimum Potential Snow Accumulation
What's this?

Low End Amount – 9 in 10 Chance (90%) of Higher Snowfall

 

This map depicts a reasonable lower-end snowfall amount for the time period shown on the graphic, based on many computer model simulations of possible snowfall totals. This lower amount is an unlikely scenario with a 9 in 10, or 90% chance that more snow will fall, and only a 1 in 10, or 10% chance that less snow will fall. This number can help serve as a lower-end scenario for planning purposes.

Expected Snowfall - Official NWS Forecast

 

This map is the official NWS snowfall forecast in inches during the time period shown on the graphic. This snowfall amount is determined by NWS forecasters to be the most likely outcome based on evaluation of data from computer models, satellite, radar, and other observations.

High End Amount – Only a 1 in 10 Chance (10%) of Higher Snowfall

 

This map depicts a reasonable upper-end snowfall amount for the time period shown on the graphic, based on many computer model simulations of possible snowfall totals. This higher amount is an unlikely scenario, with only a 1 in 10, or 10% chance that more snow will fall, and a 9 in 10, or 90% chance that less snow will fall. This number can help serve as an upper-end scenario for planning purposes.

 
The purpose of these experimental probabilistic snowfall products is to provide customers and partners a range of snowfall possibilities, in complement to existing NWS deterministic snowfall graphics, to better communicate forecast uncertainties during winter weather events. For more information visit this project's Product/Service Description Document, and please provide us your feedback here.
Percent Chance That Snow Amounts Will Be Greater Than...
Experimental -
 
What's this?

Percent Chance That Snow Amounts Will Be Greater Than

 

This series of maps shows the probability (that is, the likelihood) that snowfall will equal or exceed specific amounts during the time period shown on the graphic. These forecasts are based on many computer model simulations of possible snowfall totals.

Hover over thumbnails below to view larger image.
>=0.1"
>=0.1"
>=1"
>=1"
>=2"
>=2"
>=4"
>=4"
>=6"
>=6"
>=8"
>=8"
>=12"
>=12"
>=18"
>=18"

Snowfall Totals by Location
Experimental -
 
What's this?

Snowfall Totals by Location

 

These tables show the snowfall forecast for individual locations, and provide the same information as the graphics on this web page, just shown in a different way. All of these values are valid for the same time period as depicted on the graphics.

County:
 
Long-Range Forecast
 

Days 4-7

Day 4 Winter Weather Outlook Day 5 Winter Weather Outlook
Day 4 Winter Weather Outlook Day 5 Winter Weather Outlook
 
Day 6 Winter Weather Outlook Day 7 Winter Weather Outlook
Day 6 Winter Weather Outlook Day 7 Winter Weather Outlook
 
Days 4-5 Forecast Precipitation Days 6-7 Forecast Precipitation
Days 4-5 Precip Days 6-7 Precip
 
 

Days 6-10

Temperature  Precipitation
6-10 day temperature 6-10 day precipitation
 
 

Days 8-14

TEMPERATURE  PRECIPITATION
8-14 day temperature 8-14 day precipitation
 
 

Week 3-4

TEMPERATURE

PRECIPITATION

Week 3-4 Temperature Week 3-4 precipitation