Bulletin d’avalanche

Stevens Pass

Northwest Avalanche Center
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Danger d’avalanche

Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Heavy rain with warm temperatures will create dangerous wet snow avalanche conditions. We expect most natural avalanches to occur overnight, but increased avalanche activity could linger into Monday. Avoid traveling on steep slopes with deep, heavy, wet snow, and don't linger near gullies where wet avalanches can flow from above.

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Snow surfaces are already heavy and wet, but with the addition of heavy rain on Sunday night, the snowpack will become very weak. Rollerballs and wet, sticky snow surfaces are good indicators of this problem. Wet avalanches could start from higher in the terrain and funnel through gullies into lower elevations. Let the snowpack adjust to this drastic change and stick to low-angle terrain, avoiding steep slopes and gullies.

    Wet snow packs a lot of mass, making wet-snow avalanches very destructive and difficult to escape if you're caught. While we expect most natural avalanches to occur overnight during the heaviest precipitation, there is still potential for large wet natural avalanches during the day.  There is also a smaller chance of wet slab avalanches failing on various storm interfaces or crusts in the upper snowpack. While these are less likely, they are much more unpredictable. So stack the odds in your favor by choosing conservative terrain. 

    (3/24/2025)

    An example of large wet avalanches in steep terrain during a rain on snow event. 

    Photo: Katie Warren

Avalanche Discussion

Avalanche Fatality: On Friday, January 9th, four backcountry skiers were caught and carried by a large avalanche while descending near Longs Pass in the Teanaway River drainage. The slide occurred on an S to SE facing slope at approximately 6200ft. One member of the party was not buried. Another teammate was partially buried but injured. The other two individuals were fully buried. During the initial rescue, the team located one of the buried victims, who did not survive. Despite the group's best efforts, they could not pinpoint the fourth member of their team. The party contacted 911 via a satellite device, and Kittitas County Search and Rescue responded to the area on Friday evening. Additional rescue efforts were postponed until daylight. Search and Rescue then returned to the site on Saturday and were joined by NWAC forecasters. The teams were able to locate the remaining victim. Unfortunately, neither of the fully buried skiers survived. Our deepest condolences to the family, friends, and community of those involved in this avalanche accident. S-SE aspect, 6200ft, Avg Depth 2ft, HS-AS-R3-D2.5-O

Forecast Discussion:

Another atmospheric river (AR) is probably the last thing any of us ordered, but it's here anyway. Stevens Pass may pick up just over an inch of rain by the end of the day on Monday. We expect the brunt of the precipitation to fall overnight, but Monday will still be a soggy, warm day. This AR is fairly narrow, so there is a chance that we end up with significantly less precipitation than forecasted. 

Approximately 3-3.5' of snow rests over the January 3rd melt-freeze crust. While the overlying snow had generally been well-bonded to the crust, avalanche observations during the storm proved otherwise. A few notable deep avalanches did or were likely to have failed on this crust. If warming and rain begin to impact this crust, we may see wet slabs failing at this interface. Wet slab activity tends to be delayed, but the timing is very hard to forecast. We may see some wet slabs as early as Monday, or, if they occur at all, the tipping point may be continued warming and direct sun on Tuesday or Wednesday.

There are a few other crusts in the snowpack that serve as good markers. About  1 foot below the January 3rd crust is a thin December 24th crust, which can be found up to 5500ft. A stout crust from December 18th, should now be near the lower third of the snowpack. 

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