Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Friday night through Thursday
The Pacific Northwest is transitioning into an active December weather pattern with a series of storm systems slated to arrive every few days for the foreseeable future.
The first system consists of a weakening frontal boundary and associated short-wave trough lifting across the forecast area late Friday night through Saturday. This will bring a round of light rain and snow to the region. A deep pool of cold air and light to moderate easterly flow will generally keep precipitation frozen east of the Cascade Crest and through the passes, while areas further west will experience elevated snow levels.
Saturday afternoon will see a drying trend from south to north as a shortwave ridge works into the region.
A second, stronger frontal system arrives from the west on Sunday night and will bring warm air, increasing southerly winds and precipitation into the Olympic Peninsula by morning. The front will slowly move across the region on Sunday into Sunday evening, bringing moderate to occasionally strong crest-level winds. Warm air and rain will impact mid-elevation locations west of the Cascade Crest and Mt. Hood, while the cold air pool will maintain snow east of the Cascade crest with mixed precipitation possible for Snoqualmie Pass. Precipitation amounts will be light to moderate for most locations, but Mt. Baker (favored by the S-SW flow) could see 1.5" of precipitable water.
Weather Forecast
Hurricane Ridge
| Friday Night | Increasing high clouds lowering and thickening. A chance of very light rain arriving by morning. Light to moderate winds becoming moderate. |
| Saturday | Very light rain ending by mid-morning. Becoming partly cloudy. Light winds. |
Mt. Baker
| Friday Night | Increasing high clouds lowering and thickening. Rising freezing levels. Light winds. |
| Saturday | Light rain and snow from mid-morning onward. Light to moderate winds. |
Stevens and Snoqualmie Pass
| Friday Night | High clouds lowering and thickening. Moderate easterly winds. Light to moderate crest-level winds. |
| Saturday | Morning wintry mix in the passes with rain likely west of the Cascade Crest and all snow east of the Cascade Crest. Moderate easterly winds through the passes with light to moderate crest-level winds. |
Mt. Rainier and Crystal
| Friday Night | High clouds increasing and lowering. Light to moderate rain and snow. |
| Saturday | Light rain and snow west of the Cascade Crest with mostly snow for Crystal and White Passes, becoming partly cloudy weather in the afternoon. Decreasing light to moderate winds. |
Washington Pass and Leavenworth
| Friday Night | High clouds lowering and thickening. Light to moderate S-SE winds. |
| Saturday | Light snow developing and ending by mid-afternoon. Minor accumulation. Light to moderate SE winds. |
Mt. Hood
| Friday Night | High clouds lowering and thickening. Light winds becoming moderate. Light rain and snow arriving after midnight. |
| Saturday | Light rain and snow ending early. Decreasing winds becoming light. |
Issued: 3:35 PM PST Friday, December 7, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Friday Evening | Freezing Level * | 5000' | 4000' | 2500' | 500' | 1500' | 2500' | 3500' | 5500' |
| Friday Night | Snow Level * | 6000' | 4000' | 2500' | 1000' | 2000' | 3000' | 3500' | 5500' |
| Saturday Morning | Snow Level * | 4500' | 3500' | 2000' | 1000' | 1500' | 3000' | 3500' | 4000' |
| Saturday Afternoon | Snow Level * | 5000' | 3500' | 2500' | 1500' | 2000' | 3500' | 4500' | 5500' |
| Saturday Evening | Snow Level * | 7000' | 5000' | 2000' | 1000' | 1500' | 3000' | 5000' | 7000' |
| Saturday Night | Snow Level * | 6500' | 3500' | 1000' | 500' | 1000' | 1500' | 3000' | 6000' |
| Sunday Morning | Snow Level * | 6500' | 5500' | 2500' | 1500' | 2500' | 4000' | 5000' | 6500' |
| Sunday Afternoon | Snow Level * | 4000' | 3000' | 2500' | 2500' | 2500' | 3000' | 3500' | 4000' |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Evening |
Freezing Level 5000' (Easterly Flow *) |
| Friday Night |
Snow Level 6000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 4500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 5000' (Easterly Flow *) |
| Saturday Evening |
Snow Level 7000' (Easterly Flow *) |
| Saturday Night |
Snow Level 6500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 6500' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 4000' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Friday Evening |
Freezing Level 4000' (Easterly Flow *) |
| Friday Night |
Snow Level 4000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 3500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Saturday Evening |
Snow Level 5000' (Easterly Flow *) |
| Saturday Night |
Snow Level 3500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 5500' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 3000' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Friday Evening |
Freezing Level 2500' (Easterly Flow *) |
| Friday Night |
Snow Level 2500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 2000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Saturday Evening |
Snow Level 2000' (Easterly Flow *) |
| Saturday Night |
Snow Level 1000' (Easterly Flow *) |
| Sunday Morning |
Snow Level 2500' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Friday Evening |
Freezing Level 500' (Easterly Flow *) |
| Friday Night |
Snow Level 1000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 1000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 1500' (Easterly Flow *) |
| Saturday Evening |
Snow Level 1000' (Easterly Flow *) |
| Saturday Night |
Snow Level 500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 1500' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Friday Evening |
Freezing Level 1500' (Easterly Flow *) |
| Friday Night |
Snow Level 2000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 1500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 2000' (Easterly Flow *) |
| Saturday Evening |
Snow Level 1500' (Easterly Flow *) |
| Saturday Night |
Snow Level 1000' (Easterly Flow *) |
| Sunday Morning |
Snow Level 2500' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Friday Evening |
Freezing Level 2500' (Easterly Flow *) |
| Friday Night |
Snow Level 3000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 3000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Saturday Evening |
Snow Level 3000' (Easterly Flow *) |
| Saturday Night |
Snow Level 1500' (Easterly Flow *) |
| Sunday Morning |
Snow Level 4000' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 3000' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Friday Evening |
Freezing Level 3500' (Easterly Flow *) |
| Friday Night |
Snow Level 3500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 3500' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 4500' (Easterly Flow *) |
| Saturday Evening |
Snow Level 5000' (Easterly Flow *) |
| Saturday Night |
Snow Level 3000' (Easterly Flow *) |
| Sunday Morning |
Snow Level 5000' (Easterly Flow *) |
| Sunday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Friday Evening |
Freezing Level 5500' (Easterly Flow *) |
| Friday Night |
Snow Level 5500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 4000' (Easterly Flow *) |
| Saturday Afternoon |
Snow Level 5500' (Easterly Flow *) |
| Saturday Evening |
Snow Level 7000' (Easterly Flow *) |
| Saturday Night |
Snow Level 6000' (Easterly Flow *) |
| Sunday Morning |
Snow Level 6500' (Easterly Flow *) |
| Sunday 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
| Friday Night | Thursday | Thursday Night | Thursday | |
|---|---|---|---|---|
| 4 pm - 4 am | 4 am - 4 pm | 4 pm - 4 am | 4 am - 4 pm | |
| Hurricane Ridge | LT 0.10 | 0 | LT 0.25 | 0.25 - 0.50 |
| Mt Baker Ski Area | 0 | LT 0.25 | LT 0.10 | 1.00 |
| Washington Pass | 0 | 0 | LT 0.10 | 1.00 |
| Stevens Pass | 0 | LT 0.10 | 0 | LT 0.10 |
| Snoqualmie Pass | LT 0.10 | LT 0.10 | 0 | LT 0.25 |
| Leavenworth | 0 | 0 | 0 | LT 0.10 |
| Mission Ridge | 0 | 0 | 0 | LT 0.10 |
| Crystal Mt | LT 0.10 | LT 0.10 | 0 | 0.25 |
| Paradise | LT 0.25 | LT 0.25 | LT 0.10 | 0.25 |
| White Pass | LT 0.10 | LT 0.10 | 0 | LT 0.10 |
| Mt Hood Meadows | 0.25 | LT 0.10 | 0 | 0.25 |
| Timberline | 0.50 | LT 0.10 | 0 | 0.25 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Friday Night | LT 0.10 |
| Thursday | 0 |
| Thursday Night | LT 0.25 |
| Thursday | 0.25 - 0.50 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Friday Night | 0 |
| Thursday | LT 0.25 |
| Thursday Night | LT 0.10 |
| Thursday | 1.00 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Friday Night | 0 |
| Thursday | 0 |
| Thursday Night | LT 0.10 |
| Thursday | 1.00 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Friday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | LT 0.10 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Friday Night | LT 0.10 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | LT 0.25 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Friday Night | 0 |
| Thursday | 0 |
| Thursday Night | 0 |
| Thursday | LT 0.10 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Friday Night | 0 |
| Thursday | 0 |
| Thursday Night | 0 |
| Thursday | LT 0.10 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Friday Night | LT 0.10 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | 0.25 |
| Paradise | Precipitation Forecast |
|---|---|
| Friday Night | LT 0.25 |
| Thursday | LT 0.25 |
| Thursday Night | LT 0.10 |
| Thursday | 0.25 |
| White Pass | Precipitation Forecast |
|---|---|
| Friday Night | LT 0.10 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | LT 0.10 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Friday Night | 0.25 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | 0.25 |
| Timberline | Precipitation Forecast |
|---|---|
| Friday Night | 0.50 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | 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: 3:35 PM PST Friday, December 7, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Evening | SSE 15 - 25 | SE 10 - 20 | SSE 5 - 15 | SSE 10 - 20 | S 10 - 20 |
| Friday Night | SSE 20 - 30 | SSE 15 - 25 | SE 10 - 20 | SSE 15 - 25 | SSW 20 - 30 |
| Saturday Morning | SW 10 - 20 | SSE 15 - 25 | SSW 15 - 25 | SSW 15 - 25 | SSW 15 - 25 |
| Saturday Afternoon | S 10 - 20 | SSE 10 - 20 | S 10 - 20 | S 10 - 20 | S 15 - 25 |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Evening | SSE 15 - 25 |
| Friday Night | SSE 20 - 30 |
| Saturday Morning | SW 10 - 20 |
| Saturday Afternoon | S 10 - 20 |
| Mt. Baker | Elevation |
|---|---|
| Friday Evening | SE 10 - 20 |
| Friday Night | SSE 15 - 25 |
| Saturday Morning | SSE 15 - 25 |
| Saturday Afternoon | SSE 10 - 20 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Friday Evening | SSE 5 - 15 |
| Friday Night | SE 10 - 20 |
| Saturday Morning | SSW 15 - 25 |
| Saturday Afternoon | S 10 - 20 |
| Mt. Rainier | Elevation |
|---|---|
| Friday Evening | SSE 10 - 20 |
| Friday Night | SSE 15 - 25 |
| Saturday Morning | SSW 15 - 25 |
| Saturday Afternoon | S 10 - 20 |
| Mt. Hood | Elevation |
|---|---|
| Friday Evening | S 10 - 20 |
| Friday Night | SSW 20 - 30 |
| Saturday Morning | SSW 15 - 25 |
| Saturday Afternoon | S 15 - 25 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Friday Evening | SSE 15 - 25 |
| Friday Night | SSE 20 - 30 |
| Saturday Morning | SW 10 - 20 |
| Saturday Afternoon | S 10 - 20 |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Evening | SE 10 - 20 |
| Friday Night | SSE 15 - 25 |
| Saturday Morning | SSE 15 - 25 |
| Saturday Afternoon | SSE 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Evening | SSE 5 - 15 |
| Friday Night | SE 10 - 20 |
| Saturday Morning | SSW 15 - 25 |
| Saturday Afternoon | S 10 - 20 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Evening | SSE 10 - 20 |
| Friday Night | SSE 15 - 25 |
| Saturday Morning | SSW 15 - 25 |
| Saturday Afternoon | S 10 - 20 |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Evening | S 10 - 20 |
| Friday Night | SSW 20 - 30 |
| Saturday Morning | SSW 15 - 25 |
| Saturday Afternoon | S 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.
Free Winds at 9000' (mph)
| Mt. Baker | Washington Pass | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Evening | SW 10 - 20 | WSW 10 - 20 | WSW 10 - 20 | WSW 10 - 20 | SW 20 - 30 |
| Friday Night | SSW 20 - 30 | SW 15 - 25 | WSW 25 - 35 | SW 20 - 30 | WSW 25 - 35 |
| Saturday Morning | SSW 20 - 30 | SW 15 - 25 | WSW 25 - 35 | SW 20 - 30 | WSW 20 - 30 |
| Saturday Afternoon | SSW 15 - 25 | SW 10 - 20 | SW 10 - 20 | SW 10 - 20 | WSW 15 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Evening | SW 10 - 20 |
| Friday Night | SSW 20 - 30 |
| Saturday Morning | SSW 20 - 30 |
| Saturday Afternoon | SSW 15 - 25 |
| Washington Pass | Direction - Speed |
|---|---|
| Friday Evening | WSW 10 - 20 |
| Friday Night | SW 15 - 25 |
| Saturday Morning | SW 15 - 25 |
| Saturday Afternoon | SW 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Evening | WSW 10 - 20 |
| Friday Night | WSW 25 - 35 |
| Saturday Morning | WSW 25 - 35 |
| Saturday Afternoon | SW 10 - 20 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Evening | WSW 10 - 20 |
| Friday Night | SW 20 - 30 |
| Saturday Morning | SW 20 - 30 |
| Saturday Afternoon | SW 10 - 20 |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Evening | SW 20 - 30 |
| Friday Night | WSW 25 - 35 |
| Saturday Morning | WSW 20 - 30 |
| Saturday Afternoon | WSW 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: 3:35 PM PST Friday, December 7, 2018
Extended Weather Synopsis for Thursday night through Thursday
Modest cooling will occur Sunday night as a shortwave trough settles over the region and will linger through the day Monday, bringing cooler and unstable showery conditions.
Monday night, showers will be cut off as warm air begins to arrive aloft ahead of a potent frontal system. The system will arrive from the W-NW on Tuesday, bringing moderate to heavy rain and snow at initially elevated and then rapidly lowering snow levels. The system is expected to bring moderate W-SW winds shifting to W-NW and significant snow totals at mid and upper elevations, particularly for the west slopes of the Cascades.
Mountain snow showers will continue Tuesday night with a shortwave trough will be over the region and Wednesday with a weak ridge offshore bringing NW flow aloft.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Sunday Night | Snow Level | 2500' - 3500' | 2500' - 3500' | 3500' - 4500' | * |
| Monday | Snow Level | 2000' - 3000' | 2500' - 3500' | 2500' - 3500' | |
| Monday Night | Snow Level | 2000' - 3000' | 2000' - 3000' | 2500' - 3500' | |
| Tuesday | Snow Level | 2500' - 3000' | 2500' - 3500' | 4500' - 5500' |
| Mt. Baker | Elevation |
|---|---|
| Sunday Night |
Snow Level 2500' - 3500' (Easterly Flow *) |
| Monday |
Snow Level 2000' - 3000' |
| Monday Night |
Snow Level 2000' - 3000' |
| Tuesday |
Snow Level 2500' - 3000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Sunday Night |
Snow Level 2500' - 3500' (Easterly Flow *) |
| Monday |
Snow Level 2500' - 3500' |
| Monday Night |
Snow Level 2000' - 3000' |
| Tuesday |
Snow Level 2500' - 3500' |
| Mt. Hood | Elevation |
|---|---|
| Sunday Night |
Snow Level 3500' - 4500' (Easterly Flow *) |
| Monday |
Snow Level 2500' - 3500' |
| Monday Night |
Snow Level 2500' - 3500' |
| Tuesday |
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 6, 2018
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