Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Saturday & Wednesday
Afternoon update: Slight changes to precipitation forecasts for Day 1 and Day 2. If you're out in the mountains from late morning onward Saturday, you know it's been exceptionally windy with strong west winds seen at all elevations and at most stations. On Saturday, several NWAC stations gusted over 100 mph earlier today: White Pass, Camp Muir, Mission Ridge, Cascade Express-Hood.
Prev discussion: Our active pattern continues with the second low pressure system in 24 hours for the Pacific Northwest sliding down over the area in NW flow aloft. Precipitation has become moderate to locally heavy over the Cascade Passes this morning and precipitation rates in general should increase through the early afternoon hours. The low pressure center currently off the northern tip of Vancouver Island will pass into southern British Columbia this afternoon with the trailing front passing through the Cascades in the early afternoon. A swath of warmer air will push into the mountains from about Stevens Pass to Mt. Hood, with the north Cascades having a more muted warming trend. Snow levels should peak around 6000 ft at Mt. Hood, 4500 ft in the Crystal Paradise/Mt. Rainier area and 4000 feet for Stevens/Snoqualmie Pass mid-day. During and following the frontal passage westerly winds will be strong, but most pronounced from Snoqualmie Pass and southward. Expect sharp cooling this afternoon behind the front.
The quasi-stationary Pacific upper level ridge parked offshore will retrograde to 145W Saturday night and Sunday. This will open the door for the coldest air of the season to begin to infiltrate from the interior. As the upper level trough digs over the Pacific Northwest and northern California Sunday, a weak surface low pressure system off the Washington/Oregon coast will invigorate snow shower activity for the Mt. Hood area and the south Washington Cascades while a slow drying trend takes place over the northwest and central-west Cascades. Colder air being drawn across the Strait of Juan de Fuca will lead to upslope snow showers in the Hurricane Ridge area. Upslope snow showers also look likely along the east slopes of the Cascades on Sunday with significant accumulations potential for Mission Ridge.
Shower activity will wane Sunday night as the trough digs over the intermountain West and the flow aloft turns northerly.
Weather Forecast
Olympics
| Saturday | Light to moderate rain and snow. Warming trend peaking mid-day. Showers and strong cooling trend mid-afternoon. Becoming windy. |
| Saturday Night | Light to occasionally moderate snow showers. Strong cooling trend. Winds decreasing overnight. |
| Sunday | Light to occasionally moderate snow showers in the morning along the north slopes of the Olympics becoming scattered in the afternoon. Cold. |
| Sunday Night | Partly cloudy with isolated light snow showers. Cold. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Saturday | Stormy. Warming trend strongest from Stevens Pass to White Pass, peaking mid-day. Showers and strong cooling trend late afternoon. Very windy. |
| Saturday Night | Light to occasionally moderate snow showers. Strong cooling trend. Winds decreasing overnight. |
| Sunday | Mostly cloudy with scattered snow showers in the north Cascades. Light snow showers central and south. Cold. |
| Sunday Night | Partly cloudy with isolated light snow showers. Cold. |
East Slopes of the Washington Cascades
| Saturday | Light to moderate rain and snow. Warming trend strongest from Stevens Pass to White Pass, peaking mid-day. Light to moderate showers and strong cooling trend late afternoon. Very windy. |
| Saturday Night | Light to moderate snow showers. Strong cooling trend. Winds decreasing overnight. |
| Sunday | Light to moderate snow showers in the morning becoming scattered in the afternoon. Cold. |
| Sunday Night | Partly cloudy with isolated light snow showers. Cold. |
Mt. Hood
| Saturday | Stormy. Warming trend peaking mid-day. Showers and cooling trend late afternoon. Very windy. |
| Saturday Night | Light to occasionally moderate snow showers. Strong cooling trend. |
| Sunday | Light to moderate snow showers. Cold. Winds decreasing. |
| Sunday Night | Mostly to partly cloudy with isolated light snow showers. Cold. |
Issued: 2:52 PM PST Saturday, February 17, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Saturday Mid-day | Snow Level | 5000' | 3000' | 2500' | ' | ' | 4000' | ' | 6000' |
| Saturday Afternoon | Snow Level | 3000' | 2500' | 3000' | ' | ' | 2500' | ' | 4500' |
| Saturday Night | Snow Level | 2000' | 2000' | 2000' | ' | ' | 2000' | ' | 3000' |
| Sunday Morning | Snow Level | 1000' | 1000' | 500' | ' | ' | 1000' | ' | 2500' |
| Sunday Afternoon | Snow Level | 0' | 0' | 0' | ' | ' | 500' | ' | 1000' |
| Sunday Night | Snow Level | 0' | 0' | 0' | ' | ' | 0' | ' | 0' |
| Hurricane Ridge | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level 5000' |
| Saturday Afternoon |
Snow Level 3000' |
| Saturday Night |
Snow Level 2000' |
| Sunday Morning |
Snow Level 1000' |
| Sunday Afternoon |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Mt. Baker | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level 3000' |
| Saturday Afternoon |
Snow Level 2500' |
| Saturday Night |
Snow Level 2000' |
| Sunday Morning |
Snow Level 1000' |
| Sunday Afternoon |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Washington Pass | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level 2500' |
| Saturday Afternoon |
Snow Level 3000' |
| Saturday Night |
Snow Level 2000' |
| Sunday Morning |
Snow Level 500' |
| Sunday Afternoon |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Leavenworth | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level ' |
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' |
| Sunday Morning |
Snow Level ' |
| Sunday Afternoon |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level ' |
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' |
| Sunday Morning |
Snow Level ' |
| Sunday Afternoon |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level 4000' |
| Saturday Afternoon |
Snow Level 2500' |
| Saturday Night |
Snow Level 2000' |
| Sunday Morning |
Snow Level 1000' |
| Sunday Afternoon |
Snow Level 500' |
| Sunday Night |
Snow Level 0' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level ' |
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' |
| Sunday Morning |
Snow Level ' |
| Sunday Afternoon |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Saturday Mid-day |
Snow Level 6000' |
| Saturday Afternoon |
Snow Level 4500' |
| Saturday Night |
Snow Level 3000' |
| Sunday Morning |
Snow Level 2500' |
| Sunday Afternoon |
Snow Level 1000' |
| Sunday Night |
Snow Level 0' |
* 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
| Wednesday | Wednesday | |
|---|---|---|
| Hurricane Ridge | 0 - 1.00 | 0.25 - 0.50 |
| Mt Baker Ski Area | 1.00 - 1.50 | LT 0.10 |
| Washington Pass | 1.00 - 1.50 | LT 0.25 |
| Stevens Pass | 1.50 - 2.00 | LT 0.25 |
| Snoqualmie Pass | 0 - 2.00 | LT 0.25 |
| Mission Ridge | 0.50 - 0.75 | 0 - 0.50 |
| Crystal Mt | 0 - 1.00 | LT 0.25 |
| Paradise | 2.00 - 2.50 | 0 - 0.50 |
| White Pass | 0 - 1.50 | 0.25 - 0.50 |
| Mt Hood Meadows | 0 - 2.50 | 0.75 - 1.00 |
| Timberline | 0 - 3.00 | 0 - 1.00 |
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: 2:52 PM PST Saturday, February 17, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Saturday Afternoon | WSW 25 - 35 | SW 20 - 30 | WSW 35 - 55 | --- - | SW 45 - 55 |
| Saturday Night | WSW 15 - 25 | SW 10 - 20 | SW 25 - 35 | --- - | WSW 25 - 35 |
| Sunday Morning | NNE 10 - 20 | NE 10 - 20 | SW 10 - 20 | --- - | SW 15 - 30 |
| Sunday Afternoon | NNE 15 - 25 | NE 10 - 20 | NW 5 - 15 | --- - | VAR 5 - 15 |
| Sunday Night | NNE 15 - 25 | NE 10 - 20 | E 0 - 10 | --- - | E 5 - 15 |
| Hurricane Ridge | Elevation |
|---|---|
| Saturday Afternoon | WSW 25 - 35 |
| Saturday Night | WSW 15 - 25 |
| Sunday Morning | NNE 10 - 20 |
| Sunday Afternoon | NNE 15 - 25 |
| Sunday Night | NNE 15 - 25 |
| Mt. Baker | Elevation |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night | SW 10 - 20 |
| Sunday Morning | NE 10 - 20 |
| Sunday Afternoon | NE 10 - 20 |
| Sunday Night | NE 10 - 20 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Saturday Afternoon | WSW 35 - 55 |
| Saturday Night | SW 25 - 35 |
| Sunday Morning | SW 10 - 20 |
| Sunday Afternoon | NW 5 - 15 |
| Sunday Night | E 0 - 10 |
| Mt. Rainier | Elevation |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Saturday Afternoon | SW 45 - 55 |
| Saturday Night | WSW 25 - 35 |
| Sunday Morning | SW 15 - 30 |
| Sunday Afternoon | VAR 5 - 15 |
| Sunday Night | E 5 - 15 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 25 - 35 |
| Saturday Night | WSW 15 - 25 |
| Sunday Morning | NNE 10 - 20 |
| Sunday Afternoon | NNE 15 - 25 |
| Sunday Night | NNE 15 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night | SW 10 - 20 |
| Sunday Morning | NE 10 - 20 |
| Sunday Afternoon | NE 10 - 20 |
| Sunday Night | NE 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 35 - 55 |
| Saturday Night | SW 25 - 35 |
| Sunday Morning | SW 10 - 20 |
| Sunday Afternoon | NW 5 - 15 |
| Sunday Night | E 0 - 10 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 45 - 55 |
| Saturday Night | WSW 25 - 35 |
| Sunday Morning | SW 15 - 30 |
| Sunday Afternoon | VAR 5 - 15 |
| Sunday Night | E 5 - 15 |
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 | |
|---|---|---|---|---|---|
| Saturday Afternoon | WSW 40 - 50 | WSW 35 - 45 | WSW 65 - 80 | --- - | WSW 65 - 80 |
| Saturday Night | SW 15 - 25 | W 20 - 30 | WSW 30 - 40 | --- - | WSW 40 - 50 |
| Sunday Morning | NE 10 - 20 | N 10 - 20 | NW 5 - 15 | --- - | WSW 25 - 40 |
| Sunday Afternoon | NE 15 - 25 | NNE 15 - 25 | NW 10 - 20 | --- - | W 20 - 30 |
| Sunday Night | NE 15 - 25 | NNE 15 - 25 | N 0 - 10 | --- - | NW 5 - 15 |
| Mt. Baker | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 40 - 50 |
| Saturday Night | SW 15 - 25 |
| Sunday Morning | NE 10 - 20 |
| Sunday Afternoon | NE 15 - 25 |
| Sunday Night | NE 15 - 25 |
| Washington Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 35 - 45 |
| Saturday Night | W 20 - 30 |
| Sunday Morning | N 10 - 20 |
| Sunday Afternoon | NNE 15 - 25 |
| Sunday Night | NNE 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 65 - 80 |
| Saturday Night | WSW 30 - 40 |
| Sunday Morning | NW 5 - 15 |
| Sunday Afternoon | NW 10 - 20 |
| Sunday Night | N 0 - 10 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 65 - 80 |
| Saturday Night | WSW 40 - 50 |
| Sunday Morning | WSW 25 - 40 |
| Sunday Afternoon | W 20 - 30 |
| Sunday Night | NW 5 - 15 |
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: 2:52 PM PST Saturday, February 17, 2018
Extended Weather Synopsis for Wednesday night through Wednesday
We will be in the familiar position of N-NW flow aloft Monday through Wednesday with an upper ridge positioned offshore around 145W and longwave troughing over the intermountain West shifting to the Rockies. However, modified arctic air will be entrenched over the Olympics and Cascades for the first half of the week. Hard to time shortwaves in NW flow will approach the area Tuesday and Wednesday, potentially bringing a quick shot of light snow to the region. Alpine winds out of the north will be the a persistent feature during this period as well.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Monday Partly to mostly clear. Cold. Tuesday Fair. Cold. Wednesday Mostly cloudy with periods of light snow. Cold.Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Monday | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Monday Night | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Tuesday | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Tuesday Night | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Wednesday | Snow Level | 0' - 1000' | 0' - 1000' | 500' - 1500' |
| Mt. Baker | Elevation |
|---|---|
| Monday |
Snow Level 0' - 0' |
| Monday Night |
Snow Level 0' - 0' |
| Tuesday |
Snow Level 0' - 0' |
| Tuesday Night |
Snow Level 0' - 0' |
| Wednesday |
Snow Level 0' - 1000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday |
Snow Level 0' - 0' |
| Monday Night |
Snow Level 0' - 0' |
| Tuesday |
Snow Level 0' - 0' |
| Tuesday Night |
Snow Level 0' - 0' |
| Wednesday |
Snow Level 0' - 1000' |
| Mt. Hood | Elevation |
|---|---|
| Monday |
Snow Level 0' - 0' |
| Monday Night |
Snow Level 0' - 0' |
| Tuesday |
Snow Level 0' - 0' |
| Tuesday Night |
Snow Level 0' - 0' |
| Wednesday |
Snow Level 500' - 1500' |
* 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 Feb 17, 2018
The NWAC program is administered by the USDA-Forest Service and operates from the National Weather Service Forecast Office in Seattle. NWAC services are made possible by important collaboration and support from a wide variety of federal, state and private cooperators.