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 & Friday
Strong westerly flow will deliver a one-two punch of weather systems over the next 36 hours, with the second storm arriving tonight being the stronger of the two. The first front came through the area late morning with post-front shower activity quickly decreasing in the early afternoon. A quick pop-up in temperatures seen this morning has become a more gradual rise this afternoon. Strong westerly winds seen this morning should also ease this afternoon. Snoqualmie Pass saw a period of freezing rain late morning with an influx of warmer air.
The next system currently upstream in westerly flow will quickly move in this evening with precipitation becoming moderate to locally heavy for the south Washington Cascades and Mt. Hood Monday night. Westerly winds will be even stronger with this system and stay strong for much of Tuesday. The heaviest precipitation will also coincide with the strongest warming late tonight. Warm air should work into White and Snoqualmie Passes in the early morning hours changing snow to rain (with a period of freezing rain possible mainly at Snoqualmie), while Stevens will likely stay all snow until after the frontal passage a few hours later (after 4 am). The warming trend will be less dramatic for the north Cascades with this system versus the south Cascades and Mt. Hood.
However, warming will be brief as snow levels come crashing back down by mid-day Tuesday and settle around 2500 feet as moderate showers for the west slopes of the Cascades and Mt. Hood quickly taper down Tuesday night.
Weather Forecast
Olympics, Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
| Monday Afternoon |
Mostly cloudy with scattered light rain and and snow showers. |
| Monday Night |
Increasing moderate to locally heavy rain and snow. Warming trend initially outside of the Cascade Passes and north Cascades. Becoming very windy. |
| Tuesday Morning |
Moderate to locally heavy rain and snow transitioning to light to moderate rain and snow showers late morning. Freezing rain possible Snoqualmie Pass early morning hours. Very windy. Warmer. |
| Tuesday Mid-day - Tuesday Afternoon |
Light to moderate rain and snow showers. Windy. Rapid cooling trend. |
| Tuesday Night |
Partly to mostly cloudy with light rain and snow showers ending overnight. |
East slopes of the Washington Cascades
| Monday Afternoon |
Partly to mostly cloudy with scattered light rain and and snow showers. |
| Monday Night |
Increasing light to moderate rain and snow. Becoming very windy. |
| Tuesday Morning |
Moderate rain and snow transitioning to light rain and snow showers late morning. Very windy. Warming trend. |
| Tuesday Mid-day - Tuesday Afternoon |
Mostly cloudy with light rain and snow showers, except occasionally moderate near the Cascade crest. Windy. Rapid cooling trend. |
| Tuesday Night |
Partly cloudy with light rain and snow showers ending overnight. |
Mt. Hood Area
| Monday Afternoon |
Mostly cloudy with scattered light rain and and snow showers. |
| Monday Night |
Increasing moderate to heavy rain and snow. Warming trend. Becoming very windy. |
| Tuesday Morning |
Moderate to locally heavy rain and snow transitioning to light to moderate rain and snow showers late morning. Very windy. |
| Tuesday Mid-day - Tuesday Afternoon |
Light to moderate rain and snow showers. Windy. Rapid cooling trend. |
| Tuesday Night |
Partly to mostly cloudy with light rain and snow showers ending overnight. |
Issued: 2:47 PM PST Monday, December 19, 2016
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 | 5500' | 2500' | 1500' | ' | ' | 4000' | ' | 5500' |
| Monday Night | Snow Level * | 4500' | 2000' | 1500' | ' | ' | 3000' | ' | 6500' |
| Tuesday Morning | Snow Level | 4500' | 4000' | 3000' | ' | ' | 4500' | ' | 6000' |
| Tuesday Mid-day - Tuesday Night | Snow Level | 3000' | 2500' | 2500' | ' | ' | 2500' | ' | 2500' |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 5500' |
| Monday Night |
Snow Level 4500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4500' |
| Tuesday Mid-day - Tuesday Night |
Snow Level 3000' |
| Mt. Baker | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 2500' |
| Monday Night |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' |
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Washington Pass | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 1500' |
| Monday Night |
Snow Level 1500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 3000' |
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Leavenworth | Elevation |
|---|---|
| Monday Afternoon |
Snow Level ' |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' |
| Tuesday Mid-day - Tuesday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Monday Afternoon |
Snow Level ' |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' |
| Tuesday Mid-day - Tuesday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 4000' |
| Monday Night |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4500' |
| Tuesday Mid-day - Tuesday Night |
Snow Level 2500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Monday Afternoon |
Snow Level ' |
| Monday Night |
Snow Level ' (Easterly Flow *) |
| Tuesday Morning |
Snow Level ' |
| Tuesday Mid-day - Tuesday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Monday Afternoon |
Snow Level 5500' |
| Monday Night |
Snow Level 6500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 6000' |
| Tuesday Mid-day - Tuesday Night |
Snow Level 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.
Precipitation Forecast
| Friday | Friday | |
|---|---|---|
| Hurricane Ridge | 0.50 - 0.75 | LT 0.25 |
| Mt Baker Ski Area | 0.75 - 1.00 | 0 - 1.00 |
| Washington Pass | 0.50 - 0.75 | 0 - 0.75 |
| Stevens Pass | 1.50 - 2.00 | 0 - 1.00 |
| Snoqualmie Pass | 0 - 2.00 | 0 - 1.00 |
| Mission Ridge | 0.50 - 0.75 | LT 0.25 |
| Crystal Mt | 1.00 - 1.50 | LT 0.25 |
| Paradise | 2.50 - 3.50 | 1.00 - 1.50 |
| White Pass | 1.50 - 2.00 | 0.75 - 1.00 |
| Mt Hood Meadows | 2.00 - 3.00 | 0 - 0.75 |
| Timberline | 2.50 - 3.50 | 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: 2:47 PM PST Monday, December 19, 2016
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Monday Afternoon | SW 5 - 15 | SW 5 - 15 | SW 15 - 30 | --- - | WSW 15 - 25 |
| Monday Night | WSW 30 - 40 | SW 15 - 25 | WSW 25 - 40 | --- - | SW 25 - 35 |
| Tuesday Morning | W 40 - 50 | W 30 - 40 | W 35 - 50 | --- - | W 40 - 55 |
| Tuesday Afternoon | NW 25 - 35 | W 25 - 35 | W 30 - 45 | --- - | WNW 30 - 40 |
| Tuesday Night | W 10 - 20 | W 10 - 20 | W 10 - 20 | --- - | WNW 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Afternoon | SW 5 - 15 |
| Monday Night | WSW 30 - 40 |
| Tuesday Morning | W 40 - 50 |
| Tuesday Afternoon | NW 25 - 35 |
| Tuesday Night | W 10 - 20 |
| Mt. Baker | Elevation |
|---|---|
| Monday Afternoon | SW 5 - 15 |
| Monday Night | SW 15 - 25 |
| Tuesday Morning | W 30 - 40 |
| Tuesday Afternoon | W 25 - 35 |
| Tuesday Night | W 10 - 20 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Monday Afternoon | SW 15 - 30 |
| Monday Night | WSW 25 - 40 |
| Tuesday Morning | W 35 - 50 |
| Tuesday Afternoon | W 30 - 45 |
| Tuesday Night | W 10 - 20 |
| Mt. Rainier | Elevation |
|---|---|
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Monday Afternoon | WSW 15 - 25 |
| Monday Night | SW 25 - 35 |
| Tuesday Morning | W 40 - 55 |
| Tuesday Afternoon | WNW 30 - 40 |
| Tuesday Night | WNW 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Monday Afternoon | SW 5 - 15 |
| Monday Night | WSW 30 - 40 |
| Tuesday Morning | W 40 - 50 |
| Tuesday Afternoon | NW 25 - 35 |
| Tuesday Night | W 10 - 20 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Afternoon | SW 5 - 15 |
| Monday Night | SW 15 - 25 |
| Tuesday Morning | W 30 - 40 |
| Tuesday Afternoon | W 25 - 35 |
| Tuesday Night | W 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Afternoon | SW 15 - 30 |
| Monday Night | WSW 25 - 40 |
| Tuesday Morning | W 35 - 50 |
| Tuesday Afternoon | W 30 - 45 |
| Tuesday Night | W 10 - 20 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Afternoon | WSW 15 - 25 |
| Monday Night | SW 25 - 35 |
| Tuesday Morning | W 40 - 55 |
| Tuesday Afternoon | WNW 30 - 40 |
| Tuesday Night | WNW 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 Afternoon | W 20 - 30 | WNW 35 - 45 | W 30 - 40 | --- - | W 35 - 45 |
| Monday Night - Tuesday Morning | WSW 50 - 60 | WSW 45 - 55 | WSW 55 - 65 | --- - | W 60 - 80 |
| Tuesday Afternoon | NW 40 - 50 | NW 50 - 60 | NW 50 - 60 | --- - | NW 50 - 60 |
| Tuesday Night | NW 25 - 35 | NW 35 - 45 | NW 35 - 45 | --- - | NW 30 - 40 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Afternoon | W 20 - 30 |
| Monday Night - Tuesday Morning | WSW 50 - 60 |
| Tuesday Afternoon | NW 40 - 50 |
| Tuesday Night | NW 25 - 35 |
| Washington Pass | Direction - Speed |
|---|---|
| Monday Afternoon | WNW 35 - 45 |
| Monday Night - Tuesday Morning | WSW 45 - 55 |
| Tuesday Afternoon | NW 50 - 60 |
| Tuesday Night | NW 35 - 45 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Afternoon | W 30 - 40 |
| Monday Night - Tuesday Morning | WSW 55 - 65 |
| Tuesday Afternoon | NW 50 - 60 |
| Tuesday Night | NW 35 - 45 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Afternoon | --- - |
| Monday Night - Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Afternoon | W 35 - 45 |
| Monday Night - Tuesday Morning | W 60 - 80 |
| Tuesday Afternoon | NW 50 - 60 |
| Tuesday Night | NW 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.
Issued: 2:47 PM PST Monday, December 19, 2016
Extended Weather Synopsis for Friday night through Friday
Wednesday should be a break day inbetween weather systems with light zonal (westerly) flow aloft and with offshore flow developing through the Cascade Passes. Sunshine looks plausible on Wednesday. Free-air freezing levels will be quite moderate, but cool easterly flow through the Passes will make for locally lower freezing levels near and around the major Cascade gaps.
A weak front should approach the area Wednesday night and pass through the Cascades on Thursday. Precipitation amounts should not be particularly heavy. A trough will dig off the California coast on Friday, leaving the PNW in a cool air mass but lacking any significant source of lift and moisture leaving us with isolated mountain showers.
Extended Weather
Olympics, Washington Cascades and Mt. Hood
WednesdayPartly to mostly sunny. Milder except locally cooler Cascade Passes and along the east slopes of the Cascades.
Wednesday NightIncreasing clouds with light rain or snow developing Olympics late.
ThursdayLight to occasionally moderate rain and snow.
Thursday NightMostly cloudy with scattered light rain and snow showers. Cooling trend.
FridayPartly cloudy with isolated mountain showers.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Wednesday - Wednesday Night | Freezing Level | 3500' - 4500' | 5000' - 6000' | 6000' - 7000' | * |
| Thursday | Snow Level | 2500' - 3500' | 3000' - 4000' | 4000' - 5000' | * |
| Thursday Night - Friday | Snow Level | 1000' - 2000' | 1000' - 2000' | 2000' - 3000' |
| Mt. Baker | Elevation |
|---|---|
| Wednesday - Wednesday Night |
Freezing Level 3500' - 4500' (Easterly Flow *) |
| Thursday |
Snow Level 2500' - 3500' (Easterly Flow *) |
| Thursday Night - Friday |
Snow Level 1000' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday - Wednesday Night |
Freezing Level 5000' - 6000' (Easterly Flow *) |
| Thursday |
Snow Level 3000' - 4000' (Easterly Flow *) |
| Thursday Night - Friday |
Snow Level 1000' - 2000' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday - Wednesday Night |
Freezing Level 6000' - 7000' (Easterly Flow *) |
| Thursday |
Snow Level 4000' - 5000' (Easterly Flow *) |
| Thursday Night - 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 Dec 19, 2016
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