Issued: 2:11 PM PST Wednesday, November 17, 2021
by Robert Hahn

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Weather Synopsis

An upper-level ridge of high pressure continues to dominate the weather through Wednesday night. Moderate E winds in the early evening should ease as the surface high weakens and shifts east.  A low and associated shortwave trough move into the region Thursday through Friday. High cloud cover and light southerly winds aloft represent the precursors and should help moderate overnight temperatures slightly. Temperatures will not be quite as chilly as Tuesday night for most locations. The low moves into the Oregon near-shore waters on Thursday, bringing lowering clouds followed by light rain snow to NW Washington as a fading warm front spreads a band of precipitation onshore. Periods of light rain and snow should fill into other areas during the afternoon. Light E flow at low levels likely keeps Snoqualmie Pass just cool enough for all snow, but a mix with rain is possible Thursday afternoon.

Thursday night, the low spins just off the Oregon Coast, and the upper trough moves onshore, bringing the strongest precipitation of the storm. Expect moderate rain and snow to locations from around Snoqualmie Pass southward. Snowfall should be the most significant on the southern Cascade Volcanoes. Southerly ridgeline winds will also peak in the moderate range for these same locations. Rain and snow decrease from north to south Thursday night through Friday, but linger much of the day in the southern Cascades Volcanoes. Expect partly cloudy skies developing late in the day for the Mt. Baker and Hurricane Ridge areas.

Storm total snowfall of 8-14" is likely for Paradise while Mt. Hood can expect 8-12" above 6000 ft. Snoqualmie pass could pick up 1-5" of snow from this event with marginal temperatures at pass level limiting snowfall amounts.

Weather Forecast

Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
Use dropdown to select your zone
Wednesday Night High and increasing mid-level clouds.
Thursday Periods of light rain and snow develop by mid-morning and increase in the afternoon.
Wednesday Night High and increasing mid-level clouds.
Thursday Periods of light rain and snow develop in the morning and continue through the afternoon.
Wednesday Night High and increasing mid-level clouds.
Thursday Increasing chances of light rain or snow showers.
Wednesday Night High clouds.
Thursday Cloudy in the morning with periods of light rain or snow developing around noon.
Wednesday Night High and increasing mid-level clouds. Decreasing light to moderate E winds becoming light at the Pass.
Thursday Increasing chances of light rain or snow showers. Light E winds at the Pass.
Wednesday Night High and increasing mid-level clouds. Decreasing moderate E winds becoming light.
Thursday Increasing chances of light rain or snow showers. Precipitation is likely to stay snow at pass level. Light E winds at the Pass.
Wednesday Night High and increasing mid-level clouds.
Thursday Cloudy in the morning with light snow at times during the afternoon.
Wednesday Night High cloud cover.
Thursday Cloudy in the morning with light snow likely developing late in the day.
Wednesday Night High cloud cover.
Thursday Cloudy in the morning with light snow possible late in the day.
Wednesday Night High cloud cover.
Thursday Cloudy in the morning with light rain or snow developing in the afternoon.

Precipitation (in)

Wednesday Night Thursday Thursday Night Friday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0 0.25 - 0.50 0.25 0
Mt Baker Ski Area 0 0.25 LT 0.10 0
Mt. Loop - Barlow Pass 0 LT 0.25 0.25 - 0.50 LT 0.10
Stevens Pass 0 LT 0.25 0.25 - 0.50 LT 0.10
Snoqualmie Pass 0 LT 0.10 0.50 LT 0.10
Crystal Mt 0 LT 0.10 0.50 LT 0.10
Paradise 0 LT 0.25 1.00 LT 0.25
White Pass 0 LT 0.10 0.75 LT 0.25
Washington Pass 0 LT 0.25 LT 0.25 0
Mission Ridge 0 LT 0.10 0.25 LT 0.10
Salmon la Sac - Gallagher Head 0 LT 0.10 0.25 - 0.50 LT 0.10
Tieton River - Darland Mt. 0 LT 0.25 0.50 - 0.75 LT 0.25
Mt Hood Meadows 0 LT 0.10 0.75 0.25 - 0.50
Timberline 0 LT 0.10 0.75 -1.00 0.25
Hurricane Ridge Precipitation (in)
Wednesday Night 0
Thursday 0.25 - 0.50
Thursday Night 0.25
Friday 0
Mt Baker Ski Area Precipitation (in)
Wednesday Night 0
Thursday 0.25
Thursday Night LT 0.10
Friday 0
Mt. Loop - Barlow Pass Precipitation (in)
Wednesday Night 0
Thursday LT 0.25
Thursday Night 0.25 - 0.50
Friday LT 0.10
Stevens Pass Precipitation (in)
Wednesday Night 0
Thursday LT 0.25
Thursday Night 0.25 - 0.50
Friday LT 0.10
Snoqualmie Pass Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.50
Friday LT 0.10
Crystal Mt Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.50
Friday LT 0.10
Paradise Precipitation (in)
Wednesday Night 0
Thursday LT 0.25
Thursday Night 1.00
Friday LT 0.25
White Pass Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.75
Friday LT 0.25
Washington Pass Precipitation (in)
Wednesday Night 0
Thursday LT 0.25
Thursday Night LT 0.25
Friday 0
Mission Ridge Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.25
Friday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.25 - 0.50
Friday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Wednesday Night 0
Thursday LT 0.25
Thursday Night 0.50 - 0.75
Friday LT 0.25
Mt Hood Meadows Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.75
Friday 0.25 - 0.50
Timberline Precipitation (in)
Wednesday Night 0
Thursday LT 0.10
Thursday Night 0.75 -1.00
Friday 0.25

Snow Level (ft)

Wednesday Evening* Wednesday Night* Thursday Morning* Thursday Afternoon* Thursday Evening* Thursday Night* Friday Morning Friday Afternoon
Olympics 5500' 5500' 3500' 3000' 2500' 2500' 3000' 4000'
West North 4000' 3000' 3000' 3000' 3000' 2500' 2500' 4000'
West Central 3000' 2500' 2500' 3500' 3000' 2500' 2500' 3500'
West South 3000' 3000' 3500' 4500' 4000' 4000' 4000' 4000'
Stevens Pass 2500' 2000' 2000' 3000' 3000' 2000' 2000' 3500'
Snoqualmie Pass 2500' 2500' 2500' 3000' 3000' 2500' 3000' 3500'
East North 1500' 1000' 500' 2500' 2000' 1500' 1500' 4000'
East Central 2000' 2000' 2000' 3000' 2500' 2000' 2500' 4000'
East South 2000' 2000' 3000' 5000' 4000' 4000' 3500' 4000'
Mt. Hood 4500' 5000' 4500' 6500' 6000' 5500' 5500' 4500'
Olympics Elevation
Wednesday Evening* 5500'
Wednesday Night* 5500'
Thursday Morning* 3500'
Thursday Afternoon* 3000'
Thursday Evening* 2500'
Thursday Night* 2500'
Friday Morning 3000'
Friday Afternoon 4000'
West North Elevation
Wednesday Evening* 4000'
Wednesday Night* 3000'
Thursday Morning* 3000'
Thursday Afternoon* 3000'
Thursday Evening* 3000'
Thursday Night* 2500'
Friday Morning 2500'
Friday Afternoon 4000'
West Central Elevation
Wednesday Evening* 3000'
Wednesday Night* 2500'
Thursday Morning* 2500'
Thursday Afternoon* 3500'
Thursday Evening* 3000'
Thursday Night* 2500'
Friday Morning 2500'
Friday Afternoon 3500'
West South Elevation
Wednesday Evening* 3000'
Wednesday Night* 3000'
Thursday Morning* 3500'
Thursday Afternoon* 4500'
Thursday Evening* 4000'
Thursday Night* 4000'
Friday Morning 4000'
Friday Afternoon 4000'
Stevens Pass Elevation
Wednesday Evening* 2500'
Wednesday Night* 2000'
Thursday Morning* 2000'
Thursday Afternoon* 3000'
Thursday Evening* 3000'
Thursday Night* 2000'
Friday Morning 2000'
Friday Afternoon 3500'
Snoqualmie Pass Elevation
Wednesday Evening* 2500'
Wednesday Night* 2500'
Thursday Morning* 2500'
Thursday Afternoon* 3000'
Thursday Evening* 3000'
Thursday Night* 2500'
Friday Morning 3000'
Friday Afternoon 3500'
East North Elevation
Wednesday Evening* 1500'
Wednesday Night* 1000'
Thursday Morning* 500'
Thursday Afternoon* 2500'
Thursday Evening* 2000'
Thursday Night* 1500'
Friday Morning 1500'
Friday Afternoon 4000'
East Central Elevation
Wednesday Evening* 2000'
Wednesday Night* 2000'
Thursday Morning* 2000'
Thursday Afternoon* 3000'
Thursday Evening* 2500'
Thursday Night* 2000'
Friday Morning 2500'
Friday Afternoon 4000'
East South Elevation
Wednesday Evening* 2000'
Wednesday Night* 2000'
Thursday Morning* 3000'
Thursday Afternoon* 5000'
Thursday Evening* 4000'
Thursday Night* 4000'
Friday Morning 3500'
Friday Afternoon 4000'
Mt. Hood Elevation
Wednesday Evening* 4500'
Wednesday Night* 5000'
Thursday Morning* 4500'
Thursday Afternoon* 6500'
Thursday Evening* 6000'
Thursday Night* 5500'
Friday Morning 5500'
Friday Afternoon 4500'

5000' Temperatures (°F)

Wednesday Night Thursday
Max / Min Max / Min
Olympics 34 / 29 30 / 27
West North 29 / 27 29 / 24
West Central 28 / 23 30 / 26
West South 31 / 24 35 / 30
Stevens Pass 23 / 19 30 / 24
Snoqualmie Pass 26 / 20 32 / 25
East North 19 / 16 27 / 20
East Central 24 / 18 30 / 24
East South 26 / 19 37 / 28
Mt. Hood 34 / 26 41 / 34
Olympics 5000' Temperature Forecast
(Max / Min)
Wednesday Night 34 / 29
Thursday 30 / 27
West North 5000' Temperature Forecast
(Max / Min)
Wednesday Night 29 / 27
Thursday 29 / 24
West Central 5000' Temperature Forecast
(Max / Min)
Wednesday Night 28 / 23
Thursday 30 / 26
West South 5000' Temperature Forecast
(Max / Min)
Wednesday Night 31 / 24
Thursday 35 / 30
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Wednesday Night 23 / 19
Thursday 30 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Wednesday Night 26 / 20
Thursday 32 / 25
East North 5000' Temperature Forecast
(Max / Min)
Wednesday Night 19 / 16
Thursday 27 / 20
East Central 5000' Temperature Forecast
(Max / Min)
Wednesday Night 24 / 18
Thursday 30 / 24
East South 5000' Temperature Forecast
(Max / Min)
Wednesday Night 26 / 19
Thursday 37 / 28
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Wednesday Night 34 / 26
Thursday 41 / 34

Ridgeline Winds (mph)

Wednesday Evening Wednesday Night Thursday Morning Thursday Afternoon
Olympics S 5-15 SSW 5-15 SSW 5-15 SSW 5-15
West North SSE 5-15 S 5-15 SSW 10-20 SSW 5-15
West Central ESE 15-25 SE 5-15 S 5-15 SSW 5-15
West South SSE 5-15 SSW 5-15 SSW 5-15 SW 5-15
Stevens Pass ESE 10-20 SSE 5-15 SSW 0-10 SW 0-10
Snoqualmie Pass ESE 15-25 SE 5-15 S 0-10 SW 0-10
East North SE 10-20 S 5-15 SSW 5-15 WSW 5-15
East Central SSE 10-20 SSW 10-20 SW 10-20 WSW 10-20
East South SSE 10-20 SSW 0-10 SW 5-15 SW 5-15
Mt. Hood SSW 10-20 SW 15-25 SW 20-30 SW 20-30
Olympics Ridgeline Winds (mph)
Wednesday Evening S 5-15
Wednesday Night SSW 5-15
Thursday Morning SSW 5-15
Thursday Afternoon SSW 5-15
West North Ridgeline Winds (mph)
Wednesday Evening SSE 5-15
Wednesday Night S 5-15
Thursday Morning SSW 10-20
Thursday Afternoon SSW 5-15
West Central Ridgeline Winds (mph)
Wednesday Evening ESE 15-25
Wednesday Night SE 5-15
Thursday Morning S 5-15
Thursday Afternoon SSW 5-15
West South Ridgeline Winds (mph)
Wednesday Evening SSE 5-15
Wednesday Night SSW 5-15
Thursday Morning SSW 5-15
Thursday Afternoon SW 5-15
Stevens Pass Ridgeline Winds (mph)
Wednesday Evening ESE 10-20
Wednesday Night SSE 5-15
Thursday Morning SSW 0-10
Thursday Afternoon SW 0-10
Snoqualmie Pass Ridgeline Winds (mph)
Wednesday Evening ESE 15-25
Wednesday Night SE 5-15
Thursday Morning S 0-10
Thursday Afternoon SW 0-10
East North Ridgeline Winds (mph)
Wednesday Evening SE 10-20
Wednesday Night S 5-15
Thursday Morning SSW 5-15
Thursday Afternoon WSW 5-15
East Central Ridgeline Winds (mph)
Wednesday Evening SSE 10-20
Wednesday Night SSW 10-20
Thursday Morning SW 10-20
Thursday Afternoon WSW 10-20
East South Ridgeline Winds (mph)
Wednesday Evening SSE 10-20
Wednesday Night SSW 0-10
Thursday Morning SW 5-15
Thursday Afternoon SW 5-15
Mt. Hood Ridgeline Winds (mph)
Wednesday Evening SSW 10-20
Wednesday Night SW 15-25
Thursday Morning SW 20-30
Thursday Afternoon SW 20-30

Extended Weather Synopsis

In the wake of Thursday/Friday's weak system, a broad ridge of high pressure offshore will permit limited moisture to spill into our region on a mild WNW flow. A subtle shortwave feature on Saturday may bring very light rain/snow showers at times. Expect high clouds and mostly fair weather on Sunday with rising snow levels a milder system brings moisture into British Columbia. The associated cold front should arrive early next week.

Extended Snow Level (ft)

Friday Night Saturday Saturday Night Sunday *
West North 2500' 2000' 3000' 4000'
Snoqualmie Pass 3000' 2500' 3000' 3000'
Mt. Hood 4000' 3000' 5500' 8000'
West North Elevation
Friday Night 2500'
Saturday 2000'
Saturday Night 3000'
Sunday * 4000'
Snoqualmie Pass Elevation
Friday Night 3000'
Saturday 2500'
Saturday Night 3000'
Sunday * 3000'
Mt. Hood Elevation
Friday Night 4000'
Saturday 3000'
Saturday Night 5500'
Sunday * 8000'

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Previous forecast from Nov 16, 2021

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.

The 5000’ temperature forecast does not imply a trend over the 12 hr period and only represents the max and min temperatures within a 12 hr period in the zone. The 6-hr snow level forecast, the forecast discussion, and weather forecast sections may add detail regarding temperature trends.

The snow level forecast represents the general snow level over a 6 hr time period. Freezing levels are forecast when precipitation is not expected.

*Easterly or offshore flow is highlighted with an asterisk when we expect relatively cool east winds in the major Cascade Passes. Easterly flow will often lead to temperature inversions and is a key variable for forecasting precipitation type in the Cascade Passes. Strong easterly flow events can affect terrain on a more regional scale.

Ridgeline winds are the average wind speed and direction over a 6 hr time period.

The wind forecast represents an elevation range instead of a single elevation slice. The elevation range overlaps with the near and above treeline elevation bands in the avalanche forecast and differs per zone.

Wind direction indicates the direction the wind originates or comes from on the 16-point compass rose.

Water Equivalent (WE) is the liquid water equivalent of all precipitation types; rain, snow, ice pellets, etc., forecast to the hundredth of an inch at specific locations. To use WE as a proxy for snowfall amounts, start with a snow to water ratio of 10:1 (10 inches of snow = 1 inch WE). Temperatures at or near freezing will generally have a lower ratio (heavy wet snow) and very cold temperatures can have a much higher ratio (dry fluffy snow).

The label LT, is shorthand for ‘less than’.

Updated Mountain Weather Zone Name Changes – December 2020