Bollettino valanghe

Rattlesnake

West Central Montana Avalanche Center
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Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
Senza grado
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In sintesi

Another day of record warm temperatures and little or no refreeze overnight will create conditions where human triggered wet snow avalanches are likely, and large natural avalanches are possible. The primary hazard at mid elevation is larger avalanches running down from upper elevation into mid elevation terrain. Pay attention to the terrain above you and minimize the time you spend under large south facing slide paths today. 

If you see small point releases begginning to entrain more snow and grow in size, or find yourself sinking into wet and unsupportable snow, stay away from avalanche terrain. 

Avalanche Danger could rise to Considerable on upper elevation sunny slopes by this afternon if ridgetop winds are lighter than forecasted. 

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    The nuance of the wet snow problem changes as you move up or down in elevation and around the compass. A common theme will be that terrain size and length of slidepath will dictate how large avalanches will become. Larger paths have potential for D2+ avalanches today, while widespread D1-D1.5 avalanches are likely in smaller paths.  We expected to see a more widespread natural avalanche cycle yesterday but did not. Wet snow can be hard to predict when it will be most reactive and today has potential to be an active day in the mountains. 

    • Upper elevation West-South-East aspects are where the largest avalanches are likely to start. There is more snow in these start zones and the wet snow has not had a solid refreeze in 3 days. The top 6-12 inches of snow is saturated with water and any refreeze overnight was thin, and will break down quickly today. Buried near surface facets below the wet snow are becoming saturated with water for the first time this season rapidly decreasing the strength of the snowpack. These are also the avalanches that have potential to run down into the mid elevation band in larger paths or extreme terrain. 
    • Mid elevation West-South-East aspects do not have large amount of snow in the start zones. The snow in these areas is becoming saturated with water all the way to the ground. You are likely to trigger an avalanche in steep areas of this terrain, but avalanche size will be smaller. Keep in mind if a small avalanche runs into a terrain trap, it will still be able to bury you. Larger avalanches that start in upper elevation have potential to run down into mid elevation on these aspects in larger paths.
    • Upper elevation north aspects: We removed the problem here as increased winds today should help to keep this terrain cool. Despite 55+ degree temperatures the past two days, steeper slopes on this aspect have not progressed past being damp and wet snow avalanches are unlikely here.  Sun angles are not quite high enough in the sky to impact steeper north facing slopes, but slopes less than 35 degrees are getting strong sun and wet snow.
    • Mid elevation north aspects are where the most variability lies. Today will the the third day with temperatures approaching 60 degrees and no refreeze. Without direct sunlight, start zones with tighter green trees are much more wet than steeper open terrain. This has to do with the energy (radiation) balance within the snowpack. Snowpack totals on this aspect/elevation vary across zones and while some slopes have large amounts of snow in start zones, other areas are near dirt. The key takaway is that if you are sinking into unsupportable snow, stick to lower slope angles where wet snow avalanches will not run as easily. 

    The typical wet snow travel advice of getting out going out in the morning, then leaving avalanche terrain as the crust breaks down into wet snow does not work today. With minimal overnight refreeze, potential for wet snow avalanches will exist first thing this morning. Identify the problem by using test slopes to see how reactive the wet snow is, or just avoid slopes over 30 degrees if you find yourself sinking into wet snow. Do not linger under avalanche terrain as conditions in the start zone may be more reactive and avalanches could run naturally. 

    (2/6/2026)

    Human triggered wet loose avalanche on an upper elevation southeast aspect in Jenny Bowl

    Photo: Arden Feldman

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    While it is hard to get happy about warm weather and no new snow, the positive is that with the snowpack warming and becoming wet, we are seeing the buried layer of surface hoar become wet and even destroyed. Having said that, this layer is still present and preserved on upper elevation north aspects and in pockets of terrain at mid elevation. 

    This layer formed during the January dry period then was buried by 2-6 inches of snow. In areas where the wind drifted the snow, it is buried 6-10 inches deep. In areas with a thicker slab above it, triggering an avalanches is possible. 

    Identify the problem by digging into the snowpack and looking for a thin grey line 2-10 inches below the snow surface. If you identify the problem in your snowpit, or experience collapsing or whumfing on it, stay off slopes over 30 degrees. 

    If we see a significant snowfall event next week, we expect the buried surface hoar to become reactive with larger avalanches likely. Keep track of where you are seeing it right now to prepare for when a larger slab forms on top of it. 

     

Avalanche Discussion

Another day of warm weather and minimal refreeze. While it may feel like Spring, we need to remember that it is still early February and a rapid prolonged warming like this is a rapid change to the snowpack. For the past few days, temperatures have been in the high 40s at upper elevation and 50s at mid elevation with strong sun. Overnight, the lack of cloud cover has allowed the snowpack to cool despite minimal winds. Last night, we flipped that and saw increased cloud cover alongside increased wind. While the increased cloud cover slowed any overnight refreeze, the wind likely helped cool the snow. The sun angle is still relatively low in the sky due to the time of year but slopes that are sun facing are getting cooked. In short, there are multiple processes occurring each night that are affecting how wet the snow gets.

Great skiing and riding still exists at upper elevation on north facing slopes, but the cost of entry on approaches is increasing. Don't pick up the golf clubs yet as winter is not over. Next week looks like a pattern shift with snow returning. 

You’ll notice we’ve removed a low elevation hazard rating for Seeley Lake and the Rattlesnake. Our low elevation in these regions tops out below the extent of large run-outs, and we don’t expect avalanches from above to run all the way to 5500 feet. There is also not enough snow to trigger an avalanche at these low elevations. In the Bitterroot, Lolo Pass is likely the only area where low elevation avalanches are possible. 

Glide cracks have opened up on isolated slopes throughout the region. Cornices can also fail naturally with warming temperatures. Both of these avalanche problems are unpredictable, and avoidance is the answer. Don’t travel below cornices or open glide cracks, especially as temperatures continue to warm.

Avalanche education is a lifelong journey built on developing sound judgment, gaining experience, and applying repeatable decision-making systems in the backcountry. Our American Avalanche Association (A3) recognized Level 1, Rescue, and Level 2 courses are offered throughout the winter and help you travel smarter in avalanche terrain. Explore current courses and registration on the Education page. 

Please continue to submit observations and ski and ride safe!

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