Avalanche forecast

Stevens Pass

Jan 25 – 26, 2020Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Avalanche conditions will be defined by elevation on Sunday. New snow and wind will form slabs at higher elevations. Warming daytime temperatures and will create wet avalanche danger at lower elevations. Travel with caution, and monitor quickly changing conditions during the day.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Another round of snow, along with a burst of westerly winds at upper elevations may build shallow storm slabs. Slabs will be thicker and more reactive in wind loaded terrain. Avalanches within new and wind loaded snow may become large on upper elevation slopes 35 degrees and steeper. Use small inconsequential slopes to test how the new snow is bonding. Shooting cracks and recent avalanches are red flag signs of unstable snow. Steer around large, steep, convex slopes where you find deep new snow. Stick to lower angled and supported terrain to reduce your risk.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    The new snow that falls may become moist as the day warms up. Potential for loose wet avalanches will increase when this happens. Look for signs such as rollerballs with sticky snow, and recent fan shaped avalanche debris. If you find these signs, avoid slopes steeper than 35 degrees. Be especially cautious underneath steep slopes, near cliffs, creeks and other terrain traps. Remember that loose wet avalanches are often surprisingly powerful and being caught in even a small one can be dangerous.

Discussion

On Saturday, a small, natural wet loose cycle was noted during the afternoon hours at Stevens Pass. These were occurring within the newly fallen snow as daytime temperatures warmed up. Another round of snow and rain is expected into the day on Sunday, with snow line hovering around pass level. Fresh slabs are expected to grow at upper elevations, enhanced by a burst of moderate westerly winds. Despite the gradual cooling trend, the snowpack is still saturated from the recent rain event. Keep this in mind while traveling at lower elevations on Sunday.

Snowpack Discussion

Update: January 24th 2020 (The regional synopsis is updated every Thursday @ 6 pm)

During the afternoon of January 23, 2020 one person was buried and killed by an avalanche that released from the roof of a home north of Blewett Pass near Highway 97. The elevation was approximately 1,700ft above sea level. She was found underneath 4 to 5ft of debris. She was discovered and excavated some time after the accident, where CPR was performed. Additional emergency response arrived within 15 minutes, but they were unable to revive her.

Our deepest condolences go out to the family and friends of the victim.

 

January to Remember

A parade of storms since the New Year began brought relentless precipitation, and impressive snowpack growth throughout the region. Areas along the west slopes of the Cascades have rarely gone more than 24-48hrs without precipitation. In the past three weeks, the Volcanoes and Passes received 20-28in of water equivalent, translating into incredible snowfall totals - Mt. Baker Ski Area reported 240in of new snow since January 1. The majority of NWAC weather station sites are reporting snow depths well over 120% of normal for this time of year. Ongoing precipitation and fluctuating snow levels have maintained elevated avalanche danger throughout the month, with avalanche warnings issued for nearly all forecast zones on 4 separate days (January 6, 7, 12, 23).  

Snow depth imagery for the Northwest Region on January 23, 2020. Many areas in the Cascades and Olympics show well over 100 inches of snow on the ground. Image courtesy of NOHRSC Regional Snow Analysis. 

Location

January 1-23 Precipitation (Water Equivalent)

Hurricane Ridge

14.79”

Mt Baker Ski Area

28.65”

Harts Pass

11.2”

Stevens Pass

20.26”

Leavenworth

4.01”

Snoqualmie Pass

25.43”

Paradise, Mt Rainier

24.13”

Mt Hood Meadows

22.34”

Table 1: Precipitation totals for select weather stations January 1-23, 2020. Huge numbers at Baker, Rainier, Hood, and the Passes and there is still another week left this month.

MLK Weekend and a Pattern of Rain on Dry Snow

After a prolonged cold period with arctic air and lowland snow, MLK weekend brought unseasonably warm temperatures and a rapid thaw. High snow levels and rain caused wet avalanche activity throughout the region January 18-19. A few very large natural avalanches occurred at upper elevations where all precipitation fell as snow. A cooling trend followed, creating a pronounced crust that is now buried in almost all forecast zones. Cold, dry snow January 21-22 was followed by a rapid warm-up and the most significant rain on snow event yet, causing avalanche warnings on January 23 for 5 of our 10 forecast zones.

The crown of a very large avalanche around 10,000ft on the Newton Headwall of Mt Hood which likely occurred during the storm late last week. 01/19/20 Photo: Kevin Kayl

The buried MLK crust is widespread throughout the region and a prominent marker in the snowpack. Crystal Backcountry 01/20/20 Photo Jeremy Allyn

One More Week To Go

January isn’t over yet, and the long term forecast continues to show an active and wet weather pattern for the Northwest. The low-snow, drought-like conditions of the early season seem like a distant memory at this point. We’ve certainly made up for lost time in 2020, and this already impressive month looks to end with a bang.

Regions covered