Issued: 2:25 PM PDT Sunday, March 12, 2023
by Dallas Glass

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

Weather Synopsis

A significant winter storm is on our doorstep this afternoon. A warm front lifting northward from Oregon has spread rain and snow up into the mountains. As it continues to push further north, snow levels will creep up the mountainsides and should peak for most locations in the early morning hours. While not a particularly warm storm, these are the highest snow levels we've seen in quite some time. Easterly flow in the Passes should help moderate the effects of the warmer temperatures. However, there just isn't that much cold air east of the Cascades to help. As a result, snow should turn to rain at Snoqualmie overnight, with mixed precipitation possible at Stevens and White Passes. 

A trailing cold front will follow close behind. This will have three major impacts. Winds Sunday night will increase significantly ahead of the front. Look for strong and gusty winds in places like Mt Baker, Mission Ridge, Ahutanum Meadows, and Mt Hood. Precipitation should intensify overnight and into Monday morning. This could result in periods of heavy rain and snow near the volcanoes. It will also be associated with better spillover, carrying precipitation to areas further east. As the cold air finally arrives, snow levels will fall. This should help snow return to the Cascade Passes and most trailhead locations by mid-morning. 

Westerly winds will indicate a transition to a more showery pattern Monday. Given the time of year, this could include brief periods of locally intense showers and/or graupel. It could also mean sun breaks. You're most likely to see the sun south of I90 and east of the Cascade crest. The most interesting weather features Monday could be a convergence zone aimed at Mt Baker. This could focus a narrow band of heavier precipitation in that area. 

Showers should gradually decrease Monday night as the upper air mass dries out and we enjoy a short break in the action. While many areas could see a bit of blue sky Tuesday morning, clouds will start to increase ahead of our next weather system. Right now, the next wave of precipitation appears to hold off until Tuesday night for most areas. 

 

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 Rain and snow. Heaviest in the southern Olympics. Moderate SW winds.
Monday Showers in the morning with cooling. Sun breaks in the afternoon.
Sunday Night Stormy. Rain and snow could be heavy at times. Moderate to strong and gusty S winds, decreasing slightly overnight.
Monday Raun and snow showers could be heavy at times. Light to moderate SW winds turning W and decreasing. A few sun breaks possible late in the day.
Sunday Night Stormy. Rain and snow could be heavy at times. Moderate to strong and gusty S winds turning SW and decreasing.
Monday Rain and snow showers could be heavy at times. Light to moderate SW winds turning W.
Sunday Night Stormy. Rain and snow could be heavy at times. Moderate to strong and gusty SW winds decreasing slightly.
Monday Rain and snow showers. Heaviest near the volcanoes. Light to moderate SW winds turning W. A few sun breaks possible in the afternoon.
Sunday Night Rain and snow could be locally heavy at times. Light to moderate E flow at Pass level with mixed precipitation expected. Light to moderate S ridgetop winds turning SW.
Monday Rain and snow showers with cooling. SW winds becoming light to moderate W.
Sunday Night Rain and snow could be locally heavy at times. Mixed precipitation and rain expected at Pass level. Light to moderate E flow. Ridgetop winds moderate to strong and gusty SSW, decreasing slightly and turning SW.
Monday Rain and snow becoming showery. Cooling. SW winds turning W and becoming light to moderate.
Sunday Night Rain and snow. Moderate S winds turning SW.
Monday Rain and snow showers. Winds becoming W moderate. A few sun breaks possible in the afternoon.
Sunday Night Rain and snow. Moderate to strong and gusty SW winds.
Monday Rain and snow showers. SW winds turning W and becoming moderate to strong and gusty. Sun breaks possible in the afternoon.
Sunday Night Rain and snow. Moderate to strong and gusty SW winds.
Monday Rain and snow showers. Moderate to strong and gusty SW winds turning W and increasing in the afternoon. A few sun breaks possible.
Sunday Night Stormy. Rain and snow with warming temperatures. Precipitation could be heavy at times. Strong and gusty SW winds.
Monday Stormy. Rain and snow could be heavy at times. Very strong and gusty SW winds turning W and decreasing slightly.

Precipitation (in)

Sunday Night Monday Monday Night Tuesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.25 LT 0.25 LT 0.10 LT 0.10
Mt Baker Ski Area 1.50 - 2.00 0.75 0.25 LT 0.10
Mt. Loop - Barlow Pass 1.00 0.50 0.25 0
Stevens Pass 0.25 - 0.50 0.25 - 0.50 0.25 0
Snoqualmie Pass 0.50 - 0.75 0.25 - 0.50 0.25 0
Crystal Mt 0.75 0.50 LT 0.25 0
Paradise 1.00 0.75 LT 0.25 0
White Pass 0.25 0.50 LT 0.10 0
Washington Pass 0.25 - 0.50 0.25 LT 0.25 0
Mission Ridge LT 0.25 LT 0.25 LT 0.10 0
Salmon la Sac - Gallagher Head 0.25 - 0.50 0.25 LT 0.25 0
Tieton River - Darland Mt. 0.25 0.25 LT 0.10 0
Mt Hood Meadows 0.50 - 0.75 0.50 - 0.75 0.25 LT 0.10
Timberline 0.75 0.75 0.25 LT 0.10
Hurricane Ridge Precipitation (in)
Sunday Night 0.25
Monday LT 0.25
Monday Night LT 0.10
Tuesday LT 0.10
Mt Baker Ski Area Precipitation (in)
Sunday Night 1.50 - 2.00
Monday 0.75
Monday Night 0.25
Tuesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Sunday Night 1.00
Monday 0.50
Monday Night 0.25
Tuesday 0
Stevens Pass Precipitation (in)
Sunday Night 0.25 - 0.50
Monday 0.25 - 0.50
Monday Night 0.25
Tuesday 0
Snoqualmie Pass Precipitation (in)
Sunday Night 0.50 - 0.75
Monday 0.25 - 0.50
Monday Night 0.25
Tuesday 0
Crystal Mt Precipitation (in)
Sunday Night 0.75
Monday 0.50
Monday Night LT 0.25
Tuesday 0
Paradise Precipitation (in)
Sunday Night 1.00
Monday 0.75
Monday Night LT 0.25
Tuesday 0
White Pass Precipitation (in)
Sunday Night 0.25
Monday 0.50
Monday Night LT 0.10
Tuesday 0
Washington Pass Precipitation (in)
Sunday Night 0.25 - 0.50
Monday 0.25
Monday Night LT 0.25
Tuesday 0
Mission Ridge Precipitation (in)
Sunday Night LT 0.25
Monday LT 0.25
Monday Night LT 0.10
Tuesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday Night 0.25 - 0.50
Monday 0.25
Monday Night LT 0.25
Tuesday 0
Tieton River - Darland Mt. Precipitation (in)
Sunday Night 0.25
Monday 0.25
Monday Night LT 0.10
Tuesday 0
Mt Hood Meadows Precipitation (in)
Sunday Night 0.50 - 0.75
Monday 0.50 - 0.75
Monday Night 0.25
Tuesday LT 0.10
Timberline Precipitation (in)
Sunday Night 0.75
Monday 0.75
Monday Night 0.25
Tuesday LT 0.10

Snow Level (ft)

Sunday Evening* Sunday Night* Monday Morning Monday Afternoon Monday Evening Monday Night Tuesday Morning* Tuesday Afternoon*
Olympics 4000' 3500' 3000' 2500' 1000' 500' 1500' 2000'
West North 3000' 3000' 3500' 3000' 1000' 500' 1500' 2000'
West Central 3000' 3500' 3500' 3000' 1500' 500' 1500' 2500'
West South 4000' 4500' 4500' 4000' 1000' 500' 1500' 2500'
Stevens Pass 3000' 3500' 3500' 3500' 1500' 500' 1500' 2500'
Snoqualmie Pass 3000' 3500' 3500' 3000' 1500' 500' 1500' 2500'
East North 2500' 3000' 3000' 3500' 1000' 0 1000' 2000'
East Central 3000' 3500' 3500' 3000' 1500' 0 1500' 2000'
East South 4000' 4500' 4500' 4500' 1500' 500' 1500' 2500'
Mt. Hood 4500' 5500' 5000' 4000' 2000' 500' 2000' 2500'
Olympics Elevation
Sunday Evening* 4000'
Sunday Night* 3500'
Monday Morning 3000'
Monday Afternoon 2500'
Monday Evening 1000'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2000'
West North Elevation
Sunday Evening* 3000'
Sunday Night* 3000'
Monday Morning 3500'
Monday Afternoon 3000'
Monday Evening 1000'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2000'
West Central Elevation
Sunday Evening* 3000'
Sunday Night* 3500'
Monday Morning 3500'
Monday Afternoon 3000'
Monday Evening 1500'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
West South Elevation
Sunday Evening* 4000'
Sunday Night* 4500'
Monday Morning 4500'
Monday Afternoon 4000'
Monday Evening 1000'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
Stevens Pass Elevation
Sunday Evening* 3000'
Sunday Night* 3500'
Monday Morning 3500'
Monday Afternoon 3500'
Monday Evening 1500'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
Snoqualmie Pass Elevation
Sunday Evening* 3000'
Sunday Night* 3500'
Monday Morning 3500'
Monday Afternoon 3000'
Monday Evening 1500'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
East North Elevation
Sunday Evening* 2500'
Sunday Night* 3000'
Monday Morning 3000'
Monday Afternoon 3500'
Monday Evening 1000'
Monday Night 0'
Tuesday Morning* 1000'
Tuesday Afternoon* 2000'
East Central Elevation
Sunday Evening* 3000'
Sunday Night* 3500'
Monday Morning 3500'
Monday Afternoon 3000'
Monday Evening 1500'
Monday Night 0'
Tuesday Morning* 1500'
Tuesday Afternoon* 2000'
East South Elevation
Sunday Evening* 4000'
Sunday Night* 4500'
Monday Morning 4500'
Monday Afternoon 4500'
Monday Evening 1500'
Monday Night 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
Mt. Hood Elevation
Sunday Evening* 4500'
Sunday Night* 5500'
Monday Morning 5000'
Monday Afternoon 4000'
Monday Evening 2000'
Monday Night 500'
Tuesday Morning* 2000'
Tuesday Afternoon* 2500'

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 30 / 27 28 / 21
West North 34 / 30 34 / 28
West Central 33 / 30 34 / 28
West South 35 / 30 34 / 26
Stevens Pass 31 / 28 31 / 26
Snoqualmie Pass 30 / 29 30 / 28
East North 27 / 23 29 / 26
East Central 36 / 28 34 / 28
East South 32 / 28 34 / 30
Mt. Hood 34 / 30 33 / 28
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 27
Monday 28 / 21
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 34 / 30
Monday 34 / 28
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 33 / 30
Monday 34 / 28
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 35 / 30
Monday 34 / 26
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 31 / 28
Monday 31 / 26
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 29
Monday 30 / 28
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 23
Monday 29 / 26
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 36 / 28
Monday 34 / 28
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 32 / 28
Monday 34 / 30
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 34 / 30
Monday 33 / 28

Ridgeline Winds (mph)

Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics SW 15-25 SW 15-25 SW 5-15 W 5-15
West North S 20-30 SW 15-25 SW 10-20 W 5-15
West Central S 20-30 SW 15-25 SW 10-20 W 10-20
West South SW 20-30 SW 15-25 SW 10-20 W 10-20
Stevens Pass S 10-20 SW 10-20 SW 5-15 W 10-20
Snoqualmie Pass SSW 20-30 SW 15-25 SW 5-15 W 10-20
East North S 15-25 SW 15-25 SW 5-15 W 15-25
East Central SW 20-30 SW 20-30 SW 15-25 W 20-30
East South SW 20-30 SW 20-30 SW 20-30 W 25-35
Mt. Hood SW 25-35 SW 25-35 SW 35-50 W 30-40
Olympics Ridgeline Winds (mph)
Sunday Evening SW 15-25
Sunday Night SW 15-25
Monday Morning SW 5-15
Monday Afternoon W 5-15
West North Ridgeline Winds (mph)
Sunday Evening S 20-30
Sunday Night SW 15-25
Monday Morning SW 10-20
Monday Afternoon W 5-15
West Central Ridgeline Winds (mph)
Sunday Evening S 20-30
Sunday Night SW 15-25
Monday Morning SW 10-20
Monday Afternoon W 10-20
West South Ridgeline Winds (mph)
Sunday Evening SW 20-30
Sunday Night SW 15-25
Monday Morning SW 10-20
Monday Afternoon W 10-20
Stevens Pass Ridgeline Winds (mph)
Sunday Evening S 10-20
Sunday Night SW 10-20
Monday Morning SW 5-15
Monday Afternoon W 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Evening SSW 20-30
Sunday Night SW 15-25
Monday Morning SW 5-15
Monday Afternoon W 10-20
East North Ridgeline Winds (mph)
Sunday Evening S 15-25
Sunday Night SW 15-25
Monday Morning SW 5-15
Monday Afternoon W 15-25
East Central Ridgeline Winds (mph)
Sunday Evening SW 20-30
Sunday Night SW 20-30
Monday Morning SW 15-25
Monday Afternoon W 20-30
East South Ridgeline Winds (mph)
Sunday Evening SW 20-30
Sunday Night SW 20-30
Monday Morning SW 20-30
Monday Afternoon W 25-35
Mt. Hood Ridgeline Winds (mph)
Sunday Evening SW 25-35
Sunday Night SW 25-35
Monday Morning SW 35-50
Monday Afternoon W 30-40

Extended Weather Synopsis

A short wave system should arrive in the Pacific Northwest Tuesday night and once again bring precipitation to the mountains. The associated low pressure will quickly swing over the area bringing about 12hrs of rain and snow. Without a significant moisture tap, this storm doesn't look that impressive. However, with cold air already in place, this should be an all snow event. The storm quickly exists Wednesday night and a high pressure ridge will start to build over the region. Expect dry weather with generally warm mostly sunny days and cold clear nights. 

Extended Snow Level (ft)

Tuesday Night Wednesday Wednesday Night Thursday *
West North 0 1500' 500' 3500'
Snoqualmie Pass 500' 2000' 1000' 3500'
Mt. Hood 1500' 2500' 1000' 3500'
West North Elevation
Tuesday Night 0'
Wednesday 1500'
Wednesday Night 500'
Thursday * 3500'
Snoqualmie Pass Elevation
Tuesday Night 500'
Wednesday 2000'
Wednesday Night 1000'
Thursday * 3500'
Mt. Hood Elevation
Tuesday Night 1500'
Wednesday 2500'
Wednesday Night 1000'
Thursday * 3500'

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

Previous forecast from Mar 12, 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’.