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 & Thursday
A deep Pacific upper level and surface low is moving E-NE on Wednesday morning in the direction of the Queen Charlotte Islands and is located approximately 700 miles off the coast of Oregon. It sits north of a strong E-W jet. The Pacific Northwest lies near the western edge of a broad, shallow ridge centered to our east and the deep upper trough and low pressure to the west.
Associated with the low pressure offshore, a warm front is lifting northward over the Pacific Northwest this morning bringing a relatively narrow band of light to occasionally moderate rain and snow to the Olympics and central/north Cascades. Temperatures are borderline in the mountain passes, but easterly flow will keep much of this precipitation in the form of snow in spite of anticipated warming aloft during the late morning hours. By noon, most precipitation will have lifted north into Canada.
During the early afternoon hours on Wednesday, the associated cold front will bring rain to the Olympics and by the late afternoon hours the frontal rain band will begin to bring rain and high elevation snow to the west slopes of the Cascades with the cold front crossing the Cascade crest just before midnight. The frontal passage will usher in a cooler air mass on a SW flow and snow levels should drop to pass levels by Thursday morning.
On Thursday, The large low pressure center will begin to fill (become less deep) as it sits and spins near the southern end of the Queen Charlotte Islands with an associated trough 500 miles offshore of our coastline. A moist SW flow should continue on Thursday and Thursday night as the trough digs southward and slightly east. Significant snowfall is expected and particularly high totals can be expected in areas favored by the SW flow (Baker and Rainier) with lower water amounts expected in the Cascade Passes.
Weather Forecast
Olympics
Wednesday | Decreasing light rain and snow early in the morning. Increasing moderate to occasionally heavy rain during the afternoon. Moderate SSE crest-level winds becoming strong during the afternoon hours. |
Wednesday Night | Moderate to heavy rain and high elevation snow becoming decreasing light to moderate showers after midnight Decreasing moderate winds. Moderate to heavy rain and snow in the evening hours becoming light to moderate showers. Heaviest Baker and Mt. Rainier. Lighter in the passes. Moderate SW crest-level winds. |
Thursday | Light snow showers. |
Thursday Night | Light snow showers. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Wednesday | Clouds thickening in the afternoon with rain and high elevation snow arriving by evening. Increasing generally SSE crest-level winds becoming moderate late in the day. |
Wednesday Night | Increasing moderate to heavy rain and snow during the evening hours becoming light to moderate showers after midnight. Precipitation favors Mt Baker and to a lesser extent Mt. Rainier with less precipitation falling in the passes. Decreasing moderate crest-level SW winds. |
Thursday | Light to moderate rain or snow showers decreasing. Heaviest Mt. Rainier and Mt. Baker. |
Thursday Night | Light to moderate snow showers. Heaviest Mt. Rainier and Mt. Baker. |
East Slopes of the Washington Cascades
Wednesday | Clouds thickening in the late afternoon. Increasing generally SSE winds. |
Wednesday Night | Increasing moderate rain and snow during the evening hours becoming light showers after midnight. Decreasing moderate crest-level SW winds. |
Thursday | Light rain or snow showers decreasing, possibly dry in the central part. |
Thursday Night | Light snow showers. |
Mt. Hood
Wednesday | Cloudy skies. Moderate southerly winds developing late. |
Wednesday Night | Light to moderate rain and high elevation snow becoming moderate to heavy before changing to light to moderate showers by morning with lowering snow levels. |
Thursday | Light to moderate rain and snow showers becoming light by afternoon. |
Thursday Night | Light snow showers. |
Issued: 2:33 PM PST Wednesday, January 17, 2018
Snow/Freezing Level (ft)
Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
---|---|---|---|---|---|---|---|---|---|
Wednesday Afternoon | Snow Level * | 6000' | 6500' | 4000' | ' | ' | 6500' | ' | 8000' |
Wednesday Night | Snow Level * | 4000' | 4000' | 4000' | ' | ' | 4500' | ' | 5500' |
Thursday Morning | Snow Level | 3000' | 3000' | 3000' | ' | ' | 3000' | ' | 3500' |
Thursday Afternoon | Snow Level * | 2500' | 2500' | 2500' | ' | ' | 2500' | ' | 3000' |
Thursday Night | Snow Level * | 2500' | 2500' | 2000' | ' | ' | 2000' | ' | 2500' |
Hurricane Ridge | Elevation |
---|---|
Wednesday Afternoon |
Snow Level 6000' (Easterly Flow *) |
Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
Thursday Morning |
Snow Level 3000' |
Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
Thursday Night |
Snow Level 2500' (Easterly Flow *) |
Mt. Baker | Elevation |
---|---|
Wednesday Afternoon |
Snow Level 6500' (Easterly Flow *) |
Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
Thursday Morning |
Snow Level 3000' |
Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
Thursday Night |
Snow Level 2500' (Easterly Flow *) |
Washington Pass | Elevation |
---|---|
Wednesday Afternoon |
Snow Level 4000' (Easterly Flow *) |
Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
Thursday Morning |
Snow Level 3000' |
Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
Thursday Night |
Snow Level 2000' (Easterly Flow *) |
Leavenworth | Elevation |
---|---|
Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
Wednesday Night |
Snow Level ' (Easterly Flow *) |
Thursday Morning |
Snow Level ' |
Thursday Afternoon |
Snow Level ' (Easterly Flow *) |
Thursday Night |
Snow Level ' (Easterly Flow *) |
Stevens Pass | Elevation |
---|---|
Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
Wednesday Night |
Snow Level ' (Easterly Flow *) |
Thursday Morning |
Snow Level ' |
Thursday Afternoon |
Snow Level ' (Easterly Flow *) |
Thursday Night |
Snow Level ' (Easterly Flow *) |
Snoqualmie Pass | Elevation |
---|---|
Wednesday Afternoon |
Snow Level 6500' (Easterly Flow *) |
Wednesday Night |
Snow Level 4500' (Easterly Flow *) |
Thursday Morning |
Snow Level 3000' |
Thursday Afternoon |
Snow Level 2500' (Easterly Flow *) |
Thursday Night |
Snow Level 2000' (Easterly Flow *) |
Mt. Rainier & Crystal | Elevation |
---|---|
Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
Wednesday Night |
Snow Level ' (Easterly Flow *) |
Thursday Morning |
Snow Level ' |
Thursday Afternoon |
Snow Level ' (Easterly Flow *) |
Thursday Night |
Snow Level ' (Easterly Flow *) |
Mt. Hood | Elevation |
---|---|
Wednesday Afternoon |
Snow Level 8000' (Easterly Flow *) |
Wednesday Night |
Snow Level 5500' (Easterly Flow *) |
Thursday Morning |
Snow Level 3500' |
Thursday Afternoon |
Snow Level 3000' (Easterly Flow *) |
Thursday Night |
Snow Level 2500' (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
Thursday | Thursday | |
---|---|---|
Hurricane Ridge | 0 - 1.00 | 0 - 0.75 |
Mt Baker Ski Area | 2.00 - 2.50 | 0 - 2.00 |
Washington Pass | 0 - 0.75 | 0.25 - 0.50 |
Stevens Pass | 0.25 - 0.50 | 0.25 - 0.50 |
Snoqualmie Pass | 0 - 0.50 | 0.25 - 0.50 |
Mission Ridge | 0.25 - 0.50 | LT 0.10 |
Crystal Mt | 0 - 1.00 | 0.50 - 0.75 |
Paradise | 0 - 1.00 | 0.75 - 1.00 |
White Pass | 0 - 0.50 | 0 - 0.50 |
Mt Hood Meadows | 0.50 - 0.75 | 0.25 - 0.50 |
Timberline | 0 - 0.75 | 0 - 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: 2:33 PM PST Wednesday, January 17, 2018
Free Winds at 5000' (mph)
Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
---|---|---|---|---|---|
Wednesday Afternoon | SSE 45 - 65 | SE 35 - 50 | SE 30 - 40 | --- - | S 30 - 40 |
Wednesday Night | SSW 30 - 45 | SSW 30 - 40 | SW 20 - 30 | --- - | SW 25 - 35 |
Thursday Morning | SSW 25 - 35 | SSW 20 - 30 | SW 25 - 35 | --- - | SW 25 - 35 |
Thursday Afternoon | SSW 25 - 35 | SSW 20 - 30 | SW 20 - 30 | --- - | SW 20 - 30 |
Thursday Night | SSW 20 - 30 | S 15 - 25 | SW 15 - 25 | --- - | SW 15 - 25 |
Hurricane Ridge | Elevation |
---|---|
Wednesday Afternoon | SSE 45 - 65 |
Wednesday Night | SSW 30 - 45 |
Thursday Morning | SSW 25 - 35 |
Thursday Afternoon | SSW 25 - 35 |
Thursday Night | SSW 20 - 30 |
Mt. Baker | Elevation |
---|---|
Wednesday Afternoon | SE 35 - 50 |
Wednesday Night | SSW 30 - 40 |
Thursday Morning | SSW 20 - 30 |
Thursday Afternoon | SSW 20 - 30 |
Thursday Night | S 15 - 25 |
Stevens and Snoqualmie Pass | Elevation |
---|---|
Wednesday Afternoon | SE 30 - 40 |
Wednesday Night | SW 20 - 30 |
Thursday Morning | SW 25 - 35 |
Thursday Afternoon | SW 20 - 30 |
Thursday Night | SW 15 - 25 |
Mt. Rainier | Elevation |
---|---|
Wednesday Afternoon | --- - |
Wednesday Night | --- - |
Thursday Morning | --- - |
Thursday Afternoon | --- - |
Thursday Night | --- - |
Mt. Hood | Elevation |
---|---|
Wednesday Afternoon | S 30 - 40 |
Wednesday Night | SW 25 - 35 |
Thursday Morning | SW 25 - 35 |
Thursday Afternoon | SW 20 - 30 |
Thursday Night | SW 15 - 25 |
Hurricane Ridge | Direction - Speed |
---|---|
Wednesday Afternoon | SSE 45 - 65 |
Wednesday Night | SSW 30 - 45 |
Thursday Morning | SSW 25 - 35 |
Thursday Afternoon | SSW 25 - 35 |
Thursday Night | SSW 20 - 30 |
Mt. Baker | Direction - Speed |
---|---|
Wednesday Afternoon | SE 35 - 50 |
Wednesday Night | SSW 30 - 40 |
Thursday Morning | SSW 20 - 30 |
Thursday Afternoon | SSW 20 - 30 |
Thursday Night | S 15 - 25 |
Stevens and Snoqualmie Pass | Direction - Speed |
---|---|
Wednesday Afternoon | SE 30 - 40 |
Wednesday Night | SW 20 - 30 |
Thursday Morning | SW 25 - 35 |
Thursday Afternoon | SW 20 - 30 |
Thursday Night | SW 15 - 25 |
Mt. Rainier | Direction - Speed |
---|---|
Wednesday Afternoon | --- - |
Wednesday Night | --- - |
Thursday Morning | --- - |
Thursday Afternoon | --- - |
Thursday Night | --- - |
Mt. Hood | Direction - Speed |
---|---|
Wednesday Afternoon | S 30 - 40 |
Wednesday Night | SW 25 - 35 |
Thursday Morning | SW 25 - 35 |
Thursday Afternoon | SW 20 - 30 |
Thursday Night | SW 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 | |
---|---|---|---|---|---|
Wednesday Afternoon | SSW 70 - 90 | SSW 50 - 70 | SSW 50 - 70 | --- - | SSW 65 - 85 |
Wednesday Night | SSW 60 - 80 | SSW 40 - 60 | SSW 50 - 70 | --- - | SSW 65 - 85 |
Thursday Morning | SW 35 - 50 | SW 40 - 60 | SW 40 - 60 | --- - | SW 45 - 65 |
Thursday Afternoon | SW 30 - 40 | SW 40 - 60 | SW 30 - 40 | --- - | SW 30 - 40 |
Thursday Night | SW 30 - 40 | SW 30 - 40 | SW 30 - 40 | --- - | SW 30 - 40 |
Mt. Baker | Direction - Speed |
---|---|
Wednesday Afternoon | SSW 70 - 90 |
Wednesday Night | SSW 60 - 80 |
Thursday Morning | SW 35 - 50 |
Thursday Afternoon | SW 30 - 40 |
Thursday Night | SW 30 - 40 |
Washington Pass | Direction - Speed |
---|---|
Wednesday Afternoon | SSW 50 - 70 |
Wednesday Night | SSW 40 - 60 |
Thursday Morning | SW 40 - 60 |
Thursday Afternoon | SW 40 - 60 |
Thursday Night | SW 30 - 40 |
Stevens and Snoqualmie Pass | Direction - Speed |
---|---|
Wednesday Afternoon | SSW 50 - 70 |
Wednesday Night | SSW 50 - 70 |
Thursday Morning | SW 40 - 60 |
Thursday Afternoon | SW 30 - 40 |
Thursday Night | SW 30 - 40 |
Mt. Rainier | Direction - Speed |
---|---|
Wednesday Afternoon | --- - |
Wednesday Night | --- - |
Thursday Morning | --- - |
Thursday Afternoon | --- - |
Thursday Night | --- - |
Mt. Hood | Direction - Speed |
---|---|
Wednesday Afternoon | SSW 65 - 85 |
Wednesday Night | SSW 65 - 85 |
Thursday Morning | SW 45 - 65 |
Thursday Afternoon | SW 30 - 40 |
Thursday Night | SW 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.
Issued: 2:33 PM PST Wednesday, January 17, 2018
Extended Weather Synopsis for Thursday night through Thursday
On Friday, the trough digs south to California with its axis over the entire west coast. The weakening upper and surface low pressure centers continue to spin over the Queen Charlotte Islands bringing onshore split flow before dissipating Friday night as a well-organized system moves in from the west and replaces the original low center by early Sunday morning. Onshore westerly flow continues for the duration of the period until the surface front associated with the new low approaches Saturday night or Sunday morning, bringing a brief shift to southerly winds, brief slight warming, and then a return to westerly flow in its wake.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
---|---|---|---|---|---|
Friday | Snow Level | 2000' - 3000' | 2000' - 3000' | 2000' - 3000' | |
Friday Night | Snow Level | 2000' - 3000' | 2000' - 3000' | 1500' - 2500' | |
Saturday | Snow Level | 2000' - 3000' | 2000' - 3000' | 2000' - 3000' | |
Saturday Night | Snow Level | 2000' - 4000' | 2000' - 4000' | 2000' - 4000' | * |
Sunday | Snow Level | 2000' - 4000' | 1500' - 3500' | 2000' - 4000' |
Mt. Baker | Elevation |
---|---|
Friday |
Snow Level 2000' - 3000' |
Friday Night |
Snow Level 2000' - 3000' |
Saturday |
Snow Level 2000' - 3000' |
Saturday Night |
Snow Level 2000' - 4000' (Easterly Flow *) |
Sunday |
Snow Level 2000' - 4000' |
Snoqualmie Pass | Elevation |
---|---|
Friday |
Snow Level 2000' - 3000' |
Friday Night |
Snow Level 2000' - 3000' |
Saturday |
Snow Level 2000' - 3000' |
Saturday Night |
Snow Level 2000' - 4000' (Easterly Flow *) |
Sunday |
Snow Level 1500' - 3500' |
Mt. Hood | Elevation |
---|---|
Friday |
Snow Level 2000' - 3000' |
Friday Night |
Snow Level 1500' - 2500' |
Saturday |
Snow Level 2000' - 3000' |
Saturday Night |
Snow Level 2000' - 4000' (Easterly Flow *) |
Sunday |
Snow Level 2000' - 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.
Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Previous forecast from Jan 17, 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.