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 & Thursday
A strong and high amplitude upper ridge has moved its axis to western Montana on Monday afternoon. The ridge will provide one more day of very warm temperatures (including some record highs) as high clouds provide filtered sunlight to most areas on Monday afternoon with thicker clouds moving over the region by the evening hours. Inversion conditions persist east of the Cascade crest with cooler air, low clouds and fog persisting in the valleys with an offshore pressure gradient bringing the cooler air through the passes.
Monday night, a weakening cold front will arrive after midnight, bringing 3-4 hours of light to occasionally moderate precipitation. The cold front should moderate the airmass from the unseasonable warmth we've seen with the high pressure system.
Tuesday, in the wake of the weakening cold front, an associated upper trough will bring light rain and snow showers, mainly to the Cascade west slopes and Olympics. The trough lifts northward as it progresses eastward, allowing warmer air to work into the forecast zones and reducing instability, generally cutting off precipitation from south to north on Tuesday afternoon.
Tuesday night should feature fair weather and increasing high clouds as a stronger frontal system will be approaching the Pacific Northwest coastal waters.
Weather Forecast
Olympics
| Monday | Filtered sunlight with high clouds and warm temperatures. Clouds thickening and lowering in the afternoon. |
| Monday Night | Periods of light and occasionally moderate rain or snow, mainly after midnight. Snow line lowering overnight. Windy. |
| Tuesday | Light rain and snow showers, ending late in the day. |
| Tuesday Night | Increasing and lowering clouds with rain and snow arriving by daybreak. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Monday | High clouds bringing filtered sunshine with cloud cover increasing in the afternoon. Low clouds and cooler with inversion conditions at the passes. |
| Monday Night | Increasing clouds with light to moderate rain and snow in the early morning hours. |
| Tuesday | Light rain and snow showers, mainly volcanoes and North Cascades. Becoming mostly cloudy in the afternoon. |
| Tuesday Night | Some lingering low clouds in the north Cascades before midnight. Otherwise, increasing high clouds, thickening by morning. |
East Slopes of the Washington Cascades
| Monday | Filtered sunshine with high clouds; low clouds and cooler with inversion conditions at low elevations. |
| Monday Night | Clouds lowering with light rain or high elevation snow in the early morning hours. Possible wintry mix in some deeper valleys. |
| Tuesday | Cloudy in the morning with isolated rain and snow showers in the north, mainly high elevations; becoming partly sunny in the south and mostly cloudy in the north by the afternoon. |
| Tuesday Night | Lingering clouds in the north, decreasing. High clouds increasing. |
Mt. Hood
| Monday | High clouds bringing filtered sunshine with cloud cover increasing in the afternoon. |
| Monday Night | Light rain or snow after midnight. Snow line lowering overnight. |
| Tuesday | Light rain and snow showers decreasing or ending in the afternoon. |
| Tuesday Night | Increasing high clouds. |
Issued: 2:44 PM PST Monday, January 15, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Monday Afternoon | Freezing Level * | 9000' | 10000' | 10000' | ' | ' | 10000' | ' | 9500' |
| Monday Night | Snow Level * | 5000' | 5500' | 5000' | ' | ' | 5500' | ' | 5500' |
| Tuesday Morning | Snow Level * | 3500' | 4000' | 4000' | ' | ' | 4000' | ' | 4000' |
| Tuesday Afternoon | Snow Level * | 3500' | 3500' | 3500' | ' | ' | 3500' | ' | 4000' |
| Tuesday Night | Snow Level * | 4500' | 3000' | 3000' | ' | ' | 3000' | ' | 6000' |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level 9000' (Easterly Flow *) |
| Monday Night |
Snow Level 5000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Night |
Snow Level 4500' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level 10000' (Easterly Flow *) |
| Monday Night |
Snow Level 5500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Night |
Snow Level 3000' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level 10000' (Easterly Flow *) |
| Monday Night |
Snow Level 5000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Night |
Snow Level 3000' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Tuesday Night |
Snow Level ' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Tuesday Night |
Snow Level ' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level 10000' (Easterly Flow *) |
| Monday Night |
Snow Level 5500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Night |
Snow Level 3000' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Tuesday Night |
Snow Level ' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Monday Afternoon |
Freezing Level 9500' (Easterly Flow *) |
| Monday Night |
Snow Level 5500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Night |
Snow Level 6000' (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
| Thursday | Thursday | |
|---|---|---|
| Hurricane Ridge | LT 0.25 | LT 0.25 |
| Mt Baker Ski Area | LT 0.25 | 0 - 0.75 |
| Washington Pass | LT 0.10 | 0 - 0.50 |
| Stevens Pass | LT 0.25 | LT 0.25 |
| Snoqualmie Pass | LT 0.25 | LT 0.25 |
| Mission Ridge | LT 0.10 | LT 0.25 |
| Crystal Mt | LT 0.25 | LT 0.25 |
| Paradise | 0.25 - 0.50 | 0 - 0.50 |
| White Pass | LT 0.10 | LT 0.25 |
| Mt Hood Meadows | LT 0.25 | LT 0.25 |
| Timberline | LT 0.25 | 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: 2:44 PM PST Monday, January 15, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Monday Morning | ESE 5 - 15 | SE 10 - 20 | E 15 - 25 | --- - | ESE 10 - 20 |
| Monday Afternoon | SE 20 - 30 | ESE 10 - 20 | ESE 20 - 30 | --- - | SE 15 - 25 |
| Monday Night | S 25 - 35 | SE 15 - 25 | E 15 - 25 | --- - | SE 15 - 25 |
| Tuesday Morning | SSW 15 - 25 | S 20 - 30 | SW 15 - 25 | --- - | SW 20 - 30 |
| Tuesday Afternoon | SW 15 - 25 | S 10 - 20 | SW 20 - 30 | --- - | SW 15 - 25 |
| Tuesday Night | S 10 - 20 | S 10 - 20 | SW 10 - 20 | --- - | S 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Morning | ESE 5 - 15 |
| Monday Afternoon | SE 20 - 30 |
| Monday Night | S 25 - 35 |
| Tuesday Morning | SSW 15 - 25 |
| Tuesday Afternoon | SW 15 - 25 |
| Tuesday Night | S 10 - 20 |
| Mt. Baker | Elevation |
|---|---|
| Monday Morning | SE 10 - 20 |
| Monday Afternoon | ESE 10 - 20 |
| Monday Night | SE 15 - 25 |
| Tuesday Morning | S 20 - 30 |
| Tuesday Afternoon | S 10 - 20 |
| Tuesday Night | S 10 - 20 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Monday Morning | E 15 - 25 |
| Monday Afternoon | ESE 20 - 30 |
| Monday Night | E 15 - 25 |
| Tuesday Morning | SW 15 - 25 |
| Tuesday Afternoon | SW 20 - 30 |
| Tuesday Night | SW 10 - 20 |
| Mt. Rainier | Elevation |
|---|---|
| Monday Morning | --- - |
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Monday Morning | ESE 10 - 20 |
| Monday Afternoon | SE 15 - 25 |
| Monday Night | SE 15 - 25 |
| Tuesday Morning | SW 20 - 30 |
| Tuesday Afternoon | SW 15 - 25 |
| Tuesday Night | S 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Monday Morning | ESE 5 - 15 |
| Monday Afternoon | SE 20 - 30 |
| Monday Night | S 25 - 35 |
| Tuesday Morning | SSW 15 - 25 |
| Tuesday Afternoon | SW 15 - 25 |
| Tuesday Night | S 10 - 20 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Morning | SE 10 - 20 |
| Monday Afternoon | ESE 10 - 20 |
| Monday Night | SE 15 - 25 |
| Tuesday Morning | S 20 - 30 |
| Tuesday Afternoon | S 10 - 20 |
| Tuesday Night | S 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Morning | E 15 - 25 |
| Monday Afternoon | ESE 20 - 30 |
| Monday Night | E 15 - 25 |
| Tuesday Morning | SW 15 - 25 |
| Tuesday Afternoon | SW 20 - 30 |
| Tuesday Night | SW 10 - 20 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Morning | --- - |
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Morning | ESE 10 - 20 |
| Monday Afternoon | SE 15 - 25 |
| Monday Night | SE 15 - 25 |
| Tuesday Morning | SW 20 - 30 |
| Tuesday Afternoon | SW 15 - 25 |
| Tuesday Night | S 10 - 20 |
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 Morning | SSE 15 - 25 | SSE 15 - 25 | S 20 - 30 | --- - | S 20 - 30 |
| Monday Afternoon | S 25 - 35 | S 25 - 35 | S 25 - 35 | --- - | S 30 - 40 |
| Monday Night | S 30 - 40 | S 25 - 35 | SSW 30 - 40 | --- - | SSW 30 - 40 |
| Tuesday Morning | SSW 25 - 35 | S 30 - 40 | SSW 30 - 40 | --- - | SSW 35 - 45 |
| Tuesday Afternoon | SW 25 - 35 | SW 25 - 35 | SW 30 - 40 | --- - | WSW 30 - 40 |
| Tuesday Night | SW 20 - 30 | SW 20 - 30 | SW 30 - 40 | --- - | SW 25 - 35 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Morning | SSE 15 - 25 |
| Monday Afternoon | S 25 - 35 |
| Monday Night | S 30 - 40 |
| Tuesday Morning | SSW 25 - 35 |
| Tuesday Afternoon | SW 25 - 35 |
| Tuesday Night | SW 20 - 30 |
| Washington Pass | Direction - Speed |
|---|---|
| Monday Morning | SSE 15 - 25 |
| Monday Afternoon | S 25 - 35 |
| Monday Night | S 25 - 35 |
| Tuesday Morning | S 30 - 40 |
| Tuesday Afternoon | SW 25 - 35 |
| Tuesday Night | SW 20 - 30 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Morning | S 20 - 30 |
| Monday Afternoon | S 25 - 35 |
| Monday Night | SSW 30 - 40 |
| Tuesday Morning | SSW 30 - 40 |
| Tuesday Afternoon | SW 30 - 40 |
| Tuesday Night | SW 30 - 40 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Morning | --- - |
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Morning | S 20 - 30 |
| Monday Afternoon | S 30 - 40 |
| Monday Night | SSW 30 - 40 |
| Tuesday Morning | SSW 35 - 45 |
| Tuesday Afternoon | WSW 30 - 40 |
| Tuesday Night | SW 25 - 35 |
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: 2:44 PM PST Monday, January 15, 2018
Extended Weather Synopsis for Thursday night through Thursday
Wednesday, a warm front will lift northward bringing short-lived, but significant warming. Precipitation will largely remain north of the forecast area, but some will extend into the Olympics and West slopes of the Washington Cascades.
Wednesday night, the associated cold front arrives with a well-definied N-S oriented frontal rain-band. This feature should bring moderate crest-level winds and a strong barrier jet along the west slopes of the Cascades.
An upper trough and surface low associated with the aforementioned cold front spins approximately 500 miles off the coast of Vancouver Island on Thursday, bringing SW flow, moisture, and a colder air mass into our region.
Beginning Thursday night, the upper trough and surface low move W-SW to the Puget Sound, arriving by Saturday morning. This low brings slight cooling and sustained onshore flow with instability combining to bring a good round of precipitation at low snow levels to the mountains.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Wednesday | Snow Level | 5500' - 6500' | 4500' - 6500' | 6000' - 8000' | * |
| Wednesday Night | Snow Level | 3000' - 4000' | 3000' - 4000' | 3000' - 4000' | * |
| Thursday | Snow Level | 2000' - 3000' | 2000' - 3000' | 2500' - 3500' | |
| Thursday Night | Snow Level | 1500' - 2500' | 1500' - 2500' | 1500' - 2500' | |
| Friday | Snow Level | 2000' - 3000' | 2500' - 3500' | 2000' - 3000' |
| Mt. Baker | Elevation |
|---|---|
| Wednesday |
Snow Level 5500' - 6500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3000' - 4000' (Easterly Flow *) |
| Thursday |
Snow Level 2000' - 3000' |
| Thursday Night |
Snow Level 1500' - 2500' |
| Friday |
Snow Level 2000' - 3000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday |
Snow Level 4500' - 6500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3000' - 4000' (Easterly Flow *) |
| Thursday |
Snow Level 2000' - 3000' |
| Thursday Night |
Snow Level 1500' - 2500' |
| Friday |
Snow Level 2500' - 3500' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday |
Snow Level 6000' - 8000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3000' - 4000' (Easterly Flow *) |
| Thursday |
Snow Level 2500' - 3500' |
| Thursday Night |
Snow Level 1500' - 2500' |
| Friday |
Snow Level 2000' - 3000' |
* 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 Jan 15, 2018
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