Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Thursday & Friday
A deep upper trough will slowly spin south off the Oregon Coast today. This should translate to more clouds and shower activity closer to the low near Mt. Hood. The air mass is marginally unstable, so a general increase in afternoon cover near or above Cascade crest level is expected over the Washington Cascades. Isolated showers may pop-up in the afternoon especially in the Crystal/Mt. Rainier/Chinook Pass vicinity. Any shower activity that does form will dissipate overnight. Freezing levels will climb to 5000 feet or more feet today, but snow levels will quickly plummet during any shower activity.
The low will migrate inland on Friday with the same cool and slightly unstable air mass over our region. A notch more cloud buildup and afternoon light shower activity can be expected on Friday with again a better chance of showers for Mt. Hood and the SW Cascades including Crystal/Mt. Rainier/Chinook Pass. Again, any shower activity will wane in the evening excluding Mt. Hood, where showers will linger longer.
Weather Forecast
Olympics
| Thursday | Mostly clear becoming partly cloudy in the afternoon. Isolated afternoon showers. |
| Thursday Night | Partly to mostly clear. |
| Friday | Mostly clear becoming mostly cloudy in the afternoon with isolated showers. |
| Friday Night | Slight chance of an evening shower. Partly to mostly cloudy. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Thursday | Mostly clear becoming partly cloudy north and central Cascades and partly to mostly cloudy south Cascades in the afternoon. Isolated afternoon showers from Crystal Mountain and southward. |
| Thursday Night | Partly to mostly clear. |
| Friday | Mostly clear becoming partly to mostly cloudy north Cascades in the afternoon with isolated showers. Partly to mostly clear becoming mostly cloudy central and south Cascades in the afternoon with isolated showers. |
| Friday Night | Slight chance of an evening shower. Partly to mostly cloudy. |
East Slopes of the Washington Cascades
| Thursday | Mostly clear becoming partly cloudy northeast and central-east Cascades and partly to mostly cloudy southeast Cascades in the afternoon. Isolated afternoon showers southeast Cascades near the Cascade crest. |
| Thursday Night | Partly to mostly clear. |
| Friday | Mostly clear becoming partly to mostly cloudy in the afternoon with isolated showers near the Cascade crest. |
| Friday Night | Partly to mostly cloudy. |
Mt. Hood
| Thursday | Mostly cloudy becoming cloudy in the afternoon with light rain and snow showers. |
| Thursday Night | Mostly cloudy with light rain and snow showers. |
| Friday | Mostly cloudy becoming cloudy in the afternoon with light rain and snow showers. |
| Friday Night | Mostly cloudy with light rain and snow showers. |
Issued: 5:02 PM PDT Thursday, March 15, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Thursday Afternoon | Snow Level | 3000' | 3500' | 4000' | ' | ' | 3500' | ' | 3500' |
| Thursday Night | Snow Level | 3000' | 2000' | 1500' | ' | ' | 2500' | ' | 2500' |
| Friday Morning | Snow Level | 3000' | 2000' | 1500' | ' | ' | 2500' | ' | 2500' |
| Friday Afternoon | Snow Level | 3500' | 4500' | 4500' | ' | ' | 4500' | ' | 3500' |
| Friday Night | Snow Level | 3000' | 2500' | 2000' | ' | ' | 2500' | ' | 3000' |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 3000' |
| Thursday Night |
Snow Level 3000' |
| Friday Morning |
Snow Level 3000' |
| Friday Afternoon |
Snow Level 3500' |
| Friday Night |
Snow Level 3000' |
| Mt. Baker | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 3500' |
| Thursday Night |
Snow Level 2000' |
| Friday Morning |
Snow Level 2000' |
| Friday Afternoon |
Snow Level 4500' |
| Friday Night |
Snow Level 2500' |
| Washington Pass | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 4000' |
| Thursday Night |
Snow Level 1500' |
| Friday Morning |
Snow Level 1500' |
| Friday Afternoon |
Snow Level 4500' |
| Friday Night |
Snow Level 2000' |
| Leavenworth | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level ' |
| Thursday Night |
Snow Level ' |
| Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level ' |
| Thursday Night |
Snow Level ' |
| Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 3500' |
| Thursday Night |
Snow Level 2500' |
| Friday Morning |
Snow Level 2500' |
| Friday Afternoon |
Snow Level 4500' |
| Friday Night |
Snow Level 2500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level ' |
| Thursday Night |
Snow Level ' |
| Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 3500' |
| Thursday Night |
Snow Level 2500' |
| Friday Morning |
Snow Level 2500' |
| Friday Afternoon |
Snow Level 3500' |
| Friday Night |
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
| Friday | Friday | |
|---|---|---|
| Hurricane Ridge | LT 0.10 | LT 0.10 |
| Mt Baker Ski Area | LT 0.10 | LT 0.10 |
| Washington Pass | LT 0.10 | LT 0.10 |
| Stevens Pass | LT 0.10 | LT 0.10 |
| Snoqualmie Pass | LT 0.10 | LT 0.10 |
| Mission Ridge | LT 0.10 | LT 0.10 |
| Crystal Mt | LT 0.10 | LT 0.25 |
| Paradise | LT 0.10 | LT 0.25 |
| White Pass | LT 0.10 | LT 0.10 |
| Mt Hood Meadows | LT 0.25 | LT 0.25 |
| Timberline | LT 0.25 | LT 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: 5:02 PM PDT Thursday, March 15, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Thursday Afternoon | E 0 - 10 | N 0 - 10 | E 0 - 10 | --- - | E 5 - 15 |
| Thursday Night | NE 0 - 10 | NE 0 - 10 | E 0 - 10 | --- - | NE 5 - 15 |
| Friday Morning | NE 0 - 10 | NE 0 - 10 | E 0 - 10 | --- - | NE 5 - 15 |
| Friday Afternoon | N 0 - 10 | VAR 0 - 10 | NW 0 - 10 | --- - | NW 0 - 10 |
| Friday Night | W 0 - 10 | W 0 - 10 | W 0 - 10 | --- - | WNW 5 - 15 |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Afternoon | E 0 - 10 |
| Thursday Night | NE 0 - 10 |
| Friday Morning | NE 0 - 10 |
| Friday Afternoon | N 0 - 10 |
| Friday Night | W 0 - 10 |
| Mt. Baker | Elevation |
|---|---|
| Thursday Afternoon | N 0 - 10 |
| Thursday Night | NE 0 - 10 |
| Friday Morning | NE 0 - 10 |
| Friday Afternoon | VAR 0 - 10 |
| Friday Night | W 0 - 10 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Thursday Afternoon | E 0 - 10 |
| Thursday Night | E 0 - 10 |
| Friday Morning | E 0 - 10 |
| Friday Afternoon | NW 0 - 10 |
| Friday Night | W 0 - 10 |
| Mt. Rainier | Elevation |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Thursday Afternoon | E 5 - 15 |
| Thursday Night | NE 5 - 15 |
| Friday Morning | NE 5 - 15 |
| Friday Afternoon | NW 0 - 10 |
| Friday Night | WNW 5 - 15 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Thursday Afternoon | E 0 - 10 |
| Thursday Night | NE 0 - 10 |
| Friday Morning | NE 0 - 10 |
| Friday Afternoon | N 0 - 10 |
| Friday Night | W 0 - 10 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Afternoon | N 0 - 10 |
| Thursday Night | NE 0 - 10 |
| Friday Morning | NE 0 - 10 |
| Friday Afternoon | VAR 0 - 10 |
| Friday Night | W 0 - 10 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | E 0 - 10 |
| Thursday Night | E 0 - 10 |
| Friday Morning | E 0 - 10 |
| Friday Afternoon | NW 0 - 10 |
| Friday Night | W 0 - 10 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Afternoon | E 5 - 15 |
| Thursday Night | NE 5 - 15 |
| Friday Morning | NE 5 - 15 |
| Friday Afternoon | NW 0 - 10 |
| Friday Night | WNW 5 - 15 |
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 | |
|---|---|---|---|---|---|
| Thursday Afternoon | E 0 - 10 | E 0 - 10 | SE 10 - 20 | --- - | SSE 10 - 20 |
| Thursday Night | NE 0 - 10 | E 0 - 10 | ESE 10 - 20 | --- - | E 15 - 25 |
| Friday Morning | NE 0 - 10 | VAR 0 - 10 | E 10 - 20 | --- - | E 15 - 25 |
| Friday Afternoon | VAR 0 - 10 | VAR 0 - 10 | NE 5 - 15 | --- - | NE 5 - 15 |
| Friday Night | NW 0 - 10 | NW 0 - 10 | NW 5 - 15 | --- - | NW 5 - 15 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Afternoon | E 0 - 10 |
| Thursday Night | NE 0 - 10 |
| Friday Morning | NE 0 - 10 |
| Friday Afternoon | VAR 0 - 10 |
| Friday Night | NW 0 - 10 |
| Washington Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | E 0 - 10 |
| Thursday Night | E 0 - 10 |
| Friday Morning | VAR 0 - 10 |
| Friday Afternoon | VAR 0 - 10 |
| Friday Night | NW 0 - 10 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | SE 10 - 20 |
| Thursday Night | ESE 10 - 20 |
| Friday Morning | E 10 - 20 |
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NW 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night | --- - |
| Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Afternoon | SSE 10 - 20 |
| Thursday Night | E 15 - 25 |
| Friday Morning | E 15 - 25 |
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NW 5 - 15 |
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: 5:02 PM PDT Thursday, March 15, 2018
Extended Weather Synopsis for Friday night through Friday
The deep and broad upper level trough will continue to slowly move into the Intermountain West over the weekend, but it's broad reach will still include the Pacific Northwest through this period. It's hard to pick out any specific forcing to drive shower activity other than daytime heating over the short or long term. Onshore flow on Saturday should increase low level moisture and cloud cover for the Olympics, West slopes of the Cascades and Mt. Hood.
On Sunday, we'll have to watch for an upper level feature which could bring more organized showers into the south Cascades and Mt. Hood but the forecast will remain more generic until those details iron out. Freezing/Snow levels will remain cool over the weekend.
The broad trough should shift eastward on Monday, allowing a relative decrease in afternoon cloud cover and shower activity along with a slight warming trend.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Saturday | Snow Level | 3000' - 4000' | 3500' - 4500' | 3000' - 4000' | |
| Saturday Night | Snow Level | 1500' - 2500' | 1500' - 2500' | 1500' - 2500' | |
| Sunday | Snow Level | 3000' - 4000' | 2500' - 3500' | 2500' - 3500' | |
| Sunday Night | Snow Level | 1500' - 2500' | 1500' - 2500' | 2000' - 3000' | |
| Monday | Snow Level | 4000' - 5000' | 4000' - 5000' | 4000' - 5000' |
| Mt. Baker | Elevation |
|---|---|
| Saturday |
Snow Level 3000' - 4000' |
| Saturday Night |
Snow Level 1500' - 2500' |
| Sunday |
Snow Level 3000' - 4000' |
| Sunday Night |
Snow Level 1500' - 2500' |
| Monday |
Snow Level 4000' - 5000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday |
Snow Level 3500' - 4500' |
| Saturday Night |
Snow Level 1500' - 2500' |
| Sunday |
Snow Level 2500' - 3500' |
| Sunday Night |
Snow Level 1500' - 2500' |
| Monday |
Snow Level 4000' - 5000' |
| Mt. Hood | Elevation |
|---|---|
| Saturday |
Snow Level 3000' - 4000' |
| Saturday Night |
Snow Level 1500' - 2500' |
| Sunday |
Snow Level 2500' - 3500' |
| Sunday Night |
Snow Level 2000' - 3000' |
| Monday |
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 Mar 15, 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.
5 PM Update: Corrected Typo