Issued: 2:42 PM PDT Friday, April 30, 2021
by Robert Hahn

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

Weather Synopsis

A frontal passage Friday returns the PNW region to somewhat more unsettled springtime weather. Ridgeline winds shift westerly with the frontal passage and remain in the moderate range along the east slopes of the Cascades and on Mt. Hood Friday night through to Saturday night. Post-frontal flow also maintains mostly cloudy conditions along the west slopes of the Cascades, touching off isolated rain and snow showers and potential weak convergence through Saturday evening. A subtle upper trough moves into the region on Saturday, lowering snow levels into the 4000-5000 ft range. A subtle perturbation on the back side of the trough creates the best chance for organized convergence in the Snoqualmie Pass to Mt. Rainier areas Saturday evening, but we still expect less than 0.10" of water equivalent.
 
A transitory ridge moves into the region late Saturday night, yielding increasingly sunny weather as the day progresses on Sunday. Freezing levels rise to 5500-6500 ft by the afternoon with light winds in most areas except moderate winds remain possible at 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
Friday Night A mix of low clouds and clear skies.
Saturday Partly cloudy
Friday Night Mostly cloudy with a chance of light rain or high elevation snow showers.
Saturday Mostly cloudy with a chance of light rain or high elevation snow showers.
Friday Night Mostly cloudy with a chance of light rain or high elevation snow showers.
Saturday Mostly cloudy with a chance of light rain or high elevation snow showers.
Friday Night Mostly cloudy.
Saturday Partly cloudy.
Friday Night Mostly cloudy with a chance of light rain or high elevation snow showers. Light W winds at the Pass.
Saturday Mostly cloudy with a chance of light rain or high elevation snow showers. Light W winds at the Pass.
Friday Night Mostly cloudy with a chance of light rain or high elevation snow showers. Light W winds at the Pass.
Saturday Mostly cloudy with a chance of light rain or high elevation snow showers. Light W winds at the Pass.
Friday Night Mostly cloudy with clearer skies further east.
Saturday Partly cloudy with clearer skies further east.
Friday Night Mostly cloudy with clearer skies further east.
Saturday Partly cloudy with clearer skies further east.
Friday Night Mostly cloudy with clearer skies further east.
Saturday Partly cloudy with clearer skies further east.
Friday Night Mostly cloudy with a chance of light rain or high elevation snow showers.
Saturday Partly cloudy, with mostly clear skies in the afternoon.

Precipitation (in)

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

Snow Level (ft)

Friday Evening Friday Night Saturday Morning Saturday Afternoon Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics 7500' 6500' 5000' 5500' 5500' 5000' 4500' 5500'
West North 6000' 5500' 5000' 5000' 5500' 4500' 4000' 5500'
West Central 6500' 6000' 5000' 5000' 5500' 4500' 4000' 5500'
West South 7500' 6500' 6000' 6000' 5000' 5000' 4000' 6000'
Stevens Pass 6500' 6000' 5500' 5500' 5500' 4500' 4000' 6000'
Snoqualmie Pass 6500' 6000' 5000' 5500' 5000' 5000' 4000' 5000'
East North 7500' 7000' 6000' 6000' 6000' 4500' 4500' 7000'
East Central 8000' 7500' 6000' 6500' 6000' 5000' 4500' 6500'
East South 9000' 9500' 7500' 7000' 6500' 5000' 4500' 6500'
Mt. Hood 9000' 8500' 8500' 7000' 6500' 5500' 5000' 6000'
Olympics Elevation
Friday Evening 7500'
Friday Night 6500'
Saturday Morning 5000'
Saturday Afternoon 5500'
Saturday Evening 5500'
Saturday Night 5000'
Sunday Morning 4500'
Sunday Afternoon 5500'
West North Elevation
Friday Evening 6000'
Friday Night 5500'
Saturday Morning 5000'
Saturday Afternoon 5000'
Saturday Evening 5500'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 5500'
West Central Elevation
Friday Evening 6500'
Friday Night 6000'
Saturday Morning 5000'
Saturday Afternoon 5000'
Saturday Evening 5500'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 5500'
West South Elevation
Friday Evening 7500'
Friday Night 6500'
Saturday Morning 6000'
Saturday Afternoon 6000'
Saturday Evening 5000'
Saturday Night 5000'
Sunday Morning 4000'
Sunday Afternoon 6000'
Stevens Pass Elevation
Friday Evening 6500'
Friday Night 6000'
Saturday Morning 5500'
Saturday Afternoon 5500'
Saturday Evening 5500'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 6000'
Snoqualmie Pass Elevation
Friday Evening 6500'
Friday Night 6000'
Saturday Morning 5000'
Saturday Afternoon 5500'
Saturday Evening 5000'
Saturday Night 5000'
Sunday Morning 4000'
Sunday Afternoon 5000'
East North Elevation
Friday Evening 7500'
Friday Night 7000'
Saturday Morning 6000'
Saturday Afternoon 6000'
Saturday Evening 6000'
Saturday Night 4500'
Sunday Morning 4500'
Sunday Afternoon 7000'
East Central Elevation
Friday Evening 8000'
Friday Night 7500'
Saturday Morning 6000'
Saturday Afternoon 6500'
Saturday Evening 6000'
Saturday Night 5000'
Sunday Morning 4500'
Sunday Afternoon 6500'
East South Elevation
Friday Evening 9000'
Friday Night 9500'
Saturday Morning 7500'
Saturday Afternoon 7000'
Saturday Evening 6500'
Saturday Night 5000'
Sunday Morning 4500'
Sunday Afternoon 6500'
Mt. Hood Elevation
Friday Evening 9000'
Friday Night 8500'
Saturday Morning 8500'
Saturday Afternoon 7000'
Saturday Evening 6500'
Saturday Night 5500'
Sunday Morning 5000'
Sunday Afternoon 6000'

5000' Temperatures (°F)

Friday Night Saturday
Max / Min Max / Min
Olympics 38 / 30 37 / 29
West North 38 / 30 35 / 29
West Central 36 / 31 34 / 30
West South 41 / 31 39 / 30
Stevens Pass 38 / 32 37 / 31
Snoqualmie Pass 37 / 31 35 / 30
East North 39 / 33 38 / 32
East Central 38 / 33 39 / 32
East South 41 / 34 43 / 33
Mt. Hood 44 / 37 44 / 35
Olympics 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 38 / 30
Saturday 5am - 5pm 37 / 29
West North 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 38 / 30
Saturday 5am - 5pm 35 / 29
West Central 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 36 / 31
Saturday 5am - 5pm 34 / 30
West South 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 41 / 31
Saturday 5am - 5pm 39 / 30
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 38 / 32
Saturday 5am - 5pm 37 / 31
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 37 / 31
Saturday 5am - 5pm 35 / 30
East North 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 39 / 33
Saturday 5am - 5pm 38 / 32
East Central 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 38 / 33
Saturday 5am - 5pm 39 / 32
East South 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 41 / 34
Saturday 5am - 5pm 43 / 33
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 44 / 37
Saturday 5am - 5pm 44 / 35

Ridgeline Winds (mph)

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

Extended Weather Synopsis

High clouds spread into the region from the west Sunday night, lowering and thickening ahead of a weak frontal system arriving on Monday. Post-frontal showers continue Monday night. Tuesday should be mostly dry with increasing sunshine as ridgimg builds just offshore. Temperatures remain near seasonal norms throughout the extended forecast period.

Extended Snow Level (ft)

Sunday Night Monday Monday Night Tuesday
West North 5500' 5000' 4000' 5000'
Snoqualmie Pass 6000' 5000' 4500' 5500'
Mt. Hood 7000' 6500' 6000' 6500'
West North Elevation
Sunday Night 5500'
Monday 5000'
Monday Night 4000'
Tuesday 5000'
Snoqualmie Pass Elevation
Sunday Night 6000'
Monday 5000'
Monday Night 4500'
Tuesday 5500'
Mt. Hood Elevation
Sunday Night 7000'
Monday 6500'
Monday Night 6000'
Tuesday 6500'

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

Previous forecast from Apr 29, 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