Issued: 3:08 PM PDT Monday, April 18, 2022
by Robert Hahn

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

Weather Synopsis

A surface low tracking north of Vancouver Island ushers a north-south oriented front into the Pacific Northwest region. As of Monday afternoon, the front has reached the Olympic mountains, bringing moderate to heavy rain and snow and rising to places like Hurricane Ridge and Mt. Baker. The front should traverse the Cascades during the early evening hours with a period of moderate rain and snow. Southerly winds aloft ahead of the front have brought rising temperatures across the region. Easterly flow in advance of the front doesn't cool the passes much this time of year, snow levels will hover around 3500 ft. Behind the front, expect a transition to decreasing and increasingly showery precipitation, but strongly cooling temperatures should return snow to Snoqualmie Pass level by around midnight and boost snow/water ratios. WSW and W winds should produce convergence that enhances the Mt. Baker area. We expect the highest storm totals in these areas. Snow levels drop to around 2000 ft by Tuesday morning, rising to 2500-3000 ft in the afternoon.

Showers should rotate around a cool upper trough on Tuesday bringing several inches of snow and locally intense graupel showers to the west slopes of the Cascades while the east slopes might pick up a trace to 1". Shower activity dwindles during the early evening. Expect Partial clearing overnight as a short wave ridge traverses the region Wednesday morning. High clouds ahead of the next system should increase and lower with light rain and snow arriving on SSW flow to Mt. Hood by late Wednesday morning and to other areas during the afternoon. Snow levels should rise once again to 3500-4000 ft.

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 Decreasing light rain and snow showers. Cooling temperatures.
Tuesday Scattered light, but locally intense rain and snow showers.
Monday Night Moderate to heavy rain, snow and convergence decreasing to light snow showers overnight. Cooling temperatures.
Tuesday Scattered light, but locally intense rain and snow showers.
Monday Night Moderate rain and snow in the evening, becoming light and showery overnight as temperatures cool.
Tuesday Scattered light, but locally intense rain and snow showers.
Monday Night Light rain and snow (moderate at Paradise) in the early evening becoming light and showery from late evening onwards. Cooling temperatures.
Tuesday Scattered light, but locally intense rain and snow showers.
Monday Night Light rain and snow becoming showery from late evening onwards as temperatures cool. Light to moderate E wind switching W at the Pass.
Tuesday Scattered light, but locally intense rain and snow showers. Light W wind at the Pass.
Monday Night Light to moderate rain and snow decreasing and becoming showery from late evening onwards as temperatures cool. Light to moderate E wind switching W at the Pass.
Tuesday Scattered light, but locally intense rain and snow showers. Light W wind at the Pass.
Monday Night Light rain and snow becoming showery from late evening onwards as temperatures cool.
Tuesday Isolated light, but locally intense rain and snow showers, becoming scattered in the afternoon.
Monday Night Light rain and snow becoming showery from late evening onwards as temperatures cool.
Tuesday Isolated light, but locally intense rain and snow showers, becoming scattered in the afternoon.
Monday Night Light rain and snow becoming showery from late evening onwards as temperatures cool.
Tuesday Isolated light, but locally intense rain and snow showers, becoming scattered in the afternoon.
Monday Night Decreasing light to moderate rain and snow.
Tuesday Light, but locally intense rain and snow showers.

Issued: 3:08 PM PDT Monday, April 18, 2022

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 LT 0.25 LT 0.10 LT 0.10
Mt Baker Ski Area 0.75 -1.00 0.25 LT 0.10 LT 0.10
Mt. Loop - Barlow Pass 0.50 LT 0.25 LT 0.10 LT 0.10
Stevens Pass 0.25 LT 0.25 LT 0.10 LT 0.10
Snoqualmie Pass 0.25 - 0.50 0.25 LT 0.10 LT 0.10
Crystal Mt 0.25 LT 0.25 LT 0.10 LT 0.25
Paradise 0.75 0.25 LT 0.10 0.25
White Pass 0.25 - 0.50 LT 0.25 LT 0.10 LT 0.25
Washington Pass 0.25 LT 0.10 0 LT 0.10
Mission Ridge 0.25 LT 0.10 0 LT 0.10
Salmon la Sac - Gallagher Head 0.25 - 0.50 LT 0.25 0 LT 0.10
Tieton River - Darland Mt. 0.25 LT 0.10 0 LT 0.25
Mt Hood Meadows 0.25 - 0.50 LT 0.25 LT 0.10 0.25
Timberline 0.50 0.25 LT 0.10 0.25
Hurricane Ridge Precipitation (in)
Monday Night LT 0.25
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Mt Baker Ski Area Precipitation (in)
Monday Night 0.75 -1.00
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0.50
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Stevens Pass Precipitation (in)
Monday Night 0.25
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Snoqualmie Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday LT 0.10
Crystal Mt Precipitation (in)
Monday Night 0.25
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.25
Paradise Precipitation (in)
Monday Night 0.75
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday 0.25
White Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday LT 0.25
Washington Pass Precipitation (in)
Monday Night 0.25
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.10
Mission Ridge Precipitation (in)
Monday Night 0.25
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday LT 0.25
Tuesday Night 0
Wednesday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Monday Night 0.25
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.25
Mt Hood Meadows Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday 0.25
Timberline Precipitation (in)
Monday Night 0.50
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday 0.25

Issued: 3:08 PM PDT Monday, April 18, 2022

Snow Level (ft)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning* Wednesday Afternoon*
Olympics 2500' 1500' 1500' 2500' 2500' 2000' 2500' 3500'
West North 3500' 1500' 1500' 2500' 2000' 1000' 2000' 4000'
West Central 3500' 2000' 1500' 2500' 2500' 2000' 2500' 4000'
West South 4000' 2000' 2000' 3500' 2500' 1500' 2500' 4000'
Stevens Pass 3500' 2000' 2000' 3000' 2500' 2000' 2500' 3500'
Snoqualmie Pass 3500' 2000' 2000' 3000' 2500' 2000' 2500' 3500'
East North 3500' 2000' 1000' 3000' 3500' 1500' 2500' 3500'
East Central 4000' 2000' 2000' 3500' 3500' 2000' 2500' 3500'
East South 4000' 2000' 2000' 3500' 3500' 2000' 2500' 4000'
Mt. Hood 4000' 2500' 2500' 3000' 3000' 2500' 2500' 3500'
Olympics Elevation
Monday Evening 2500'
Monday Night 1500'
Tuesday Morning 1500'
Tuesday Afternoon 2500'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning* 2500'
Wednesday Afternoon* 3500'
West North Elevation
Monday Evening 3500'
Monday Night 1500'
Tuesday Morning 1500'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 1000'
Wednesday Morning* 2000'
Wednesday Afternoon* 4000'
West Central Elevation
Monday Evening 3500'
Monday Night 2000'
Tuesday Morning 1500'
Tuesday Afternoon 2500'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning* 2500'
Wednesday Afternoon* 4000'
West South Elevation
Monday Evening 4000'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 3500'
Tuesday Evening 2500'
Tuesday Night 1500'
Wednesday Morning* 2500'
Wednesday Afternoon* 4000'
Stevens Pass Elevation
Monday Evening 3500'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 3000'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning* 2500'
Wednesday Afternoon* 3500'
Snoqualmie Pass Elevation
Monday Evening 3500'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 3000'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning* 2500'
Wednesday Afternoon* 3500'
East North Elevation
Monday Evening 3500'
Monday Night 2000'
Tuesday Morning 1000'
Tuesday Afternoon 3000'
Tuesday Evening 3500'
Tuesday Night 1500'
Wednesday Morning* 2500'
Wednesday Afternoon* 3500'
East Central Elevation
Monday Evening 4000'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 3500'
Tuesday Evening 3500'
Tuesday Night 2000'
Wednesday Morning* 2500'
Wednesday Afternoon* 3500'
East South Elevation
Monday Evening 4000'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 3500'
Tuesday Evening 3500'
Tuesday Night 2000'
Wednesday Morning* 2500'
Wednesday Afternoon* 4000'
Mt. Hood Elevation
Monday Evening 4000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3000'
Tuesday Evening 3000'
Tuesday Night 2500'
Wednesday Morning* 2500'
Wednesday Afternoon* 3500'

Issued: 3:08 PM PDT Monday, April 18, 2022

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 28 / 23 30 / 22
West North 32 / 23 30 / 22
West Central 31 / 25 30 / 24
West South 31 / 23 32 / 22
Stevens Pass 33 / 24 31 / 23
Snoqualmie Pass 31 / 25 31 / 24
East North 31 / 20 30 / 19
East Central 32 / 23 31 / 22
East South 33 / 24 33 / 23
Mt. Hood 31 / 26 34 / 25
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 23
Tuesday 30 / 22
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 23
Tuesday 30 / 22
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 25
Tuesday 30 / 24
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 23
Tuesday 32 / 22
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 33 / 24
Tuesday 31 / 23
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 25
Tuesday 31 / 24
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 20
Tuesday 30 / 19
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 23
Tuesday 31 / 22
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 33 / 24
Tuesday 33 / 23
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 26
Tuesday 34 / 25

Issued: 3:08 PM PDT Monday, April 18, 2022

Ridgeline Winds (mph)

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

Issued: 3:08 PM PDT Monday, April 18, 2022

Extended Weather Synopsis

A deep, cool upper trough should maintain semi-organized bands of showers Wednesday night and Thursday. The trough digs south into California Thursday night and Friday, but temperatures aloft will be plenty cool for afternoon instability rain/snow showers.

Extended Snow Level (ft)

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

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

Previous forecast from Apr 17, 2022

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’.