Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Sunday & Tuesday
Afternoon update: No major changes, some slight increases to north Cascade winds at 9000 ft.
Previous Discussion: The Pacific Northwest will be in cold northerly flow aloft as the Pacific upper level ridge stays parked near 145W and the longwave upper level trough associated with Saturday's storm system digs south and east over the next 48 hours.
Weak surface low pressure SE of the Olympics and off the Washington Coast will continue to stream snow showers into the SW Cascades and Mt. Hood through this afternoon, with the heaviest accumulations likely from Mt. Rainier and south, and especially at Mt. Hood. Northerly winds from Fraser Outflow is picking up moisture across the Strait of Juan de Fuca and delivering some light upslope snow to the north slopes of the Olympics. Upslope snow showers seen against the northeast Cascades should shift south during the day and deliver some light snowfall particularly to the Mission Ridge area. Drier and much colder air moving in from the north should allow some clearing for the north Cascades in the afternoon. High pressure over the interior of British Columbia will help drive down the coldest air mass seen this season over our area.
The weather will be fair Monday and Monday night, with some clouds likely trapped below ridgecrest specific to the central-west and southwest slopes of the Cascades and Mt. Hood, and clearer skies expected elsewhere.
Weather Forecast
Olympics
| Sunday | Light to occasionally moderate snow showers becoming mostly cloudy with scattered light snow showers in the afternoon. Colder. |
| Sunday Night | Partly cloudy. Cold. |
| Monday | Mostly sunny. Cold. |
| Monday Night | Partly cloudy. Cold. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Sunday | Light snow showers this morning, occasionally moderate Mt. Rainier to White Pass. Light showers becoming scattered in the afternoon with partial clearing in the north Cascades. Colder. |
| Sunday Night | Partly to mostly cloudy with isolated light snow showers ending late tonight. Cold. |
| Monday | Mostly clear north. Partly cloudy central and south Cascades. Cold. |
| Monday Night | Partly cloudy. Cold. |
East Slopes of the Washington Cascades
| Sunday | Light snow showers NE Cascades becoming scattered in the afternoon with partial clearing. Light to occasionally moderate snow showers developing central-east and southeast Cascades late morning. Colder. |
| Sunday Night | Partly to mostly cloudy with isolated light snow showers ending late tonight. Cold. |
| Monday | Mostly clear north. Partly cloudy central and south Cascades near the crest. Cold. |
| Monday Night | Partly to mostly clear. Cold. |
Mt. Hood
| Sunday | Light to moderate snow showers, tapering slightly in the afternoon. Winds decreasing in the afternoon. Colder. |
| Sunday Night | Mostly cloudy with scattered light snow showers ending late tonight. Cold. |
| Monday | Partly cloudy. Cold. |
| Monday Night | Partly cloudy. Cold. |
Issued: 3:06 PM PST Sunday, February 18, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Sunday | Snow Level | 0' | 0' | 0' | ' | ' | 0' | ' | 500' |
| Sunday Night | Snow Level | 0' | 0' | 0' | ' | ' | 0' | ' | 0' |
| Monday | Freezing Level | 0' | 0' | 0' | ' | ' | 0' | ' | 0' |
| Monday Night | Freezing Level | 0' | 0' | 0' | ' | ' | 0' | ' | 0' |
| Hurricane Ridge | Elevation |
|---|---|
| Sunday |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Monday |
Freezing Level 0' |
| Monday Night |
Freezing Level 0' |
| Mt. Baker | Elevation |
|---|---|
| Sunday |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Monday |
Freezing Level 0' |
| Monday Night |
Freezing Level 0' |
| Washington Pass | Elevation |
|---|---|
| Sunday |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Monday |
Freezing Level 0' |
| Monday Night |
Freezing Level 0' |
| Leavenworth | Elevation |
|---|---|
| Sunday |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Monday |
Freezing Level ' |
| Monday Night |
Freezing Level ' |
| Stevens Pass | Elevation |
|---|---|
| Sunday |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Monday |
Freezing Level ' |
| Monday Night |
Freezing Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Sunday |
Snow Level 0' |
| Sunday Night |
Snow Level 0' |
| Monday |
Freezing Level 0' |
| Monday Night |
Freezing Level 0' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Sunday |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Monday |
Freezing Level ' |
| Monday Night |
Freezing Level ' |
| Mt. Hood | Elevation |
|---|---|
| Sunday |
Snow Level 500' |
| Sunday Night |
Snow Level 0' |
| Monday |
Freezing Level 0' |
| Monday Night |
Freezing Level 0' |
* 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 0.10 |
| Mt Baker Ski Area | LT 0.10 | LT 0.10 |
| Washington Pass | LT 0.25 | LT 0.10 |
| Stevens Pass | LT 0.10 | LT 0.10 |
| Snoqualmie Pass | LT 0.25 | LT 0.10 |
| Mission Ridge | LT 0.25 | LT 0.10 |
| Crystal Mt | LT 0.25 | LT 0.10 |
| Paradise | 0 - 0.50 | LT 0.10 |
| White Pass | 0 - 0.50 | LT 0.10 |
| Mt Hood Meadows | 0 - 1.00 | LT 0.10 |
| Timberline | 1.00 - 1.50 | LT 0.10 |
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: 3:06 PM PST Sunday, February 18, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Sunday Afternoon | NNE 15 - 25 | NE 15 - 25 | NW 5 - 15 | --- - | SW 10 - 20 |
| Sunday Night | NE 15 - 25 | NE 15 - 25 | NE 0 - 10 | --- - | NE 5 - 15 |
| Monday Morning | NE 5 - 15 | NE 10 - 20 | VAR 0 - 10 | --- - | E 5 - 15 |
| Monday Afternoon | N 0 - 10 | NE 5 - 15 | NW 0 - 10 | --- - | VAR 0 - 10 |
| Monday Night | W 0 - 10 | W 0 - 10 | W 0 - 10 | --- - | W 0 - 10 |
| Hurricane Ridge | Elevation |
|---|---|
| Sunday Afternoon | NNE 15 - 25 |
| Sunday Night | NE 15 - 25 |
| Monday Morning | NE 5 - 15 |
| Monday Afternoon | N 0 - 10 |
| Monday Night | W 0 - 10 |
| Mt. Baker | Elevation |
|---|---|
| Sunday Afternoon | NE 15 - 25 |
| Sunday Night | NE 15 - 25 |
| Monday Morning | NE 10 - 20 |
| Monday Afternoon | NE 5 - 15 |
| Monday Night | W 0 - 10 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Sunday Afternoon | NW 5 - 15 |
| Sunday Night | NE 0 - 10 |
| Monday Morning | VAR 0 - 10 |
| Monday Afternoon | NW 0 - 10 |
| Monday Night | W 0 - 10 |
| Mt. Rainier | Elevation |
|---|---|
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Monday Morning | --- - |
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Sunday Afternoon | SW 10 - 20 |
| Sunday Night | NE 5 - 15 |
| Monday Morning | E 5 - 15 |
| Monday Afternoon | VAR 0 - 10 |
| Monday Night | W 0 - 10 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Sunday Afternoon | NNE 15 - 25 |
| Sunday Night | NE 15 - 25 |
| Monday Morning | NE 5 - 15 |
| Monday Afternoon | N 0 - 10 |
| Monday Night | W 0 - 10 |
| Mt. Baker | Direction - Speed |
|---|---|
| Sunday Afternoon | NE 15 - 25 |
| Sunday Night | NE 15 - 25 |
| Monday Morning | NE 10 - 20 |
| Monday Afternoon | NE 5 - 15 |
| Monday Night | W 0 - 10 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Sunday Afternoon | NW 5 - 15 |
| Sunday Night | NE 0 - 10 |
| Monday Morning | VAR 0 - 10 |
| Monday Afternoon | NW 0 - 10 |
| Monday Night | W 0 - 10 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Monday Morning | --- - |
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Sunday Afternoon | SW 10 - 20 |
| Sunday Night | NE 5 - 15 |
| Monday Morning | E 5 - 15 |
| Monday Afternoon | VAR 0 - 10 |
| Monday Night | W 0 - 10 |
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 | |
|---|---|---|---|---|---|
| Sunday Afternoon | NE 15 - 25 | NE 15 - 30 | NE 0 - 10 | --- - | WSW 25 - 35 |
| Sunday Night | NE 15 - 30 | NE 15 - 30 | NW 5 - 15 | --- - | NW 5 - 15 |
| Monday Morning | NE 20 - 30 | NE 15 - 30 | NNW 10 - 20 | --- - | NW 10 - 20 |
| Monday Afternoon | N 20 - 30 | N 15 - 25 | NNW 15 - 25 | --- - | NW 10 - 20 |
| Monday Night | NW 10 - 20 | NW 10 - 20 | NW 15 - 25 | --- - | NW 15 - 25 |
| Mt. Baker | Direction - Speed |
|---|---|
| Sunday Afternoon | NE 15 - 25 |
| Sunday Night | NE 15 - 30 |
| Monday Morning | NE 20 - 30 |
| Monday Afternoon | N 20 - 30 |
| Monday Night | NW 10 - 20 |
| Washington Pass | Direction - Speed |
|---|---|
| Sunday Afternoon | NE 15 - 30 |
| Sunday Night | NE 15 - 30 |
| Monday Morning | NE 15 - 30 |
| Monday Afternoon | N 15 - 25 |
| Monday Night | NW 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Sunday Afternoon | NE 0 - 10 |
| Sunday Night | NW 5 - 15 |
| Monday Morning | NNW 10 - 20 |
| Monday Afternoon | NNW 15 - 25 |
| Monday Night | NW 15 - 25 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Monday Morning | --- - |
| Monday Afternoon | --- - |
| Monday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Sunday Afternoon | WSW 25 - 35 |
| Sunday Night | NW 5 - 15 |
| Monday Morning | NW 10 - 20 |
| Monday Afternoon | NW 10 - 20 |
| Monday Night | NW 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: 3:06 PM PST Sunday, February 18, 2018
Extended Weather Synopsis for Tuesday night through Tuesday
Little change will be seen over the extended as the Pacific Northwest sits in N-NW flow aloft between the mean upper level ridge parked offshore near 145W and the upper level trough over the intermountain West. Temperatures will remain cold throughout this period. Due to poor forecast model agreement, the series of weak weather systems expected midweek will either glance or pass over the area Tuesday through Thursday. Light snow is possible at times but significant accumulations are not expected.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Tuesday | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Tuesday Night | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Wednesday | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Wednesday Night | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' | |
| Thursday | Snow Level | 0' - 0' | 0' - 0' | 0' - 0' |
| Mt. Baker | Elevation |
|---|---|
| Tuesday |
Snow Level 0' - 0' |
| Tuesday Night |
Snow Level 0' - 0' |
| Wednesday |
Snow Level 0' - 0' |
| Wednesday Night |
Snow Level 0' - 0' |
| Thursday |
Snow Level 0' - 0' |
| Snoqualmie Pass | Elevation |
|---|---|
| Tuesday |
Snow Level 0' - 0' |
| Tuesday Night |
Snow Level 0' - 0' |
| Wednesday |
Snow Level 0' - 0' |
| Wednesday Night |
Snow Level 0' - 0' |
| Thursday |
Snow Level 0' - 0' |
| Mt. Hood | Elevation |
|---|---|
| Tuesday |
Snow Level 0' - 0' |
| Tuesday Night |
Snow Level 0' - 0' |
| Wednesday |
Snow Level 0' - 0' |
| Wednesday Night |
Snow Level 0' - 0' |
| Thursday |
Snow Level 0' - 0' |
* 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 Feb 18, 2018
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