Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Monday night through Thursday
Warm frontal moisture has held its fire on the northern end of the Olympic peninsula or the NW part of Whatcom county for much of the day. Mild temperatures and high freezing levels are all throughout the region save some of the colder deeper valleys in the northeast Cascades or at Cascade Pass level where easterly flow continues to create temperature inversions.
The frontal boundary that has been quasi-stationary over south and central British Columbia will sag south tonight over the Olympics and northwest Cascades before pushing further south tomorrow. While the rainfall intensity looks likely to peter out as it pushes south of the Hwy 2 and I-90 corridors tomorrow, some forecast models suggest another wave developing along the frontal boundary to reinvigorate precipitation rates for the south Washington Cascades and Mt hood - yikes. Right now this forecast represents the solution where the precipitation totals and rates taper from north to south through tomorrow afternoon. Strong westerly winds are a better bet out ahead and with the front, as it sags south late tonight and tomorrow. High snow levels will push well over onto the east slopes of the Cascades with this storm.
A drying trend should ensue Tuesday night. Forecast models disagree whether or not a weak surface trough will pass through on Wednesday. Snow levels will trend cooler Tuesday night and Wednesday.
Weather Forecast
Hurricane Ridge
| Monday Night | Light rain developing in the evening. Mild. Strong winds. |
| Tuesday | Light to moderate rain and snow becoming isolated light showers in the afternoon. Slow cooling trend. |
Mt. Baker
| Monday Night | Moderate rain and high elevation snow developing in the evening. Mild. Strong winds. |
| Tuesday | Moderate to heavy rain and high elevation snow in the morning tapering off in the afternoon. Slow cooling trend. Winds easing in the morning. |
Washington Pass and Leavenworth
| Monday Night | Light rain and snow developing overnight. Mild. Strong to extreme alpine winds. |
| Tuesday | Light to occasionally moderate rain and snow easing in the afternoon. Light freezing rain possible in deeper colder valleys. Strong alpine winds easing late in the afternoon. |
Stevens and Snoqualmie Pass
| Monday Night | Cloudy with light rain developing late. Mild. Light east wind at Pass level becoming variable late. Increasing ridgeline winds late. |
| Tuesday | Light to moderate rain and snow. Slow cooling trend. Strong ridgeline winds easing in the afternoon. |
Mt. Rainier, Crystal and White Pass
| Monday Night | Cloudy, mild, increasing ridgeline winds late. |
| Tuesday | Cloudy with periods of light rain and high elevation snow. Mild. Slow cooling trend. Strong ridgetop winds easing in the afternoon. |
Mt. Hood
| Monday Night | Becoming overcast overnight. Mild. |
| Tuesday | Cloudy with periods of light rain beginning late morning. Mild. Strong alpine winds. |
Issued: 2:00 PM PST Monday, December 7, 2020
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Monday Evening | Snow Level * | 10000' | 7000' | 7500' | 9000' | 9000' | 9000' | 9000' | 12000' |
| Monday Night | Snow Level * | 10000' | 8000' | 8500' | 9000' | 9000' | 9000' | 9000' | 12000' |
| Tuesday Morning | Snow Level | 7500' | 7500' | 8000' | 8000' | 8000' | 8000' | 9000' | 12000' |
| Tuesday Afternoon | Snow Level | 6000' | 6000' | 6000' | 7000' | 6500' | 6500' | 8000' | 8000' |
| Tuesday Evening | Snow Level | 5500' | 5000' | 5000' | 6000' | 5500' | 5500' | 6500' | 7500' |
| Tuesday Night | Snow Level | 5000' | 4000' | 4000' | 5000' | 4500' | 4500' | 5000' | 7000' |
| Wednesday Morning | Snow Level | 4000' | 3500' | 3500' | 4500' | 4000' | 4000' | 4500' | 5500' |
| Wednesday Afternoon | Snow Level | 3500' | 3500' | 3500' | 4000' | 3500' | 3500' | 4000' | 4000' |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Evening |
Snow Level 10000' (Easterly Flow *) |
| Monday Night |
Snow Level 10000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 7500' |
| Tuesday Afternoon |
Snow Level 6000' |
| Tuesday Evening |
Snow Level 5500' |
| Tuesday Night |
Snow Level 5000' |
| Wednesday Morning |
Snow Level 4000' |
| Wednesday Afternoon |
Snow Level 3500' |
| Mt. Baker | Elevation |
|---|---|
| Monday Evening |
Snow Level 7000' (Easterly Flow *) |
| Monday Night |
Snow Level 8000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 7500' |
| Tuesday Afternoon |
Snow Level 6000' |
| Tuesday Evening |
Snow Level 5000' |
| Tuesday Night |
Snow Level 4000' |
| Wednesday Morning |
Snow Level 3500' |
| Wednesday Afternoon |
Snow Level 3500' |
| Washington Pass | Elevation |
|---|---|
| Monday Evening |
Snow Level 7500' (Easterly Flow *) |
| Monday Night |
Snow Level 8500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 8000' |
| Tuesday Afternoon |
Snow Level 6000' |
| Tuesday Evening |
Snow Level 5000' |
| Tuesday Night |
Snow Level 4000' |
| Wednesday Morning |
Snow Level 3500' |
| Wednesday Afternoon |
Snow Level 3500' |
| Leavenworth | Elevation |
|---|---|
| Monday Evening |
Snow Level 9000' (Easterly Flow *) |
| Monday Night |
Snow Level 9000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 8000' |
| Tuesday Afternoon |
Snow Level 7000' |
| Tuesday Evening |
Snow Level 6000' |
| Tuesday Night |
Snow Level 5000' |
| Wednesday Morning |
Snow Level 4500' |
| Wednesday Afternoon |
Snow Level 4000' |
| Stevens Pass | Elevation |
|---|---|
| Monday Evening |
Snow Level 9000' (Easterly Flow *) |
| Monday Night |
Snow Level 9000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 8000' |
| Tuesday Afternoon |
Snow Level 6500' |
| Tuesday Evening |
Snow Level 5500' |
| Tuesday Night |
Snow Level 4500' |
| Wednesday Morning |
Snow Level 4000' |
| Wednesday Afternoon |
Snow Level 3500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday Evening |
Snow Level 9000' (Easterly Flow *) |
| Monday Night |
Snow Level 9000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 8000' |
| Tuesday Afternoon |
Snow Level 6500' |
| Tuesday Evening |
Snow Level 5500' |
| Tuesday Night |
Snow Level 4500' |
| Wednesday Morning |
Snow Level 4000' |
| Wednesday Afternoon |
Snow Level 3500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Monday Evening |
Snow Level 9000' (Easterly Flow *) |
| Monday Night |
Snow Level 9000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 9000' |
| Tuesday Afternoon |
Snow Level 8000' |
| Tuesday Evening |
Snow Level 6500' |
| Tuesday Night |
Snow Level 5000' |
| Wednesday Morning |
Snow Level 4500' |
| Wednesday Afternoon |
Snow Level 4000' |
| Mt. Hood | Elevation |
|---|---|
| Monday Evening |
Snow Level 12000' (Easterly Flow *) |
| Monday Night |
Snow Level 12000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 12000' |
| Tuesday Afternoon |
Snow Level 8000' |
| Tuesday Evening |
Snow Level 7500' |
| Tuesday Night |
Snow Level 7000' |
| Wednesday Morning |
Snow Level 5500' |
| Wednesday Afternoon |
Snow Level 4000' |
* 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
| Monday Night | Thursday | Thursday Night | Thursday | |
|---|---|---|---|---|
| 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 0.10 |
| Mt Baker Ski Area | 0.50 - 0.75 | 0.75 -1.00 | LT 0.10 | LT 0.10 |
| Washington Pass | LT 0.25 | 0.50 | 0 | 0 |
| Leavenworth | 0 | LT 0.25 | 0 | 0 |
| Stevens Pass | LT 0.10 | 0.50 | LT 0.25 | LT 0.10 |
| Snoqualmie Pass | LT 0.10 | 0.50 | LT 0.25 | LT 0.10 |
| Mission Ridge | 0 | LT 0.10 | 0 | 0 |
| Crystal Mt | 0 | LT 0.25 | LT 0.25 | LT 0.10 |
| Paradise | 0 | 0.25 - 0.50 | 0.25 | LT 0.10 |
| White Pass | 0 | LT 0.25 | LT 0.25 | LT 0.10 |
| Mt Hood Meadows | 0 | LT 0.10 | 0.25 | LT 0.10 |
| Timberline | 0 | LT 0.10 | 0.25 | LT 0.10 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Monday Night | 0.25 |
| Thursday | 0.50 |
| Thursday Night | LT 0.10 |
| Thursday | LT 0.10 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Monday Night | 0.50 - 0.75 |
| Thursday | 0.75 -1.00 |
| Thursday Night | LT 0.10 |
| Thursday | LT 0.10 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.25 |
| Thursday | 0.50 |
| Thursday Night | 0 |
| Thursday | 0 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | LT 0.25 |
| Thursday Night | 0 |
| Thursday | 0 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Thursday | 0.50 |
| Thursday Night | LT 0.25 |
| Thursday | LT 0.10 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Thursday | 0.50 |
| Thursday Night | LT 0.25 |
| Thursday | LT 0.10 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0 |
| Thursday | 0 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | LT 0.25 |
| Thursday Night | LT 0.25 |
| Thursday | LT 0.10 |
| Paradise | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | 0.25 - 0.50 |
| Thursday Night | 0.25 |
| Thursday | LT 0.10 |
| White Pass | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | LT 0.25 |
| Thursday Night | LT 0.25 |
| Thursday | LT 0.10 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0.25 |
| Thursday | LT 0.10 |
| Timberline | Precipitation Forecast |
|---|---|
| Monday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0.25 |
| Thursday | LT 0.10 |
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: 2:00 PM PST Monday, December 7, 2020
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Monday Evening | SW 30 - 40 | S 25 - 35 | SW 20 - 30 | SW 20 - 30 | SW 5 - 15 |
| Monday Night | SW 30 - 40 | S 40 - 50 | SW 25 - 35 | WSW 25 - 35 | SW 15 - 25 |
| Tuesday Morning | W 15 - 25 | SW 10 - 20 | WSW 30 - 40 | WSW 30 - 40 | SW 15 - 25 |
| Tuesday Afternoon | WNW 10 - 20 | W 5 - 15 | W 15 - 25 | WSW 15 - 25 | W 15 - 25 |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Evening | SW 30 - 40 |
| Monday Night | SW 30 - 40 |
| Tuesday Morning | W 15 - 25 |
| Tuesday Afternoon | WNW 10 - 20 |
| Mt. Baker | Elevation |
|---|---|
| Monday Evening | S 25 - 35 |
| Monday Night | S 40 - 50 |
| Tuesday Morning | SW 10 - 20 |
| Tuesday Afternoon | W 5 - 15 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Monday Evening | SW 20 - 30 |
| Monday Night | SW 25 - 35 |
| Tuesday Morning | WSW 30 - 40 |
| Tuesday Afternoon | W 15 - 25 |
| Mt. Rainier | Elevation |
|---|---|
| Monday Evening | SW 20 - 30 |
| Monday Night | WSW 25 - 35 |
| Tuesday Morning | WSW 30 - 40 |
| Tuesday Afternoon | WSW 15 - 25 |
| Mt. Hood | Elevation |
|---|---|
| Monday Evening | SW 5 - 15 |
| Monday Night | SW 15 - 25 |
| Tuesday Morning | SW 15 - 25 |
| Tuesday Afternoon | W 15 - 25 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Monday Evening | SW 30 - 40 |
| Monday Night | SW 30 - 40 |
| Tuesday Morning | W 15 - 25 |
| Tuesday Afternoon | WNW 10 - 20 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Evening | S 25 - 35 |
| Monday Night | S 40 - 50 |
| Tuesday Morning | SW 10 - 20 |
| Tuesday Afternoon | W 5 - 15 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Evening | SW 20 - 30 |
| Monday Night | SW 25 - 35 |
| Tuesday Morning | WSW 30 - 40 |
| Tuesday Afternoon | W 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Evening | SW 20 - 30 |
| Monday Night | WSW 25 - 35 |
| Tuesday Morning | WSW 30 - 40 |
| Tuesday Afternoon | WSW 15 - 25 |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Evening | SW 5 - 15 |
| Monday Night | SW 15 - 25 |
| Tuesday Morning | SW 15 - 25 |
| Tuesday Afternoon | W 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 | |
|---|---|---|---|---|---|
| Monday Evening | SW 40 - 50 | SW 50 - 60 | SW 50 - 60 | SW 50 - 60 | WSW 40 - 60 |
| Monday Night | SW 35 - 45 | WSW 55 - 65 | SW 55 - 65 | SW 45 - 55 | W 30 - 40 |
| Tuesday Morning | SW 30 - 40 | WSW 40 - 50 | SW 55 - 65 | SW 45 - 55 | WSW 40 - 50 |
| Tuesday Afternoon | W 20 - 30 | W 25 - 35 | WSW 40 - 50 | WSW 35 - 45 | WSW 35 - 45 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Evening | SW 40 - 50 |
| Monday Night | SW 35 - 45 |
| Tuesday Morning | SW 30 - 40 |
| Tuesday Afternoon | W 20 - 30 |
| Washington Pass | Direction - Speed |
|---|---|
| Monday Evening | SW 50 - 60 |
| Monday Night | WSW 55 - 65 |
| Tuesday Morning | WSW 40 - 50 |
| Tuesday Afternoon | W 25 - 35 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Evening | SW 50 - 60 |
| Monday Night | SW 55 - 65 |
| Tuesday Morning | SW 55 - 65 |
| Tuesday Afternoon | WSW 40 - 50 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Evening | SW 50 - 60 |
| Monday Night | SW 45 - 55 |
| Tuesday Morning | SW 45 - 55 |
| Tuesday Afternoon | WSW 35 - 45 |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Evening | WSW 40 - 60 |
| Monday Night | W 30 - 40 |
| Tuesday Morning | WSW 40 - 50 |
| Tuesday Afternoon | WSW 35 - 45 |
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: 2:00 PM PST Monday, December 7, 2020
Extended Weather Synopsis for Thursday night through Thursday
Forecast models are out of phase beginning Tuesday (as in tomorrow) so that puts a big question mark on timing and tracking weather systems in the extended forecast. What looks likely at this point is a weather system every other day through Friday bringing light to moderate amounts of new snow with seasonally cool snow levels (snow down to at least the major Cascade Passes). A more vigorous storm cycle may start either this weekend or early next week.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Wednesday Night | Snow Level | 2500' - 3500' | 3500' - 4500' | 3500' - 4500' | |
| Thursday | Snow Level | 3000' - 4000' | 3000' - 4000' | 3000' - 4000' | |
| Thursday Night | Snow Level | 1000' - 2000' | 1000' - 2000' | 1500' - 2500' | |
| Friday | Snow Level | 1000' - 2000' | 1500' - 2500' | 1500' - 2500' |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Night |
Snow Level 2500' - 3500' |
| Thursday |
Snow Level 3000' - 4000' |
| Thursday Night |
Snow Level 1000' - 2000' |
| Friday |
Snow Level 1000' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Night |
Snow Level 3500' - 4500' |
| Thursday |
Snow Level 3000' - 4000' |
| Thursday Night |
Snow Level 1000' - 2000' |
| Friday |
Snow Level 1500' - 2500' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Night |
Snow Level 3500' - 4500' |
| Thursday |
Snow Level 3000' - 4000' |
| Thursday Night |
Snow Level 1500' - 2500' |
| Friday |
Snow Level 1500' - 2500' |
* 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 7, 2020
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