Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Thursday night through Friday
A deep low pressure system passing to our north brought high winds and mild temperatures to the Olympics and west slopes of the Cascades today. Mt. Baker (Pan Dome) recorded 3 consecutive hours of gusts over 100 mph! The associated cold front has passed through the Cascades early this afternoon, so locations that were spared the strongest of winds during the day like the Passes and the east slopes of the Cascades will see stronger winds materialize later this afternoon and tonight. A sharp cooling trend has begun as much colder air is advected into the region. Post-frontal showers will produce light to moderate snow accumulations along the west slopes of the Cascades and Mt. Hood overnight with lighter amounts for the east slopes of the Cascades.
Shortwave upper level ridging will build over the area on Friday representing a relative break in the action, but there will still be a chance of showers for the mountains with lingering instability and weak onshore flow. A weak frontal boundary producing generally light rain and snow will stall over the north Cascades and Olympics Friday night through Saturday morning with drier conditions likely for the south Washington Cascades and Mt. Hood. The next Pacific frontal system should reach the Olympic Peninsula by late Saturday afternoon.
Weather Forecast
Hurricane Ridge
| Thursday Night | Light to occasionally moderate rain and snow showers in the evening, becoming scattered showers after midnight. Sharp cooling trend. Winds easing overnight. |
| Friday | Mostly cloudy with isolated light rain and snow showers. |
Mt. Baker
| Thursday Night | Light to moderate rain and snow showers in the evening, becoming scattered showers after midnight. Sharp cooling trend. Winds easing overnight. |
| Friday | Partly to mostly cloudy with scattered light rain and snow showers. |
Washington Pass and Leavenworth
| Thursday Night | Light rain and snow showers in the evening, becoming isolated showers after midnight. Sharp cooling trend. Winds easing overnight. |
| Friday | Partly to mostly cloudy with isolated light rain and snow showers. |
Stevens and Snoqualmie Pass
| Thursday Night | Light to occasionally moderate rain and snow showers in the evening, becoming scattered showers late. Sharp cooling trend. Windy in the alpine. Moderate west winds at Pass level. |
| Friday | Partly to mostly cloudy with isolated light rain and snow showers mainly near the Cascade crest. Light west winds at Pass level. |
Mt. Rainier, Crystal and White Pass
| Thursday Night | Light to occasionally moderate rain and snow showers in the evening, becoming scattered showers late. Sharp cooling trend. Windy. |
| Friday | Partly to mostly cloudy with isolated light rain and snow showers. |
Mt. Hood
| Thursday Night | Light to occasionally moderate rain and snow showers. Sharp cooling trend. Windy in the alpine. |
| Friday | Partly cloudy with isolated light rain and snow showers. |
Issued: 2:36 PM PST Thursday, December 20, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Thursday Evening | Snow Level | 2500' | 2500' | 3500' | 3500' | 2500' | 2500' | 3000' | 4000' |
| Thursday Night | Snow Level | 1500' | 1000' | 500' | 1500' | 1000' | 1000' | 1500' | 2000' |
| Friday Morning | Snow Level | 1000' | 500' | 500' | 500' | 1000' | 1000' | 1500' | 1500' |
| Friday Afternoon | Snow Level | 1500' | 1000' | 500' | 1500' | 1500' | 1500' | 1500' | 2000' |
| Friday Evening | Snow Level | 2000' | 1000' | 500' | 1500' | 1500' | 1500' | 2000' | 2000' |
| Friday Night | Snow Level | 2500' | 1000' | 500' | 500' | 1000' | 1000' | 1500' | 2000' |
| Saturday Morning | Snow Level * | 3500' | 2000' | 500' | 1500' | 2000' | 2500' | 4000' | 3500' |
| Saturday Afternoon | Snow Level * | 3500' | 2500' | 1000' | 1000' | 2000' | 2500' | 3500' | 4000' |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Evening |
Snow Level 2500' |
| Thursday Night |
Snow Level 1500' |
| Friday Morning |
Snow Level 1000' |
| Friday Afternoon |
Snow Level 1500' |
| Friday Evening |
Snow Level 2000' |
| Friday Night |
Snow Level 2500' |
| Saturday Morning |
Snow Level 3500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Thursday Evening |
Snow Level 2500' |
| Thursday Night |
Snow Level 1000' |
| Friday Morning |
Snow Level 500' |
| Friday Afternoon |
Snow Level 1000' |
| Friday Evening |
Snow Level 1000' |
| Friday Night |
Snow Level 1000' |
| Saturday Morning |
Snow Level 2000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Thursday Evening |
Snow Level 3500' |
| Thursday Night |
Snow Level 500' |
| Friday Morning |
Snow Level 500' |
| Friday Afternoon |
Snow Level 500' |
| Friday Evening |
Snow Level 500' |
| Friday Night |
Snow Level 500' |
| Saturday Morning |
Snow Level 500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 1000' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Thursday Evening |
Snow Level 3500' |
| Thursday Night |
Snow Level 1500' |
| Friday Morning |
Snow Level 500' |
| Friday Afternoon |
Snow Level 1500' |
| Friday Evening |
Snow Level 1500' |
| Friday Night |
Snow Level 500' |
| Saturday Morning |
Snow Level 1500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 1000' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Thursday Evening |
Snow Level 2500' |
| Thursday Night |
Snow Level 1000' |
| Friday Morning |
Snow Level 1000' |
| Friday Afternoon |
Snow Level 1500' |
| Friday Evening |
Snow Level 1500' |
| Friday Night |
Snow Level 1000' |
| Saturday Morning |
Snow Level 2000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 2000' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday Evening |
Snow Level 2500' |
| Thursday Night |
Snow Level 1000' |
| Friday Morning |
Snow Level 1000' |
| Friday Afternoon |
Snow Level 1500' |
| Friday Evening |
Snow Level 1500' |
| Friday Night |
Snow Level 1000' |
| Saturday Morning |
Snow Level 2500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Thursday Evening |
Snow Level 3000' |
| Thursday Night |
Snow Level 1500' |
| Friday Morning |
Snow Level 1500' |
| Friday Afternoon |
Snow Level 1500' |
| Friday Evening |
Snow Level 2000' |
| Friday Night |
Snow Level 1500' |
| Saturday Morning |
Snow Level 4000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Thursday Evening |
Snow Level 4000' |
| Thursday Night |
Snow Level 2000' |
| Friday Morning |
Snow Level 1500' |
| Friday Afternoon |
Snow Level 2000' |
| Friday Evening |
Snow Level 2000' |
| Friday Night |
Snow Level 2000' |
| Saturday Morning |
Snow Level 3500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 4000' (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 Night | Friday | Friday Night | Friday | |
|---|---|---|---|---|
| 4 pm - 4 am | 4 am - 4 pm | 4 pm - 4 am | 4 am - 4 pm | |
| Hurricane Ridge | 0.25 - 0.50 | LT 0.10 | LT 0.25 | 0.25 |
| Mt Baker Ski Area | 0.50 | LT 0.25 | LT 0.25 | 0.25 |
| Washington Pass | 0.25 | LT 0.10 | LT 0.25 | LT 0.10 |
| Leavenworth | LT 0.10 | LT 0.10 | 0 | LT 0.10 |
| Stevens Pass | 0.25 - 0.50 | LT 0.10 | LT 0.10 | LT 0.10 |
| Snoqualmie Pass | 0.50 - 0.75 | LT 0.10 | LT 0.10 | LT 0.10 |
| Mission Ridge | LT 0.25 | 0 | 0 | 0 |
| Crystal Mt | 0.25 | LT 0.10 | 0 | LT 0.10 |
| Paradise | 0.50 | LT 0.10 | LT 0.10 | LT 0.10 |
| White Pass | 0.25 | LT 0.10 | 0 | LT 0.10 |
| Mt Hood Meadows | 0.50 | LT 0.10 | 0 | 0 |
| Timberline | 0.75 | LT 0.10 | 0 | 0 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Thursday Night | 0.25 - 0.50 |
| Friday | LT 0.10 |
| Friday Night | LT 0.25 |
| Friday | 0.25 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Thursday Night | 0.50 |
| Friday | LT 0.25 |
| Friday Night | LT 0.25 |
| Friday | 0.25 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Thursday Night | 0.25 |
| Friday | LT 0.10 |
| Friday Night | LT 0.25 |
| Friday | LT 0.10 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Thursday Night | LT 0.10 |
| Friday | LT 0.10 |
| Friday Night | 0 |
| Friday | LT 0.10 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Thursday Night | 0.25 - 0.50 |
| Friday | LT 0.10 |
| Friday Night | LT 0.10 |
| Friday | LT 0.10 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Thursday Night | 0.50 - 0.75 |
| Friday | LT 0.10 |
| Friday Night | LT 0.10 |
| Friday | LT 0.10 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Thursday Night | LT 0.25 |
| Friday | 0 |
| Friday Night | 0 |
| Friday | 0 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Thursday Night | 0.25 |
| Friday | LT 0.10 |
| Friday Night | 0 |
| Friday | LT 0.10 |
| Paradise | Precipitation Forecast |
|---|---|
| Thursday Night | 0.50 |
| Friday | LT 0.10 |
| Friday Night | LT 0.10 |
| Friday | LT 0.10 |
| White Pass | Precipitation Forecast |
|---|---|
| Thursday Night | 0.25 |
| Friday | LT 0.10 |
| Friday Night | 0 |
| Friday | LT 0.10 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Thursday Night | 0.50 |
| Friday | LT 0.10 |
| Friday Night | 0 |
| Friday | 0 |
| Timberline | Precipitation Forecast |
|---|---|
| Thursday Night | 0.75 |
| Friday | LT 0.10 |
| Friday Night | 0 |
| Friday | 0 |
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: 2:36 PM PST Thursday, December 20, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Thursday Evening | WSW 25 - 35 | SW 20 - 30 | WSW 25 - 40 | SW 20 - 35 | W 25 - 35 |
| Thursday Night | W 20 - 30 | SW 15 - 25 | WSW 25 - 40 | W 20 - 30 | W 20 - 30 |
| Friday Morning | W 10 - 20 | SW 5 - 15 | W 10 - 20 | W 10 - 20 | W 15 - 25 |
| Friday Afternoon | SW 0 - 10 | SW 5 - 15 | W 5 - 15 | W 5 - 15 | W 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Evening | WSW 25 - 35 |
| Thursday Night | W 20 - 30 |
| Friday Morning | W 10 - 20 |
| Friday Afternoon | SW 0 - 10 |
| Mt. Baker | Elevation |
|---|---|
| Thursday Evening | SW 20 - 30 |
| Thursday Night | SW 15 - 25 |
| Friday Morning | SW 5 - 15 |
| Friday Afternoon | SW 5 - 15 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Thursday Evening | WSW 25 - 40 |
| Thursday Night | WSW 25 - 40 |
| Friday Morning | W 10 - 20 |
| Friday Afternoon | W 5 - 15 |
| Mt. Rainier | Elevation |
|---|---|
| Thursday Evening | SW 20 - 35 |
| Thursday Night | W 20 - 30 |
| Friday Morning | W 10 - 20 |
| Friday Afternoon | W 5 - 15 |
| Mt. Hood | Elevation |
|---|---|
| Thursday Evening | W 25 - 35 |
| Thursday Night | W 20 - 30 |
| Friday Morning | W 15 - 25 |
| Friday Afternoon | W 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Thursday Evening | WSW 25 - 35 |
| Thursday Night | W 20 - 30 |
| Friday Morning | W 10 - 20 |
| Friday Afternoon | SW 0 - 10 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Evening | SW 20 - 30 |
| Thursday Night | SW 15 - 25 |
| Friday Morning | SW 5 - 15 |
| Friday Afternoon | SW 5 - 15 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Evening | WSW 25 - 40 |
| Thursday Night | WSW 25 - 40 |
| Friday Morning | W 10 - 20 |
| Friday Afternoon | W 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Evening | SW 20 - 35 |
| Thursday Night | W 20 - 30 |
| Friday Morning | W 10 - 20 |
| Friday Afternoon | W 5 - 15 |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Evening | W 25 - 35 |
| Thursday Night | W 20 - 30 |
| Friday Morning | W 15 - 25 |
| Friday Afternoon | W 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 | |
|---|---|---|---|---|---|
| Thursday Evening | SW 40 - 50 | SW 50 - 70 | SW 40 - 60 | SW 40 - 60 | WSW 40 - 50 |
| Thursday Night | WSW 20 - 30 | W 35 - 50 | WNW 40 - 50 | W 45 - 55 | WNW 40 - 50 |
| Friday Morning | W 20 - 30 | W 20 - 30 | NW 35 - 45 | WNW 25 - 35 | WNW 20 - 30 |
| Friday Afternoon | W 15 - 25 | W 15 - 25 | W 25 - 35 | WNW 20 - 30 | WNW 20 - 30 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Evening | SW 40 - 50 |
| Thursday Night | WSW 20 - 30 |
| Friday Morning | W 20 - 30 |
| Friday Afternoon | W 15 - 25 |
| Washington Pass | Direction - Speed |
|---|---|
| Thursday Evening | SW 50 - 70 |
| Thursday Night | W 35 - 50 |
| Friday Morning | W 20 - 30 |
| Friday Afternoon | W 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Evening | SW 40 - 60 |
| Thursday Night | WNW 40 - 50 |
| Friday Morning | NW 35 - 45 |
| Friday Afternoon | W 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Evening | SW 40 - 60 |
| Thursday Night | W 45 - 55 |
| Friday Morning | WNW 25 - 35 |
| Friday Afternoon | WNW 20 - 30 |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Evening | WSW 40 - 50 |
| Thursday Night | WNW 40 - 50 |
| Friday Morning | WNW 20 - 30 |
| Friday Afternoon | WNW 20 - 30 |
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: 2:36 PM PST Thursday, December 20, 2018
Extended Weather Synopsis for Friday night through Friday
You don't need to worry about the pattern taking it down a notch in the extended...the active weather continues. We should see a frontal passage Saturday night. The jet will sink south into Oregon and weaken the initial front as it passes inland. However, the parent upper low off the coast of Vancouver Island should spin a series of disturbances inland Sunday and Sunday night, continuing significant shower activity that favors the west slopes of the Cascades. The next developing low pressure system on Monday is forecast to drop south towards Oregon. Forecast models disagree how much far north the precipitation shield will reach into Washington state.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Saturday Night | Snow Level | 1000' - 2000' | 1000' - 2000' | 3000' - 4000' | |
| Sunday | Snow Level | 2500' - 3500' | 3000' - 4000' | 3500' - 4500' | |
| Sunday Night | Snow Level | 2500' - 3500' | 3000' - 4000' | 4000' - 5000' | |
| Monday | Snow Level | 3000' - 4000' | 3000' - 4000' | 4500' - 5500' |
| Mt. Baker | Elevation |
|---|---|
| Saturday Night |
Snow Level 1000' - 2000' |
| Sunday |
Snow Level 2500' - 3500' |
| Sunday Night |
Snow Level 2500' - 3500' |
| Monday |
Snow Level 3000' - 4000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday Night |
Snow Level 1000' - 2000' |
| Sunday |
Snow Level 3000' - 4000' |
| Sunday Night |
Snow Level 3000' - 4000' |
| Monday |
Snow Level 3000' - 4000' |
| Mt. Hood | Elevation |
|---|---|
| Saturday Night |
Snow Level 3000' - 4000' |
| Sunday |
Snow Level 3500' - 4500' |
| Sunday Night |
Snow Level 4000' - 5000' |
| Monday |
Snow Level 4500' - 5500' |
* 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, 2018
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