Issued: 2:31 PM PDT Monday, April 12, 2021
by Dennis D'Amico

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

Weather Synopsis

An upper level disturbance passing down the backside on an upper level trough has sparked ample cloud cover over the eastern Cascades near and north of Hwy 2 with clouds carrying over to the west-side of the Cascade crest. Clearer conditions are found further west and south.  Easterly ridgeline winds which are blowing in the moderate range over the Cascades and strong down at Mt Hood will increase further tonight. This is in response to an upper trough carving over the Great Basin and upper level ridging building over central British Columbia, creating NE flow aloft and dry northerly flow at sea-level.  

We'll see a bit of warming tomorrow with much fewer afternoon clouds on Tuesday and winds starting to ease a bit in the afternoon. The upper low will very slowly shift east on Wednesday and we can expect the same trend to follow; milder overnights, warmer days, clear skies and E-NE ridgeline winds relaxing, with winds lingering longest 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
Monday Night Mostly clear.
Tuesday Mostly sunny.
Monday Night Partly cloudy in the evening, then mostly clear after midnight.
Tuesday Mostly sunny.
Monday Night Partly cloudy in the evening, then mostly clear after midnight. Moderate to strong ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon. Moderate to strong ridgeline winds decreasing in the afternoon.
Monday Night Partly cloudy in the evening, then mostly clear after midnight. Strong ridgeline winds.
Tuesday Mostly sunny. Strong ridgeline winds.
Monday Night Partly to mostly cloudy in the evening becoming mostly clear after midnight. Moderate to strong ridgeline winds. Moderate to strong ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon. Moderate to strong ridgeline winds decreasing in the afternoon.
Monday Night Partly cloudy in the evening, then mostly clear after midnight. Strong ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon. Moderate to strong ridgeline winds decreasing in the afternoon.
Monday Night Partly to mostly cloudy in the evening becoming mostly clear after midnight. Moderate ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon.
Monday Night Partly to mostly cloudy in the evening becoming mostly clear after midnight. Strong ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon. Strong ridgeline winds.
Monday Night Partly cloudy in the evening, then mostly clear after midnight. Strong ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon. Strong ridgeline winds.
Monday Night Mostly clear. Strong to extreme ridgeline winds.
Tuesday Mostly sunny. A few clouds in the afternoon. Strong to extreme ridgeline winds.

Issued: 2:31 PM PDT Monday, April 12, 2021

Precipitation (in)

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

Issued: 2:31 PM PDT Monday, April 12, 2021

Snow Level (ft)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning Wednesday Afternoon
Olympics 5000' 4000' 5000' 6500' 6500' 6000' 7000' 8000'
West North 5000' 4000' 5000' 6500' 6500' 6000' 7000' 8500'
West Central 5000' 3500' 5000' 6500' 6500' 6000' 7000' 8000'
West South 5000' 3500' 5000' 6500' 6500' 6000' 7000' 8000'
Stevens Pass 5000' 3500' 4500' 6500' 6500' 6000' 7000' 8000'
Snoqualmie Pass 5000' 3500' 4500' 6500' 6500' 6000' 7000' 8000'
East North 5000' 2500' 5000' 6500' 5500' 5000' 7000' 8000'
East Central 5000' 3000' 5000' 6500' 6500' 6000' 7000' 8000'
East South 5000' 3000' 4500' 6500' 6500' 6000' 7000' 8000'
Mt. Hood 5000' 2500' 4500' 6000' 5500' 5000' 6000' 7000'
Olympics Elevation
Monday Evening 5000'
Monday Night 4000'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
West North Elevation
Monday Evening 5000'
Monday Night 4000'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8500'
West Central Elevation
Monday Evening 5000'
Monday Night 3500'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
West South Elevation
Monday Evening 5000'
Monday Night 3500'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
Stevens Pass Elevation
Monday Evening 5000'
Monday Night 3500'
Tuesday Morning 4500'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
Snoqualmie Pass Elevation
Monday Evening 5000'
Monday Night 3500'
Tuesday Morning 4500'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
East North Elevation
Monday Evening 5000'
Monday Night 2500'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 5500'
Tuesday Night 5000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
East Central Elevation
Monday Evening 5000'
Monday Night 3000'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
East South Elevation
Monday Evening 5000'
Monday Night 3000'
Tuesday Morning 4500'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6000'
Wednesday Morning 7000'
Wednesday Afternoon 8000'
Mt. Hood Elevation
Monday Evening 5000'
Monday Night 2500'
Tuesday Morning 4500'
Tuesday Afternoon 6000'
Tuesday Evening 5500'
Tuesday Night 5000'
Wednesday Morning 6000'
Wednesday Afternoon 7000'

Issued: 2:31 PM PDT Monday, April 12, 2021

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 32 / 26 38 / 26
West North 34 / 26 39 / 25
West Central 34 / 26 38 / 25
West South 35 / 27 39 / 28
Stevens Pass 34 / 26 39 / 26
Snoqualmie Pass 34 / 26 38 / 25
East North 34 / 23 40 / 23
East Central 34 / 24 40 / 25
East South 34 / 24 40 / 26
Mt. Hood 34 / 26 37 / 26
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 26
Tuesday 38 / 26
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 26
Tuesday 39 / 25
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 26
Tuesday 38 / 25
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 27
Tuesday 39 / 28
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 26
Tuesday 39 / 26
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 26
Tuesday 38 / 25
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 23
Tuesday 40 / 23
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 24
Tuesday 40 / 25
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 24
Tuesday 40 / 26
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 26
Tuesday 37 / 26

Issued: 2:31 PM PDT Monday, April 12, 2021

Ridgeline Winds (mph)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics NE 10-20 NE 10-20 NE 5-15 NE 10-20
West North NE 15-25 NE 10-20 NE 10-20 NE 5-15
West Central NE 15-25 NE 20-30 NE 15-25 ENE 10-20
West South ENE 20-30 ENE 25-35 ENE 25-35 ENE 20-30
Stevens Pass ENE 15-25 ENE 25-35 ENE 15-25 ENE 10-20
Snoqualmie Pass ENE 20-30 ENE 25-35 ENE 15-25 ENE 10-20
East North ENE 15-25 ENE 10-20 NE 10-20 ENE 10-20
East Central NE 20-30 ENE 25-35 ENE 25-35 ENE 20-30
East South NE 20-30 ENE 20-30 ENE 20-30 ENE 15-25
Mt. Hood ENE 25-35 NE 30-40 NE 30-40 NE 20-30
Olympics Ridgeline Winds (mph)
Monday Evening NE 10-20
Monday Night NE 10-20
Tuesday Morning NE 5-15
Tuesday Afternoon NE 10-20
West North Ridgeline Winds (mph)
Monday Evening NE 15-25
Monday Night NE 10-20
Tuesday Morning NE 10-20
Tuesday Afternoon NE 5-15
West Central Ridgeline Winds (mph)
Monday Evening NE 15-25
Monday Night NE 20-30
Tuesday Morning NE 15-25
Tuesday Afternoon ENE 10-20
West South Ridgeline Winds (mph)
Monday Evening ENE 20-30
Monday Night ENE 25-35
Tuesday Morning ENE 25-35
Tuesday Afternoon ENE 20-30
Stevens Pass Ridgeline Winds (mph)
Monday Evening ENE 15-25
Monday Night ENE 25-35
Tuesday Morning ENE 15-25
Tuesday Afternoon ENE 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Monday Evening ENE 20-30
Monday Night ENE 25-35
Tuesday Morning ENE 15-25
Tuesday Afternoon ENE 10-20
East North Ridgeline Winds (mph)
Monday Evening ENE 15-25
Monday Night ENE 10-20
Tuesday Morning NE 10-20
Tuesday Afternoon ENE 10-20
East Central Ridgeline Winds (mph)
Monday Evening NE 20-30
Monday Night ENE 25-35
Tuesday Morning ENE 25-35
Tuesday Afternoon ENE 20-30
East South Ridgeline Winds (mph)
Monday Evening NE 20-30
Monday Night ENE 20-30
Tuesday Morning ENE 20-30
Tuesday Afternoon ENE 15-25
Mt. Hood Ridgeline Winds (mph)
Monday Evening ENE 25-35
Monday Night NE 30-40
Tuesday Morning NE 30-40
Tuesday Afternoon NE 20-30

Issued: 2:31 PM PDT Monday, April 12, 2021

Extended Weather Synopsis

The upper level ridge will become the dominant weather feature later this week as the upper low shifts into the front-range of the Rockies. The warmest conditions of the spring will likely develop towards the end of the week and extend into the weekend. Keep an eye on when freezing levels begin to crack 10,000' with 5000' temperatures well into the 50s. 

Extended Snow Level (ft)

Wednesday Night Thursday Thursday Night Friday
West North 8000' 8500' 8000' 9000'
Snoqualmie Pass 8000' 8500' 7500' 9000'
Mt. Hood 7500' 8000' 7000' 8000'
West North Elevation
Wednesday Night 8000'
Thursday 8500'
Thursday Night 8000'
Friday 9000'
Snoqualmie Pass Elevation
Wednesday Night 8000'
Thursday 8500'
Thursday Night 7500'
Friday 9000'
Mt. Hood Elevation
Wednesday Night 7500'
Thursday 8000'
Thursday Night 7000'
Friday 8000'

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

Previous forecast from Apr 12, 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’.