Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Monday & Saturday
On Monday, we will have strong westerly flow over the Pacific northwest with a strong N-S temperature gradient with an E-W oriented front lingering of the central and southern Cascades.
On Monday night, continued strong southwest flow lifts a front north to the Olympics and Washington Cascades.
Tuesday, a deepening surface low and front cross the Olympics in the late morning and the north Cascades early in the afternoon. Alpine winds will be strong and shifting over the course of the day.
Tuesday night, a deep, sharp upper trough swings across the Pafcific Northwest bringing decreasing and shifting winds with decreasing snow levels.
Weather Forecast
Olympics
| Monday | Increasing light rain and snow in the afternoon. |
| Monday Night | Increasing moderate to heavy rain and snow; shifting alpine winds. |
| Tuesday | Increasing moderate to heavy rain and snow in the morning with light showers in the afternoon. Shifting alpine winds. |
| Tuesday Night | Light showers and decreasing alpine winds. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Monday | Decreasing light to moderate rain and snow Monday afternoon, south and central Cascades. |
| Monday Night | Increasing light to moderate rain and snow becoming increasing moderate to heavy after midnight. Increasing, shifting alpine winds. |
| Tuesday | Increasing moderate to heavy rain and snow. Strong , shifting alpine winds. |
| Tuesday Night | Decreasing moderate showers. Decreasing alpine winds. |
East Slopes of the Washington Cascades
| Monday | Decreasing light rain and snow Monday afternoon, south and central Cascades. |
| Monday Night | Decreasing light rain and snow, heaviest south and central parts. |
| Tuesday | Increasing moderate rain and snow. Strong alpine winds shifting late in the day. |
| Tuesday Night | Decreasing light to moderate snow showers. Decreasing alpine winds. |
Mt. Hood
| Monday | Moderate rain and snow. |
| Monday Night | Light, occasionally moderate rain and snow increasing an hour or two before sunrise. Strong alpine winds. |
| Tuesday | Increasing moderate to heavy rain and snow especially in the afternoon. Strong to extreme alpine winds. |
| Tuesday Night | Decreasing showers and decreasing alpine winds. |
Issued: 2:19 PM PST Monday, December 18, 2017
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Monday Afternoon | Snow Level | 3000' | 2500' | 2500' | ' | ' | 3000' | ' | 6000' |
| Monday Night | Snow Level * | 2000' | 2000' | 2000' | ' | ' | 3000' | ' | 6000' |
| Tuesday Morning | Snow Level * | 3500' | 2500' | 2500' | ' | ' | 4000' | ' | 5000' |
| Tuesday Afternoon | Snow Level | 1000' | 2000' | 3000' | ' | ' | 2500' | ' | 3000' |
| Tuesday Night | Snow Level | 500' | 500' | 500' | ' | ' | 1000' | ' | 1500' |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 3000' |
| Monday Night |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 1000' |
| Tuesday Night |
Snow Level 500' |
| Mt. Baker | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 2500' |
| Monday Night |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 2500' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 2000' |
| Tuesday Night |
Snow Level 500' |
| Washington Pass | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 2500' |
| Monday Night |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 2500' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3000' |
| Tuesday Night |
Snow Level 500' |
| Leavenworth | Elevation |
|---|---|
| Monday Afternoon |
Snow Level ' |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level ' |
| Tuesday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Monday Afternoon |
Snow Level ' |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level ' |
| Tuesday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 3000' |
| Monday Night |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 2500' |
| Tuesday Night |
Snow Level 1000' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Monday Afternoon |
Snow Level ' |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level ' |
| Tuesday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 6000' |
| Monday Night |
Snow Level 6000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 5000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3000' |
| Tuesday Night |
Snow Level 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.
Precipitation Forecast
| Saturday | Saturday | |
|---|---|---|
| Hurricane Ridge | 0 - 1.00 | 0 - 1.00 |
| Mt Baker Ski Area | 0 - 0.75 | 0 - 2.00 |
| Washington Pass | 0.50 - 0.75 | 1.00 - 1.50 |
| Stevens Pass | 0 - 1.50 | 0 - 1.50 |
| Snoqualmie Pass | 1.50 - 2.00 | 0 - 1.50 |
| Mission Ridge | 0.25 - 0.50 | 0.50 - 0.75 |
| Crystal Mt | 0 - 0.75 | 0 - 1.00 |
| Paradise | 1.50 - 2.00 | 2.00 - 2.50 |
| White Pass | 0.75 - 1.00 | 0 - 1.00 |
| Mt Hood Meadows | 1.00 - 1.50 | 1.00 - 1.50 |
| Timberline | 0 - 1.50 | 0 - 1.50 |
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: 2:19 PM PST Monday, December 18, 2017
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Monday Afternoon | W 5 - 15 | SW 5 - 15 | W 10 - 20 | --- - | WSW 25 - 35 |
| Monday Night | SSE 10 - 20 | SE 5 - 15 | S 20 - 30 | --- - | SW 35 - 50 |
| Tuesday Morning | WSW 10 - 20 | SSE 15 - 25 | S 25 - 35 | --- - | SW 40 - 55 |
| Tuesday Afternoon | W 20 - 30 | W 5 - 15 | WSW 35 - 50 | --- - | W 30 - 45 |
| Tuesday Night | N 5 - 15 | N 5 - 15 | W 15 - 25 | --- - | WSW 30 - 45 |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Afternoon | W 5 - 15 |
| Monday Night | SSE 10 - 20 |
| Tuesday Morning | WSW 10 - 20 |
| Tuesday Afternoon | W 20 - 30 |
| Tuesday Night | N 5 - 15 |
| Mt. Baker | Elevation |
|---|---|
| Monday Afternoon | SW 5 - 15 |
| Monday Night | SE 5 - 15 |
| Tuesday Morning | SSE 15 - 25 |
| Tuesday Afternoon | W 5 - 15 |
| Tuesday Night | N 5 - 15 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Monday Afternoon | W 10 - 20 |
| Monday Night | S 20 - 30 |
| Tuesday Morning | S 25 - 35 |
| Tuesday Afternoon | WSW 35 - 50 |
| Tuesday Night | W 15 - 25 |
| Mt. Rainier | Elevation |
|---|---|
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Monday Afternoon | WSW 25 - 35 |
| Monday Night | SW 35 - 50 |
| Tuesday Morning | SW 40 - 55 |
| Tuesday Afternoon | W 30 - 45 |
| Tuesday Night | WSW 30 - 45 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Monday Afternoon | W 5 - 15 |
| Monday Night | SSE 10 - 20 |
| Tuesday Morning | WSW 10 - 20 |
| Tuesday Afternoon | W 20 - 30 |
| Tuesday Night | N 5 - 15 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Afternoon | SW 5 - 15 |
| Monday Night | SE 5 - 15 |
| Tuesday Morning | SSE 15 - 25 |
| Tuesday Afternoon | W 5 - 15 |
| Tuesday Night | N 5 - 15 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Afternoon | W 10 - 20 |
| Monday Night | S 20 - 30 |
| Tuesday Morning | S 25 - 35 |
| Tuesday Afternoon | WSW 35 - 50 |
| Tuesday Night | W 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Afternoon | WSW 25 - 35 |
| Monday Night | SW 35 - 50 |
| Tuesday Morning | SW 40 - 55 |
| Tuesday Afternoon | W 30 - 45 |
| Tuesday Night | WSW 30 - 45 |
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 | |
|---|---|---|---|---|---|
| Monday Afternoon | WSW 40 - 60 | WSW 25 - 35 | WSW 45 - 65 | --- - | WSW 40 - 60 |
| Monday Night | SW 45 - 65 | SSW 40 - 60 | SW 50 - 70 | --- - | SW 50 - 80 |
| Tuesday Morning | SW 30 - 45 | S 50 - 70 | SW 60 - 80 | --- - | SW 65 - 85 |
| Tuesday Afternoon | W 25 - 35 | WSW 15 - 25 | WSW 45 - 65 | --- - | W 50 - 70 |
| Tuesday Night | W 10 - 20 | NW 10 - 20 | W 35 - 45 | --- - | W 40 - 60 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Afternoon | WSW 40 - 60 |
| Monday Night | SW 45 - 65 |
| Tuesday Morning | SW 30 - 45 |
| Tuesday Afternoon | W 25 - 35 |
| Tuesday Night | W 10 - 20 |
| Washington Pass | Direction - Speed |
|---|---|
| Monday Afternoon | WSW 25 - 35 |
| Monday Night | SSW 40 - 60 |
| Tuesday Morning | S 50 - 70 |
| Tuesday Afternoon | WSW 15 - 25 |
| Tuesday Night | NW 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Afternoon | WSW 45 - 65 |
| Monday Night | SW 50 - 70 |
| Tuesday Morning | SW 60 - 80 |
| Tuesday Afternoon | WSW 45 - 65 |
| Tuesday Night | W 35 - 45 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Afternoon | WSW 40 - 60 |
| Monday Night | SW 50 - 80 |
| Tuesday Morning | SW 65 - 85 |
| Tuesday Afternoon | W 50 - 70 |
| Tuesday Night | W 40 - 60 |
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: 2:19 PM PST Monday, December 18, 2017
Extended Weather Synopsis for Saturday night through Saturday
On Wednesday, the deep, sharp upper trough will move east, bringing a drier, northerly flow to the forecast area.
By Thursday, the upper ridge re-develops over the US coastal waters and BC.
On Friday, a moisture-starved short-wave in northerly N-NW flow aloft may brush the forecast area.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Wednesday | Freezing Level | 1000' - 2000' | 1500' - 2500' | 2000' - 3000' | |
| Wednesday Night | Freezing Level | 1000' - 2000' | 2500' - 3500' | 1000' - 2000' | |
| Thursday | Freezing Level | 1000' - 2000' | 1500' - 2500' | 2000' - 4000' | |
| Thursday Night | Snow Level | 500' - 1500' | 1000' - 2000' | 1500' - 2500' | |
| Friday | Snow Level | 0' - 2000' | 0' - 2000' | 0' - 2000' |
| Mt. Baker | Elevation |
|---|---|
| Wednesday |
Freezing Level 1000' - 2000' |
| Wednesday Night |
Freezing Level 1000' - 2000' |
| Thursday |
Freezing Level 1000' - 2000' |
| Thursday Night |
Snow Level 500' - 1500' |
| Friday |
Snow Level 0' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday |
Freezing Level 1500' - 2500' |
| Wednesday Night |
Freezing Level 2500' - 3500' |
| Thursday |
Freezing Level 1500' - 2500' |
| Thursday Night |
Snow Level 1000' - 2000' |
| Friday |
Snow Level 0' - 2000' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday |
Freezing Level 2000' - 3000' |
| Wednesday Night |
Freezing Level 1000' - 2000' |
| Thursday |
Freezing Level 2000' - 4000' |
| Thursday Night |
Snow Level 1500' - 2500' |
| Friday |
Snow Level 0' - 2000' |
* 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 18, 2017
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.