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 deep trough in the NE Pacific and a strong westerly jet will send a significant storm through our region on Tuesday. Warm frontal moisture will move into the region late Monday night and continue through Tuesday creating stormy conditions for nearly all areas. Cool easterly flow will initially insulate the Cascade Passes from the warming trend, but mixed precipitation and a switch to rain is expected for all Passes in the latter half of the day.
The associated cold front will sweep through the Cascades Tuesday evening and snow levels will quickly lower Tuesday night. Post-frontal showers should lead to decent snowfall accumulations along the West Slopes of the Cascades and the Mt. Hood area Tuesday night.
There won't be much off a break in the weather on Wednesday. As showers diminish, warm frontal moisture along a quasi-stationary boundary will impact the Olympics, the north Cascades and southern B.C by Wednesday afternoon.
Weather Forecast
Hurricane Ridge
| Monday Night | Light to moderate rain and snow developing overnight. Warming trend. |
| Tuesday | Stormy with light to moderate rain and snow. Mild. |
Mt. Baker
| Monday Night | Light to moderate rain and snow developing overnight. |
| Tuesday | Stormy with moderate to heavy rain and snow. Warming trend. |
Washington Pass and Leavenworth
| Monday Night | Light rain and snow developing overnight. |
| Tuesday | Stormy with light to moderate rain and snow, heaviest near the Cascade crest. Warming trend. |
Stevens and Snoqualmie Pass
| Monday Night | Light rain and snow developing overnight. Light east wind in the Passes becoming moderate overnight. |
| Tuesday | Stormy with moderate to occasionally heavy snow in the morning, becoming mixed precipitation late morning or mid-day. Rain likely at Pass levels in the afternoon. Warming trend. Moderate east wind in the Passes. |
Mt. Rainier, Crystal and White Pass
| Monday Night | Light rain and snow developing overnight. |
| Tuesday | Stormy with light to moderate rain or snow, occasionally heavy Paradise. Warming trend. |
Mt. Hood
| Monday Night | Light rain and snow developing late overnight. |
| Tuesday | Stormy with moderate to occasionally heavy rain and snow. Warming trend. |
Issued: 3:25 PM PST Monday, December 10, 2018
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 | 3000' | 3000' | 2500' | 2500' | 3000' | 3000' | 3000' | 3500' |
| Monday Night | Snow Level * | 3500' | 2500' | 2000' | 2000' | 2500' | 2500' | 3000' | 3000' |
| Tuesday Morning | Snow Level * | 5000' | 3000' | 2000' | 1500' | 3000' | 3000' | 4000' | 5000' |
| Tuesday Afternoon | Snow Level | 6500' | 4000' | 3500' | 4000' | 4500' | 5500' | 5500' | 7000' |
| Tuesday Evening | Snow Level | 4000' | 4000' | 4000' | 4500' | 4500' | 4500' | 4500' | 6000' |
| Tuesday Night | Snow Level | 2500' | 2500' | 2500' | 3500' | 2500' | 2500' | 2500' | 3000' |
| Wednesday Morning | Snow Level | 2000' | 2000' | 1500' | 1500' | 2000' | 2000' | 2500' | 2500' |
| Wednesday Afternoon | Snow Level | 3500' | 2500' | 2000' | 2500' | 2500' | 2500' | 3000' | 3000' |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Evening |
Snow Level 3000' |
| Monday Night |
Snow Level 3500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 5000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 6500' |
| Tuesday Evening |
Snow Level 4000' |
| Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Snow Level 2000' |
| Wednesday Afternoon |
Snow Level 3500' |
| Mt. Baker | Elevation |
|---|---|
| Monday Evening |
Snow Level 3000' |
| Monday Night |
Snow Level 2500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 4000' |
| Tuesday Evening |
Snow Level 4000' |
| Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Snow Level 2000' |
| Wednesday Afternoon |
Snow Level 2500' |
| Washington Pass | Elevation |
|---|---|
| Monday Evening |
Snow Level 2500' |
| Monday Night |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 3500' |
| Tuesday Evening |
Snow Level 4000' |
| Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Snow Level 1500' |
| Wednesday Afternoon |
Snow Level 2000' |
| Leavenworth | Elevation |
|---|---|
| Monday Evening |
Snow Level 2500' |
| Monday Night |
Snow Level 2000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 1500' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 4000' |
| Tuesday Evening |
Snow Level 4500' |
| Tuesday Night |
Snow Level 3500' |
| Wednesday Morning |
Snow Level 1500' |
| Wednesday Afternoon |
Snow Level 2500' |
| Stevens Pass | Elevation |
|---|---|
| Monday Evening |
Snow Level 3000' |
| Monday Night |
Snow Level 2500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 4500' |
| Tuesday Evening |
Snow Level 4500' |
| Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Snow Level 2000' |
| Wednesday Afternoon |
Snow Level 2500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday Evening |
Snow Level 3000' |
| Monday Night |
Snow Level 2500' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 5500' |
| Tuesday Evening |
Snow Level 4500' |
| Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Snow Level 2000' |
| Wednesday Afternoon |
Snow Level 2500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Monday Evening |
Snow Level 3000' |
| Monday Night |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 5500' |
| Tuesday Evening |
Snow Level 4500' |
| Tuesday Night |
Snow Level 2500' |
| Wednesday Morning |
Snow Level 2500' |
| Wednesday Afternoon |
Snow Level 3000' |
| Mt. Hood | Elevation |
|---|---|
| Monday Evening |
Snow Level 3500' |
| Monday Night |
Snow Level 3000' (Easterly Flow *) |
| Tuesday Morning |
Snow Level 5000' (Easterly Flow *) |
| Tuesday Afternoon |
Snow Level 7000' |
| Tuesday Evening |
Snow Level 6000' |
| Tuesday Night |
Snow Level 3000' |
| Wednesday Morning |
Snow Level 2500' |
| Wednesday Afternoon |
Snow Level 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.
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 | 0.75 -1.00 | 0.25 - 0.50 | LT 0.25 |
| Mt Baker Ski Area | 0.50 | 1.50 - 2.00 | 0.50 | LT 0.25 |
| Washington Pass | LT 0.10 | 1.00 | 0.25 - 0.50 | LT 0.10 |
| Leavenworth | LT 0.10 | 0.50 | 0.25 - 0.50 | LT 0.10 |
| Stevens Pass | LT 0.25 | 1.50 | 1.00 | 0.25 - 0.50 |
| Snoqualmie Pass | LT 0.25 | 1.50 - 2.00 | 1.50 | 0.25 - 0.50 |
| Mission Ridge | LT 0.10 | 0.50 | 0.50 - 0.75 | LT 0.10 |
| Crystal Mt | LT 0.10 | 0.75 -1.00 | 1.00 | LT 0.25 |
| Paradise | LT 0.25 | 1.50 - 2.00 | 1.00 - 1.50 | 0.25 |
| White Pass | LT 0.10 | 1.00 | 1.00 - 1.50 | LT 0.25 |
| Mt Hood Meadows | LT 0.10 | 1.00 - 1.50 | 1.50 | 0.25 |
| Timberline | LT 0.10 | 1.50 | 2.00 | 0.25 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Monday Night | 0.25 |
| Friday | 0.75 -1.00 |
| Friday Night | 0.25 - 0.50 |
| Friday | LT 0.25 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Monday Night | 0.50 |
| Friday | 1.50 - 2.00 |
| Friday Night | 0.50 |
| Friday | LT 0.25 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 1.00 |
| Friday Night | 0.25 - 0.50 |
| Friday | LT 0.10 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 0.50 |
| Friday Night | 0.25 - 0.50 |
| Friday | LT 0.10 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.25 |
| Friday | 1.50 |
| Friday Night | 1.00 |
| Friday | 0.25 - 0.50 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.25 |
| Friday | 1.50 - 2.00 |
| Friday Night | 1.50 |
| Friday | 0.25 - 0.50 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 0.50 |
| Friday Night | 0.50 - 0.75 |
| Friday | LT 0.10 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 0.75 -1.00 |
| Friday Night | 1.00 |
| Friday | LT 0.25 |
| Paradise | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.25 |
| Friday | 1.50 - 2.00 |
| Friday Night | 1.00 - 1.50 |
| Friday | 0.25 |
| White Pass | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 1.00 |
| Friday Night | 1.00 - 1.50 |
| Friday | LT 0.25 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 1.00 - 1.50 |
| Friday Night | 1.50 |
| Friday | 0.25 |
| Timberline | Precipitation Forecast |
|---|---|
| Monday Night | LT 0.10 |
| Friday | 1.50 |
| Friday Night | 2.00 |
| Friday | 0.25 |
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: 3:25 PM PST Monday, December 10, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Monday Evening | S 5 - 15 | S 10 - 20 | S 5 - 15 | S 5 - 15 | SW 0 - 10 |
| Monday Night | S 15 - 25 | SE 10 - 20 | SE 10 - 20 | S 5 - 15 | SW 5 - 15 |
| Tuesday Morning | SW 20 - 30 | SSE 25 - 40 | S 20 - 30 | SSW 20 - 30 | SW 20 - 30 |
| Tuesday Afternoon | WSW 20 - 30 | S 25 - 35 | SW 25 - 35 | SW 30 - 40 | SW 35 - 45 |
| Hurricane Ridge | Elevation |
|---|---|
| Monday Evening | S 5 - 15 |
| Monday Night | S 15 - 25 |
| Tuesday Morning | SW 20 - 30 |
| Tuesday Afternoon | WSW 20 - 30 |
| Mt. Baker | Elevation |
|---|---|
| Monday Evening | S 10 - 20 |
| Monday Night | SE 10 - 20 |
| Tuesday Morning | SSE 25 - 40 |
| Tuesday Afternoon | S 25 - 35 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Monday Evening | S 5 - 15 |
| Monday Night | SE 10 - 20 |
| Tuesday Morning | S 20 - 30 |
| Tuesday Afternoon | SW 25 - 35 |
| Mt. Rainier | Elevation |
|---|---|
| Monday Evening | S 5 - 15 |
| Monday Night | S 5 - 15 |
| Tuesday Morning | SSW 20 - 30 |
| Tuesday Afternoon | SW 30 - 40 |
| Mt. Hood | Elevation |
|---|---|
| Monday Evening | SW 0 - 10 |
| Monday Night | SW 5 - 15 |
| Tuesday Morning | SW 20 - 30 |
| Tuesday Afternoon | SW 35 - 45 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Monday Evening | S 5 - 15 |
| Monday Night | S 15 - 25 |
| Tuesday Morning | SW 20 - 30 |
| Tuesday Afternoon | WSW 20 - 30 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Evening | S 10 - 20 |
| Monday Night | SE 10 - 20 |
| Tuesday Morning | SSE 25 - 40 |
| Tuesday Afternoon | S 25 - 35 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Evening | S 5 - 15 |
| Monday Night | SE 10 - 20 |
| Tuesday Morning | S 20 - 30 |
| Tuesday Afternoon | SW 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Evening | S 5 - 15 |
| Monday Night | S 5 - 15 |
| Tuesday Morning | SSW 20 - 30 |
| Tuesday Afternoon | SW 30 - 40 |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Evening | SW 0 - 10 |
| Monday Night | SW 5 - 15 |
| Tuesday Morning | SW 20 - 30 |
| Tuesday Afternoon | SW 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.
Free Winds at 9000' (mph)
| Mt. Baker | Washington Pass | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Monday Evening | SW 10 - 20 | SW 10 - 20 | SW 20 - 30 | SW 15 - 25 | WSW 15 - 25 |
| Monday Night | SW 25 - 35 | SW 20 - 30 | SW 40 - 50 | SW 35 - 45 | W 40 - 50 |
| Tuesday Morning | SW 35 - 45 | SW 40 - 50 | SW 50 - 60 | SW 45 - 55 | WSW 45 - 55 |
| Tuesday Afternoon | SW 40 - 50 | SW 45 - 55 | SW 55 - 65 | SW 60 - 70 | SW 60 - 70 |
| Mt. Baker | Direction - Speed |
|---|---|
| Monday Evening | SW 10 - 20 |
| Monday Night | SW 25 - 35 |
| Tuesday Morning | SW 35 - 45 |
| Tuesday Afternoon | SW 40 - 50 |
| Washington Pass | Direction - Speed |
|---|---|
| Monday Evening | SW 10 - 20 |
| Monday Night | SW 20 - 30 |
| Tuesday Morning | SW 40 - 50 |
| Tuesday Afternoon | SW 45 - 55 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Monday Evening | SW 20 - 30 |
| Monday Night | SW 40 - 50 |
| Tuesday Morning | SW 50 - 60 |
| Tuesday Afternoon | SW 55 - 65 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Monday Evening | SW 15 - 25 |
| Monday Night | SW 35 - 45 |
| Tuesday Morning | SW 45 - 55 |
| Tuesday Afternoon | SW 60 - 70 |
| Mt. Hood | Direction - Speed |
|---|---|
| Monday Evening | WSW 15 - 25 |
| Monday Night | W 40 - 50 |
| Tuesday Morning | WSW 45 - 55 |
| Tuesday Afternoon | SW 60 - 70 |
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: 3:25 PM PST Monday, December 10, 2018
Extended Weather Synopsis for Friday night through Friday
A low pressure system is expected to develop along the quasi-stationary frontal boundary hung up over the northern half of our forecast area and southern B.C. Wednesday night and Thursday, with lesser amounts forecast further south. A slight warming trend should peak Thursday afternoon and night. The frontal boundary should become north-south oriented and pass through Friday, weakening and splitting in the process.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Wednesday Night | Snow Level | 2500' - 3500' | 2500' - 3500' | 3500' - 4500' | |
| Thursday | Snow Level | 4000' - 5000' | 4500' - 5500' | 5500' - 6500' | * |
| Thursday Night | Snow Level | 4500' - 5500' | 5000' - 6000' | 6000' - 7000' | * |
| Friday | Snow Level | 2500' - 3500' | 3000' - 4000' | 4000' - 5000' |
| Mt. Baker | Elevation |
|---|---|
| Wednesday Night |
Snow Level 2500' - 3500' |
| Thursday |
Snow Level 4000' - 5000' (Easterly Flow *) |
| Thursday Night |
Snow Level 4500' - 5500' (Easterly Flow *) |
| Friday |
Snow Level 2500' - 3500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Wednesday Night |
Snow Level 2500' - 3500' |
| Thursday |
Snow Level 4500' - 5500' (Easterly Flow *) |
| Thursday Night |
Snow Level 5000' - 6000' (Easterly Flow *) |
| Friday |
Snow Level 3000' - 4000' |
| Mt. Hood | Elevation |
|---|---|
| Wednesday Night |
Snow Level 3500' - 4500' |
| Thursday |
Snow Level 5500' - 6500' (Easterly Flow *) |
| Thursday Night |
Snow Level 6000' - 7000' (Easterly Flow *) |
| Friday |
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 7, 2018
The NWAC program is administered by the USDA-Forest Service and operates from the National Weather Service Forecast Office in Seattle. NWAC services are made possible by important collaboration and support from a wide variety of federal, state and private cooperators.