Issued: 2:35 PM PDT Monday, April 10, 2023
by Robert Hahn

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

Weather Synopsis

A frontal wave along a relatively stationary cold front continues to feed subtropical moisture into the Cascades as of Monday afternoon. The Frontal boundary separates unseasonably warm air over Mt Hood and the southern Washington Cascades from cooler-than-average temperatures further north and west over the Olympics. Stratiform precipitation continues to stream over much of the region, extending as far north as Mt. Baker.

This package shifts eastward Monday afternoon, allowing the stratiform (continuous) precipitation to taper Monday evening as a sharp upper trough approaches the region. WSW winds increase as the upper trough brings in rapidly cooling temperatures and light to moderate snow showers focusing on the W slopes of the Cascades. Models indicate the potential for convergence banding to develop and oscillate around the northern Mtn Loop to Mt Baker region during the early morning through early afternoon hours on Tuesday. Ridgeline winds increase in the moderate range through Tuesday with acceleration through the mountain gaps and on the E slopes of the Cascades producing locally strong winds. Very cold air moving in aloft will increase the potential for graupel, locally heavy squalls, and an isolated Thunderstorm, particularly during the afternoon hours. 

Snow shower activity decreases overnight as a weak upper and surface low embedded within the trough approaches the area. The low moves onshore in SW Washington early Wednesday and will focus snow shower activity on the SW Washington Cascades.

Snow levels should linger in the 2000-3000 ft range Tuesday through Wednesday. Chilly for mid-April.

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 Light rain and snow showers.
Tuesday Light rain and snow showers. Increasing moderate ridgeline winds.
Monday Night Light rain and snow becoming showery by morning with a chance of convergence in the early morning hours.
Tuesday Moderate rain and snow showers with a chance of heavier precipitation in convergence or afternoon convective showers. Increasing moderate ridgeline winds.
Monday Night Light rain and snow becoming showery by morning with a chance of convergence in the early morning hours.
Tuesday Moderate rain and snow showers with a chance of heavier precipitation in convergence or afternoon convective showers. Increasing moderate ridgeline winds.
Monday Night Decreasing light rain and snow becoming showery.
Tuesday Light to moderate rain and snow showers, heaviest at Paradise. Increasing moderate ridgeline winds.
Monday Night Decreasing light rain and snow showers. Increasing light to occasionally moderate ridgeline and W wind at the Pass.
Tuesday Light rain and snow showers. Increasing moderate ridgeline and light to moderate W wind at the Pass.
Monday Night Decreasing light rain and snow showers. Snow level dropping back down to the Pass level by morning. Light to occasionally moderate ridgeline and W wind at the Pass.
Tuesday Light rain and snow showers. Increasing moderate ridgeline and light to moderate W wind at the Pass.
Monday Night Decreasing light rain and snow showers.
Tuesday Scattered convective snow showers, intensify in the afternoon.
Monday Night Decreasing light rain and snow showers.
Tuesday Scattered convective snow showers, intensify in the afternoon.
Monday Night Decreasing light rain and snow showers.
Tuesday Scattered convective snow showers, intensify in the afternoon.
Monday Night Decreasing light to moderate rain and snow showers. Moderate to strong ridgeline winds.
Tuesday Increasing light to moderate rain and snow showers, occasionally intense in the afternoon. Moderate to strong ridgeline winds.

Issued: 2:35 PM PDT Monday, April 10, 2023

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 LT 0.25 0.25 LT 0.10 LT 0.25
Mt Baker Ski Area 0.25 - 0.50 0.75 LT 0.10 LT 0.10
Mt. Loop - Barlow Pass 0.25 - 0.50 0.50 LT 0.25 LT 0.10
Stevens Pass 0.25 0.25 LT 0.10 LT 0.10
Snoqualmie Pass 0.25 0.25 LT 0.25 LT 0.10
Crystal Mt 0.25 LT 0.25 LT 0.10 LT 0.10
Paradise 0.25 - 0.50 0.50 LT 0.25 LT 0.10
White Pass 0.25 - 0.50 0.25 - 0.50 LT 0.25 LT 0.25
Washington Pass LT 0.25 LT 0.25 LT 0.10 LT 0.10
Mission Ridge LT 0.25 LT 0.10 LT 0.10 0
Salmon la Sac - Gallagher Head 0.25 0.25 LT 0.10 LT 0.10
Tieton River - Darland Mt. LT 0.25 0.25 LT 0.10 LT 0.10
Mt Hood Meadows 0.25 0.25 - 0.50 0.25 0.25
Timberline 0.25 - 0.50 0.50 0.25 0.25
Hurricane Ridge Precipitation (in)
Monday Night LT 0.25
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday LT 0.25
Mt Baker Ski Area Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.75
Tuesday Night LT 0.10
Wednesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.50
Tuesday Night LT 0.25
Wednesday LT 0.10
Stevens Pass Precipitation (in)
Monday Night 0.25
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Snoqualmie Pass Precipitation (in)
Monday Night 0.25
Tuesday 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10
Crystal Mt Precipitation (in)
Monday Night 0.25
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Paradise Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.50
Tuesday Night LT 0.25
Wednesday LT 0.10
White Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.25 - 0.50
Tuesday Night LT 0.25
Wednesday LT 0.25
Washington Pass Precipitation (in)
Monday Night LT 0.25
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Mission Ridge Precipitation (in)
Monday Night LT 0.25
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0.25
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Monday Night LT 0.25
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Mt Hood Meadows Precipitation (in)
Monday Night 0.25
Tuesday 0.25 - 0.50
Tuesday Night 0.25
Wednesday 0.25
Timberline Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.50
Tuesday Night 0.25
Wednesday 0.25

Issued: 2:35 PM PDT Monday, April 10, 2023

Snow Level (ft)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning Wednesday Afternoon
Olympics 3000' 2000' 2000' 2000'
West North 3500' 2500' 2000' 2000'
West Central 3500' 2500' 2000' 2000'
West South 4000' 3000' 2000' 2000'
Stevens Pass 4000' 3000' 2000' 2500'
Snoqualmie Pass 4000' 3000' 2000' 2000'
East North 4000' 3500' 2500' 3000'
East Central 4500' 3500' 2500' 3000'
East South 5000' 3500' 2500' 3000'
Mt. Hood 6000' 3000' 2000' 2500'
Olympics Elevation
Monday Evening 3000'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 2000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
West North Elevation
Monday Evening 3500'
Monday Night 2500'
Tuesday Morning 2000'
Tuesday Afternoon 2000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
West Central Elevation
Monday Evening 3500'
Monday Night 2500'
Tuesday Morning 2000'
Tuesday Afternoon 2000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
West South Elevation
Monday Evening 4000'
Monday Night 3000'
Tuesday Morning 2000'
Tuesday Afternoon 2000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
Stevens Pass Elevation
Monday Evening 4000'
Monday Night 3000'
Tuesday Morning 2000'
Tuesday Afternoon 2500'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
Snoqualmie Pass Elevation
Monday Evening 4000'
Monday Night 3000'
Tuesday Morning 2000'
Tuesday Afternoon 2000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
East North Elevation
Monday Evening 4000'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 3000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
East Central Elevation
Monday Evening 4500'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 3000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
East South Elevation
Monday Evening 5000'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 3000'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '
Mt. Hood Elevation
Monday Evening 6000'
Monday Night 3000'
Tuesday Morning 2000'
Tuesday Afternoon 2500'
Tuesday Evening '
Tuesday Night '
Wednesday Morning '
Wednesday Afternoon '

Issued: 2:35 PM PDT Monday, April 10, 2023

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 31 / 21 24 / 23
West North 32 / 22 25 / 22
West Central 32 / 24 24 / 23
West South 34 / 24 27 / 24
Stevens Pass 33 / 24 27 / 24
Snoqualmie Pass 32 / 25 24 / 24
East North 35 / 22 28 / 21
East Central 35 / 25 27 / 24
East South 35 / 25 27 / 24
Mt. Hood 37 / 25 26 / 24
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 21
Tuesday 24 / 23
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 22
Tuesday 25 / 22
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 24
Tuesday 24 / 23
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 24
Tuesday 27 / 24
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 33 / 24
Tuesday 27 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 25
Tuesday 24 / 24
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 22
Tuesday 28 / 21
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 25
Tuesday 27 / 24
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 25
Tuesday 27 / 24
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 37 / 25
Tuesday 26 / 24

Issued: 2:35 PM PDT Monday, April 10, 2023

Ridgeline Winds (mph)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics SW 0-10 SW 10-20 SW 10-20 WSW 15-25
West North SSW 0-10 WSW 5-15 SSW 10-20 WSW 15-25
West Central WSW 5-15 SW 5-15 SW 10-20 WSW 15-25
West South WSW 5-15 WSW 10-20 SW 10-20 WSW 15-25
Stevens Pass W 5-15 WSW 10-20 WSW 15-25 WSW 15-25
Snoqualmie Pass W 5-15 W 10-20 WSW 15-25 W 20-30
East North W 5-15 WSW 10-20 WSW 15-25 WSW 20-30
East Central W 5-15 W 15-25 WSW 20-30 W 25-35
East South W 10-20 W 10-20 WSW 15-25 W 15-25
Mt. Hood WSW 20-30 WSW 25-35 WSW 25-35 WSW 20-30
Olympics Ridgeline Winds (mph)
Monday Evening SW 0-10
Monday Night SW 10-20
Tuesday Morning SW 10-20
Tuesday Afternoon WSW 15-25
West North Ridgeline Winds (mph)
Monday Evening SSW 0-10
Monday Night WSW 5-15
Tuesday Morning SSW 10-20
Tuesday Afternoon WSW 15-25
West Central Ridgeline Winds (mph)
Monday Evening WSW 5-15
Monday Night SW 5-15
Tuesday Morning SW 10-20
Tuesday Afternoon WSW 15-25
West South Ridgeline Winds (mph)
Monday Evening WSW 5-15
Monday Night WSW 10-20
Tuesday Morning SW 10-20
Tuesday Afternoon WSW 15-25
Stevens Pass Ridgeline Winds (mph)
Monday Evening W 5-15
Monday Night WSW 10-20
Tuesday Morning WSW 15-25
Tuesday Afternoon WSW 15-25
Snoqualmie Pass Ridgeline Winds (mph)
Monday Evening W 5-15
Monday Night W 10-20
Tuesday Morning WSW 15-25
Tuesday Afternoon W 20-30
East North Ridgeline Winds (mph)
Monday Evening W 5-15
Monday Night WSW 10-20
Tuesday Morning WSW 15-25
Tuesday Afternoon WSW 20-30
East Central Ridgeline Winds (mph)
Monday Evening W 5-15
Monday Night W 15-25
Tuesday Morning WSW 20-30
Tuesday Afternoon W 25-35
East South Ridgeline Winds (mph)
Monday Evening W 10-20
Monday Night W 10-20
Tuesday Morning WSW 15-25
Tuesday Afternoon W 15-25
Mt. Hood Ridgeline Winds (mph)
Monday Evening WSW 20-30
Monday Night WSW 25-35
Tuesday Morning WSW 25-35
Tuesday Afternoon WSW 20-30

Issued: 2:35 PM PDT Monday, April 10, 2023

Extended Weather Synopsis

Wednesday evening, winds shift W with the PNW near the back edge of an eastward moving trough. This should produce some light snow flurries and clouds banked along the W slopes of the Cascades before a short-lived and shallow ridge brings fully dry conditions overnight. A weak shortwave trough brings a chance of light snow showers on Thursday through the evening hours, with another shortwave ridge bringing clearing overnight and through much of the day on Friday. Temperatures remain below normal for mid-April with snow levels at or below all the major mountain passes.

Extended Snow Level (ft)

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

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

Previous forecast from Apr 10, 2023

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’.