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 & Monday
On Tuesday, a high pressure wedge sits over the region bringing another day of mostly sunny, spring-like weather, with light winds. Strong march sunshine and mostly clear weather has elevated temperatures above freezing at many NWAC low and mid-elevation sites. The exception is in the north where cloud-cover is keeping temperatures cooler. Popcorn cumulus are dotting the central Cascades. No precipitation is expected.
A deep trough with an upper low slides S-SE offfshore of the Alaskan panhandle and a closed low drifting NE well off the California Coast will be the major players for the remainder of the week.
Tuesday night, the ridge disappears as the two systems flatten out the wedge and the deep trough subsumes the closed low.
On Wednesday, the subsumed feature with surface low centers moves NE toward our region ahead of the trough, bringing moisture into our region and periods of gradually increasing light rain/snow mainly for the Mt. Hood region and South Cascades during daylight hours.
On Wednesday night, the N-S elongated trough centered just west of the Queen Charlottes, ushers the old cutoff subsumed low toward our region on a S-SW flow.
Temperatures will remain warmer than seasonal norms throughout the short-term forecast period.
Weather Forecast
Olympics
| Tuesday | A mix of clouds and sun. |
| Tuesday Night | Fair with high cloud cover over most areas keeping surface temperatures relatively warm. |
| Wednesday | High clouds with some sun breaks in the morning, then clouds increasing in the afternoon. |
| Wednesday Night | Periods of light rain and snow, with heaviest precipitation in the South Cascades. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Tuesday | Mostly sunny southern part with a mix of clouds and sun northern part. |
| Tuesday Night | Fair with high cloud cover over most areas keeping surface temperatures relatively warm. |
| Wednesday | Mainly high clouds in the morning with clouds thickening and lowering in the afternoon. Very light rain and snow developing in the afternoon. |
| Wednesday Night | Light to moderate rain and snow. |
East Slopes of the Washington Cascades
| Tuesday | Mostly sunny southern part with a mix of clouds and sun northern part. |
| Tuesday Night | Fair with high cloud cover over most areas keeping surface temperatures relatively warm. |
| Wednesday | Mainly high clouds in the morning with clouds thickening and lowering in the afternoon. Very light rain and snow possible near the crest during the afternoon. |
| Wednesday Night | Light to moderate rain and snow. |
Mt. Hood
| Tuesday | Mostly sunny. |
| Tuesday Night | Fair with high cloud cover over most areas keeping surface temperatures relatively warm. |
| Wednesday | Periods of light rain and snow, increasing in intensity toward evening. |
| Wednesday Night | Moderate rain and snow. |
Issued: 3:01 PM PDT Tuesday, March 20, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Tuesday Afternoon | Freezing Level | 4000' | 4500' | 5500' | ' | ' | 5500' | ' | 6000' |
| Tuesday Night | Freezing Level * | 3500' | 3500' | 3500' | ' | ' | 3500' | ' | 5000' |
| Wednesday Morning | Snow Level * | 3500' | 4000' | 4500' | ' | ' | 4000' | ' | 4500' |
| Wednesday Afternoon | Snow Level * | 4000' | 4000' | 4500' | ' | ' | 5000' | ' | 5500' |
| Wednesday Night | Snow Level * | 4000' | 4500' | 4000' | ' | ' | 5000' | ' | 5500' |
| Hurricane Ridge | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level 4000' |
| Tuesday Night |
Freezing Level 3500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 3500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 4000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
| Mt. Baker | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level 4500' |
| Tuesday Night |
Freezing Level 3500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 4000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 4500' (Easterly Flow *) |
| Washington Pass | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level 5500' |
| Tuesday Night |
Freezing Level 3500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 4500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 4500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 4000' (Easterly Flow *) |
| Leavenworth | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level ' |
| Tuesday Night |
Freezing Level ' (Easterly Flow *) |
| Wednesday Morning |
Snow Level ' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Wednesday Night |
Snow Level ' (Easterly Flow *) |
| Stevens Pass | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level ' |
| Tuesday Night |
Freezing Level ' (Easterly Flow *) |
| Wednesday Morning |
Snow Level ' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Wednesday Night |
Snow Level ' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level 5500' |
| Tuesday Night |
Freezing Level 3500' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 4000' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 5000' (Easterly Flow *) |
| Wednesday Night |
Snow Level 5000' (Easterly Flow *) |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level ' |
| Tuesday Night |
Freezing Level ' (Easterly Flow *) |
| Wednesday Morning |
Snow Level ' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level ' (Easterly Flow *) |
| Wednesday Night |
Snow Level ' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Tuesday Afternoon |
Freezing Level 6000' |
| Tuesday Night |
Freezing Level 5000' (Easterly Flow *) |
| Wednesday Morning |
Snow Level 4500' (Easterly Flow *) |
| Wednesday Afternoon |
Snow Level 5500' (Easterly Flow *) |
| Wednesday Night |
Snow Level 5500' (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
| Monday | Monday | |
|---|---|---|
| Hurricane Ridge | LT 0.10 | LT 0.25 |
| Mt Baker Ski Area | LT 0.10 | LT 0.25 |
| Washington Pass | LT 0.10 | LT 0.25 |
| Stevens Pass | LT 0.10 | LT 0.25 |
| Snoqualmie Pass | LT 0.10 | LT 0.25 |
| Mission Ridge | LT 0.10 | LT 0.25 |
| Crystal Mt | LT 0.10 | 0.25 - 0.50 |
| Paradise | LT 0.10 | 0 - 0.50 |
| White Pass | LT 0.10 | LT 0.25 |
| Mt Hood Meadows | LT 0.10 | 0.50 - 0.75 |
| Timberline | LT 0.10 | 0 - 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: 3:01 PM PDT Tuesday, March 20, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Tuesday Morning | WSW 5 - 15 | SW 5 - 15 | W 0 - 10 | --- - | W 0 - 10 |
| Tuesday Afternoon | W 5 - 15 | WSW 5 - 15 | W 5 - 15 | --- - | W 0 - 10 |
| Tuesday Night | S 5 - 15 | SE 5 - 15 | SE 5 - 15 | --- - | SSE 0 - 10 |
| Wednesday Morning | SSE 5 - 15 | SE 5 - 15 | ESE 5 - 15 | --- - | SSE 15 - 25 |
| Wednesday Afternoon | SSE 10 - 20 | SE 10 - 20 | ESE 15 - 25 | --- - | SE 10 - 20 |
| Wednesday Night | SE 25 - 35 | E 20 - 30 | ESE 25 - 35 | --- - | ESE 20 - 30 |
| Hurricane Ridge | Elevation |
|---|---|
| Tuesday Morning | WSW 5 - 15 |
| Tuesday Afternoon | W 5 - 15 |
| Tuesday Night | S 5 - 15 |
| Wednesday Morning | SSE 5 - 15 |
| Wednesday Afternoon | SSE 10 - 20 |
| Wednesday Night | SE 25 - 35 |
| Mt. Baker | Elevation |
|---|---|
| Tuesday Morning | SW 5 - 15 |
| Tuesday Afternoon | WSW 5 - 15 |
| Tuesday Night | SE 5 - 15 |
| Wednesday Morning | SE 5 - 15 |
| Wednesday Afternoon | SE 10 - 20 |
| Wednesday Night | E 20 - 30 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Tuesday Morning | W 0 - 10 |
| Tuesday Afternoon | W 5 - 15 |
| Tuesday Night | SE 5 - 15 |
| Wednesday Morning | ESE 5 - 15 |
| Wednesday Afternoon | ESE 15 - 25 |
| Wednesday Night | ESE 25 - 35 |
| Mt. Rainier | Elevation |
|---|---|
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Wednesday Morning | --- - |
| Wednesday Afternoon | --- - |
| Wednesday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Tuesday Morning | W 0 - 10 |
| Tuesday Afternoon | W 0 - 10 |
| Tuesday Night | SSE 0 - 10 |
| Wednesday Morning | SSE 15 - 25 |
| Wednesday Afternoon | SE 10 - 20 |
| Wednesday Night | ESE 20 - 30 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Tuesday Morning | WSW 5 - 15 |
| Tuesday Afternoon | W 5 - 15 |
| Tuesday Night | S 5 - 15 |
| Wednesday Morning | SSE 5 - 15 |
| Wednesday Afternoon | SSE 10 - 20 |
| Wednesday Night | SE 25 - 35 |
| Mt. Baker | Direction - Speed |
|---|---|
| Tuesday Morning | SW 5 - 15 |
| Tuesday Afternoon | WSW 5 - 15 |
| Tuesday Night | SE 5 - 15 |
| Wednesday Morning | SE 5 - 15 |
| Wednesday Afternoon | SE 10 - 20 |
| Wednesday Night | E 20 - 30 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Tuesday Morning | W 0 - 10 |
| Tuesday Afternoon | W 5 - 15 |
| Tuesday Night | SE 5 - 15 |
| Wednesday Morning | ESE 5 - 15 |
| Wednesday Afternoon | ESE 15 - 25 |
| Wednesday Night | ESE 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Wednesday Morning | --- - |
| Wednesday Afternoon | --- - |
| Wednesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Tuesday Morning | W 0 - 10 |
| Tuesday Afternoon | W 0 - 10 |
| Tuesday Night | SSE 0 - 10 |
| Wednesday Morning | SSE 15 - 25 |
| Wednesday Afternoon | SE 10 - 20 |
| Wednesday Night | ESE 20 - 30 |
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 Morning | W 10 - 20 | W 10 - 20 | W 15 - 25 | --- - | WSW 5 - 15 |
| Tuesday Afternoon | WSW 10 - 20 | WSW 10 - 20 | SW 10 - 20 | --- - | S 5 - 15 |
| Tuesday Night | SSW 15 - 25 | SSW 10 - 20 | SSW 10 - 20 | --- - | SSW 20 - 30 |
| Wednesday Morning | S 20 - 30 | SSE 15 - 25 | SSE 15 - 25 | --- - | SSW 25 - 35 |
| Wednesday Afternoon | SSE 20 - 30 | SSE 20 - 30 | SSW 30 - 40 | --- - | SSW 20 - 30 |
| Wednesday Night | SSE 30 - 40 | SSE 30 - 40 | S 45 - 65 | --- - | SSE 50 - 70 |
| Mt. Baker | Direction - Speed |
|---|---|
| Tuesday Morning | W 10 - 20 |
| Tuesday Afternoon | WSW 10 - 20 |
| Tuesday Night | SSW 15 - 25 |
| Wednesday Morning | S 20 - 30 |
| Wednesday Afternoon | SSE 20 - 30 |
| Wednesday Night | SSE 30 - 40 |
| Washington Pass | Direction - Speed |
|---|---|
| Tuesday Morning | W 10 - 20 |
| Tuesday Afternoon | WSW 10 - 20 |
| Tuesday Night | SSW 10 - 20 |
| Wednesday Morning | SSE 15 - 25 |
| Wednesday Afternoon | SSE 20 - 30 |
| Wednesday Night | SSE 30 - 40 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Tuesday Morning | W 15 - 25 |
| Tuesday Afternoon | SW 10 - 20 |
| Tuesday Night | SSW 10 - 20 |
| Wednesday Morning | SSE 15 - 25 |
| Wednesday Afternoon | SSW 30 - 40 |
| Wednesday Night | S 45 - 65 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Tuesday Morning | --- - |
| Tuesday Afternoon | --- - |
| Tuesday Night | --- - |
| Wednesday Morning | --- - |
| Wednesday Afternoon | --- - |
| Wednesday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Tuesday Morning | WSW 5 - 15 |
| Tuesday Afternoon | S 5 - 15 |
| Tuesday Night | SSW 20 - 30 |
| Wednesday Morning | SSW 25 - 35 |
| Wednesday Afternoon | SSW 20 - 30 |
| Wednesday Night | SSE 50 - 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: 3:01 PM PDT Tuesday, March 20, 2018
Extended Weather Synopsis for Monday night through Monday
On Thursday, the upper trough broadens and approaches in the morning, bringing moderate S-SW winds and a period of moderate rain and snow, followed by the frontal passage and strong cooling with little wind shift and lighter rain/snow showers. A high elevation snow line will rapidly lower on Thursday afternoon.
On Thursday night through Friday, the low center continues drifting SE off Vancouver Island with chunks of energy around it and continued cooling as the cold air mass settles into place. Periods of light to occasionally moderate snow showers will continue.
Convective energy will be in place so don't be surprised to see some isolated heavier bursts of snow and even thunder snow.
On Friday night the trough will be centered over the Pacific Northwest, allowing the cold air mass to fully settle into the region as snow shower activity decreases with a surface circulation center dropping south off the Oregon Coast.
Snow shower activity will continue to decrease as a weak westerly flow continues to keep moisture over the west slopes of the Cascades.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Thursday | Snow Level | 3000' - 5000' | 3500' - 5500' | 2000' - 4000' | |
| Thursday Night | Snow Level | 0' - 1000' | 0' - 1000' | 500' - 1500' | |
| Friday | Snow Level | 0' - 2000' | 0' - 2000' | 1000' - 2000' | |
| Friday Night | Snow Level | 0' - 1000' | 0' - 1000' | 0' - 1000' | |
| Saturday | Snow Level | 1000' - 2000' | 1000' - 2000' | 1000' - 2000' |
| Mt. Baker | Elevation |
|---|---|
| Thursday |
Snow Level 3000' - 5000' |
| Thursday Night |
Snow Level 0' - 1000' |
| Friday |
Snow Level 0' - 2000' |
| Friday Night |
Snow Level 0' - 1000' |
| Saturday |
Snow Level 1000' - 2000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday |
Snow Level 3500' - 5500' |
| Thursday Night |
Snow Level 0' - 1000' |
| Friday |
Snow Level 0' - 2000' |
| Friday Night |
Snow Level 0' - 1000' |
| Saturday |
Snow Level 1000' - 2000' |
| Mt. Hood | Elevation |
|---|---|
| Thursday |
Snow Level 2000' - 4000' |
| Thursday Night |
Snow Level 500' - 1500' |
| Friday |
Snow Level 1000' - 2000' |
| Friday Night |
Snow Level 0' - 1000' |
| Saturday |
Snow Level 1000' - 2000' |
* 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 Mar 20, 2018
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