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 & Friday
Our persistent upper ridge and warm airmass has returned to its full glory and will bring us one more day of unseasonably warm weather aloft. A surface high pressure located east of the Cascades will continue to support offshore flow across the Cascades today. Inversion conditions will continue to cause areas of low clouds and cooler temperatures at lower elevations east of the crest and through the Cascade passes.
On Thursday night, the first in a series of storms, a weak cold front and shortwave ridge will continue to flatten our ridge and will be arriving on our coastline by morning.
A shortwave and associated weakening cold front will pass the Olympics and Cascades during the mid-morning hours with SW flow aloft switching to WNW behind the front.
Weather Forecast
Olympics
| Thursday |
Mostly sunny with some high clouds. |
| Thursday Night |
High clouds lowering late with increasing light to moderate rain by morning. |
| Friday |
Light to moderate rain and snow in the morning becoming decreasing light to moderate rain and snow showers in the afternoon. |
| Friday Night |
Mostly cloudy. |
Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
| Thursday |
Mostly sunny with some high clouds. Low clouds and cooler in the passes, mainly Snoqualmie. |
| Thursday Night |
Increasing high clouds with lower-level clouds arriving by morning. Cooler with low clouds all night in the passes, mainly Snoqualmie. |
| Friday |
Increasing light to moderate rain, snow and areas of freezing rain initially in deep valleys and passes. Precipitation starts early in the north and moves south as the morning progresses, bringing 3-6 hours of precipitation to most locations before becoming light to moderate rain and snow showers by afternoon, with the afternoon precipitation heaviest in the central part. |
| Friday Night |
Lingering light rain and snow showers, mainly central part. |
East slopes of the Washington Cascades
| Thursday |
Mostly sunny with some high clouds. Low clouds at lower elevations with the inversion. |
| Thursday Night |
Increasing high clouds with lower-level clouds arriving by morning. Low clouds at lower elevations with the inversion. |
| Friday |
Increasing light to moderate rain, snow or freezing rain initially changing to all snow. Precipitation starts early in the north and moves south as the morning progresses, bringing 3-6 hours of precipitation to most locations before becoming light snow showers by afternoon, with the afternoon precipitation heaviest in the central part. |
| Friday Night |
Lingering light snow showers, mainly central part higher elevations. |
Mt. Hood Area
| Thursday |
Mostly sunny with some high clouds. |
| Thursday Night |
Increasing high clouds lowering toward morning. |
| Friday |
Increasing rain and snow starting mid-morning becoming light rain and snow showers by evening. |
| Friday Night |
Decreasing light snow showers. |
Issued: 3:45 PM PST Thursday, December 14, 2017
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Thursday Afternoon | Freezing Level * | 11500' | 11500' | 12000' | ' | ' | 12500' | ' | 13000' |
| Thursday Night | Snow Level * | 6500' | 5000' | 6500' | ' | ' | 8000' | ' | 10500' |
| Friday Morning | Snow Level | 4000' | 3000' | 3500' | ' | ' | 4000' | ' | 6000' |
| Friday Afternoon | Snow Level | 2500' | 2500' | 3000' | ' | ' | 3000' | ' | 3000' |
| Friday Night | Snow Level | 2500' | 1500' | 1500' | ' | ' | 2000' | ' | 2000' |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level 11500' (Easterly Flow *) |
| Thursday Night |
Snow Level 6500' (Easterly Flow *) |
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 2500' |
| Friday Night |
Snow Level 2500' |
| Mt. Baker | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level 11500' (Easterly Flow *) |
| Thursday Night |
Snow Level 5000' (Easterly Flow *) |
| Friday Morning |
Snow Level 3000' |
| Friday Afternoon |
Snow Level 2500' |
| Friday Night |
Snow Level 1500' |
| Washington Pass | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level 12000' (Easterly Flow *) |
| Thursday Night |
Snow Level 6500' (Easterly Flow *) |
| Friday Morning |
Snow Level 3500' |
| Friday Afternoon |
Snow Level 3000' |
| Friday Night |
Snow Level 1500' |
| Leavenworth | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Thursday Night |
Snow Level ' (Easterly Flow *) |
| Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Thursday Night |
Snow Level ' (Easterly Flow *) |
| Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level 12500' (Easterly Flow *) |
| Thursday Night |
Snow Level 8000' (Easterly Flow *) |
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 3000' |
| Friday Night |
Snow Level 2000' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level ' (Easterly Flow *) |
| Thursday Night |
Snow Level ' (Easterly Flow *) |
| Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Thursday Afternoon |
Freezing Level 13000' (Easterly Flow *) |
| Thursday Night |
Snow Level 10500' (Easterly Flow *) |
| Friday Morning |
Snow Level 6000' |
| Friday Afternoon |
Snow Level 3000' |
| Friday Night |
Snow Level 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.
Precipitation Forecast
| Friday | Friday | |
|---|---|---|
| Hurricane Ridge | LT 0.10 | 0 - 0.50 |
| Mt Baker Ski Area | LT 0.10 | 0.25 - 0.50 |
| Washington Pass | LT 0.10 | LT 0.25 |
| Stevens Pass | LT 0.10 | 0.25 - 0.50 |
| Snoqualmie Pass | LT 0.10 | 0 - 0.50 |
| Mission Ridge | LT 0.10 | LT 0.10 |
| Crystal Mt | LT 0.10 | 0 - 0.50 |
| Paradise | LT 0.10 | 0 - 0.50 |
| White Pass | LT 0.10 | LT 0.25 |
| 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: 3:45 PM PST Thursday, December 14, 2017
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Thursday Afternoon | WSW 10 - 15 | SSW 5 - 10 | VAR 0 - 10 | --- - | S 5 - 10 |
| Thursday Night | WSW 10 - 15 | WSW 5 - 10 | W 10 - 15 | --- - | WSW 15 - 20 |
| Friday Morning | W 15 - 20 | SW 10 - 15 | W 10 - 15 | --- - | WSW 20 - 25 |
| Friday Afternoon | W 20 - 25 | W 15 - 20 | W 15 - 20 | --- - | W 25 - 30 |
| Friday Night | W 20 - 25 | WSW 10 - 15 | W 15 - 20 | --- - | WNW 25 - 30 |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Afternoon | WSW 10 - 15 |
| Thursday Night | WSW 10 - 15 |
| Friday Morning | W 15 - 20 |
| Friday Afternoon | W 20 - 25 |
| Friday Night | W 20 - 25 |
| Mt. Baker | Elevation |
|---|---|
| Thursday Afternoon | SSW 5 - 10 |
| Thursday Night | WSW 5 - 10 |
| Friday Morning | SW 10 - 15 |
| Friday Afternoon | W 15 - 20 |
| Friday Night | WSW 10 - 15 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Thursday Afternoon | VAR 0 - 10 |
| Thursday Night | W 10 - 15 |
| Friday Morning | W 10 - 15 |
| Friday Afternoon | W 15 - 20 |
| Friday Night | W 15 - 20 |
| Mt. Rainier | Elevation |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Thursday Afternoon | S 5 - 10 |
| Thursday Night | WSW 15 - 20 |
| Friday Morning | WSW 20 - 25 |
| Friday Afternoon | W 25 - 30 |
| Friday Night | WNW 25 - 30 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Thursday Afternoon | WSW 10 - 15 |
| Thursday Night | WSW 10 - 15 |
| Friday Morning | W 15 - 20 |
| Friday Afternoon | W 20 - 25 |
| Friday Night | W 20 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Afternoon | SSW 5 - 10 |
| Thursday Night | WSW 5 - 10 |
| Friday Morning | SW 10 - 15 |
| Friday Afternoon | W 15 - 20 |
| Friday Night | WSW 10 - 15 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | VAR 0 - 10 |
| Thursday Night | W 10 - 15 |
| Friday Morning | W 10 - 15 |
| Friday Afternoon | W 15 - 20 |
| Friday Night | W 15 - 20 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Afternoon | S 5 - 10 |
| Thursday Night | WSW 15 - 20 |
| Friday Morning | WSW 20 - 25 |
| Friday Afternoon | W 25 - 30 |
| Friday Night | WNW 25 - 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.
Free Winds at 9000' (mph)
| Mt. Baker | Washington Pass | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Thursday Afternoon | W 20 - 25 | WSW 20 - 25 | W 20 - 25 | --- - | WNW 15 - 20 |
| Thursday Night | WSW 30 - 40 | WSW 35 - 50 | WSW 40 - 55 | --- - | WSW 25 - 30 |
| Friday Morning | W 20 - 25 | W 20 - 25 | W 25 - 35 | --- - | WSW 35 - 50 |
| Friday Afternoon | W 15 - 20 | W 20 - 30 | W 30 - 40 | --- - | W 40 - 55 |
| Friday Night | W 25 - 35 | W 20 - 25 | WNW 40 - 55 | --- - | NW 45 - 65 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Afternoon | W 20 - 25 |
| Thursday Night | WSW 30 - 40 |
| Friday Morning | W 20 - 25 |
| Friday Afternoon | W 15 - 20 |
| Friday Night | W 25 - 35 |
| Washington Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | WSW 20 - 25 |
| Thursday Night | WSW 35 - 50 |
| Friday Morning | W 20 - 25 |
| Friday Afternoon | W 20 - 30 |
| Friday Night | W 20 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | W 20 - 25 |
| Thursday Night | WSW 40 - 55 |
| Friday Morning | W 25 - 35 |
| Friday Afternoon | W 30 - 40 |
| Friday Night | WNW 40 - 55 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Afternoon | WNW 15 - 20 |
| Thursday Night | WSW 25 - 30 |
| Friday Morning | WSW 35 - 50 |
| Friday Afternoon | W 40 - 55 |
| Friday Night | NW 45 - 65 |
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: 3:45 PM PST Thursday, December 14, 2017
Extended Weather Synopsis for Friday night through Friday
Friday's front will dig a shortwave trough into the intermountain west by Saturday morning. On Saturday, warm frontal moisture will begin over-running the cold air in place after Friday's shortwave passes. The warm front will usher in warmer temperatures Saturday night, changing frozen precipitation to rain in many areas and a cold front will continue to drop southward into the Pacific Northwest region.
On Sunday, the cold front stalls over Washington state, bringing plenty of moisture along with it along with a north-south oriented temperature gradient.
The front drops south on Monday, cutting off moisture and ushering in colder temperatures. The last in the series of storms will be poised offshore and has the potential to bring significant weather to our region.
Extended Weather
All Zones
Periods of light snow arrives first in the Olympics and spread to the Cascades west slopes, with rising freezing levels light and occasionally moderate rain and snow will continue Saturday afternoon and Saturday night.
On Sunday, moderate to occasionally heavy rain and snow will be seen throughout the Cascades and Olympics with the heaviest precipitation likely in Washington State.
On Monday, the moderate to occasionally heavy rain and snow will cut off from north to south.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Saturday | Snow Level | 1500' - 2500' | 1500' - 2500' | 2000' - 3000' | |
| Saturday Night | Snow Level | 3000' - 4000' | 4000' - 5000' | 3000' - 4000' | |
| Sunday | Snow Level | 4000' - 5000' | 5000' - 6000' | 6500' - 7500' | |
| Sunday Night | Snow Level | 3500' - 4500' | 4500' - 5500' | 6000' - 7000' | |
| Monday | Snow Level | 3000' - 4000' | 4500' - 5500' | 6000' - 7000' | |
| Monday Night | Snow Level | ' - ' | ' - ' | ' - ' |
| Mt. Baker | Elevation |
|---|---|
| Saturday |
Snow Level 1500' - 2500' |
| Saturday Night |
Snow Level 3000' - 4000' |
| Sunday |
Snow Level 4000' - 5000' |
| Sunday Night |
Snow Level 3500' - 4500' |
| Monday |
Snow Level 3000' - 4000' |
| Monday Night |
Snow Level ' - ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday |
Snow Level 1500' - 2500' |
| Saturday Night |
Snow Level 4000' - 5000' |
| Sunday |
Snow Level 5000' - 6000' |
| Sunday Night |
Snow Level 4500' - 5500' |
| Monday |
Snow Level 4500' - 5500' |
| Monday Night |
Snow Level ' - ' |
| Mt. Hood | Elevation |
|---|---|
| Saturday |
Snow Level 2000' - 3000' |
| Saturday Night |
Snow Level 3000' - 4000' |
| Sunday |
Snow Level 6500' - 7500' |
| Sunday Night |
Snow Level 6000' - 7000' |
| Monday |
Snow Level 6000' - 7000' |
| Monday 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.
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 14, 2017
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