Issued: 2:35 PM PDT Sunday, April 4, 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 cool upper trough shifts from NW to SE across the region Saturday evening. The cold air aloft combined with a northerly wind shift could bring a dusting of snow areas from the central Washington Cascades southward with the best chances of snow on the north side of Mt. Rainier. Colder air continues to filter into the region from aloft while clearing skies support strong radiational cooling. Expect cold temperatures overnight that linger into the morning hours.

A weak ridge of high pressure edges into the region on Monday. Sunny weather will help temperatures rebound to highs in the upper 30s to mid-40s at 5000 ft. The flow aloft remains light out of the north, while low-level light west winds maintain temperatures 3-5F warmer east of the Cascade Crest.

The ridge axis shifts over our region preserving clear skies Monday night. Temperatures will be cool, but not as cold as Monday night.

Upper-level flow shifts westerly as the next system begins to approach the region from the NW. Temperatures continue to increase with warming the most pronounced in the southern parts of the forecast region. Mt. Hood could see freezing levels back up to 9000 ft by the afternoon.

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 Clearing skies.
Monday Mostly sunny with scattered cumulus clouds in the afternoon.
Sunday Night Scattered clouds early, then becoming mostly clear.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy, then becoming mostly clear overnight.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy with very light snow or snow flurries early, then becoming mostly clear overnight.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy, then becoming mostly clear overnight. Light W wind at the Pass.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy with snow flurries possible in the evening, then becoming mostly clear overnight. Light W wind at the Pass.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy early, then becoming mostly clear.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night A few clouds early, then becoming mostly clear.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy with isolated snow flurries early, then becoming mostly clear.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.
Sunday Night Partly cloudy with snow flurries possible early, then clearing skies.
Monday Mostly sunny with a few shallow cumulus clouds in the afternoon.

Issued: 2:35 PM PDT Sunday, April 4, 2021

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

Issued: 2:35 PM PDT Sunday, April 4, 2021

Snow Level (ft)

Sunday Evening Sunday Night Monday Morning Monday Afternoon Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics 2500' 2500' 3000' 4500' 5000' 5000' 5000' 6000'
West North 3000' 1500' 2000' 4500' 4500' 2500' 3000' 5000'
West Central 3000' 2000' 2000' 4500' 4500' 2500' 3000' 5500'
West South 2500' 2000' 2000' 5000' 5000' 3500' 4500' 7500'
Stevens Pass 3000' 2000' 2500' 4500' 4500' 3000' 3500' 6000'
Snoqualmie Pass 2000' 2000' 2500' 4500' 4500' 3000' 3500' 6000'
East North 4000' 2500' 2500' 5500' 5500' 4000' 4000' 6500'
East Central 4000' 2500' 2500' 5500' 5500' 4000' 4500' 7500'
East South 4000' 2500' 3000' 5500' 6000' 4500' 5500' 8500'
Mt. Hood 3000' 2000' 2500' 5000' 5500' 4500' 6000' 9000'
Olympics Elevation
Sunday Evening 2500'
Sunday Night 2500'
Monday Morning 3000'
Monday Afternoon 4500'
Monday Evening 5000'
Monday Night 5000'
Tuesday Morning 5000'
Tuesday Afternoon 6000'
West North Elevation
Sunday Evening 3000'
Sunday Night 1500'
Monday Morning 2000'
Monday Afternoon 4500'
Monday Evening 4500'
Monday Night 2500'
Tuesday Morning 3000'
Tuesday Afternoon 5000'
West Central Elevation
Sunday Evening 3000'
Sunday Night 2000'
Monday Morning 2000'
Monday Afternoon 4500'
Monday Evening 4500'
Monday Night 2500'
Tuesday Morning 3000'
Tuesday Afternoon 5500'
West South Elevation
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2000'
Monday Afternoon 5000'
Monday Evening 5000'
Monday Night 3500'
Tuesday Morning 4500'
Tuesday Afternoon 7500'
Stevens Pass Elevation
Sunday Evening 3000'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 4500'
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 3500'
Tuesday Afternoon 6000'
Snoqualmie Pass Elevation
Sunday Evening 2000'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 4500'
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 3500'
Tuesday Afternoon 6000'
East North Elevation
Sunday Evening 4000'
Sunday Night 2500'
Monday Morning 2500'
Monday Afternoon 5500'
Monday Evening 5500'
Monday Night 4000'
Tuesday Morning 4000'
Tuesday Afternoon 6500'
East Central Elevation
Sunday Evening 4000'
Sunday Night 2500'
Monday Morning 2500'
Monday Afternoon 5500'
Monday Evening 5500'
Monday Night 4000'
Tuesday Morning 4500'
Tuesday Afternoon 7500'
East South Elevation
Sunday Evening 4000'
Sunday Night 2500'
Monday Morning 3000'
Monday Afternoon 5500'
Monday Evening 6000'
Monday Night 4500'
Tuesday Morning 5500'
Tuesday Afternoon 8500'
Mt. Hood Elevation
Sunday Evening 3000'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 5000'
Monday Evening 5500'
Monday Night 4500'
Tuesday Morning 6000'
Tuesday Afternoon 9000'

Issued: 2:35 PM PDT Sunday, April 4, 2021

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 30 / 22 40 / 24
West North 31 / 20 38 / 23
West Central 29 / 21 38 / 23
West South 32 / 21 41 / 23
Stevens Pass 30 / 20 39 / 23
Snoqualmie Pass 30 / 20 39 / 23
East North 32 / 21 43 / 23
East Central 32 / 23 43 / 25
East South 34 / 23 44 / 25
Mt. Hood 35 / 22 43 / 24
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 22
Monday 40 / 24
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 31 / 20
Monday 38 / 23
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 29 / 21
Monday 38 / 23
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 32 / 21
Monday 41 / 23
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 20
Monday 39 / 23
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 20
Monday 39 / 23
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night 32 / 21
Monday 43 / 23
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 32 / 23
Monday 43 / 25
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 34 / 23
Monday 44 / 25
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 35 / 22
Monday 43 / 24

Issued: 2:35 PM PDT Sunday, April 4, 2021

Ridgeline Winds (mph)

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

Issued: 2:35 PM PDT Sunday, April 4, 2021

Extended Weather Synopsis

The weak ridge yields to another system approaching on NW flow Wednesday night with cooling temperatures and clouds filtering into the region. The cooling will mean that much of the precipitation will fall in the form of snow once it arrives. Rain and snow should spread from NW to SE across the region on Wednesday and may become moderate in northern parts of the region by the afternoon. The upper trough axis transits the region overnight, bringing moderate to heavy snow to the Cascades. Post-frontal light snow showers linger on NW flow Thursday morning and weak ridging restores dry conditions to the region during the afternoon.

Extended Snow Level (ft)

Tuesday Night Wednesday Wednesday Night Thursday
West North 4000' 2500' 2000' 2000'
Snoqualmie Pass 5000' 3000' 2500' 2500'
Mt. Hood 8000' 5500' 3500' 3000'
West North Elevation
Tuesday Night 4000'
Wednesday 2500'
Wednesday Night 2000'
Thursday 2000'
Snoqualmie Pass Elevation
Tuesday Night 5000'
Wednesday 3000'
Wednesday Night 2500'
Thursday 2500'
Mt. Hood Elevation
Tuesday Night 8000'
Wednesday 5500'
Wednesday Night 3500'
Thursday 3000'

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

Previous forecast from Apr 4, 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’.