Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Tuesday night through Thursday
Cool easterly flow is keeping milder freezing levels at bay this afternoon in the Cascade Passes and closer to the crest. Further west of the crest, mountain weather sites like Mt. Baker and Paradise have warmed above freezing. Light warm frontal moisture continues to squeeze out light precipitation for the Mt. Baker area and the Olympics with snow levels around 4000-5000'. The light precipitation should taper off tonight as the front lifts north.
A weak N-S oriented low will split as it approaches the Washington coast tonight. Disorganized and generally light precipitation will be slow to move inland until a trailing frontal system pushes through Wednesday night. There will be a brief switch from east to west flow post-frontal Thursday morning, but snow levels will stay below the Passes through this event.
This first weather system will be the opening salvo in what will be a very wet end to the work week. An atmospheric river will begin to take aim at the Pacific Northwest on Thursday with moderate to heavy precipitation spreading over the region from south to north. Precipitation likely won't reach the central and north Cascades until Thursday night.
Weather Forecast
Hurricane Ridge
| Tuesday Night | Periods of light rain and snow tapering off in the evening. |
| Wednesday | Light to occasionally moderate rain and snow. |
Mt. Baker
| Tuesday Night | Light rain and snow tapering off late in the evening. |
| Wednesday | Light to occasionally moderate rain and snow developing in the afternoon. |
Washington Pass and Leavenworth
| Tuesday Night | Cloudy. Light snow flurries near Washington Pass. |
| Wednesday | Cloudy. Light snow flurries near Washington Pass. |
Stevens and Snoqualmie Pass
| Tuesday Night | Cloudy. Moderate east winds at Pass level. |
| Wednesday | Light to occasionally moderate rain and snow developing late in the afternoon. Cloudy. Moderate east winds at Pass level. |
Mt. Rainier, Crystal and White Pass
| Tuesday Night | High overcast. |
| Wednesday | Light to occasionally moderate rain and snow developing late in the afternoon. |
Mt. Hood
| Tuesday Night | High overcast. |
| Wednesday | Light to occasionally moderate rain and snow developing mid-day. |
Issued: 1:57 PM PST Tuesday, December 17, 2019
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Tuesday Evening | Freezing Level * | 4500' | 4000' | 1500' | 1500' | 2000' | 3000' | 5000' | 6500' |
| Tuesday Night | Freezing Level * | 4500' | 4000' | 1500' | 1500' | 2000' | 3000' | 4000' | 6500' |
| Wednesday Morning | Snow Level * | 4000' | 3500' | 0' | 0' | 1500' | 1500' | 3500' | 6000' |
| Wednesday Afternoon | Snow Level * | 3500' | 3000' | 0' | 0' | 1500' | 1500' | 3000' | 3000' |
| Wednesday Evening | Snow Level * | 3000' | 3000' | 1000' | 1000' | 1500' | 1500' | 3000' | 3000' |
| Wednesday Night | Snow Level * | 3500' | 2000' | 1000' | 1000' | 1500' | 1500' | 3500' | 4000' |
| Thursday Morning | Snow Level | 3500' | 2000' | 1500' | 1500' | 2500' | 2500' | 3500' | 3500' |
| Thursday Afternoon | Snow Level * | 3500' | 3000' | 2000' | 2000' | 2500' | 2500' | 3500' | 4500' |
| Hurricane Ridge | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 4500' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 4500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 4000' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 4000' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 2000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 2000' |
| Thursday Afternoon |
Snow Level 3000' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 1500' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 1500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 0' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 0' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 1000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 1000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 1500' |
| Thursday Afternoon |
Snow Level 2000' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 1500' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 1500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 0' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 0' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 1000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 1000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 1500' |
| Thursday Afternoon |
Snow Level 2000' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 2000' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 2000' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 1500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 2500' |
| Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 3000' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 3000' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 1500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 2500' |
| Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 5000' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 4000' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Tuesday Evening |
Freezing Level 6500' (Easterly Flow *) |
| Tuesday Night |
Freezing Level 6500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 6000' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Evening |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3500' |
| Thursday Afternoon |
Snow Level 4500' (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
| Tuesday 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 | 0.25 | 0.25 | LT 0.25 |
| Mt Baker Ski Area | LT 0.10 | 0.25 - 0.50 | 0.50 - 0.75 | 0.25 |
| Washington Pass | LT 0.10 | LT 0.10 | 0.25 | LT 0.10 |
| Leavenworth | 0 | 0 | LT 0.25 | LT 0.10 |
| Stevens Pass | 0 | LT 0.10 | 0.25 - 0.50 | LT 0.25 |
| Snoqualmie Pass | 0 | LT 0.10 | 0.50 | 0.25 |
| Mission Ridge | 0 | 0 | LT 0.25 | LT 0.25 |
| Crystal Mt | 0 | LT 0.10 | 0.25 - 0.50 | LT 0.25 |
| Paradise | 0 | LT 0.25 | 0.75 | 0.25 - 0.50 |
| White Pass | 0 | LT 0.10 | 0.25 - 0.50 | 0.25 |
| Mt Hood Meadows | 0 | LT 0.25 | 0.50 | 0.50 - 0.75 |
| Timberline | 0 | 0.25 | 0.50 | 0.75 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Tuesday Night | LT 0.10 |
| Thursday | 0.25 |
| Thursday Night | 0.25 |
| Thursday | LT 0.25 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Tuesday Night | LT 0.10 |
| Thursday | 0.25 - 0.50 |
| Thursday Night | 0.50 - 0.75 |
| Thursday | 0.25 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Tuesday Night | LT 0.10 |
| Thursday | LT 0.10 |
| Thursday Night | 0.25 |
| Thursday | LT 0.10 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | 0 |
| Thursday Night | LT 0.25 |
| Thursday | LT 0.10 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0.25 - 0.50 |
| Thursday | LT 0.25 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0.50 |
| Thursday | 0.25 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | 0 |
| Thursday Night | LT 0.25 |
| Thursday | LT 0.25 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0.25 - 0.50 |
| Thursday | LT 0.25 |
| Paradise | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | LT 0.25 |
| Thursday Night | 0.75 |
| Thursday | 0.25 - 0.50 |
| White Pass | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | LT 0.10 |
| Thursday Night | 0.25 - 0.50 |
| Thursday | 0.25 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | LT 0.25 |
| Thursday Night | 0.50 |
| Thursday | 0.50 - 0.75 |
| Timberline | Precipitation Forecast |
|---|---|
| Tuesday Night | 0 |
| Thursday | 0.25 |
| Thursday Night | 0.50 |
| Thursday | 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: 1:57 PM PST Tuesday, December 17, 2019
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Tuesday Evening | S 20 - 30 | S 15 - 25 | SE 10 - 20 | SE 10 - 20 | SW 10 - 20 |
| Tuesday Night | S 15 - 25 | S 10 - 20 | SE 15 - 25 | SE 15 - 25 | SW 10 - 20 |
| Wednesday Morning | S 15 - 25 | S 15 - 25 | SE 15 - 25 | SE 15 - 25 | S 10 - 20 |
| Wednesday Afternoon | SW 20 - 30 | SE 20 - 30 | SE 15 - 25 | SE 15 - 25 | SE 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Tuesday Evening | S 20 - 30 |
| Tuesday Night | S 15 - 25 |
| Wednesday Morning | S 15 - 25 |
| Wednesday Afternoon | SW 20 - 30 |
| Mt. Baker | Elevation |
|---|---|
| Tuesday Evening | S 15 - 25 |
| Tuesday Night | S 10 - 20 |
| Wednesday Morning | S 15 - 25 |
| Wednesday Afternoon | SE 20 - 30 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Tuesday Evening | SE 10 - 20 |
| Tuesday Night | SE 15 - 25 |
| Wednesday Morning | SE 15 - 25 |
| Wednesday Afternoon | SE 15 - 25 |
| Mt. Rainier | Elevation |
|---|---|
| Tuesday Evening | SE 10 - 20 |
| Tuesday Night | SE 15 - 25 |
| Wednesday Morning | SE 15 - 25 |
| Wednesday Afternoon | SE 15 - 25 |
| Mt. Hood | Elevation |
|---|---|
| Tuesday Evening | SW 10 - 20 |
| Tuesday Night | SW 10 - 20 |
| Wednesday Morning | S 10 - 20 |
| Wednesday Afternoon | SE 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Tuesday Evening | S 20 - 30 |
| Tuesday Night | S 15 - 25 |
| Wednesday Morning | S 15 - 25 |
| Wednesday Afternoon | SW 20 - 30 |
| Mt. Baker | Direction - Speed |
|---|---|
| Tuesday Evening | S 15 - 25 |
| Tuesday Night | S 10 - 20 |
| Wednesday Morning | S 15 - 25 |
| Wednesday Afternoon | SE 20 - 30 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Tuesday Evening | SE 10 - 20 |
| Tuesday Night | SE 15 - 25 |
| Wednesday Morning | SE 15 - 25 |
| Wednesday Afternoon | SE 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Tuesday Evening | SE 10 - 20 |
| Tuesday Night | SE 15 - 25 |
| Wednesday Morning | SE 15 - 25 |
| Wednesday Afternoon | SE 15 - 25 |
| Mt. Hood | Direction - Speed |
|---|---|
| Tuesday Evening | SW 10 - 20 |
| Tuesday Night | SW 10 - 20 |
| Wednesday Morning | S 10 - 20 |
| Wednesday Afternoon | SE 10 - 20 |
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 | |
|---|---|---|---|---|---|
| Tuesday Evening | SW 35 - 45 | SW 30 - 40 | S 25 - 35 | SW 20 - 30 | SW 20 - 30 |
| Tuesday Night | SW 30 - 40 | SW 25 - 35 | SW 20 - 30 | SW 20 - 30 | SW 20 - 30 |
| Wednesday Morning | S 25 - 35 | SW 15 - 25 | S 20 - 30 | S 20 - 30 | SW 20 - 30 |
| Wednesday Afternoon | SW 30 - 40 | SW 15 - 25 | SW 25 - 35 | SW 25 - 35 | SW 25 - 35 |
| Mt. Baker | Direction - Speed |
|---|---|
| Tuesday Evening | SW 35 - 45 |
| Tuesday Night | SW 30 - 40 |
| Wednesday Morning | S 25 - 35 |
| Wednesday Afternoon | SW 30 - 40 |
| Washington Pass | Direction - Speed |
|---|---|
| Tuesday Evening | SW 30 - 40 |
| Tuesday Night | SW 25 - 35 |
| Wednesday Morning | SW 15 - 25 |
| Wednesday Afternoon | SW 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Tuesday Evening | S 25 - 35 |
| Tuesday Night | SW 20 - 30 |
| Wednesday Morning | S 20 - 30 |
| Wednesday Afternoon | SW 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Tuesday Evening | SW 20 - 30 |
| Tuesday Night | SW 20 - 30 |
| Wednesday Morning | S 20 - 30 |
| Wednesday Afternoon | SW 25 - 35 |
| Mt. Hood | Direction - Speed |
|---|---|
| Tuesday Evening | SW 20 - 30 |
| Tuesday Night | SW 20 - 30 |
| Wednesday Morning | SW 20 - 30 |
| Wednesday Afternoon | SW 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.
Issued: 1:57 PM PST Tuesday, December 17, 2019
Extended Weather Synopsis for Thursday night through Thursday
Forecast models are in fair agreement that an atmospheric river will deliver several inches of water to our mountains Thursday through Saturday. Warm frontal precipitation extending from a parent low in the NE Pacific should bring moderate to heavy precipitation to all areas Thursday night. The main frontal band will likely stall over the Washington Cascades for much of Friday.
A general warming trend will accompany the precipitation but the exact positioning of the boundary will determine how far north warm air is advected. While this event is several days out, several models suggest the north Cascades will be on the cool side of this storm while Mt. Hood sees much warmer air flood into the region. Easterly flow through the Cascade Passes will initially keep precipitation in the form of snow, but a switch to westerly flow would allow snow levels to rise above Pass levels at some point on Friday.
We could be in for a final wave of moisture Friday night and Saturday before transitioning to drier conditions.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Thursday Night | Snow Level | 2000' - 3000' | 2500' - 4000' | 5500' - 6500' | * |
| Friday | Snow Level | 3000' - 4000' | 4000' - 5000' | 5500' - 6500' | |
| Friday Night | Snow Level | 2500' - 3500' | 3000' - 4000' | 5000' - 6000' | * |
| Saturday | Snow Level | 2500' - 3500' | 3000' - 4000' | 4000' - 5000' |
| Mt. Baker | Elevation |
|---|---|
| Thursday Night |
Snow Level 2000' - 3000' (Easterly Flow *) |
| Friday |
Snow Level 3000' - 4000' |
| Friday Night |
Snow Level 2500' - 3500' (Easterly Flow *) |
| Saturday |
Snow Level 2500' - 3500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday Night |
Snow Level 2500' - 4000' (Easterly Flow *) |
| Friday |
Snow Level 4000' - 5000' |
| Friday Night |
Snow Level 3000' - 4000' (Easterly Flow *) |
| Saturday |
Snow Level 3000' - 4000' |
| Mt. Hood | Elevation |
|---|---|
| Thursday Night |
Snow Level 5500' - 6500' (Easterly Flow *) |
| Friday |
Snow Level 5500' - 6500' |
| Friday Night |
Snow Level 5000' - 6000' (Easterly Flow *) |
| Saturday |
Snow Level 4000' - 5000' |
* 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 17, 2019
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