Issued: 2:25 PM PDT Sunday, May 2, 2021
by Dennis D'Amico

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

Weather Synopsis

A fair bit of stratocumulus remains trapped along the central Cascades near and west of the Cascade crest this afternoon with mountain temperatures largely in the mid-30s to mid-40s across the area. A weak Pacific frontal system will approach from the west tonight, spreading high clouds over the area. Light precipitation will start for the Olympics and northwest Cascades Monday morning and slowly spread inland during the day. Snow levels will fall to around 5000' with the onset of the light precipitation. Ridgeline winds will bump into the moderate range in the afternoon for the central/south Washington Cascades and Mt. Hood. Post-frontal showers will be light Monday night, but we may squeeze out a few inches of snow above 4500' for areas affected by a Puget Sound Convergence Zone. 

Tuesday should be a dry day with rebounding temperatures as strong upper level ridging builds offshore. However, there will be plenty of left-over low level moisture/clouds Tuesday for areas near and west of the Cascade crest including the Olympics Mountains. More consistent and widepread sunshine can be found further east and down near Mt Hood. 

This will be the last Mountain Weather Forecast of the 2020-2021 Season. Enjoy the Spring and Summer from all of us here at the Northwest Avalanche Center!  

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
Sunday Night Mostly cloudy in the evening, becoming cloudy after midnight.
Monday Cloudy with light rain and snow developing in the morning, then scattered light rain and snow showers in the afternoon.
Sunday Night Partly cloudy in the evening, becoming cloudy after midnight.
Monday Cloudy with light to occasionally moderate rain and snow developing late morning, then scattered light rain and snow showers late in the afternoon.
Sunday Night Mostly cloudy in the evening, becoming cloudy after midnight.
Monday Cloudy. Light to occasionally moderate rain and snow developing mid-day.
Sunday Night Partly cloudy in the evening, becoming mostly cloudy after midnight with increasing high clouds.
Monday Partly cloudy in the morning, then cloudy with light rain and snow developing mid-day.
Sunday Night Partly cloudy in the evening, becoming cloudy after midnight with increasing high clouds.
Monday Mostly cloudy in the morning, then cloudy with light rain and snow developing mid-day.
Sunday Night Partly cloudy in the evening, becoming cloudy after midnight with increasing high clouds.
Monday Mostly cloudy in the morning, then cloudy with light rain and snow developing mid-day.
Sunday Night Partly cloudy in the evening, then mostly cloudy with increasing high clouds after midnight.
Monday Mostly cloudy in the morning, then cloudy with light rain and snow developing mid-day.
Sunday Night Mostly clear in the evening, becoming partly cloudy after midnight with increasing high clouds.
Monday Partly cloudy in the morning, then cloudy in the afternoon. Slight chance of rain or snow in the afternoon near the Cascade crest.
Sunday Night Mostly clear in the evening, becoming partly cloudy after midnight with increasing high clouds.
Monday Partly cloudy in the morning, then cloudy in the afternoon. Slight chance of rain or snow in the afternoon near the Cascade crest.
Sunday Night Mostly clear in the evening, becoming partly cloudy after midnight with increasing high clouds.
Monday Mostly sunny in the morning, then mostly cloudy in the afternoon. Chance of rain in the afternoon.

Precipitation (in)

Sunday Night Monday Monday Night Tuesday
5 pm - 5 am 5 am - 5 pm 5 pm - 5 am 5 am - 5 pm
Hurricane Ridge 0 LT 0.10 LT 0.10 0
Mt Baker Ski Area 0 LT 0.25 LT 0.10 0
Mt. Loop - Barlow Pass 0 LT 0.10 LT 0.10 0
Stevens Pass 0 LT 0.10 LT 0.10 0
Snoqualmie Pass 0 LT 0.10 LT 0.25 0
Crystal Mt 0 LT 0.10 LT 0.10 0
Paradise 0 LT 0.10 LT 0.10 0
White Pass 0 LT 0.10 LT 0.10 0
Washington Pass 0 LT 0.10 0 0
Mission Ridge 0 0 0 0
Salmon la Sac - Gallagher Head 0 0 LT 0.10 0
Tieton River - Darland Mt. 0 0 LT 0.10 0
Mt Hood Meadows 0 0 LT 0.10 0
Timberline 0 LT 0.10 LT 0.10 0
Hurricane Ridge Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0
Mt Baker Ski Area Precipitation (in)
Sunday Night 0
Monday LT 0.25
Monday Night LT 0.10
Tuesday 0
Mt. Loop - Barlow Pass Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0
Stevens Pass Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0
Snoqualmie Pass Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.25
Tuesday 0
Crystal Mt Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0
Paradise Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0
White Pass Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0
Washington Pass Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night 0
Tuesday 0
Mission Ridge Precipitation (in)
Sunday Night 0
Monday 0
Monday Night 0
Tuesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday Night 0
Monday 0
Monday Night LT 0.10
Tuesday 0
Tieton River - Darland Mt. Precipitation (in)
Sunday Night 0
Monday 0
Monday Night LT 0.10
Tuesday 0
Mt Hood Meadows Precipitation (in)
Sunday Night 0
Monday 0
Monday Night LT 0.10
Tuesday 0
Timberline Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night LT 0.10
Tuesday 0

Snow Level (ft)

Sunday Evening Sunday Night Monday Morning Monday Afternoon Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics 5500' 5000' 5000' 5500' 5000' 4500' 5500' 6500'
West North 5500' 5000' 4500' 4500' 4500' 4500' 5000' 6000'
West Central 5500' 5000' 5000' 5000' 5000' 4500' 5500' 6500'
West South 5500' 5000' 5500' 5500' 5000' 4500' 5500' 7000'
Stevens Pass 5500' 5000' 5000' 5000' 5000' 4500' 5500' 6500'
Snoqualmie Pass 5500' 5000' 5000' 5000' 5000' 4500' 5500' 6500'
East North 5500' 5000' 5500' 5500' 5000' 4500' 5500' 7000'
East Central 6500' 6000' 6500' 5500' 5500' 4500' 6000' 7500'
East South 6500' 6000' 6500' 6000' 5500' 4500' 6000' 7500'
Mt. Hood 6500' 6000' 6500' 6000' 5500' 5000' 6000' 7500'
Olympics Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 5000'
Monday Afternoon 5500'
Monday Evening 5000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 6500'
West North Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 4500'
Monday Afternoon 4500'
Monday Evening 4500'
Monday Night 4500'
Tuesday Morning 5000'
Tuesday Afternoon 6000'
West Central Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 5000'
Monday Afternoon 5000'
Monday Evening 5000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 6500'
West South Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 5500'
Monday Afternoon 5500'
Monday Evening 5000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 7000'
Stevens Pass Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 5000'
Monday Afternoon 5000'
Monday Evening 5000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 6500'
Snoqualmie Pass Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 5000'
Monday Afternoon 5000'
Monday Evening 5000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 6500'
East North Elevation
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 5500'
Monday Afternoon 5500'
Monday Evening 5000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 7000'
East Central Elevation
Sunday Evening 6500'
Sunday Night 6000'
Monday Morning 6500'
Monday Afternoon 5500'
Monday Evening 5500'
Monday Night 4500'
Tuesday Morning 6000'
Tuesday Afternoon 7500'
East South Elevation
Sunday Evening 6500'
Sunday Night 6000'
Monday Morning 6500'
Monday Afternoon 6000'
Monday Evening 5500'
Monday Night 4500'
Tuesday Morning 6000'
Tuesday Afternoon 7500'
Mt. Hood Elevation
Sunday Evening 6500'
Sunday Night 6000'
Monday Morning 6500'
Monday Afternoon 6000'
Monday Evening 5500'
Monday Night 5000'
Tuesday Morning 6000'
Tuesday Afternoon 7500'

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 36 / 32 37 / 32
West North 37 / 31 37 / 32
West Central 36 / 31 37 / 31
West South 39 / 30 38 / 30
Stevens Pass 39 / 30 38 / 30
Snoqualmie Pass 36 / 31 38 / 31
East North 41 / 30 39 / 32
East Central 40 / 31 39 / 31
East South 41 / 32 41 / 32
Mt. Hood 40 / 32 41 / 33
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 36 / 32
Monday 5am - 5pm 37 / 32
West North 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 37 / 31
Monday 5am - 5pm 37 / 32
West Central 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 36 / 31
Monday 5am - 5pm 37 / 31
West South 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 39 / 30
Monday 5am - 5pm 38 / 30
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 39 / 30
Monday 5am - 5pm 38 / 30
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 36 / 31
Monday 5am - 5pm 38 / 31
East North 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 41 / 30
Monday 5am - 5pm 39 / 32
East Central 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 40 / 31
Monday 5am - 5pm 39 / 31
East South 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 41 / 32
Monday 5am - 5pm 41 / 32
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday 5pm - 5am 40 / 32
Monday 5am - 5pm 41 / 33

Ridgeline Winds (mph)

Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics SW 0-10 SW 5-15 WSW 10-20 W 5-15
West North SW 0-10 SW 0-10 SW 5-15 SSW 10-20
West Central W 0-10 W 0-10 W 5-15 W 10-20
West South NW 0-10 W 5-15 W 5-15 WNW 15-25
Stevens Pass WNW 5-15 W 5-15 WNW 5-15 W 10-20
Snoqualmie Pass WNW 5-15 WNW 5-15 WNW 10-20 WNW 15-25
East North WNW 5-15 SW 0-10 SW 5-15 W 10-20
East Central WNW 5-15 W 5-15 W 10-20 WNW 15-25
East South WNW 5-15 W 0-10 W 5-15 WNW 10-20
Mt. Hood WSW 10-20 WNW 15-25 WNW 10-20 W 15-25
Olympics Ridgeline Winds (mph)
Sunday Evening SW 0-10
Sunday Night SW 5-15
Monday Morning WSW 10-20
Monday Afternoon W 5-15
West North Ridgeline Winds (mph)
Sunday Evening SW 0-10
Sunday Night SW 0-10
Monday Morning SW 5-15
Monday Afternoon SSW 10-20
West Central Ridgeline Winds (mph)
Sunday Evening W 0-10
Sunday Night W 0-10
Monday Morning W 5-15
Monday Afternoon W 10-20
West South Ridgeline Winds (mph)
Sunday Evening NW 0-10
Sunday Night W 5-15
Monday Morning W 5-15
Monday Afternoon WNW 15-25
Stevens Pass Ridgeline Winds (mph)
Sunday Evening WNW 5-15
Sunday Night W 5-15
Monday Morning WNW 5-15
Monday Afternoon W 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Evening WNW 5-15
Sunday Night WNW 5-15
Monday Morning WNW 10-20
Monday Afternoon WNW 15-25
East North Ridgeline Winds (mph)
Sunday Evening WNW 5-15
Sunday Night SW 0-10
Monday Morning SW 5-15
Monday Afternoon W 10-20
East Central Ridgeline Winds (mph)
Sunday Evening WNW 5-15
Sunday Night W 5-15
Monday Morning W 10-20
Monday Afternoon WNW 15-25
East South Ridgeline Winds (mph)
Sunday Evening WNW 5-15
Sunday Night W 0-10
Monday Morning W 5-15
Monday Afternoon WNW 10-20
Mt. Hood Ridgeline Winds (mph)
Sunday Evening WSW 10-20
Sunday Night WNW 15-25
Monday Morning WNW 10-20
Monday Afternoon W 15-25

Extended Weather Synopsis

The ridge amplifies further on Wednesday as it passes inland. This should be the warmest day this week with freezing levels around 9000' in the north and 12,000' ft in the south. High clouds may increase in the afternoon in advance of the next weather system. 

After a warm Wednesday night, a developing frontal system off the Oregon coast swings northward during the day. While precipitation amounts do not look very impressive on Thursday, this system will open the door to cooler unsettled weather with potentially stronger weather systems late next week. 

Extended Snow Level (ft)

Tuesday Night Wednesday Wednesday Night Thursday
West North 6500' 8500' 10000' 7000'
Snoqualmie Pass 8000' 9500' 11000' 6500'
Mt. Hood 9000' 12000' 12000' 6500'
West North Elevation
Tuesday Night 6500'
Wednesday 8500'
Wednesday Night 10000'
Thursday 7000'
Snoqualmie Pass Elevation
Tuesday Night 8000'
Wednesday 9500'
Wednesday Night 11000'
Thursday 6500'
Mt. Hood Elevation
Tuesday Night 9000'
Wednesday 12000'
Wednesday Night 12000'
Thursday 6500'

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

Previous forecast from May 1, 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