Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k
Weather Synopsis for Wednesday & Monday
A deepening, open trough offfshore of the Alaskan panhandle will drop south Wednesday as it combines with several closed low circulations off the California coast which are currently impacting California with plentiful moisture. The combined trough and associated developing S-SW flow aloft over our region will tap into some of this moisture and mild air and will bringing it over the forecast area, particularly overnight and Thursday morning ahead of a surface frontal feature dropping south and then eastward Wednesday and Wednesday night. By the time the front reaches our forecast area the front will be oriented N-S, arriving on the Oregon coast Thursday morning around 8 AM, Hood and the Olympics by 11 AM and it will have passed the Washington Cascades by 2 PM.
Moisture will increase ahead of the frontal system as initially light rain and high elevation snow will become periodically moderate overnight and tomorrow morning with models indicating the potential for more rain and snow on the east slopes than the west slopes due to the low-level SE flow ahead of the surface frontal passage.
The cold front will lower snow levels rapidly to below pass level in all areas by late Thursday afternoon and flow will become SW at lower levels. Precipitation will decrease behind the front on Thursday afternoon.
Thursday night as the upper trough and surface low continues moving S-SE, the flow aloft will once again become more southerly with a SE wind component at lower levels. Snow showers will increase in some areas Thursday night as the upper trough approaches.
In general, the Cascade volcanoes will receive the most moisture from this system, followed by the east slopes of the Cascades the Cascade passes will receive less moisture.
Weather Forecast
Olympics
| Wednesday | Sunny in the morning with high clouds increasing and lowering. |
| Wednesday Night | Cloudy with light rain or snow possible after midnight. |
| Thursday | Light rain or snow in the morning with strong cooling. Snow showers decreasing in the afternoon. |
| Thursday Night | Light snow showers. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Wednesday | Increasing clouds lowering, then very light rain and snow developing in some areas from south to north. |
| Wednesday Night | Periods of light to occasionally moderate rain and high elevation snow. Moderate SE flow through the passes. |
| Thursday | A wave of moderate rain and snow moves through mid-day. Then light showers. Moderate W-SW crest-level flow. |
| Thursday Night | Light snow showers with moderate amounts possible in locations favored by S-SW flow such as the Cascade volcanoes. |
East Slopes of the Washington Cascades
| Wednesday | Increasing clouds lowering, then very light rain and snow developing in some areas from south to north. |
| Wednesday Night | Periods of light to moderate rain and snow. East slopes are favored by low-level E flow. Moderate SE flow through the passes. |
| Thursday | A wave of moderate rain and snow moves through mid-day. Then light showers. Moderate W-SW crest-level flow. |
| Thursday Night | Light snow showers possible. |
Mt. Hood
| Wednesday | Increasing light rain and high elevation snow. Becoming moderate by evening. Increasing light S wind becoming moderate by evening. |
| Wednesday Night | Moderate rain and snow. Moderate to strong winds in the alpine. |
| Thursday | Light to moderate rain and snow becoming all snow showers in the afternoon. |
| Thursday Night | Light to occasional moderate snow showers. |
Issued: 8:04 AM PDT Wednesday, March 21, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Wednesday Morning | Snow Level * | 3500' | 4500' | 4500' | ' | ' | 4500' | ' | 5000' |
| Wednesday Afternoon | Snow Level * | 4000' | 5000' | 5000' | ' | ' | 5000' | ' | 5500' |
| Wednesday Night | Snow Level * | 4000' | 5500' | 5000' | ' | ' | 5500' | ' | 6000' |
| Thursday Morning | Snow Level | 2000' | 4500' | 5000' | ' | ' | 3500' | ' | 2500' |
| Thursday Afternoon | Snow Level | 1500' | 2000' | 2500' | ' | ' | 2000' | ' | 2500' |
| Thursday Night | Snow Level * | 1500' | 1500' | 1000' | ' | ' | 1500' | ' | 1500' |
| Hurricane Ridge | Elevation |
|---|---|
| Wednesday Morning |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 4000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 2000' |
| Thursday Afternoon |
Snow Level 1500' |
| Thursday Night |
Snow Level 1500' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Morning |
Snow Level 4500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 5000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 5500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 4500' |
| Thursday Afternoon |
Snow Level 2000' |
| Thursday Night |
Snow Level 1500' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Wednesday Morning |
Snow Level 4500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 5000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 5000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 5000' |
| Thursday Afternoon |
Snow Level 2500' |
| Thursday Night |
Snow Level 1000' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Wednesday Morning |
Snow Level ' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Wednesday Night |
Snow Level ' (Easterly Flow *) |
| Thursday Morning |
Snow Level ' |
| Thursday Afternoon |
Snow Level ' |
| Thursday Night |
Snow Level ' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Wednesday Morning |
Snow Level ' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Wednesday Night |
Snow Level ' (Easterly Flow *) |
| Thursday Morning |
Snow Level ' |
| Thursday Afternoon |
Snow Level ' |
| Thursday Night |
Snow Level ' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Morning |
Snow Level 4500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 5000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 5500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 2000' |
| Thursday Night |
Snow Level 1500' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Wednesday Morning |
Snow Level ' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Wednesday Night |
Snow Level ' (Easterly Flow *) |
| Thursday Morning |
Snow Level ' |
| Thursday Afternoon |
Snow Level ' |
| Thursday Night |
Snow Level ' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Morning |
Snow Level 5000' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 6000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 2500' |
| Thursday Afternoon |
Snow Level 2500' |
| Thursday Night |
Snow Level 1500' (Easterly Flow *) |
* 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
| Monday | Monday | |
|---|---|---|
| Hurricane Ridge | LT 0.10 | 0 - 0.50 |
| Mt Baker Ski Area | LT 0.25 | 0.75 - 1.00 |
| Washington Pass | 0.25 - 0.50 | 0.50 - 0.75 |
| Stevens Pass | LT 0.25 | 0 - 0.50 |
| Snoqualmie Pass | LT 0.25 | 0.25 - 0.50 |
| Mission Ridge | 0.25 - 0.50 | 0 - 0.50 |
| Crystal Mt | 0.25 - 0.50 | 0.50 - 0.75 |
| Paradise | 0 - 0.50 | 0.75 - 1.00 |
| White Pass | LT 0.25 | 0 - 0.50 |
| Mt Hood Meadows | 0.50 - 0.75 | 0 - 0.50 |
| Timberline | 0 - 0.75 | 0 - 0.50 |
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: 8:04 AM PDT Wednesday, March 21, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Wednesday Morning | SSE 10 - 20 | SE 10 - 20 | ESE 10 - 20 | --- - | SSE 10 - 20 |
| Wednesday Afternoon | SSE 10 - 20 | SSE 10 - 20 | ESE 10 - 20 | --- - | S 15 - 25 |
| Wednesday Night | SE 20 - 30 | SE 20 - 30 | ESE 20 - 30 | --- - | ESE 20 - 30 |
| Thursday Morning | SW 15 - 25 | SSW 15 - 25 | WSW 20 - 30 | --- - | WSW 25 - 35 |
| Thursday Afternoon | SW 15 - 25 | SW 15 - 25 | WSW 15 - 25 | --- - | WSW 25 - 35 |
| Thursday Night | S 20 - 30 | ENE 15 - 25 | SE 15 - 25 | --- - | SSE 30 - 40 |
| Hurricane Ridge | Elevation |
|---|---|
| Wednesday Morning | SSE 10 - 20 |
| Wednesday Afternoon | SSE 10 - 20 |
| Wednesday Night | SE 20 - 30 |
| Thursday Morning | SW 15 - 25 |
| Thursday Afternoon | SW 15 - 25 |
| Thursday Night | S 20 - 30 |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Morning | SE 10 - 20 |
| Wednesday Afternoon | SSE 10 - 20 |
| Wednesday Night | SE 20 - 30 |
| Thursday Morning | SSW 15 - 25 |
| Thursday Afternoon | SW 15 - 25 |
| Thursday Night | ENE 15 - 25 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Morning | ESE 10 - 20 |
| Wednesday Afternoon | ESE 10 - 20 |
| Wednesday Night | ESE 20 - 30 |
| Thursday Morning | WSW 20 - 30 |
| Thursday Afternoon | WSW 15 - 25 |
| Thursday Night | SE 15 - 25 |
| Mt. Rainier | Elevation |
|---|---|
| Wednesday Morning | --- - |
| Wednesday Afternoon | --- - |
| Wednesday Night | --- - |
| Thursday Morning | --- - |
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Morning | SSE 10 - 20 |
| Wednesday Afternoon | S 15 - 25 |
| Wednesday Night | ESE 20 - 30 |
| Thursday Morning | WSW 25 - 35 |
| Thursday Afternoon | WSW 25 - 35 |
| Thursday Night | SSE 30 - 40 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Wednesday Morning | SSE 10 - 20 |
| Wednesday Afternoon | SSE 10 - 20 |
| Wednesday Night | SE 20 - 30 |
| Thursday Morning | SW 15 - 25 |
| Thursday Afternoon | SW 15 - 25 |
| Thursday Night | S 20 - 30 |
| Mt. Baker | Direction - Speed |
|---|---|
| Wednesday Morning | SE 10 - 20 |
| Wednesday Afternoon | SSE 10 - 20 |
| Wednesday Night | SE 20 - 30 |
| Thursday Morning | SSW 15 - 25 |
| Thursday Afternoon | SW 15 - 25 |
| Thursday Night | ENE 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Wednesday Morning | ESE 10 - 20 |
| Wednesday Afternoon | ESE 10 - 20 |
| Wednesday Night | ESE 20 - 30 |
| Thursday Morning | WSW 20 - 30 |
| Thursday Afternoon | WSW 15 - 25 |
| Thursday Night | SE 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Wednesday Morning | --- - |
| Wednesday Afternoon | --- - |
| Wednesday Night | --- - |
| Thursday Morning | --- - |
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Wednesday Morning | SSE 10 - 20 |
| Wednesday Afternoon | S 15 - 25 |
| Wednesday Night | ESE 20 - 30 |
| Thursday Morning | WSW 25 - 35 |
| Thursday Afternoon | WSW 25 - 35 |
| Thursday Night | SSE 30 - 40 |
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 | |
|---|---|---|---|---|---|
| Wednesday Morning | S 25 - 35 | S 15 - 25 | SSE 15 - 25 | --- - | SSW 20 - 30 |
| Wednesday Afternoon | SSE 20 - 30 | SSE 15 - 25 | S 25 - 35 | --- - | S 30 - 40 |
| Wednesday Night | SSE 30 - 40 | SSE 30 - 40 | SSE 35 - 50 | --- - | SE 55 - 75 |
| Thursday Morning | SSE 25 - 35 | SSE 25 - 35 | S 30 - 40 | --- - | S 40 - 60 |
| Thursday Afternoon | S 20 - 30 | S 20 - 30 | S 25 - 35 | --- - | SSW 40 - 60 |
| Thursday Night | SSW 30 - 45 | SSW 25 - 35 | SSW 30 - 40 | --- - | SSW 40 - 60 |
| Mt. Baker | Direction - Speed |
|---|---|
| Wednesday Morning | S 25 - 35 |
| Wednesday Afternoon | SSE 20 - 30 |
| Wednesday Night | SSE 30 - 40 |
| Thursday Morning | SSE 25 - 35 |
| Thursday Afternoon | S 20 - 30 |
| Thursday Night | SSW 30 - 45 |
| Washington Pass | Direction - Speed |
|---|---|
| Wednesday Morning | S 15 - 25 |
| Wednesday Afternoon | SSE 15 - 25 |
| Wednesday Night | SSE 30 - 40 |
| Thursday Morning | SSE 25 - 35 |
| Thursday Afternoon | S 20 - 30 |
| Thursday Night | SSW 25 - 35 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Wednesday Morning | SSE 15 - 25 |
| Wednesday Afternoon | S 25 - 35 |
| Wednesday Night | SSE 35 - 50 |
| Thursday Morning | S 30 - 40 |
| Thursday Afternoon | S 25 - 35 |
| Thursday Night | SSW 30 - 40 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Wednesday Morning | --- - |
| Wednesday Afternoon | --- - |
| Wednesday Night | --- - |
| Thursday Morning | --- - |
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Wednesday Morning | SSW 20 - 30 |
| Wednesday Afternoon | S 30 - 40 |
| Wednesday Night | SE 55 - 75 |
| Thursday Morning | S 40 - 60 |
| Thursday Afternoon | SSW 40 - 60 |
| Thursday Night | SSW 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.
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Previous forecast from Mar 20, 2018
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