Issued: 2:29 PM PDT Monday, April 5, 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

Upper level ridging will flop inland tonight, leaving us with dry conditions and clear skies.  Temperatures and freezing levels will dip over the Cascades but stay elevated over the Olympics and Mt Hood as milder air begins to work into the region. 

A frontal system dropping south along the British Columbia coast will flatten and kick the ridge east on Tuesday. A few high clouds will pass over the area in the morning, thickening closer to the Canadian border by mid-afternoon. Freezing levels will rise the highest in the south and along the east slopes of the Cascades. 

The frontal system will spread increasing mid and high clouds inland Tuesday night, with precipitation beginning around daybreak on Wednesday for the Olympics and Mt Baker area. Snow levels will drop quickly with the onset of precipitation and ridgeline westerly winds will increase during the day. Mt Hood and the south Washington Cascades will see an increase in clouds but may not see measurable precipitation until early Wednesday evening. 

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 in the morning with periods of high clouds, becoming mostly cloudy with increasing high clouds in the afternoon.
Monday Night Mostly clear.
Tuesday Mostly sunny in the morning with periods of high clouds, becoming mostly cloudy with increasing high clouds late in the afternoon.
Monday Night Mostly clear.
Tuesday Mostly sunny in the morning with periods of high clouds, becoming partly sunny with increasing high clouds late in the afternoon.
Monday Night Mostly clear.
Tuesday Mostly sunny. Increasing high clouds late.
Monday Night Mostly clear.
Tuesday Mostly sunny. Increasing high clouds late.
Monday Night Mostly clear.
Tuesday Mostly sunny. Increasing high clouds late.
Monday Night Mostly clear.
Tuesday Mostly sunny in the morning with periods of high clouds, becoming partly sunny with increasing high clouds late in the afternoon.
Monday Night Mostly clear.
Tuesday Mostly sunny. Increasing high clouds late.
Monday Night Mostly clear.
Tuesday Mostly sunny. Increasing high clouds late.
Monday Night Mostly clear.
Tuesday Mostly sunny.

Issued: 2:29 PM PDT Monday, April 5, 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 LT 0.25
Mt Baker Ski Area 0 0 0 0.25 - 0.50
Mt. Loop - Barlow Pass 0 0 0 0.25
Stevens Pass 0 0 0 LT 0.10
Snoqualmie Pass 0 0 0 LT 0.10
Crystal Mt 0 0 0 0
Paradise 0 0 0 LT 0.10
White Pass 0 0 0 0
Washington Pass 0 0 0 LT 0.10
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 LT 0.25
Mt Baker Ski Area Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0.25 - 0.50
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0.25
Stevens Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday LT 0.10
Snoqualmie Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday LT 0.10
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 LT 0.10
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 LT 0.10
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: 2:29 PM PDT Monday, April 5, 2021

Snow Level (ft)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning Wednesday Afternoon
Olympics 4500' 4000' 5000' 7000' 6000' 5000' 3000' 3000'
West North 4500' 2500' 4500' 6000' 5500' 4000' 3500' 3000'
West Central 4500' 3000' 5000' 6500' 5500' 4000' 4000' 3500'
West South 4500' 3000' 5000' 7500' 6000' 4500' 4500' 4000'
Stevens Pass 4500' 2500' 5000' 6500' 5500' 4000' 4000' 3500'
Snoqualmie Pass 4500' 3000' 5000' 6500' 5500' 4000' 4000' 3500'
East North 4500' 2500' 5500' 7000' 6000' 4000' 5000' 5000'
East Central 4500' 3000' 5500' 7500' 6500' 5000' 5000' 5000'
East South 4500' 3000' 6000' 8000' 6500' 5500' 5500' 5000'
Mt. Hood 4500' 6000' 7000' 9000' 8000' 7500' 6500' 5000'
Olympics Elevation
Monday Evening 4500'
Monday Night 4000'
Tuesday Morning 5000'
Tuesday Afternoon 7000'
Tuesday Evening 6000'
Tuesday Night 5000'
Wednesday Morning 3000'
Wednesday Afternoon 3000'
West North Elevation
Monday Evening 4500'
Monday Night 2500'
Tuesday Morning 4500'
Tuesday Afternoon 6000'
Tuesday Evening 5500'
Tuesday Night 4000'
Wednesday Morning 3500'
Wednesday Afternoon 3000'
West Central Elevation
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 5500'
Tuesday Night 4000'
Wednesday Morning 4000'
Wednesday Afternoon 3500'
West South Elevation
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 5000'
Tuesday Afternoon 7500'
Tuesday Evening 6000'
Tuesday Night 4500'
Wednesday Morning 4500'
Wednesday Afternoon 4000'
Stevens Pass Elevation
Monday Evening 4500'
Monday Night 2500'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 5500'
Tuesday Night 4000'
Wednesday Morning 4000'
Wednesday Afternoon 3500'
Snoqualmie Pass Elevation
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 5000'
Tuesday Afternoon 6500'
Tuesday Evening 5500'
Tuesday Night 4000'
Wednesday Morning 4000'
Wednesday Afternoon 3500'
East North Elevation
Monday Evening 4500'
Monday Night 2500'
Tuesday Morning 5500'
Tuesday Afternoon 7000'
Tuesday Evening 6000'
Tuesday Night 4000'
Wednesday Morning 5000'
Wednesday Afternoon 5000'
East Central Elevation
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 5500'
Tuesday Afternoon 7500'
Tuesday Evening 6500'
Tuesday Night 5000'
Wednesday Morning 5000'
Wednesday Afternoon 5000'
East South Elevation
Monday Evening 4500'
Monday Night 3000'
Tuesday Morning 6000'
Tuesday Afternoon 8000'
Tuesday Evening 6500'
Tuesday Night 5500'
Wednesday Morning 5500'
Wednesday Afternoon 5000'
Mt. Hood Elevation
Monday Evening 4500'
Monday Night 6000'
Tuesday Morning 7000'
Tuesday Afternoon 9000'
Tuesday Evening 8000'
Tuesday Night 7500'
Wednesday Morning 6500'
Wednesday Afternoon 5000'

Issued: 2:29 PM PDT Monday, April 5, 2021

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 34 / 30 41 / 30
West North 32 / 24 37 / 25
West Central 32 / 24 39 / 26
West South 33 / 24 45 / 28
Stevens Pass 30 / 24 43 / 25
Snoqualmie Pass 31 / 25 41 / 27
East North 33 / 27 43 / 27
East Central 35 / 29 45 / 30
East South 37 / 29 47 / 32
Mt. Hood 35 / 30 49 / 31
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 30
Tuesday 41 / 30
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 24
Tuesday 37 / 25
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 24
Tuesday 39 / 26
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 33 / 24
Tuesday 45 / 28
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 30 / 24
Tuesday 43 / 25
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 25
Tuesday 41 / 27
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 33 / 27
Tuesday 43 / 27
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 29
Tuesday 45 / 30
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 37 / 29
Tuesday 47 / 32
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 30
Tuesday 49 / 31

Issued: 2:29 PM PDT Monday, April 5, 2021

Ridgeline Winds (mph)

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

Issued: 2:29 PM PDT Monday, April 5, 2021

Extended Weather Synopsis

The front should pass through the Cascades around midnight Wednesday night, with a burst of moderate to strong WNW winds and several inches of snow above 3000', especially along the west slopes of the Cascades. A convergence zone will likely form Wednesday night behind the front, enhancing storm totals in the central Cascades.  Thursday will be cool and showery as an upper-level ridging builds offshore. Another frontal system dropping down from the NW should spread a new round of precipitation into the Olympics and north Cascades by Friday afternoon. 

Extended Snow Level (ft)

Wednesday Night Thursday Thursday Night Friday
West North 2000' 3000' 2000' 3500'
Snoqualmie Pass 2500' 3000' 2000' 4500'
Mt. Hood 3000' 4000' 3500' 5500'
West North Elevation
Wednesday Night 2000'
Thursday 3000'
Thursday Night 2000'
Friday 3500'
Snoqualmie Pass Elevation
Wednesday Night 2500'
Thursday 3000'
Thursday Night 2000'
Friday 4500'
Mt. Hood Elevation
Wednesday Night 3000'
Thursday 4000'
Thursday Night 3500'
Friday 5500'

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

Previous forecast from Apr 5, 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’.