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 & Tuesday
A vertically stacked low pressure system off the southern British Columbia coast will continue the unsettled weather pattern for the Pacific Northwest over the short term. An upper level shortwave lifted north over the area Wednesday night, resulting in modest amounts of precipitation with new snow above 4000-5000 feet along both the east slopes and west slopes of the Cascades. With a cool unstable air mass overhead, look for increasing shower activity this afternoon over the Cascades. The air mass is marginally unstable such that an isolated thunderstorm can't be ruled out this afternoon. Shower activity should wane overnight with the loss of day-time heating although showers will be the heaviest and linger longest in the Mt. Baker area overnight.
The story on Friday will be similar with the same low pressure system nearly stationary off of Vancouver Island, however the air mass will be slightly cooler. Once again, look for shower coverage and intensity to increase in the afternoon/early evening especially for the west slopes of the Cascades including Mt. Hood. Sunbreaks may be most plentiful in the late morning through mid-day. After an upper level shortwave passes through Friday morning, onshore flow should increase, forming a convergence zone potentially in the Stevens Pass-Mountain Loop Highway area. Shower activity should once again ease Friday night.
Weather Forecast
Olympics
| Thursday Afternoon - Thursday Evening |
Mostly cloudy with light to occasionally moderate rain and snow showers. Afternoon sunbreaks possible. Slight chance of a thunderstorm. |
| Thursday Night - Friday Morning |
Mostly cloudy with scattered light rain and snow showers. |
| Friday Afternoon - Friday Evening |
Mostly cloudy with light rain to occasionally moderate rain and snow showers. Mid-day to afternoon sunbreaks possible. Slight chance of a thunderstorm. |
| Friday Night |
Partly to mostly cloudy with scattered light rain and snow showers diminishing overnight. |
Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
| Thursday Afternoon - Thursday Evening |
Mostly cloudy with light to occasionally moderate rain and snow showers. Afternoon sunbreaks possible. Slight chance of a thunderstorm. |
| Thursday Night - Friday Morning |
Mostly cloudy with scattered light rain and snow showers except occasionally moderate Mt. Baker area overnight. |
| Friday Afternoon - Friday Evening |
Mostly cloudy with light rain to occasionally moderate rain and snow showers. Mid-day to afternoon sunbreaks possible. Slight chance of a thunderstorm in the afternoon and evening. Locally heavier accumulations possible near a convergence zone Mountain Loop Highway area. |
| Friday Night |
Partly to mostly cloudy with scattered light rain and snow showers diminishing overnight. |
East slopes of the Washington Cascades
| Thursday Mid-day - Thursday Evening |
Partly to mostly cloudy with light to occasionally moderate rain and snow showers, heaviest showers near the Cascade crest. Slight chance of a thunderstorm. |
| Thursday Night - Friday Morning |
Partly cloudy with isolated light rain and snow showers. |
| Friday Afternoon - Friday Evening |
Partly to mostly cloudy with light rain to occasionally moderate rain and snow showers especially near the Cascade crest. Mid-day to afternoon sunbreaks possible. Slight chance of a thunderstorm. |
| Friday Night |
Partly cloudy with scattered light rain and snow showers diminishing overnight. |
Mt. Hood Area
| Thursday Afternoon - Thursday Evening |
Mostly cloudy with light to occasionally moderate rain and snow showers. Afternoon sunbreaks possible. Slight chance of a thunderstorm. |
| Thursday Night - Friday Morning |
Mostly cloudy with scattered light rain and snow showers. |
| Friday Afternoon - Friday Evening |
Mostly cloudy with light rain to occasionally moderate rain and snow showers. Afternoon sunbreaks possible. Slight chance of a thunderstorm. |
| Friday Night |
Partly to mostly cloudy with scattered light rain and snow showers diminishing overnight. |
Issued: 3:18 PM PDT Thursday, April 13, 2017
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 | 5000' | 4500' | 5000' | ' | ' | 4500' | ' | 5000' |
| Thursday Night - Friday Morning | Snow Level | 2500' | 2500' | 2000' | ' | ' | 2500' | ' | 2500' |
| Friday Afternoon | Snow Level | 3500' | 3500' | 4000' | ' | ' | 3500' | ' | 4000' |
| Friday Night | Snow Level | 2500' | 2500' | 2000' | ' | ' | 2500' | ' | 2500' |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Night - Friday Morning |
Snow Level 2500' |
| Friday Afternoon |
Snow Level 3500' |
| Friday Night |
Snow Level 2500' |
| Mt. Baker | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 4500' |
| Thursday Night - Friday Morning |
Snow Level 2500' |
| Friday Afternoon |
Snow Level 3500' |
| Friday Night |
Snow Level 2500' |
| Washington Pass | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Night - Friday Morning |
Snow Level 2000' |
| Friday Afternoon |
Snow Level 4000' |
| Friday Night |
Snow Level 2000' |
| Leavenworth | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level ' |
| Thursday Night - Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level ' |
| Thursday Night - Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 4500' |
| Thursday Night - Friday Morning |
Snow Level 2500' |
| Friday Afternoon |
Snow Level 3500' |
| Friday Night |
Snow Level 2500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level ' |
| Thursday Night - Friday Morning |
Snow Level ' |
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Thursday Afternoon |
Snow Level 5000' |
| Thursday Night - Friday Morning |
Snow Level 2500' |
| Friday Afternoon |
Snow Level 4000' |
| Friday Night |
Snow Level 2500' |
* 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
| Tuesday | Tuesday | |
|---|---|---|
| Hurricane Ridge | LT 0.25 | LT 0.25 |
| Mt Baker Ski Area | 0.75 - 1.00 | 0.25 - 0.50 |
| Washington Pass | 0.25 - 0.50 | LT 0.25 |
| Stevens Pass | 0 - 0.50 | 0.50 - 0.75 |
| Snoqualmie Pass | 0.25 - 0.50 | 0.50 - 0.75 |
| Mission Ridge | LT 0.10 | LT 0.10 |
| Crystal Mt | LT 0.25 | 0.25 - 0.50 |
| Paradise | 0.50 - 0.75 | 0 - 0.75 |
| White Pass | 0.25 - 0.50 | 0 - 0.50 |
| Mt Hood Meadows | 0.25 - 0.50 | 0 - 0.50 |
| Timberline | 0 - 0.50 | 0.50 - 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: 3:18 PM PDT Thursday, April 13, 2017
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Thursday Afternoon | SW 10 - 20 | SW 15 - 30 | WSW 10 - 20 | --- - | WSW 10 - 20 |
| Thursday Night - Friday Morning | SW 5 - 15 | SW 5 - 15 | WSW 10 - 20 | --- - | WSW 15 - 25 |
| Friday Afternoon | SW 5 - 15 | SW 5 - 15 | WSW 15 - 25 | --- - | WSW 15 - 25 |
| Friday Night | SW 0 - 10 | SW 0 - 10 | WSW 10 - 20 | --- - | WSW 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Thursday Afternoon | SW 10 - 20 |
| Thursday Night - Friday Morning | SW 5 - 15 |
| Friday Afternoon | SW 5 - 15 |
| Friday Night | SW 0 - 10 |
| Mt. Baker | Elevation |
|---|---|
| Thursday Afternoon | SW 15 - 30 |
| Thursday Night - Friday Morning | SW 5 - 15 |
| Friday Afternoon | SW 5 - 15 |
| Friday Night | SW 0 - 10 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Thursday Afternoon | WSW 10 - 20 |
| Thursday Night - Friday Morning | WSW 10 - 20 |
| Friday Afternoon | WSW 15 - 25 |
| Friday Night | WSW 10 - 20 |
| Mt. Rainier | Elevation |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night - Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Thursday Afternoon | WSW 10 - 20 |
| Thursday Night - Friday Morning | WSW 15 - 25 |
| Friday Afternoon | WSW 15 - 25 |
| Friday Night | WSW 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Thursday Afternoon | SW 10 - 20 |
| Thursday Night - Friday Morning | SW 5 - 15 |
| Friday Afternoon | SW 5 - 15 |
| Friday Night | SW 0 - 10 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Afternoon | SW 15 - 30 |
| Thursday Night - Friday Morning | SW 5 - 15 |
| Friday Afternoon | SW 5 - 15 |
| Friday Night | SW 0 - 10 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | WSW 10 - 20 |
| Thursday Night - Friday Morning | WSW 10 - 20 |
| Friday Afternoon | WSW 15 - 25 |
| Friday Night | WSW 10 - 20 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night - Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Afternoon | WSW 10 - 20 |
| Thursday Night - Friday Morning | WSW 15 - 25 |
| Friday Afternoon | WSW 15 - 25 |
| Friday Night | WSW 10 - 20 |
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 | SW 20 - 30 | SW 10 - 20 | SW 20 - 30 | --- - | SW 25 - 35 |
| Thursday Night - Friday Morning | SW 10 - 20 | W 5 - 15 | W 20 - 30 | --- - | W 20 - 30 |
| Friday Afternoon | W 10 - 20 | W 10 - 20 | WSW 20 - 30 | --- - | WSW 20 - 30 |
| Friday Afternoon - Friday Night | W 10 - 20 | W 15 - 25 | W 15 - 25 | --- - | W 15 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Thursday Afternoon | SW 20 - 30 |
| Thursday Night - Friday Morning | SW 10 - 20 |
| Friday Afternoon | W 10 - 20 |
| Friday Afternoon - Friday Night | W 10 - 20 |
| Washington Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | SW 10 - 20 |
| Thursday Night - Friday Morning | W 5 - 15 |
| Friday Afternoon | W 10 - 20 |
| Friday Afternoon - Friday Night | W 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Thursday Afternoon | SW 20 - 30 |
| Thursday Night - Friday Morning | W 20 - 30 |
| Friday Afternoon | WSW 20 - 30 |
| Friday Afternoon - Friday Night | W 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Thursday Afternoon | --- - |
| Thursday Night - Friday Morning | --- - |
| Friday Afternoon | --- - |
| Friday Afternoon - Friday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Thursday Afternoon | SW 25 - 35 |
| Thursday Night - Friday Morning | W 20 - 30 |
| Friday Afternoon | WSW 20 - 30 |
| Friday Afternoon - Friday Night | W 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.
Issued: 3:18 PM PDT Thursday, April 13, 2017
Extended Weather Synopsis for Tuesday night through Tuesday
Cool and somewhat showery weather should continue on Saturday as the low pressure system offshore dissolves into weak westerly flow aloft. Weak upper level ridging passing overhead mid-day Saturday may trap low level moisture especially along the west slopes of the Cascades and prevent much of a clearing trend.
Weak zonal flow (westerly) aloft on Sunday paired with weak offshore flow (easterly) at the surface should make for a dry day with warmer freezing levels. However, mid-high level cloud cover is a bit hard to pin down at this point due to the westerly flow aloft.
Upper level ridging will build over the area Sunday night but unfortunately will be very short lived. A Pacific frontal system will spread light rain and snow into the region from the SW during the day on Monday.
Extended Weather
Olympics, Washington Cascades and Mt. Hood
Mostly cloudy with scattered light rain and snow showers Olympics and west slopes of the Cascades with occasional sunbreaks. Partly to mostly cloudy with isolated light rain and snow showers east slopes of the Cascades and Mt. Hood.
Partly to mostly cloudy with shower activity ending.
Partly cloudy. Warmer.
Becoming cloudy with light rain and snow developing for Olympics and south Cascades mid-day and spreading northward in the afternoon.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Saturday - Saturday Night | Snow Level | 3500' - 4500' | 3500' - 4500' | 4500' - 5500' | |
| Sunday - Sunday Night | Freezing Level | 5000' - 6000' | 6000' - 7000' | 6500' - 7500' | |
| Monday | Snow Level | 5000' - 6000' | 5500' - 6500' | 6000' - 7000' |
| Mt. Baker | Elevation |
|---|---|
| Saturday - Saturday Night |
Snow Level 3500' - 4500' |
| Sunday - Sunday Night |
Freezing Level 5000' - 6000' |
| Monday |
Snow Level 5000' - 6000' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday - Saturday Night |
Snow Level 3500' - 4500' |
| Sunday - Sunday Night |
Freezing Level 6000' - 7000' |
| Monday |
Snow Level 5500' - 6500' |
| Mt. Hood | Elevation |
|---|---|
| Saturday - Saturday Night |
Snow Level 4500' - 5500' |
| Sunday - Sunday Night |
Freezing Level 6500' - 7500' |
| Monday |
Snow Level 6000' - 7000' |
* 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 Apr 13, 2017
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