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 Friday
A rapidly intensifying storm tracks NNE toward the norther tip of Vancouver Island Monday through Tuesday morning and will become the deepest low pressure system to impact our region so far this season. The powerful storm has tapped into subtropical moisture and temperatures which continue to invade the NWAC forecast region on strong SSW flow from late Monday through Tuesday morning. The first act, a northward-lifting warm front continues to bring moderate to locally heavy precipitation to our mountains along with rapidly rising snow levels through Monday evening. By this time, most of the moisture should focus on the North Cascades and Mt. Baker regions where up to an inch of additional water could fall before the frontal moisture fully exits into Canada. Thereafter, relatively dry, cloudy, and very mild conditions characterize the warm sector of this storm through early Tuesday morning. E low-level flow should initially keep parts of the NE Cascades cooler, but the sustained SSW winds aloft will gradually scour out the lingering cool air by Tuesday morning. The second act of the storm, the associated cold-frontal feature spreads moderate to heavy rain, very high elevation snow (above 7000-9000 ft), and further strengthening SSW winds out ahead of it from the already strong winds Monday night. They will be particularly strong in exposed areas in the Mt. Baker and Olympics regions where extreme winds are likely in the alpine. The front should cross the Cascades shortly after noon.
Moderate rain and snow showers continue behind the front on a brisk, but decreasing SW flow Tuesday afternoon, decreasing slightly overnight as cooler air moves back, lowering snow levels lower to near pass levels by Wednesday morning. A more organized feature should bring another shot of more sustained moderate rain and snow during the late morning and mid-day hours on Wednesday before more showery weather returns by afternoon.
From Tuesday afternoon through the end of the day on Wednesday, the most significant snow accumulations will be at mid and upper elevations on the Cascades Volcanoes where 1-2 ft of snow are possible.
Weather Forecast
Hurricane Ridge
Monday Night | Lingering light to moderate rain in evening, then becoming cloudy. Very mild with continued warming. Moderate to strong winds in the evening becoming strong. |
Tuesday | Very mild with moderate rain in the morning, becoming moderate rain and snow showers with cooling temperatures in the afternoon. Strong winds with extreme gusts in the morning, then strong winds in the afternoon. |
Mt. Baker
Monday Night | Heavy rain and high elevation snow tapering and ending by midnight. Snow possible at the highest elevations. Continued rapidly rising snow levels. Moderate to strong winds in the evening becoming moderate with strong gusts after midnight. |
Tuesday | Very mild with moderate to heavy rain in the morning, changing to snow at mid and upper elevations in the afternoon. Strong to extreme winds decreasing slightly in the afternoon. |
Washington Pass and Leavenworth
Monday Night | Moderate rain and snow ending in the evening, then becoming cloudy. Rising snow levels. Moderate to strong 5000 ft winds. E flow likely to keep Washington Pass as snow. |
Tuesday | Very mild with light rain in the morning, changing to snow at mid and upper elevations in the afternoon. Moderate to strong winds peaking in the morning. Extreme gusts possible at higher elevations. |
Stevens and Snoqualmie Pass
Monday Night | Light rain ending in the early evening, then cloudy. Moderate 5000 ft winds. Moderate E winds through the passes. |
Tuesday | Light rain and very mild in the morning, changing to snow at mid and upper elevations in the afternoon. Strong 5000 ft winds. Moderate E wind through the passes in the morning, becoming light and possibly shifting W late. |
Mt. Rainier, Crystal and White Pass
Monday Night | Light sprinkles ending in the early evening, then cloudy. Very mild with above freezing temperatures extending well into the alpine. Moderate 5000 ft winds that may be strong to extreme in the alpine. |
Tuesday | Moderate rain and snow. Strong winds at 5000 ft, with extreme winds in the alpine. |
Mt. Hood
Monday Night | Cloudy and very mild. Moderate winds at 5000 ft, with strong winds in the alpine. |
Tuesday | Light to moderate rain and very mild temperatures in the morning, changing to snow at upper elevations in the afternoon. Strong winds at 5000 ft, with extreme winds in the alpine. |
Issued: 2:06 PM PST Monday, November 16, 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 * | 8500' | 6000' | 4000' | 6000' | 6000' | 8000' | 9000' | 10000' |
Monday Night | Snow Level * | 9500' | 8500' | 7500' | 9500' | 9000' | 10000' | 10500' | 10500' |
Tuesday Morning | Snow Level * | 8000' | 8500' | 7000' | 9000' | 8500' | 9000' | 8500' | 9000' |
Tuesday Afternoon | Snow Level * | 5500' | 5500' | 5500' | 5500' | 5500' | 5500' | 5500' | 6000' |
Tuesday Evening | Snow Level | 4000' | 4500' | 4500' | 5000' | 4500' | 4500' | 4500' | 5000' |
Tuesday Night | Snow Level | 3500' | 3500' | 4000' | 4000' | 3500' | 4000' | 4000' | 4000' |
Wednesday Morning | Snow Level * | 3500' | 3000' | 2500' | 3000' | 2500' | 3000' | 3000' | 4000' |
Wednesday Afternoon | Snow Level | 3000' | 3000' | 3500' | 3000' | 3500' | 3500' | 3500' | 3500' |
Hurricane Ridge | Elevation |
---|---|
Monday Evening |
Snow Level 8500' (Easterly Flow *) |
Monday Night |
Snow Level 9500' (Easterly Flow *) |
Tuesday Morning |
Snow Level 8000' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 4000' |
Tuesday Night |
Snow Level 3500' |
Wednesday Morning |
Snow Level 3500' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3000' |
Mt. Baker | Elevation |
---|---|
Monday Evening |
Snow Level 6000' (Easterly Flow *) |
Monday Night |
Snow Level 8500' (Easterly Flow *) |
Tuesday Morning |
Snow Level 8500' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 4500' |
Tuesday Night |
Snow Level 3500' |
Wednesday Morning |
Snow Level 3000' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3000' |
Washington Pass | Elevation |
---|---|
Monday Evening |
Snow Level 4000' (Easterly Flow *) |
Monday Night |
Snow Level 7500' (Easterly Flow *) |
Tuesday Morning |
Snow Level 7000' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 4500' |
Tuesday Night |
Snow Level 4000' |
Wednesday Morning |
Snow Level 2500' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3500' |
Leavenworth | Elevation |
---|---|
Monday Evening |
Snow Level 6000' (Easterly Flow *) |
Monday Night |
Snow Level 9500' (Easterly Flow *) |
Tuesday Morning |
Snow Level 9000' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 5000' |
Tuesday Night |
Snow Level 4000' |
Wednesday Morning |
Snow Level 3000' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3000' |
Stevens Pass | Elevation |
---|---|
Monday Evening |
Snow Level 6000' (Easterly Flow *) |
Monday Night |
Snow Level 9000' (Easterly Flow *) |
Tuesday Morning |
Snow Level 8500' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 4500' |
Tuesday Night |
Snow Level 3500' |
Wednesday Morning |
Snow Level 2500' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3500' |
Snoqualmie Pass | Elevation |
---|---|
Monday Evening |
Snow Level 8000' (Easterly Flow *) |
Monday Night |
Snow Level 10000' (Easterly Flow *) |
Tuesday Morning |
Snow Level 9000' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 4500' |
Tuesday Night |
Snow Level 4000' |
Wednesday Morning |
Snow Level 3000' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3500' |
Mt. Rainier & Crystal | Elevation |
---|---|
Monday Evening |
Snow Level 9000' (Easterly Flow *) |
Monday Night |
Snow Level 10500' (Easterly Flow *) |
Tuesday Morning |
Snow Level 8500' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
Tuesday Evening |
Snow Level 4500' |
Tuesday Night |
Snow Level 4000' |
Wednesday Morning |
Snow Level 3000' (Easterly Flow *) |
Wednesday Afternoon |
Snow Level 3500' |
Mt. Hood | Elevation |
---|---|
Monday Evening |
Snow Level 10000' (Easterly Flow *) |
Monday Night |
Snow Level 10500' (Easterly Flow *) |
Tuesday Morning |
Snow Level 9000' (Easterly Flow *) |
Tuesday Afternoon |
Snow Level 6000' (Easterly Flow *) |
Tuesday Evening |
Snow Level 5000' |
Tuesday Night |
Snow Level 4000' |
Wednesday Morning |
Snow Level 4000' (Easterly Flow *) |
Wednesday 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
Monday 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 | 0.50 - 0.75 | LT 0.25 | 0.25 |
Mt Baker Ski Area | 1.00 | 0.75 | 0.75 -1.00 | 0.75 |
Washington Pass | 0.50 | 0.25 | 0.25 - 0.50 | 0.25 |
Leavenworth | LT 0.10 | LT 0.10 | LT 0.10 | LT 0.25 |
Stevens Pass | LT 0.10 | LT 0.25 | 0.25 - 0.50 | 0.25 |
Snoqualmie Pass | 0 | 0.25 | 0.25 - 0.50 | 0.25 - 0.50 |
Mission Ridge | 0 | 0 | LT 0.10 | 0.25 |
Crystal Mt | LT 0.10 | 0.50 | 0.25 - 0.50 | 0.50 |
Paradise | LT 0.10 | 0.75 | 0.75 | 1.00 |
White Pass | 0 | 0.25 | 0.25 - 0.50 | 0.50 |
Mt Hood Meadows | 0 | 0.25 - 0.50 | 0.25 | 0.75 -1.00 |
Timberline | 0 | 0.25 - 0.50 | 0.25 | 0.75 |
Hurricane Ridge | Precipitation Forecast |
---|---|
Monday Night | 0.25 - 0.50 |
Friday | 0.50 - 0.75 |
Friday Night | LT 0.25 |
Friday | 0.25 |
Mt Baker Ski Area | Precipitation Forecast |
---|---|
Monday Night | 1.00 |
Friday | 0.75 |
Friday Night | 0.75 -1.00 |
Friday | 0.75 |
Washington Pass | Precipitation Forecast |
---|---|
Monday Night | 0.50 |
Friday | 0.25 |
Friday Night | 0.25 - 0.50 |
Friday | 0.25 |
Leavenworth | Precipitation Forecast |
---|---|
Monday Night | LT 0.10 |
Friday | LT 0.10 |
Friday Night | LT 0.10 |
Friday | LT 0.25 |
Stevens Pass | Precipitation Forecast |
---|---|
Monday Night | LT 0.10 |
Friday | LT 0.25 |
Friday Night | 0.25 - 0.50 |
Friday | 0.25 |
Snoqualmie Pass | Precipitation Forecast |
---|---|
Monday Night | 0 |
Friday | 0.25 |
Friday Night | 0.25 - 0.50 |
Friday | 0.25 - 0.50 |
Mission Ridge | Precipitation Forecast |
---|---|
Monday Night | 0 |
Friday | 0 |
Friday Night | LT 0.10 |
Friday | 0.25 |
Crystal Mt | Precipitation Forecast |
---|---|
Monday Night | LT 0.10 |
Friday | 0.50 |
Friday Night | 0.25 - 0.50 |
Friday | 0.50 |
Paradise | Precipitation Forecast |
---|---|
Monday Night | LT 0.10 |
Friday | 0.75 |
Friday Night | 0.75 |
Friday | 1.00 |
White Pass | Precipitation Forecast |
---|---|
Monday Night | 0 |
Friday | 0.25 |
Friday Night | 0.25 - 0.50 |
Friday | 0.50 |
Mt Hood Meadows | Precipitation Forecast |
---|---|
Monday Night | 0 |
Friday | 0.25 - 0.50 |
Friday Night | 0.25 |
Friday | 0.75 -1.00 |
Timberline | Precipitation Forecast |
---|---|
Monday Night | 0 |
Friday | 0.25 - 0.50 |
Friday Night | 0.25 |
Friday | 0.75 |
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: 2:06 PM PST Monday, November 16, 2020
Free Winds at 5000' (mph)
Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
---|---|---|---|---|---|
Monday Evening | SSW 25 - 35 | S 25 - 35 | SSE 20 - 30 | SSE 20 - 30 | S 20 - 30 |
Monday Night | SSE 30 - 40 | SSE 20 - 30 | ESE 20 - 30 | ESE 20 - 30 | SE 15 - 25 |
Tuesday Morning | S 40 - 55 | S 45 - 65 | ESE 30 - 40 | SSE 35 - 45 | S 30 - 40 |
Tuesday Afternoon | SSW 30 - 40 | SSE 35 - 50 | S 30 - 40 | S 30 - 40 | SE 30 - 40 |
Hurricane Ridge | Elevation |
---|---|
Monday Evening | SSW 25 - 35 |
Monday Night | SSE 30 - 40 |
Tuesday Morning | S 40 - 55 |
Tuesday Afternoon | SSW 30 - 40 |
Mt. Baker | Elevation |
---|---|
Monday Evening | S 25 - 35 |
Monday Night | SSE 20 - 30 |
Tuesday Morning | S 45 - 65 |
Tuesday Afternoon | SSE 35 - 50 |
Stevens and Snoqualmie Pass | Elevation |
---|---|
Monday Evening | SSE 20 - 30 |
Monday Night | ESE 20 - 30 |
Tuesday Morning | ESE 30 - 40 |
Tuesday Afternoon | S 30 - 40 |
Mt. Rainier | Elevation |
---|---|
Monday Evening | SSE 20 - 30 |
Monday Night | ESE 20 - 30 |
Tuesday Morning | SSE 35 - 45 |
Tuesday Afternoon | S 30 - 40 |
Mt. Hood | Elevation |
---|---|
Monday Evening | S 20 - 30 |
Monday Night | SE 15 - 25 |
Tuesday Morning | S 30 - 40 |
Tuesday Afternoon | SE 30 - 40 |
Hurricane Ridge | Direction - Speed |
---|---|
Monday Evening | SSW 25 - 35 |
Monday Night | SSE 30 - 40 |
Tuesday Morning | S 40 - 55 |
Tuesday Afternoon | SSW 30 - 40 |
Mt. Baker | Direction - Speed |
---|---|
Monday Evening | S 25 - 35 |
Monday Night | SSE 20 - 30 |
Tuesday Morning | S 45 - 65 |
Tuesday Afternoon | SSE 35 - 50 |
Stevens and Snoqualmie Pass | Direction - Speed |
---|---|
Monday Evening | SSE 20 - 30 |
Monday Night | ESE 20 - 30 |
Tuesday Morning | ESE 30 - 40 |
Tuesday Afternoon | S 30 - 40 |
Mt. Rainier | Direction - Speed |
---|---|
Monday Evening | SSE 20 - 30 |
Monday Night | ESE 20 - 30 |
Tuesday Morning | SSE 35 - 45 |
Tuesday Afternoon | S 30 - 40 |
Mt. Hood | Direction - Speed |
---|---|
Monday Evening | S 20 - 30 |
Monday Night | SE 15 - 25 |
Tuesday Morning | S 30 - 40 |
Tuesday Afternoon | SE 30 - 40 |
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 50 - 70 | SW 40 - 60 | SW 50 - 70 | SW 45 - 65 | SW 45 - 65 |
Monday Night | SW 45 - 65 | SW 35 - 50 | SW 40 - 60 | SW 40 - 60 | SW 45 - 65 |
Tuesday Morning | S 40 - 60 | S 35 - 50 | SSW 40 - 60 | SSW 50 - 70 | SSW 50 - 70 |
Tuesday Afternoon | SSW 50 - 70 | SSW 35 - 50 | SW 50 - 70 | WSW 35 - 50 | WSW 45 - 65 |
Mt. Baker | Direction - Speed |
---|---|
Monday Evening | SW 50 - 70 |
Monday Night | SW 45 - 65 |
Tuesday Morning | S 40 - 60 |
Tuesday Afternoon | SSW 50 - 70 |
Washington Pass | Direction - Speed |
---|---|
Monday Evening | SW 40 - 60 |
Monday Night | SW 35 - 50 |
Tuesday Morning | S 35 - 50 |
Tuesday Afternoon | SSW 35 - 50 |
Stevens and Snoqualmie Pass | Direction - Speed |
---|---|
Monday Evening | SW 50 - 70 |
Monday Night | SW 40 - 60 |
Tuesday Morning | SSW 40 - 60 |
Tuesday Afternoon | SW 50 - 70 |
Mt. Rainier | Direction - Speed |
---|---|
Monday Evening | SW 45 - 65 |
Monday Night | SW 40 - 60 |
Tuesday Morning | SSW 50 - 70 |
Tuesday Afternoon | WSW 35 - 50 |
Mt. Hood | Direction - Speed |
---|---|
Monday Evening | SW 45 - 65 |
Monday Night | SW 45 - 65 |
Tuesday Morning | SSW 50 - 70 |
Tuesday Afternoon | WSW 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: 2:06 PM PST Monday, November 16, 2020
Extended Weather Synopsis for Friday night through Friday
Cool, unsettled, and showery weather prevails as the upper trough moves onshore and settles in over the region with moderate snow shower activity expected Wednesday evening and becoming light on Thursday, further decreasing going forward in time. The timing of organized features will be difficult to predict this far out. Snow levels drop below pass level. WSW flow Wednesday night and Thursday morning should shift W by Thursday afternoon with the trough directly over the region.
Extended Snow/Freezing Levels
Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
---|---|---|---|---|---|
Wednesday Night | Snow Level | 1500' - 2500' | 2000' - 3000' | 2000' - 3000' | |
Thursday | Snow Level | 1000' - 2000' | 1500' - 2500' | 2000' - 3000' | |
Thursday Night | Snow Level | 1000' - 2000' | 1500' - 2500' | 1500' - 2500' | |
Friday | Snow Level | 1500' - 2500' | 2000' - 3000' | 2000' - 3000' |
Mt. Baker | Elevation |
---|---|
Wednesday Night |
Snow Level 1500' - 2500' |
Thursday |
Snow Level 1000' - 2000' |
Thursday Night |
Snow Level 1000' - 2000' |
Friday |
Snow Level 1500' - 2500' |
Snoqualmie Pass | Elevation |
---|---|
Wednesday Night |
Snow Level 2000' - 3000' |
Thursday |
Snow Level 1500' - 2500' |
Thursday Night |
Snow Level 1500' - 2500' |
Friday |
Snow Level 2000' - 3000' |
Mt. Hood | Elevation |
---|---|
Wednesday Night |
Snow Level 2000' - 3000' |
Thursday |
Snow Level 2000' - 3000' |
Thursday Night |
Snow Level 1500' - 2500' |
Friday |
Snow Level 2000' - 3000' |
* 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 Nov 15, 2020
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