Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Saturday & Saturday
The shortwave trough that moved through last night has moved to the Great Basin by mid-day Saturday. To our west, a weak, shortwave ridge extends our coastal waters to central British Columbia. A moist westerly jet from the central Pacific is spreading moisture into that weak ridge as a warm frontal zone brings us clouds and some very light precipitation this afternoon. The majority of the rain and snow will remain offshore today and this evening. The warm front will begin over-running the cold air in place as it arrives early Sunday morning. The warming will be particularly sharp overnight in the Olympics, with modest warming elsewhere.
On Sunday, the warm frontal rain/snow band arrives, bringing plentiful precipitation with continued warming as our forecast area will be on the warm side of the storm as the E-W jetstream that sits over northern Vancouver Island. However, light easterly flow at the surface should keep Snoqualmie snowing into late morning or mid-day hours and Stevens Passes as snow into the mid-afternoon hours before the eventual transition to rain.
Sunday night, there will be a tight north-south temperature gradient in place as moisture continues streaming into our forecast zones.
Weather Forecast
Olympics
| Saturday | Cloudy with increasing light snow. |
| Saturday Night | Increasing light to moderate rain and snow. Sharp warming trend. |
| Sunday | Increasing light to moderate rain and snow. Continued warming trend. |
| Sunday Night | Decreasing light to moderate rain and snow. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Saturday | Light snow showers between Snoqualmie and Stevens Pass, ending. Decreasing pass-level clouds will be replaced by increasing mid-level and high-level clouds. |
| Saturday Night | Increasing light rain and snow north, heavier in the north and mainly after midnight. |
| Sunday | Increasing light rain and snow in the morning becoming moderate central and north. Increasing light to moderate rain and snow by afternoon in the south. Warming trend. |
| Sunday Night | Moderate rain and snow ending north. Continued moderate to heavy rain and snow central. Increasing moderate to heavy rain and snow south. |
East Slopes of the Washington Cascades
| Saturday | Increasing mid-level and high-level clouds. |
| Saturday Night | Increasing light snow north and central. |
| Sunday | Increasing light to moderate moderate rain and snow north and central; becoming light in the south. Gradual warming trend. |
| Sunday Night | Decreasing light to moderate rain and snow. |
Mt. Hood
| Saturday | Light showers ending in the morning. Increasing mid and high-level clouds in the afternoon. |
| Saturday Night | Increasing light rain and snow by morning. Warming trend. |
| Sunday | Light rain and snow. Warming trend. |
| Sunday Night | Increasing light rain and snow. |
Issued: 3:23 PM PST Saturday, December 16, 2017
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Saturday Afternoon | Snow Level | 2500' | 2000' | 1500' | ' | ' | 2500' | ' | 2500' |
| Saturday Night | Snow Level * | 7000' | 3000' | 2500' | ' | ' | 3500' | ' | 3500' |
| Sunday Morning | Snow Level * | 6000' | 3500' | 3000' | ' | ' | 4000' | ' | 6000' |
| Sunday Afternoon | Snow Level | 6000' | 4500' | 4000' | ' | ' | 6500' | ' | 6500' |
| Sunday Night | Snow Level | 5500' | 4500' | 4500' | ' | ' | 5500' | ' | 7000' |
| Sunday Night | Snow Level | ' | ' | ' | ' | ' | ' | ' | ' |
| Hurricane Ridge | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level 2500' |
| Saturday Night |
Snow Level 7000' (Easterly Flow *) |
| Sunday Morning |
Snow Level 6000' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 6000' |
| Sunday Night |
Snow Level 5500' |
| Sunday Night |
Snow Level ' |
| Mt. Baker | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level 2000' |
| Saturday Night |
Snow Level 3000' (Easterly Flow *) |
| Sunday Morning |
Snow Level 3500' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 4500' |
| Sunday Night |
Snow Level 4500' |
| Sunday Night |
Snow Level ' |
| Washington Pass | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level 1500' |
| Saturday Night |
Snow Level 2500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 3000' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 4000' |
| Sunday Night |
Snow Level 4500' |
| Sunday Night |
Snow Level ' |
| Leavenworth | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' (Easterly Flow *) |
| Sunday Morning |
Snow Level ' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' (Easterly Flow *) |
| Sunday Morning |
Snow Level ' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level 2500' |
| Saturday Night |
Snow Level 3500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 4000' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 6500' |
| Sunday Night |
Snow Level 5500' |
| Sunday Night |
Snow Level ' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' (Easterly Flow *) |
| Sunday Morning |
Snow Level ' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Saturday Afternoon |
Snow Level 2500' |
| Saturday Night |
Snow Level 3500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 6000' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 6500' |
| Sunday Night |
Snow Level 7000' |
| Sunday Night |
Snow Level ' |
* 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 | LT 0.25 | 0 - 0.50 |
| Mt Baker Ski Area | LT 0.25 | 1.00 - 1.50 |
| Washington Pass | LT 0.10 | 0.50 - 0.75 |
| Stevens Pass | LT 0.25 | 2.00 - 3.00 |
| Snoqualmie Pass | LT 0.25 | 2.00 - 3.00 |
| Mission Ridge | LT 0.10 | 0.25 - 0.50 |
| Crystal Mt | LT 0.10 | 0.25 - 0.50 |
| Paradise | LT 0.10 | 1.00 - 2.00 |
| White Pass | LT 0.10 | 0.50 - 0.75 |
| Mt Hood Meadows | LT 0.10 | LT 0.25 |
| Timberline | LT 0.10 | 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: 3:23 PM PST Saturday, December 16, 2017
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Saturday Afternoon | W 5 - 15 | SW 5 - 15 | W 10 - 20 | --- - | WNW 10 - 20 |
| Saturday Night | WSW 15 - 25 | SSW 15 - 25 | WSW 15 - 25 | --- - | W 15 - 25 |
| Sunday Morning | WSW 20 - 30 | SSW 15 - 25 | WSW 15 - 25 | --- - | W 15 - 25 |
| Sunday Afternoon | WSW 20 - 30 | SW 20 - 30 | WSW 30 - 40 | --- - | W 20 - 30 |
| Sunday Night | W 20 - 30 | SW 20 - 30 | WSW 30 - 40 | --- - | W 25 - 35 |
| Sunday Night | --- - | --- - | --- - | --- - | --- - |
| Hurricane Ridge | Elevation |
|---|---|
| Saturday Afternoon | W 5 - 15 |
| Saturday Night | WSW 15 - 25 |
| Sunday Morning | WSW 20 - 30 |
| Sunday Afternoon | WSW 20 - 30 |
| Sunday Night | W 20 - 30 |
| Sunday Night | --- - |
| Mt. Baker | Elevation |
|---|---|
| Saturday Afternoon | SW 5 - 15 |
| Saturday Night | SSW 15 - 25 |
| Sunday Morning | SSW 15 - 25 |
| Sunday Afternoon | SW 20 - 30 |
| Sunday Night | SW 20 - 30 |
| Sunday Night | --- - |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Saturday Afternoon | W 10 - 20 |
| Saturday Night | WSW 15 - 25 |
| Sunday Morning | WSW 15 - 25 |
| Sunday Afternoon | WSW 30 - 40 |
| Sunday Night | WSW 30 - 40 |
| Sunday Night | --- - |
| Mt. Rainier | Elevation |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Sunday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Saturday Afternoon | WNW 10 - 20 |
| Saturday Night | W 15 - 25 |
| Sunday Morning | W 15 - 25 |
| Sunday Afternoon | W 20 - 30 |
| Sunday Night | W 25 - 35 |
| Sunday Night | --- - |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Saturday Afternoon | W 5 - 15 |
| Saturday Night | WSW 15 - 25 |
| Sunday Morning | WSW 20 - 30 |
| Sunday Afternoon | WSW 20 - 30 |
| Sunday Night | W 20 - 30 |
| Sunday Night | --- - |
| Mt. Baker | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 5 - 15 |
| Saturday Night | SSW 15 - 25 |
| Sunday Morning | SSW 15 - 25 |
| Sunday Afternoon | SW 20 - 30 |
| Sunday Night | SW 20 - 30 |
| Sunday Night | --- - |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | W 10 - 20 |
| Saturday Night | WSW 15 - 25 |
| Sunday Morning | WSW 15 - 25 |
| Sunday Afternoon | WSW 30 - 40 |
| Sunday Night | WSW 30 - 40 |
| Sunday Night | --- - |
| Mt. Rainier | Direction - Speed |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Sunday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Saturday Afternoon | WNW 10 - 20 |
| Saturday Night | W 15 - 25 |
| Sunday Morning | W 15 - 25 |
| Sunday Afternoon | W 20 - 30 |
| Sunday Night | W 25 - 35 |
| Sunday Night | --- - |
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 | |
|---|---|---|---|---|---|
| Saturday Afternoon | WNW 25 - 35 | WNW 20 - 30 | NW 30 - 40 | --- - | NNW 30 - 40 |
| Saturday Night | W 35 - 45 | WSW 35 - 45 | W 35 - 45 | --- - | NW 30 - 40 |
| Sunday Morning | WSW 35 - 45 | WSW 40 - 50 | WSW 35 - 45 | --- - | WNW 25 - 35 |
| Sunday Afternoon | W 40 - 50 | W 40 - 50 | W 45 - 55 | --- - | W 35 - 45 |
| Sunday Night | W 40 - 50 | W 45 - 55 | W 50 - 60 | --- - | W 50 - 60 |
| Sunday Night | --- - | --- - | --- - | --- - | --- - |
| Mt. Baker | Direction - Speed |
|---|---|
| Saturday Afternoon | WNW 25 - 35 |
| Saturday Night | W 35 - 45 |
| Sunday Morning | WSW 35 - 45 |
| Sunday Afternoon | W 40 - 50 |
| Sunday Night | W 40 - 50 |
| Sunday Night | --- - |
| Washington Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | WNW 20 - 30 |
| Saturday Night | WSW 35 - 45 |
| Sunday Morning | WSW 40 - 50 |
| Sunday Afternoon | W 40 - 50 |
| Sunday Night | W 45 - 55 |
| Sunday Night | --- - |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | NW 30 - 40 |
| Saturday Night | W 35 - 45 |
| Sunday Morning | WSW 35 - 45 |
| Sunday Afternoon | W 45 - 55 |
| Sunday Night | W 50 - 60 |
| Sunday Night | --- - |
| Mt. Rainier | Direction - Speed |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Sunday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Saturday Afternoon | NNW 30 - 40 |
| Saturday Night | NW 30 - 40 |
| Sunday Morning | WNW 25 - 35 |
| Sunday Afternoon | W 35 - 45 |
| Sunday Night | W 50 - 60 |
| Sunday Night | --- - |
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: 3:23 PM PST Saturday, December 16, 2017
Extended Weather Synopsis for Saturday night through Saturday
By Monday morning, the jet sags south toward the US-Canadian border and the front sags south with it. Moisture continues and spreads throughout the Washington Cascades and briefly ends in the north Monday night.
On Tuesday, a developing and strong low tracks off Tatoosh Island with a rapid increase in precipitation. Most stations should be in the pre-frontal warm sector (Baker only briefly). The low should bring strong winds as it passes over the San Juan Islands by Tuesday afternoon with a strong Frontal Passage expected, dropping temperatures rapidly Tuesday night with anticipated post-frontal snowfall.
On Wednesday, the cold upper level trough will be over Washington State, with a large ridge over the Pacific, extending to Southern Alaska.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Monday | Snow Level | 2500' - 4000' | 3500' - 5000' | 6000' - 7000' | |
| Monday Night | Snow Level | 2000' - 4000' | 4000' - 5000' | 6000' - 7000' | * |
| Tuesday | Snow Level | 2000' - 4000' | 3000' - 4500' | 4000' - 5500' | * |
| Tuesday Night | Snow Level | 1500' - 3500' | 1500' - 3500' | 1500' - 3500' | |
| Wednesday | Snow Level | 0' - 2000' | 0' - 2000' | 0' - 2000' |
| Mt. Baker | Elevation |
|---|---|
| Monday |
Snow Level 2500' - 4000' |
| Monday Night |
Snow Level 2000' - 4000' (Easterly Flow *) |
| Tuesday |
Snow Level 2000' - 4000' (Easterly Flow *) |
| Tuesday Night |
Snow Level 1500' - 3500' |
| Wednesday |
Snow Level 0' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday |
Snow Level 3500' - 5000' |
| Monday Night |
Snow Level 4000' - 5000' (Easterly Flow *) |
| Tuesday |
Snow Level 3000' - 4500' (Easterly Flow *) |
| Tuesday Night |
Snow Level 1500' - 3500' |
| Wednesday |
Snow Level 0' - 2000' |
| Mt. Hood | Elevation |
|---|---|
| Monday |
Snow Level 6000' - 7000' |
| Monday Night |
Snow Level 6000' - 7000' (Easterly Flow *) |
| Tuesday |
Snow Level 4000' - 5500' (Easterly Flow *) |
| Tuesday Night |
Snow Level 1500' - 3500' |
| Wednesday |
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 16, 2017
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