Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Tuesday & Tuesday
A strong Pacific weather system came through Monday night in strong westerly flow. Steady rain and snow transitioned to showers Monday morning, heaviest along the west slopes. Cold cumulus clouds started to stream into western Washington behind the frontal system and after a warm-up was seen Monday night through the early morning hours of Tuesday, a rapid cooling trend ensued through the late morning hours. Alpine winds will stay strong all day, shifting from SW early this morning to NW this afternoon.
Shower activity should quickly taper off along the west slopes tonight as surface high pressure shifts inland. Wednesday looks like a quiet weather day with a quick bump up in free air freezing levels Wednesday afternoon. However light and cool easterly flow near Mt. Hood and through the Cascade Passes will create areas of multiple freezing levels. High clouds may stream over the northern Cascades Wednesday.
A weak frontal system will approach from the NW Wednesday night, perhaps reaching the Olympics by daybreak Thursday.
Weather Forecast
Olympics
| Tuesday Afternoon |
Mostly cloudy with scattered snow showers. |
| Tuesday Night |
Mostly clear. |
| Wednesday |
Partly to mostly cloudy with periods of high clouds. Milder in the afternoon. |
| Wednesday Night |
Increasing high and mid level clouds overnight. |
Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
| Tuesday Afternoon |
Mostly cloudy with light to occasionally moderate rain and snow showers. Alpine winds still strong. |
| Tuesday Night |
Showers ending and becoming partly cloudy. |
| Wednesday |
Partly to mostly cloudy north Cascades with high clouds, partly to mostly sunny central and south Cascades. Milder except locally cooler near the Cascade Passes with easterly flow developing. |
| Wednesday Night |
Increasing high and mid level clouds overnight. |
East slopes of the Washington Cascades
| Tuesday Afternoon |
Mostly cloudy with scattered light rain and snow showers, especially Washington Pass area. Partly sunny further east of the Cascade crest. Alpine winds still strong, especially Mission Ridge area. |
| Tuesday Night |
Scattered showers ending and becoming partly cloudy. |
| Wednesday |
Partly to mostly cloudy northeast Cascades with high clouds, partly to mostly sunny central and southeast Cascades. |
| Wednesday Night |
Increasing high and mid level clouds overnight. |
Mt. Hood Area
| Tuesday Afternoon |
Becoming partly cloudy with isolated rain and snow showers. Alpine winds still strong. |
| Tuesday Night |
Becoming mostly clear overnight. |
| Wednesday |
Mostly sunny. Multiple freezing levels with light easterly flow developing Wednesday afternoon. |
| Wednesday Night |
Increasing high and mid level clouds overnight. |
Issued: 2:42 PM PST Tuesday, December 20, 2016
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Tuesday Mid-day - Tuesday Night | Snow Level | 2500' | 2500' | 2500' | ' | ' | 2500' | ' | 2500' |
| Wednesday Morning | Freezing Level | 2500' | 2000' | 1500' | ' | ' | 1500' | ' | 3000' |
| Wednesday Afternoon - Wednesday Night | Freezing Level * | 5500' | 4500' | 2500' | ' | ' | 5500' | ' | 7000' |
| Hurricane Ridge | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Freezing Level 2500' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level 5500' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Freezing Level 2000' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level 4500' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Freezing Level 1500' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level 2500' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level ' |
| Wednesday Morning |
Freezing Level ' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level ' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level ' |
| Wednesday Morning |
Freezing Level ' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level ' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Freezing Level 1500' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level 5500' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level ' |
| Wednesday Morning |
Freezing Level ' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level ' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Freezing Level 3000' |
| Wednesday Afternoon - Wednesday Night |
Freezing Level 7000' (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
| Tuesday | Tuesday | |
|---|---|---|
| Hurricane Ridge | LT 0.25 | LT 0.10 |
| Mt Baker Ski Area | 0.50 - 0.75 | LT 0.10 |
| Washington Pass | 0.50 - 0.75 | LT 0.10 |
| Stevens Pass | 0 - 1.00 | LT 0.10 |
| Snoqualmie Pass | 0.75 - 1.00 | LT 0.10 |
| Mission Ridge | LT 0.25 | LT 0.10 |
| Crystal Mt | LT 0.25 | LT 0.10 |
| Paradise | 0.75 - 1.00 | LT 0.10 |
| White Pass | 0.50 - 0.75 | LT 0.10 |
| Mt Hood Meadows | 0 - 1.00 | LT 0.10 |
| Timberline | 0 - 1.00 | LT 0.10 |
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: 2:42 PM PST Tuesday, December 20, 2016
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Tuesday Afternoon | WNW 15 - 30 | W 20 - 35 | W 20 - 35 | --- - | WNW 20 - 30 |
| Tuesday Night | W 5 - 15 | SW 10 - 20 | SW 5 - 15 | --- - | NW 5 - 15 |
| Wednesday - Wednesday Night | SW 5 - 15 | S 0 - 10 | SSE 0 - 10 | --- - | SE 5 - 15 |
| Wednesday Night | SW 10 - 20 | SW 10 - 20 | SSE 5 - 15 | --- - | S 5 - 15 |
| Hurricane Ridge | Elevation |
|---|---|
| Tuesday Afternoon | WNW 15 - 30 |
| Tuesday Night | W 5 - 15 |
| Wednesday - Wednesday Night | SW 5 - 15 |
| Wednesday Night | SW 10 - 20 |
| Mt. Baker | Elevation |
|---|---|
| Tuesday Afternoon | W 20 - 35 |
| Tuesday Night | SW 10 - 20 |
| Wednesday - Wednesday Night | S 0 - 10 |
| Wednesday Night | SW 10 - 20 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Tuesday Afternoon | W 20 - 35 |
| Tuesday Night | SW 5 - 15 |
| Wednesday - Wednesday Night | SSE 0 - 10 |
| Wednesday Night | SSE 5 - 15 |
| Mt. Rainier | Elevation |
|---|---|
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Wednesday - Wednesday Night | --- - |
| Wednesday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Tuesday Afternoon | WNW 20 - 30 |
| Tuesday Night | NW 5 - 15 |
| Wednesday - Wednesday Night | SE 5 - 15 |
| Wednesday Night | S 5 - 15 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Tuesday Afternoon | WNW 15 - 30 |
| Tuesday Night | W 5 - 15 |
| Wednesday - Wednesday Night | SW 5 - 15 |
| Wednesday Night | SW 10 - 20 |
| Mt. Baker | Direction - Speed |
|---|---|
| Tuesday Afternoon | W 20 - 35 |
| Tuesday Night | SW 10 - 20 |
| Wednesday - Wednesday Night | S 0 - 10 |
| Wednesday Night | SW 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Tuesday Afternoon | W 20 - 35 |
| Tuesday Night | SW 5 - 15 |
| Wednesday - Wednesday Night | SSE 0 - 10 |
| Wednesday Night | SSE 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Wednesday - Wednesday Night | --- - |
| Wednesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Tuesday Afternoon | WNW 20 - 30 |
| Tuesday Night | NW 5 - 15 |
| Wednesday - Wednesday Night | SE 5 - 15 |
| Wednesday Night | S 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 | |
|---|---|---|---|---|---|
| Tuesday Afternoon | NW 40 - 50 | WNW 55 - 70 | NW 45 - 60 | --- - | NW 50 - 60 |
| Tuesday Night | NW 25 - 40 | NW 30 - 45 | NW 30 - 40 | --- - | NW 15 - 30 |
| Wednesday | W 25 - 35 | W 25 - 35 | W 15 - 25 | --- - | SW 10 - 20 |
| Wednesday Night | SW 30 - 40 | SW 35 - 45 | SW 25 - 35 | --- - | SW 15 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Tuesday Afternoon | NW 40 - 50 |
| Tuesday Night | NW 25 - 40 |
| Wednesday | W 25 - 35 |
| Wednesday Night | SW 30 - 40 |
| Washington Pass | Direction - Speed |
|---|---|
| Tuesday Afternoon | WNW 55 - 70 |
| Tuesday Night | NW 30 - 45 |
| Wednesday | W 25 - 35 |
| Wednesday Night | SW 35 - 45 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Tuesday Afternoon | NW 45 - 60 |
| Tuesday Night | NW 30 - 40 |
| Wednesday | W 15 - 25 |
| Wednesday Night | SW 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Wednesday | --- - |
| Wednesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Tuesday Afternoon | NW 50 - 60 |
| Tuesday Night | NW 15 - 30 |
| Wednesday | SW 10 - 20 |
| Wednesday Night | SW 15 - 25 |
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: 2:42 PM PST Tuesday, December 20, 2016
Extended Weather Synopsis for Tuesday night through Tuesday
A weak front will wash out over the area on Thursday, stalling long enough to bring light to moderate amounts of snow for Cascades and Olympics. An upper low will dig off the California coast Thursday night and Friday, and in the process may rotate up areas of light snow for the Mt. Hood and even along the east slopes. The air mass overhead will be cold, but forecast models are in poor agreement how much moisture may rotate up from the south Friday and Saturday.
Extended Weather
Olympics, Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
Light to occasionally moderate rain and snow.
Mostly cloudy with light rain and snow showers ending.
Mostly cloudy with periods of light snow, mainly Mt. Hood and south Washington Cascades.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Thursday - Thursday Night | Snow Level | 2000' - 3000' | 2500' - 3500' | 3500' - 4500' | |
| Friday | Snow Level | 500' - 1500' | 1500' - 2500' | 2000' - 3000' | |
| Friday Night - Saturday | Snow Level | 500' - 1500' | 500' - 1500' | 1000' - 2500' |
| Mt. Baker | Elevation |
|---|---|
| Thursday - Thursday Night |
Snow Level 2000' - 3000' |
| Friday |
Snow Level 500' - 1500' |
| Friday Night - Saturday |
Snow Level 500' - 1500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday - Thursday Night |
Snow Level 2500' - 3500' |
| Friday |
Snow Level 1500' - 2500' |
| Friday Night - Saturday |
Snow Level 500' - 1500' |
| Mt. Hood | Elevation |
|---|---|
| Thursday - Thursday Night |
Snow Level 3500' - 4500' |
| Friday |
Snow Level 2000' - 3000' |
| Friday Night - Saturday |
Snow Level 1000' - 2500' |
* 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 20, 2016
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