Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Wednesday night through Sunday
A very active, wet and windy weather pattern continues over the Pacific Northwest.
The next in the line of low-pressure systems heads for SE Alaska, but the associated warm front stalls, increasing moisture to the region Wednesday afternoon with the heavy stuff arriving Wednesday night and Thursday morning. The northwest Washington windward slopes will experience the heaviest rain and snow throughout the storm, with a sharp precipitation boundary at the southeast edge such that Mt. Hood barely receives any precipitation and Mt. Rainier experiences drying late Thursday as the front lifts northward.
Moderate to heavy snowfall Wednesday night into Thursday morning will change to rain at the lower Cascade passes by mid-morning as the warm front moves across the region and lifts northward. Although light easterly flow will develop late Wednesday night in the passes, there is not enough cold air east of the Cascades to prevent a changeover to rain.
Winds will also be a major story with this system as moderate westerly flow becomes strong out of the SW Wednesday night and Thursday morning with winds gradually moderating Thursday afternoon from south to north.
Thursday night, the next system develops along a front associated with the previous system and lifts the warm front over Washington northward to the Canadian border, drying out most of Washington except the Mt. Baker and Olympic areas where light rain may persist. Winds will remain moderate to strong west of the Cascade crest as the next system approaches.
Another major system will impact the region on Friday with a N-S oriented cold front bringing moderate rain and snow, lowering snow levels and a strong southerly barrier jet, switching to moderate to strong W-NW flow behind the front. Snow levels should return to Snoqualmie Pass level by the end of the day.
Weather Forecast
Hurricane Ridge
| Wednesday Night | Light to moderate rain and snow. Rapidly rising snow levels. Strong S-SW winds. |
| Thursday | Light rain. High snow levels. Strong SW winds. |
Mt. Baker
| Wednesday Night | Light snow becoming moderate to heavy after midnight. Increasing moderate S-SW winds. Slowly rising snow levels. |
| Thursday | Heavy rain and snow. Snow levels rising sharply in the afternoon. Moderate S-SW winds with strong gusts. |
Washington Pass and Leavenworth
| Wednesday Night | Increasing light snow becoming moderate after midnight. Increasing moderate winds. |
| Thursday | Moderate to occasionally heavy rain and snow. Snow levels rising with snow potentially mixing with rain by the afternoon at Washington Pass. Moderate winds. |
Stevens and Snoqualmie Pass
| Wednesday Night | Light snow before midnight becoming moderate during the early morning hours. Winds increasing to sustained moderate after midnight. Very light easterly low-level flow through the passes. |
| Thursday | Moderate snow switching to rain at the passes during the mid-morning hours. Rain and snow decreasing in the afternoon. Moderate winds with strong gusts. Light easterly low-level flow through the passes. |
Mt. Rainier, Crystal and White Pass
| Wednesday Night | Light rain and snow becoming moderate at Paradise after midnight. Moisture largely blocked after midnight at Crystal. Winds becoming moderate with strong gusts after midnight. |
| Thursday | Moderate rain and high elevation snow with moderate gusting strong winds. Rapidly rising snow levels in the late morning hours. Rain and snow decreasing sharply in the afternoon. |
Mt. Hood
| Wednesday Night | Light rain and snow after midnight. Increasing moderate winds, gusting to strong after midnight. |
| Thursday | Mid to high-level cloud cover. Moderate winds. High freezing levels. |
Issued: 2:45 PM PST Wednesday, December 12, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Wednesday Evening | Snow Level | 4000' | 2500' | 1500' | 2500' | 2500' | 2500' | 2500' | 2500' |
| Wednesday Night | Snow Level * | 6000' | 3000' | 2500' | 3000' | 2500' | 2500' | 3000' | 2000' |
| Thursday Morning | Snow Level | 6000' | 3000' | 3500' | 4500' | 4500' | 4000' | 3500' | 3500' |
| Thursday Afternoon | Snow Level | 6000' | 4500' | 5000' | 5000' | 5000' | 5000' | 5000' | 6000' |
| Thursday Evening | Snow Level * | 6500' | 5500' | 5000' | 6000' | 5500' | 5500' | 4500' | 5500' |
| Thursday Night | Snow Level * | 7000' | 5000' | 4500' | 5500' | 5500' | 5000' | 4000' | 6500' |
| Friday Morning | Snow Level * | 4000' | 4000' | 3000' | 3000' | 3000' | 3000' | 3500' | 5000' |
| Friday Afternoon | Snow Level | 3500' | 3000' | 2500' | 3000' | 3500' | 4000' | 3500' | 3500' |
| Hurricane Ridge | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 4000' |
| Wednesday Night |
Snow Level 6000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 6000' |
| Thursday Afternoon |
Snow Level 6000' |
| Thursday Evening |
Snow Level 6500' (Easterly Flow *) |
| Thursday Night |
Snow Level 7000' (Easterly Flow *) |
| Friday Morning |
Snow Level 4000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 3500' |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2500' |
| Wednesday Night |
Snow Level 3000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3000' |
| Thursday Afternoon |
Snow Level 4500' |
| Thursday Evening |
Snow Level 5500' (Easterly Flow *) |
| Thursday Night |
Snow Level 5000' (Easterly Flow *) |
| Friday Morning |
Snow Level 4000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 3000' |
| Washington Pass | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 1500' |
| Wednesday Night |
Snow Level 2500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Evening |
Snow Level 5000' (Easterly Flow *) |
| Thursday Night |
Snow Level 4500' (Easterly Flow *) |
| Friday Morning |
Snow Level 3000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 2500' |
| Leavenworth | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2500' |
| Wednesday Night |
Snow Level 3000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 4500' |
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Evening |
Snow Level 6000' (Easterly Flow *) |
| Thursday Night |
Snow Level 5500' (Easterly Flow *) |
| Friday Morning |
Snow Level 3000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 3000' |
| Stevens Pass | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2500' |
| Wednesday Night |
Snow Level 2500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 4500' |
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Evening |
Snow Level 5500' (Easterly Flow *) |
| Thursday Night |
Snow Level 5500' (Easterly Flow *) |
| Friday Morning |
Snow Level 3000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 3500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2500' |
| Wednesday Night |
Snow Level 2500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 4000' |
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Evening |
Snow Level 5500' (Easterly Flow *) |
| Thursday Night |
Snow Level 5000' (Easterly Flow *) |
| Friday Morning |
Snow Level 3000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 4000' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2500' |
| Wednesday Night |
Snow Level 3000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Evening |
Snow Level 4500' (Easterly Flow *) |
| Thursday Night |
Snow Level 4000' (Easterly Flow *) |
| Friday Morning |
Snow Level 3500' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 3500' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2500' |
| Wednesday Night |
Snow Level 2000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 6000' |
| Thursday Evening |
Snow Level 5500' (Easterly Flow *) |
| Thursday Night |
Snow Level 6500' (Easterly Flow *) |
| Friday Morning |
Snow Level 5000' (Easterly Flow *) |
| Friday Afternoon |
Snow Level 3500' |
* 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
| Wednesday Night | Sunday | Sunday Night | Sunday | |
|---|---|---|---|---|
| 4 pm - 4 am | 4 am - 4 pm | 4 pm - 4 am | 4 am - 4 pm | |
| Hurricane Ridge | 0.50 | 0.50 | LT 0.25 | 0.50 |
| Mt Baker Ski Area | 1.50 - 2.00 | 1.50 | 1.00 - 1.50 | 0.50 - 0.75 |
| Washington Pass | 0.75 -1.00 | 1.00 - 1.50 | 0.25 | LT 0.10 |
| Leavenworth | LT 0.10 | LT 0.10 | LT 0.10 | LT 0.10 |
| Stevens Pass | 0.50 - 0.75 | 0.25 | LT 0.10 | LT 0.10 |
| Snoqualmie Pass | 0.50 | 0.50 - 0.75 | LT 0.10 | LT 0.10 |
| Mission Ridge | LT 0.25 | LT 0.25 | 0 | LT 0.10 |
| Crystal Mt | LT 0.25 | LT 0.25 | LT 0.10 | 0.25 - 0.50 |
| Paradise | 0.75 | 0.75 -1.00 | 0 | 0.25 - 0.50 |
| White Pass | 0.25 - 0.50 | 0.25 | 0 | 0.25 |
| Mt Hood Meadows | LT 0.25 | 0 | 0 | 0.50 |
| Timberline | LT 0.25 | 0 | 0 | 0.50 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.50 |
| Sunday | 0.50 |
| Sunday Night | LT 0.25 |
| Sunday | 0.50 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Wednesday Night | 1.50 - 2.00 |
| Sunday | 1.50 |
| Sunday Night | 1.00 - 1.50 |
| Sunday | 0.50 - 0.75 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.75 -1.00 |
| Sunday | 1.00 - 1.50 |
| Sunday Night | 0.25 |
| Sunday | LT 0.10 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.10 |
| Sunday | LT 0.10 |
| Sunday Night | LT 0.10 |
| Sunday | LT 0.10 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.50 - 0.75 |
| Sunday | 0.25 |
| Sunday Night | LT 0.10 |
| Sunday | LT 0.10 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.50 |
| Sunday | 0.50 - 0.75 |
| Sunday Night | LT 0.10 |
| Sunday | LT 0.10 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.25 |
| Sunday | LT 0.25 |
| Sunday Night | 0 |
| Sunday | LT 0.10 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.25 |
| Sunday | LT 0.25 |
| Sunday Night | LT 0.10 |
| Sunday | 0.25 - 0.50 |
| Paradise | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.75 |
| Sunday | 0.75 -1.00 |
| Sunday Night | 0 |
| Sunday | 0.25 - 0.50 |
| White Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.25 - 0.50 |
| Sunday | 0.25 |
| Sunday Night | 0 |
| Sunday | 0.25 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.25 |
| Sunday | 0 |
| Sunday Night | 0 |
| Sunday | 0.50 |
| Timberline | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.25 |
| Sunday | 0 |
| Sunday Night | 0 |
| Sunday | 0.50 |
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: 2:45 PM PST Wednesday, December 12, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Wednesday Evening | S 35 - 50 | S 25 - 35 | SSW 25 - 35 | SSW 20 - 30 | SW 20 - 30 |
| Wednesday Night | SSW 40 - 60 | SSE 30 - 45 | SSW 35 - 50 | SSW 35 - 50 | SW 30 - 45 |
| Thursday Morning | SW 40 - 60 | S 30 - 45 | SW 35 - 50 | SSW 35 - 50 | SW 30 - 45 |
| Thursday Afternoon | SW 25 - 35 | S 25 - 35 | SSW 25 - 35 | SSW 25 - 35 | SSW 25 - 35 |
| Hurricane Ridge | Elevation |
|---|---|
| Wednesday Evening | S 35 - 50 |
| Wednesday Night | SSW 40 - 60 |
| Thursday Morning | SW 40 - 60 |
| Thursday Afternoon | SW 25 - 35 |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Evening | S 25 - 35 |
| Wednesday Night | SSE 30 - 45 |
| Thursday Morning | S 30 - 45 |
| Thursday Afternoon | S 25 - 35 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Evening | SSW 25 - 35 |
| Wednesday Night | SSW 35 - 50 |
| Thursday Morning | SW 35 - 50 |
| Thursday Afternoon | SSW 25 - 35 |
| Mt. Rainier | Elevation |
|---|---|
| Wednesday Evening | SSW 20 - 30 |
| Wednesday Night | SSW 35 - 50 |
| Thursday Morning | SSW 35 - 50 |
| Thursday Afternoon | SSW 25 - 35 |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Evening | SW 20 - 30 |
| Wednesday Night | SW 30 - 45 |
| Thursday Morning | SW 30 - 45 |
| Thursday Afternoon | SSW 25 - 35 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Wednesday Evening | S 35 - 50 |
| Wednesday Night | SSW 40 - 60 |
| Thursday Morning | SW 40 - 60 |
| Thursday Afternoon | SW 25 - 35 |
| Mt. Baker | Direction - Speed |
|---|---|
| Wednesday Evening | S 25 - 35 |
| Wednesday Night | SSE 30 - 45 |
| Thursday Morning | S 30 - 45 |
| Thursday Afternoon | S 25 - 35 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Wednesday Evening | SSW 25 - 35 |
| Wednesday Night | SSW 35 - 50 |
| Thursday Morning | SW 35 - 50 |
| Thursday Afternoon | SSW 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Wednesday Evening | SSW 20 - 30 |
| Wednesday Night | SSW 35 - 50 |
| Thursday Morning | SSW 35 - 50 |
| Thursday Afternoon | SSW 25 - 35 |
| Mt. Hood | Direction - Speed |
|---|---|
| Wednesday Evening | SW 20 - 30 |
| Wednesday Night | SW 30 - 45 |
| Thursday Morning | SW 30 - 45 |
| Thursday Afternoon | SSW 25 - 35 |
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 | |
|---|---|---|---|---|---|
| Wednesday Evening | SSW 40 - 60 | SW 40 - 60 | WSW 35 - 50 | WSW 30 - 45 | W 35 - 50 |
| Wednesday Night | SW 50 - 70 | SW 50 - 70 | WSW 50 - 70 | WSW 50 - 70 | WSW 45 - 65 |
| Thursday Morning | SW 55 - 75 | SW 60 - 80 | WSW 50 - 70 | WSW 55 - 75 | WSW 35 - 50 |
| Thursday Afternoon | SW 45 - 65 | SW 45 - 65 | SW 45 - 65 | SW 45 - 65 | SW 35 - 50 |
| Mt. Baker | Direction - Speed |
|---|---|
| Wednesday Evening | SSW 40 - 60 |
| Wednesday Night | SW 50 - 70 |
| Thursday Morning | SW 55 - 75 |
| Thursday Afternoon | SW 45 - 65 |
| Washington Pass | Direction - Speed |
|---|---|
| Wednesday Evening | SW 40 - 60 |
| Wednesday Night | SW 50 - 70 |
| Thursday Morning | SW 60 - 80 |
| Thursday Afternoon | SW 45 - 65 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Wednesday Evening | WSW 35 - 50 |
| Wednesday Night | WSW 50 - 70 |
| Thursday Morning | WSW 50 - 70 |
| Thursday Afternoon | SW 45 - 65 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Wednesday Evening | WSW 30 - 45 |
| Wednesday Night | WSW 50 - 70 |
| Thursday Morning | WSW 55 - 75 |
| Thursday Afternoon | SW 45 - 65 |
| Mt. Hood | Direction - Speed |
|---|---|
| Wednesday Evening | W 35 - 50 |
| Wednesday Night | WSW 45 - 65 |
| Thursday Morning | WSW 35 - 50 |
| Thursday Afternoon | SW 35 - 50 |
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: 2:45 PM PST Wednesday, December 12, 2018
Extended Weather Synopsis for Sunday night through Sunday
Friday night will bring decreasing snow showers, focused on the west slopes of the Cascades.
Saturday will see a break in the action with another wet frontal system ahead of deep trough offshore, approaching Saturday evening and arriving on Sunday.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Friday Night | Snow Level | 1500' - 2500' | 1500' - 2500' | 2000' - 3000' | |
| Saturday | Snow Level | 1000' - 3000' | 1000' - 3000' | 2000' - 4000' | |
| Saturday Night | Snow Level | 1500' - 3500' | 1500' - 3500' | 3500' - 5500' | * |
| Sunday | Snow Level | 3000' - 5000' | 3000' - 5000' | 4500' - 6500' | * |
| Mt. Baker | Elevation |
|---|---|
| Friday Night |
Snow Level 1500' - 2500' |
| Saturday |
Snow Level 1000' - 3000' |
| Saturday Night |
Snow Level 1500' - 3500' (Easterly Flow *) |
| Sunday |
Snow Level 3000' - 5000' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Friday Night |
Snow Level 1500' - 2500' |
| Saturday |
Snow Level 1000' - 3000' |
| Saturday Night |
Snow Level 1500' - 3500' (Easterly Flow *) |
| Sunday |
Snow Level 3000' - 5000' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Friday Night |
Snow Level 2000' - 3000' |
| Saturday |
Snow Level 2000' - 4000' |
| Saturday Night |
Snow Level 3500' - 5500' (Easterly Flow *) |
| Sunday |
Snow Level 4500' - 6500' (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.
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 12, 2018
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