Issued: 2:18 PM PDT Saturday, May 1, 2021
by Robert Hahn

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

Weather Synopsis

A subtle upper-level trough moves over northern Washington through Saturday evening touching off light showers and weak convergence bands. This precipitation falls as rain below 5000 ft with a dusting of snow possible above that elevation. The trough should continue to sustain moderate ridgeline winds through major mountain gaps and along the east slopes of the Cascades which should diminish by Sunday morning.

Upper-level flow turns NW as the trough exits late Saturday night and a transient ridge builds into the region. The ridge may trap some low cloud on Sunday, providing a partly cloudy day for most areas west of the Cascade Crest, with mostly sunny skies further east. Increasing sunshine may create enough instability to build afternoon cumulus that could clouds that touch off a few showers in the Olympic mountains.

Widespread cloud cover increases Sunday night ahead of the next weak frontal system, with light rain (and snow above around 5000 ft) spreading across western Washington on Monday. By the afternoon, westerly ridgeline winds may once again increase into the moderate range for the higher mountain gaps, east slopes of the Cascades, and Mt. Hood.

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
Saturday Night Mostly clear skies with patchy low clouds.
Sunday Mostly clear in the morning, then becoming mostly cloudy with isolated showers in the afternoon.
Saturday Night Partly cloudy. A chance of isolated showers.
Sunday Partly cloudy in the morning, then becoming mostly cloudy in the afternoon.
Saturday Night Mostly cloudy with decreasing chances of light showers or weak convergence at times.
Sunday Partly to mostly cloudy skies.
Saturday Night Mostly cloudy with decreasing chances of light showers at times.
Sunday Partly cloudy.
Saturday Night Mostly cloudy with decreasing chances of light showers or weak convergence at times. Light W winds at the Pass.
Sunday Partly cloudy. Light W winds at the Pass.
Saturday Night Mostly cloudy with decreasing chances of light showers or weak convergence at times. Light W winds at the Pass.
Sunday Partly cloudy. Light W winds at the Pass.
Saturday Night Partly cloudy near the Cascades Crest, with mostly clear skies further east.
Sunday Mostly clear in the morning with broken skies scattered clouds in the afternoon.
Saturday Night Partly cloudy near the Cascades Crest, with mostly clear skies further east.
Sunday Mostly clear in the morning with broken skies scattered clouds in the afternoon.
Saturday Night Partly cloudy near the Cascades Crest, with mostly clear skies further east.
Sunday Mostly clear in the morning with broken skies scattered clouds in the afternoon.
Saturday Night Low clouds providing mostly cloudy skies.
Sunday Low clouds decreasing during the morning hours, then becoming mostly clear.

Precipitation (in)

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

Snow Level (ft)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics 5500' 5000' 4500' 5500' 6000' 6500' 5500' 5500'
West North 5500' 4500' 4000' 5500' 6000' 5500' 4500' 5000'
West Central 5000' 4000' 4000' 5000' 6000' 5500' 5500' 5500'
West South 5000' 4500' 4000' 5500' 6500' 5500' 5000' 6000'
Stevens Pass 5000' 4000' 4000' 6000' 6500' 5000' 5500' 6000'
Snoqualmie Pass 5000' 4000' 4000' 5000' 6000' 5500' 5500' 5500'
East North 6000' 4500' 4500' 7000' 7500' 5500' 5500' 7000'
East Central 6000' 5000' 4500' 6500' 7000' 6000' 6000' 7000'
East South 6500' 5000' 4500' 6500' 7500' 6000' 66000' 7500'
Mt. Hood 7000' 5500' 5000' 6000' 6500' 7000' 6500' 7000'
Olympics Elevation
Saturday Evening 5500'
Saturday Night 5000'
Sunday Morning 4500'
Sunday Afternoon 5500'
Sunday Evening 6000'
Sunday Night 6500'
Monday Morning 5500'
Monday Afternoon 5500'
West North Elevation
Saturday Evening 5500'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 5500'
Sunday Evening 6000'
Sunday Night 5500'
Monday Morning 4500'
Monday Afternoon 5000'
West Central Elevation
Saturday Evening 5000'
Saturday Night 4000'
Sunday Morning 4000'
Sunday Afternoon 5000'
Sunday Evening 6000'
Sunday Night 5500'
Monday Morning 5500'
Monday Afternoon 5500'
West South Elevation
Saturday Evening 5000'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 5500'
Sunday Evening 6500'
Sunday Night 5500'
Monday Morning 5000'
Monday Afternoon 6000'
Stevens Pass Elevation
Saturday Evening 5000'
Saturday Night 4000'
Sunday Morning 4000'
Sunday Afternoon 6000'
Sunday Evening 6500'
Sunday Night 5000'
Monday Morning 5500'
Monday Afternoon 6000'
Snoqualmie Pass Elevation
Saturday Evening 5000'
Saturday Night 4000'
Sunday Morning 4000'
Sunday Afternoon 5000'
Sunday Evening 6000'
Sunday Night 5500'
Monday Morning 5500'
Monday Afternoon 5500'
East North Elevation
Saturday Evening 6000'
Saturday Night 4500'
Sunday Morning 4500'
Sunday Afternoon 7000'
Sunday Evening 7500'
Sunday Night 5500'
Monday Morning 5500'
Monday Afternoon 7000'
East Central Elevation
Saturday Evening 6000'
Saturday Night 5000'
Sunday Morning 4500'
Sunday Afternoon 6500'
Sunday Evening 7000'
Sunday Night 6000'
Monday Morning 6000'
Monday Afternoon 7000'
East South Elevation
Saturday Evening 6500'
Saturday Night 5000'
Sunday Morning 4500'
Sunday Afternoon 6500'
Sunday Evening 7500'
Sunday Night 6000'
Monday Morning 66000'
Monday Afternoon 7500'
Mt. Hood Elevation
Saturday Evening 7000'
Saturday Night 5500'
Sunday Morning 5000'
Sunday Afternoon 6000'
Sunday Evening 6500'
Sunday Night 7000'
Monday Morning 6500'
Monday Afternoon 7000'

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 39 / 28 38 / 28
West North 34 / 28 39 / 27
West Central 34 / 26 38 / 27
West South 34 / 27 40 / 27
Stevens Pass 36 / 27 42 / 27
Snoqualmie Pass 34 / 27 38 / 27
East North 36 / 27 43 / 27
East Central 37 / 29 44 / 29
East South 38 / 28 45 / 28
Mt. Hood 39 / 30 44 / 28
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 39 / 28
Sunday 38 / 28
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 34 / 28
Sunday 39 / 27
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 34 / 26
Sunday 38 / 27
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 34 / 27
Sunday 40 / 27
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 36 / 27
Sunday 42 / 27
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 34 / 27
Sunday 38 / 27
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 36 / 27
Sunday 43 / 27
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 37 / 29
Sunday 44 / 29
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 38 / 28
Sunday 45 / 28
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 39 / 30
Sunday 44 / 28

Ridgeline Winds (mph)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics W 5-15 NE 0-10 NE 0-10 WNW 0-10
West North WNW 10-20 WNW 0-10 NW 0-10 WNW 0-10
West Central NW 5-15 NW 5-15 NNW 5-15 WNW 5-15
West South WNW 5-15 N 0-10 NNW 0-10 NW 0-10
Stevens Pass WNW 10-20 WNW 5-15 WNW 5-15 WNW 5-15
Snoqualmie Pass NW 10-20 NW 10-20 NNW 10-20 NW 5-15
East North WNW 10-20 NNW 5-15 NNW 5-15 NW 5-15
East Central WNW 20-30 NW 10-20 NNW 5-15 NNW 0-10
East South WNW 10-20 NW 10-20 NNW 5-15 NW 0-10
Mt. Hood W 15-25 WNW 10-20 WNW 10-20 W 10-20
Olympics Ridgeline Winds (mph)
Saturday Evening W 5-15
Saturday Night NE 0-10
Sunday Morning NE 0-10
Sunday Afternoon WNW 0-10
West North Ridgeline Winds (mph)
Saturday Evening WNW 10-20
Saturday Night WNW 0-10
Sunday Morning NW 0-10
Sunday Afternoon WNW 0-10
West Central Ridgeline Winds (mph)
Saturday Evening NW 5-15
Saturday Night NW 5-15
Sunday Morning NNW 5-15
Sunday Afternoon WNW 5-15
West South Ridgeline Winds (mph)
Saturday Evening WNW 5-15
Saturday Night N 0-10
Sunday Morning NNW 0-10
Sunday Afternoon NW 0-10
Stevens Pass Ridgeline Winds (mph)
Saturday Evening WNW 10-20
Saturday Night WNW 5-15
Sunday Morning WNW 5-15
Sunday Afternoon WNW 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Saturday Evening NW 10-20
Saturday Night NW 10-20
Sunday Morning NNW 10-20
Sunday Afternoon NW 5-15
East North Ridgeline Winds (mph)
Saturday Evening WNW 10-20
Saturday Night NNW 5-15
Sunday Morning NNW 5-15
Sunday Afternoon NW 5-15
East Central Ridgeline Winds (mph)
Saturday Evening WNW 20-30
Saturday Night NW 10-20
Sunday Morning NNW 5-15
Sunday Afternoon NNW 0-10
East South Ridgeline Winds (mph)
Saturday Evening WNW 10-20
Saturday Night NW 10-20
Sunday Morning NNW 5-15
Sunday Afternoon NW 0-10
Mt. Hood Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night WNW 10-20
Sunday Morning WNW 10-20
Sunday Afternoon W 10-20

Extended Weather Synopsis

Cool westerly flow behind Monday's system keeps clouds banked along the west slopes of the Cascades along with a chance of light showers into early Tuesday. A ridge amplifies as it moves onshore, yielding increasingly sunny conditions late Tuesday and rapidly warming temperatures through Wednesday. Freezing levels Tuesday afternoon should rise to 5000-7000 ft, and by Wednesday they should be in the 8500-11000 ft range.

Extended Snow Level (ft)

Monday Night Tuesday Tuesday Night Wednesday
West North 4000' 5000' 6000' 8500'
Snoqualmie Pass 4500' 5500' 7000' 9500'
Mt. Hood 6000' 6500' 9000' 11000'
West North Elevation
Monday Night 4000'
Tuesday 5000'
Tuesday Night 6000'
Wednesday 8500'
Snoqualmie Pass Elevation
Monday Night 4500'
Tuesday 5500'
Tuesday Night 7000'
Wednesday 9500'
Mt. Hood Elevation
Monday Night 6000'
Tuesday 6500'
Tuesday Night 9000'
Wednesday 11000'

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

Previous forecast from Apr 30, 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’.