Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Friday & Friday
Afternoon update: Day 1 Precipitation Forecast has been increased for Mt. Hood.
Earlier today, an upper level shortwave upstream in NW flow aloft caused cloudy conditions with periods of light snow for the Olympics and the west slopes of the Cascades including the Passes. Light snowfall has shifted south of Snoqualmie Pass this afternoon with a partial clearing trend to the north. As warm frontal moisture slips under a ridge located offshore, snow will become occasionally moderate over the Mt. Hood region and the far south Washington Cascades Friday night. Recent moderate NW winds in the alpine should relax over the Washington Cascades this afternoon but stay moderate over Mt. Hood.
Upper level ridging will temporarily build over the area on Saturday with continued NW flow aloft. Mostly clear conditions are expected. However, strong arctic high pressure sliding south through British Columbia will increase offshore gradients, with moderate easterly winds at Pass level expected Saturday afternoon and night. An approaching Pacific frontal system will spread clouds into the region Saturday night.
Weather Forecast
Olympics
| Friday | Periods of light snow tapering off mid-day. Partial clearing trend expected in the afternoon. Light snow along the north slopes of the Olympics. |
| Friday Night | Partly to mostly clear. |
| Saturday | Mostly clear. |
| Saturday Night | Increasing clouds. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Friday | Light snow shifting from north to south during the day. Clearing trend expected in the north in the afternoon. |
| Friday Night | Mostly clear north. Partly cloudy south. |
| Saturday | Mostly clear. |
| Saturday Night | Increasing clouds. Locally breezy east winds Cascade Passes. |
East Slopes of the Washington Cascades
| Friday | Periods of light snow, mainly near the Cascade crest, shifting from north to south during the day. Clearing trend expected in the north in the afternoon. |
| Friday Night | Mostly clear north. Partly cloudy south. |
| Saturday | Mostly clear. |
| Saturday Night | Increasing clouds. |
Mt. Hood
| Friday | Cloudy with periods of light snow later in the morning, increasing in the afternoon. |
| Friday Night | Light to moderate snow. |
| Saturday | Light snow in the morning ending with partial clearing expected in the afternoon. |
| Saturday Night | Increasing clouds. |
Issued: 3:30 PM PST Friday, December 22, 2017
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Friday | Snow Level | 1000' | 500' | 0' | ' | ' | 1000' | ' | 2500' |
| Friday Night | Snow Level | 500' | 0' | 0' | ' | ' | 0' | ' | 2000' |
| Saturday Morning | Freezing Level * | 0' | 0' | 0' | ' | ' | 0' | ' | 0' |
| Saturday Afternoon | Freezing Level * | 1500' | 500' | 0' | ' | ' | 500' | ' | 1000' |
| Saturday Night | Freezing Level * | 2500' | 1000' | 0' | ' | ' | 500' | ' | 1000' |
| Saturday Night | Snow Level | ' | ' | ' | ' | ' | ' | ' | ' |
| Hurricane Ridge | Elevation |
|---|---|
| Friday |
Snow Level 1000' |
| Friday Night |
Snow Level 500' |
| Saturday Morning |
Freezing Level 0' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level 1500' (Easterly Flow *) |
| Saturday Night |
Freezing Level 2500' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Mt. Baker | Elevation |
|---|---|
| Friday |
Snow Level 500' |
| Friday Night |
Snow Level 0' |
| Saturday Morning |
Freezing Level 0' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level 500' (Easterly Flow *) |
| Saturday Night |
Freezing Level 1000' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Washington Pass | Elevation |
|---|---|
| Friday |
Snow Level 0' |
| Friday Night |
Snow Level 0' |
| Saturday Morning |
Freezing Level 0' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level 0' (Easterly Flow *) |
| Saturday Night |
Freezing Level 0' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Leavenworth | Elevation |
|---|---|
| Friday |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Saturday Morning |
Freezing Level ' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Saturday Night |
Freezing Level ' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Friday |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Saturday Morning |
Freezing Level ' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Saturday Night |
Freezing Level ' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Friday |
Snow Level 1000' |
| Friday Night |
Snow Level 0' |
| Saturday Morning |
Freezing Level 0' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level 500' (Easterly Flow *) |
| Saturday Night |
Freezing Level 500' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Friday |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Saturday Morning |
Freezing Level ' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Saturday Night |
Freezing Level ' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Friday |
Snow Level 2500' |
| Friday Night |
Snow Level 2000' |
| Saturday Morning |
Freezing Level 0' (Easterly Flow *) |
| Saturday Afternoon |
Freezing Level 1000' (Easterly Flow *) |
| Saturday Night |
Freezing Level 1000' (Easterly Flow *) |
| Saturday Night |
Snow Level ' |
* Easterly flow in the Cascade Passes can cause locally lower Snow or Freezing levels than areas further west.
Freezing Level is when no precipitation is forecast.
Precipitation Forecast
| Friday | Friday | |
|---|---|---|
| Hurricane Ridge | LT 0.10 | LT 0.10 |
| Mt Baker Ski Area | LT 0.25 | LT 0.10 |
| Washington Pass | LT 0.10 | LT 0.10 |
| Stevens Pass | LT 0.25 | LT 0.10 |
| Snoqualmie Pass | LT 0.25 | LT 0.10 |
| Mission Ridge | LT 0.10 | LT 0.10 |
| Crystal Mt | LT 0.25 | LT 0.10 |
| Paradise | LT 0.25 | LT 0.10 |
| White Pass | LT 0.25 | LT 0.10 |
| Mt Hood Meadows | 0 - 0.75 | LT 0.25 |
| Timberline | 0 - 1.00 | LT 0.25 |
LT = less than; WE or Water equivalent is the liquid water equivalent of melted snow in hundredths of inches. As a rough approximation 1 inch of snow = about .10 inches WE, or 10 inches of snow = about 1 inch WE.
Issued: 3:30 PM PST Friday, December 22, 2017
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Afternoon | NE 0 - 10 | NE 5 - 15 | NW 5 - 15 | --- - | W 15 - 25 |
| Friday Night | NE 5 - 15 | NE 5 - 15 | VAR 0 - 10 | --- - | W 0 - 10 |
| Saturday Morning | E 10 - 20 | ENE 10 - 20 | E 5 - 15 | --- - | E 5 - 15 |
| Saturday Afternoon | ENE 5 - 15 | ENE 0 - 10 | E 10 - 20 | --- - | ESE 10 - 20 |
| Saturday Night | SE 0 - 10 | E 0 - 10 | ESE 10 - 20 | --- - | ESE 5 - 15 |
| Saturday Night | --- - | --- - | --- - | --- - | --- - |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Afternoon | NE 0 - 10 |
| Friday Night | NE 5 - 15 |
| Saturday Morning | E 10 - 20 |
| Saturday Afternoon | ENE 5 - 15 |
| Saturday Night | SE 0 - 10 |
| Saturday Night | --- - |
| Mt. Baker | Elevation |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NE 5 - 15 |
| Saturday Morning | ENE 10 - 20 |
| Saturday Afternoon | ENE 0 - 10 |
| Saturday Night | E 0 - 10 |
| Saturday Night | --- - |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Friday Afternoon | NW 5 - 15 |
| Friday Night | VAR 0 - 10 |
| Saturday Morning | E 5 - 15 |
| Saturday Afternoon | E 10 - 20 |
| Saturday Night | ESE 10 - 20 |
| Saturday Night | --- - |
| Mt. Rainier | Elevation |
|---|---|
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Saturday Morning | --- - |
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Saturday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Friday Afternoon | W 15 - 25 |
| Friday Night | W 0 - 10 |
| Saturday Morning | E 5 - 15 |
| Saturday Afternoon | ESE 10 - 20 |
| Saturday Night | ESE 5 - 15 |
| Saturday Night | --- - |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Friday Afternoon | NE 0 - 10 |
| Friday Night | NE 5 - 15 |
| Saturday Morning | E 10 - 20 |
| Saturday Afternoon | ENE 5 - 15 |
| Saturday Night | SE 0 - 10 |
| Saturday Night | --- - |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NE 5 - 15 |
| Saturday Morning | ENE 10 - 20 |
| Saturday Afternoon | ENE 0 - 10 |
| Saturday Night | E 0 - 10 |
| Saturday Night | --- - |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Afternoon | NW 5 - 15 |
| Friday Night | VAR 0 - 10 |
| Saturday Morning | E 5 - 15 |
| Saturday Afternoon | E 10 - 20 |
| Saturday Night | ESE 10 - 20 |
| Saturday Night | --- - |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Saturday Morning | --- - |
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Saturday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Afternoon | W 15 - 25 |
| Friday Night | W 0 - 10 |
| Saturday Morning | E 5 - 15 |
| Saturday Afternoon | ESE 10 - 20 |
| Saturday Night | ESE 5 - 15 |
| Saturday Night | --- - |
Directions above indicate the direction the wind blows from on the 16-point cardinal scale. These winds indicate "free" winds, or those winds in the atmosphere not influenced by terrain. Topographical effects may produce greater or lower wind speeds in certain locations as well as significant variations in direction.
Free Winds at 9000' (mph)
| Mt. Baker | Washington Pass | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Afternoon | NW 0 - 10 | NW 5 - 15 | W 20 - 35 | --- - | W 30 - 40 |
| Friday Night | N 10 - 20 | N 10 - 20 | NW 15 - 25 | --- - | W 20 - 30 |
| Saturday Morning | NNE 15 - 25 | NNW 10 - 20 | NNW 10 - 20 | --- - | NNW 15 - 25 |
| Saturday Afternoon | N 10 - 20 | NNW 15 - 25 | NW 10 - 20 | --- - | WNW 5 - 15 |
| Saturday Night | SW 5 - 15 | SW 5 - 15 | SW 10 - 20 | --- - | SW 15 - 25 |
| Saturday Night | --- - | --- - | --- - | --- - | --- - |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Afternoon | NW 0 - 10 |
| Friday Night | N 10 - 20 |
| Saturday Morning | NNE 15 - 25 |
| Saturday Afternoon | N 10 - 20 |
| Saturday Night | SW 5 - 15 |
| Saturday Night | --- - |
| Washington Pass | Direction - Speed |
|---|---|
| Friday Afternoon | NW 5 - 15 |
| Friday Night | N 10 - 20 |
| Saturday Morning | NNW 10 - 20 |
| Saturday Afternoon | NNW 15 - 25 |
| Saturday Night | SW 5 - 15 |
| Saturday Night | --- - |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Afternoon | W 20 - 35 |
| Friday Night | NW 15 - 25 |
| Saturday Morning | NNW 10 - 20 |
| Saturday Afternoon | NW 10 - 20 |
| Saturday Night | SW 10 - 20 |
| Saturday Night | --- - |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Saturday Morning | --- - |
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Saturday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Afternoon | W 30 - 40 |
| Friday Night | W 20 - 30 |
| Saturday Morning | NNW 15 - 25 |
| Saturday Afternoon | WNW 5 - 15 |
| Saturday Night | SW 15 - 25 |
| Saturday Night | --- - |
Directions above indicate the direction the wind blows from on the 16-point cardinal scale. These winds indicate "free" winds, or those winds in the atmosphere not influenced by terrain. Topographical effects may produce greater or lower wind speeds in certain locations as well as significant variations in direction.
Issued: 3:30 PM PST Friday, December 22, 2017
Extended Weather Synopsis for Friday night through Friday
The upper level ridge that was over the area Saturday night will prove to be fleeting as a Pacific frontal system spreads light snow over the region on Sunday. Snowfall rates may locally become moderate in the southwest Cascades Sunday afternoon, but should predominately be light through the daylight hours. Snowfall should increase Sunday evening as a surface low passes to the south of the Olympics overnight. Post-frontal showers Sunday night through Monday morning will ease later in the afternoon. By Christmas afternoon, we should be left with partly to mostly cloudy skies with a few leftover mountain showers. Snow levels will remain low during this stretch.
Weak upper level ridging on Tuesday should lead to a dry and fair weather day.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Sunday | Snow Level | 500' - 1500' | 0' - 500' | 2000' - 3000' | |
| Sunday Night | Snow Level | 0' - 500' | 500' - 1500' | 1500' - 2500' | |
| Monday | Snow Level | 0' - 500' | 0' - 1000' | 1000' - 2000' | |
| Monday Night | Freezing Level | 0' - 500' | 0' - 500' | 1000' - 2000' | |
| Tuesday | Freezing Level | 1000' - 2000' | 2000' - 3000' | 4500' - 5500' |
| Mt. Baker | Elevation |
|---|---|
| Sunday |
Snow Level 500' - 1500' |
| Sunday Night |
Snow Level 0' - 500' |
| Monday |
Snow Level 0' - 500' |
| Monday Night |
Freezing Level 0' - 500' |
| Tuesday |
Freezing Level 1000' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Sunday |
Snow Level 0' - 500' |
| Sunday Night |
Snow Level 500' - 1500' |
| Monday |
Snow Level 0' - 1000' |
| Monday Night |
Freezing Level 0' - 500' |
| Tuesday |
Freezing Level 2000' - 3000' |
| Mt. Hood | Elevation |
|---|---|
| Sunday |
Snow Level 2000' - 3000' |
| Sunday Night |
Snow Level 1500' - 2500' |
| Monday |
Snow Level 1000' - 2000' |
| Monday Night |
Freezing Level 1000' - 2000' |
| Tuesday |
Freezing Level 4500' - 5500' |
* Easterly flow in the Cascade Passes can cause locally lower Snow or Freezing levels than areas further west.
Freezing Level is when no precipitation is forecast.
Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Previous forecast from Dec 22, 2017
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