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 Wednesday
A series of systems will bring the most impactful weather to our mountains so far this winter.
An average frontal system spreads rain and snow throughout the Cascades and Olympics Wednesday night, favoring the volcanoes (particularly Mt. Hood) with SSW winds ahead of the system and SW winds behind it. Expect E flow through the Passes switching to westerly, but temperatures should be cool enough that the precipitation stays snow at Snoqualmie Pass. Light to moderate post-frontal rain and snow showers continue on Thursday, decreasing over the central and northern Washington Cascades in the afternoon. Pass-level flow switches back easterly in the afternoon as the next system approaches from the south.
The second system is an atmospheric river event that brings subtropical moisture into mid-latitudes. This system's leading-edge will be a strong warm front arriving early Thursday afternoon for Mt. Hood and late in the day for the southern Washington Cascades, bringing heavy rain/snow, strong to extreme winds, and rising snow levels.
Thursday night, the warm front continues lifting northward, spreading the very stormy weather and heavy rain/snow with it. Expect significant accumulations at 1-3" per hour rates. Cold air entrenched E of the Cascade Crest and E flow should keep the Passes cold through the evening hours with a shift to rain at Snoqualmie Pass likely before midnight and then Stevens Pass, likely after midnight as E flow diminishes and the cold air pool gets replaced with warmer air flushing in from the subtropics. There is a potential for some freezing rain near and E of the passes as warmer air moves in at mid-levels.
On Friday, the atmospheric river continues to take aim on the Washington Cascades with very stormy and wet weather and a slight cooling trend during the day.
Weather Forecast
Hurricane Ridge
| Wednesday Night | Moderate rain and snow in the evening, tapering to light showers after 10 PM. |
| Thursday | Scattered light snow showers. |
Mt. Baker
| Wednesday Night | Moderate to heavy rain and snow. |
| Thursday | Light to occasionally moderate snow showers. |
Washington Pass and Leavenworth
| Wednesday Night | Periods of light snow. |
| Thursday | Light snow showers. |
Stevens and Snoqualmie Pass
| Wednesday Night | Moderate rain and snow with significant accumulations at the Passes. Moderate E winds through the Passes becoming light by morning. |
| Thursday | Light rain and snow showers. Variable winds becoming moderate out of the E in the afternoon. |
Mt. Rainier, Crystal and White Pass
| Wednesday Night | Moderate rain and snow - heaviest at Paradise. |
| Thursday | Light snow becoming moderate to heavy with rising snow levels late in the day. 5000 ft winds becoming strong by the end of the day. |
Mt. Hood
| Wednesday Night | Heavy rain and snow. |
| Thursday | Moderate to heavy rain and snow. Stong winds becoming extreme late in the day. |
Issued: 2:36 PM PST Wednesday, December 18, 2019
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 * | 3500' | 3000' | 1000' | 1000' | 1500' | 2000' | 3000' | 3500' |
| Wednesday Night | Snow Level * | 3000' | 2000' | 500' | 500' | 1000' | 1500' | 3000' | 3500' |
| Thursday Morning | Snow Level | 3000' | 2000' | 500' | 500' | 1500' | 2000' | 3000' | 4000' |
| Thursday Afternoon | Snow Level * | 3500' | 3000' | 2000' | 1500' | 2500' | 2500' | 3500' | 4500' |
| Thursday Evening | Snow Level | 4000' | 3000' | 2000' | 1500' | 2000' | 2500' | 4000' | 6000' |
| Thursday Night | Snow Level | 5000' | 3000' | 2000' | 2500' | 3000' | 4500' | 5500' | 6000' |
| Friday Morning | Snow Level | 4000' | 4000' | 3000' | 4500' | 4500' | 5000' | 5500' | 6000' |
| Friday Afternoon | Snow Level | 3500' | 3500' | 4000' | 5000' | 4500' | 5000' | 5000' | 6000' |
| Hurricane Ridge | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3000' |
| Thursday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Thursday Evening |
Snow Level 4000' |
| Thursday Night |
Snow Level 5000' |
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 3500' |
| Mt. Baker | Elevation |
|---|---|
| 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 *) |
| Thursday Evening |
Snow Level 3000' |
| Thursday Night |
Snow Level 3000' |
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 3500' |
| Washington Pass | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 1000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 500' |
| Thursday Afternoon |
Snow Level 2000' (Easterly Flow *) |
| Thursday Evening |
Snow Level 2000' |
| Thursday Night |
Snow Level 2000' |
| Friday Morning |
Snow Level 3000' |
| Friday Afternoon |
Snow Level 4000' |
| Leavenworth | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 1000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 500' |
| Thursday Afternoon |
Snow Level 1500' (Easterly Flow *) |
| Thursday Evening |
Snow Level 1500' |
| Thursday Night |
Snow Level 2500' |
| Friday Morning |
Snow Level 4500' |
| Friday Afternoon |
Snow Level 5000' |
| Stevens Pass | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 1500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 1000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 1500' |
| Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Thursday Evening |
Snow Level 2000' |
| Thursday Night |
Snow Level 3000' |
| Friday Morning |
Snow Level 4500' |
| Friday Afternoon |
Snow Level 4500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 2000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 1500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 2000' |
| Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
| Thursday Evening |
Snow Level 2500' |
| Thursday Night |
Snow Level 4500' |
| Friday Morning |
Snow Level 5000' |
| Friday Afternoon |
Snow Level 5000' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 3000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3000' (Easterly Flow *) |
| Thursday Morning |
Snow Level 3000' |
| Thursday Afternoon |
Snow Level 3500' (Easterly Flow *) |
| Thursday Evening |
Snow Level 4000' |
| Thursday Night |
Snow Level 5500' |
| Friday Morning |
Snow Level 5500' |
| Friday Afternoon |
Snow Level 5000' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Evening |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 3500' (Easterly Flow *) |
| Thursday Morning |
Snow Level 4000' |
| Thursday Afternoon |
Snow Level 4500' (Easterly Flow *) |
| Thursday Evening |
Snow Level 6000' |
| Thursday Night |
Snow Level 6000' |
| Friday Morning |
Snow Level 6000' |
| Friday Afternoon |
Snow Level 6000' |
* 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 | Wednesday | Wednesday Night | Wednesday | |
|---|---|---|---|---|
| 4 pm - 4 am | 4 am - 4 pm | 4 pm - 4 am | 4 am - 4 pm | |
| Hurricane Ridge | 0.25 | LT 0.25 | 1.00 | 0.50 |
| Mt Baker Ski Area | 0.75 -1.00 | 0.25 - 0.50 | 2.00 | 1.00 |
| Washington Pass | LT 0.25 | LT 0.10 | 1.00 - 1.50 | 0.75 -1.00 |
| Leavenworth | LT 0.10 | LT 0.10 | 0.50 - 0.75 | 0.25 |
| Stevens Pass | 0.25 | 0.25 | 1.00 | 1.00 |
| Snoqualmie Pass | 0.50 | 0.25 | 1.50 | 1.00 - 1.50 |
| Mission Ridge | 0.25 | LT 0.25 | 0.50 - 0.75 | LT 0.25 |
| Crystal Mt | 0.25 - 0.50 | 0.25 - 0.50 | 1.50 - 2.00 | 1.00 - 1.50 |
| Paradise | 0.75 | 0.75 | 2.00 | 1.50 - 2.00 |
| White Pass | 0.25 - 0.50 | 0.25 - 0.50 | 1.00 - 1.50 | 1.00 |
| Mt Hood Meadows | 0.75 -1.00 | 1.00 - 1.50 | 0.50 | 0.50 |
| Timberline | 1.00 | 1.00 - 1.50 | 0.50 | 0.50 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.25 |
| Wednesday | LT 0.25 |
| Wednesday Night | 1.00 |
| Wednesday | 0.50 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.75 -1.00 |
| Wednesday | 0.25 - 0.50 |
| Wednesday Night | 2.00 |
| Wednesday | 1.00 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.25 |
| Wednesday | LT 0.10 |
| Wednesday Night | 1.00 - 1.50 |
| Wednesday | 0.75 -1.00 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Wednesday Night | LT 0.10 |
| Wednesday | LT 0.10 |
| Wednesday Night | 0.50 - 0.75 |
| Wednesday | 0.25 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.25 |
| Wednesday | 0.25 |
| Wednesday Night | 1.00 |
| Wednesday | 1.00 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.50 |
| Wednesday | 0.25 |
| Wednesday Night | 1.50 |
| Wednesday | 1.00 - 1.50 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.25 |
| Wednesday | LT 0.25 |
| Wednesday Night | 0.50 - 0.75 |
| Wednesday | LT 0.25 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.25 - 0.50 |
| Wednesday | 0.25 - 0.50 |
| Wednesday Night | 1.50 - 2.00 |
| Wednesday | 1.00 - 1.50 |
| Paradise | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.75 |
| Wednesday | 0.75 |
| Wednesday Night | 2.00 |
| Wednesday | 1.50 - 2.00 |
| White Pass | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.25 - 0.50 |
| Wednesday | 0.25 - 0.50 |
| Wednesday Night | 1.00 - 1.50 |
| Wednesday | 1.00 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Wednesday Night | 0.75 -1.00 |
| Wednesday | 1.00 - 1.50 |
| Wednesday Night | 0.50 |
| Wednesday | 0.50 |
| Timberline | Precipitation Forecast |
|---|---|
| Wednesday Night | 1.00 |
| Wednesday | 1.00 - 1.50 |
| Wednesday Night | 0.50 |
| Wednesday | 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: 2:36 PM PST Wednesday, December 18, 2019
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Wednesday Evening | S 20 - 30 | SSE 20 - 30 | SE 20 - 30 | S 15 - 25 | SW 25 - 35 |
| Wednesday Night | SSW 10 - 20 | S 20 - 30 | SSW 20 - 30 | SW 15 - 25 | WSW 25 - 35 |
| Thursday Morning | S 5 - 15 | S 5 - 15 | S 5 - 15 | S 5 - 15 | SW 10 - 20 |
| Thursday Afternoon | SSE 15 - 25 | E 10 - 20 | ESE 15 - 25 | SSE 15 - 25 | SW 40 - 50 |
| Hurricane Ridge | Elevation |
|---|---|
| Wednesday Evening | S 20 - 30 |
| Wednesday Night | SSW 10 - 20 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | SSE 15 - 25 |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Evening | SSE 20 - 30 |
| Wednesday Night | S 20 - 30 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | E 10 - 20 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Evening | SE 20 - 30 |
| Wednesday Night | SSW 20 - 30 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | ESE 15 - 25 |
| Mt. Rainier | Elevation |
|---|---|
| Wednesday Evening | S 15 - 25 |
| Wednesday Night | SW 15 - 25 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | SSE 15 - 25 |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Evening | SW 25 - 35 |
| Wednesday Night | WSW 25 - 35 |
| Thursday Morning | SW 10 - 20 |
| Thursday Afternoon | SW 40 - 50 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Wednesday Evening | S 20 - 30 |
| Wednesday Night | SSW 10 - 20 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | SSE 15 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Wednesday Evening | SSE 20 - 30 |
| Wednesday Night | S 20 - 30 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | E 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Wednesday Evening | SE 20 - 30 |
| Wednesday Night | SSW 20 - 30 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | ESE 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Wednesday Evening | S 15 - 25 |
| Wednesday Night | SW 15 - 25 |
| Thursday Morning | S 5 - 15 |
| Thursday Afternoon | SSE 15 - 25 |
| Mt. Hood | Direction - Speed |
|---|---|
| Wednesday Evening | SW 25 - 35 |
| Wednesday Night | WSW 25 - 35 |
| Thursday Morning | SW 10 - 20 |
| Thursday Afternoon | SW 40 - 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.
Free Winds at 9000' (mph)
| Mt. Baker | Washington Pass | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Wednesday Evening | SSW 35 - 45 | SW 30 - 40 | SW 40 - 50 | SW 35 - 50 | WSW 40 - 55 |
| Wednesday Night | WSW 30 - 40 | WSW 30 - 40 | WSW 35 - 45 | WSW 35 - 45 | WSW 45 - 60 |
| Thursday Morning | SW 20 - 30 | WSW 15 - 25 | WSW 20 - 30 | WSW 20 - 30 | WSW 35 - 45 |
| Thursday Afternoon | SSW 15 - 25 | SSW 15 - 25 | SW 30 - 40 | SW 35 - 45 | WSW 60 - 80 |
| Mt. Baker | Direction - Speed |
|---|---|
| Wednesday Evening | SSW 35 - 45 |
| Wednesday Night | WSW 30 - 40 |
| Thursday Morning | SW 20 - 30 |
| Thursday Afternoon | SSW 15 - 25 |
| Washington Pass | Direction - Speed |
|---|---|
| Wednesday Evening | SW 30 - 40 |
| Wednesday Night | WSW 30 - 40 |
| Thursday Morning | WSW 15 - 25 |
| Thursday Afternoon | SSW 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Wednesday Evening | SW 40 - 50 |
| Wednesday Night | WSW 35 - 45 |
| Thursday Morning | WSW 20 - 30 |
| Thursday Afternoon | SW 30 - 40 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Wednesday Evening | SW 35 - 50 |
| Wednesday Night | WSW 35 - 45 |
| Thursday Morning | WSW 20 - 30 |
| Thursday Afternoon | SW 35 - 45 |
| Mt. Hood | Direction - Speed |
|---|---|
| Wednesday Evening | WSW 40 - 55 |
| Wednesday Night | WSW 45 - 60 |
| Thursday Morning | WSW 35 - 45 |
| Thursday Afternoon | WSW 60 - 80 |
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: 2:36 PM PST Wednesday, December 18, 2019
Extended Weather Synopsis for Wednesday night through Wednesday
Friday night, the firehose continues, with another rise in snow levels as another along the frontal system lifts northward.
On Saturday and Saturday night, precipitation should decrease and gradually become showery with gradually lowering snow levels that should reach Snoqualmie Pass level overnight Saturday.
The cooling and drying trend continues on Sunday with light to occasionally moderate snow showers and a weak trough over our region.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Friday Night | Snow Level | 2500' - 3500' | 3000' - 4000' | 5500' - 6500' | |
| Saturday | Snow Level | 3000' - 4000' | 3500' - 4500' | 4000' - 5500' | |
| Saturday Night | Snow Level | 2000' - 3000' | 2500' - 3500' | 3000' - 4000' | |
| Sunday | Snow Level | 1000' - 2000' | 1000' - 2500' | 2000' - 3000' |
| Mt. Baker | Elevation |
|---|---|
| Friday Night |
Snow Level 2500' - 3500' |
| Saturday |
Snow Level 3000' - 4000' |
| Saturday Night |
Snow Level 2000' - 3000' |
| Sunday |
Snow Level 1000' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Friday Night |
Snow Level 3000' - 4000' |
| Saturday |
Snow Level 3500' - 4500' |
| Saturday Night |
Snow Level 2500' - 3500' |
| Sunday |
Snow Level 1000' - 2500' |
| Mt. Hood | Elevation |
|---|---|
| Friday Night |
Snow Level 5500' - 6500' |
| Saturday |
Snow Level 4000' - 5500' |
| Saturday Night |
Snow Level 3000' - 4000' |
| Sunday |
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 Dec 18, 2019
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