Bulletin d’avalanche

Central Cascades

Central Oregon Avalanche Center
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Danger d’avalanche

Tue
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible
Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Avalanches are unlikely on Monday.  There are several weak layers of snow in our uppermost snow pack, but they have not proven weak enough to result in avalanches.  If you are riding somewhere steep near treeline or on protected alpine slopes it is worth investigating these layers by digging into the snow.  As always heed any signs of instability such audible whumphs or collapsing in the snowpack and stick with safe travel techniques.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1–2

    We have two persistent weak layers that we are paying attention to.  Both are in the upper snow pack and neither has proven weak enough to result in avalanches.  That doesn't mean that it is OK to disregard them.  Riding steep and committing slopes at the indicated elevations and aspects without some investigation would be fool hardy.  The compression test is a perfect tool for learning about these layers.

    The first is a layer of buried surface hoar that is down 20 cm. and present on sheltered slopes predominently near treeline and just above.

    The second weak layer consists of poorly developed facets beneath a crust that is down 30 cm.  It is most prevalent and weakest on the coldest slopes (shady North slopes near treeline and above).

    We'll be watching and remembering these layers, particularly if we receive a lot of new snow.

     

Avalanche Discussion

What a difference an inch or two of new snow makes this winter, and some more wintery temperatures! 

Our layers of interest are the two previously mentioned persistent weak layers in the upper 30 cm. of the snow pack.  This is a great time to refresh your compression test skills (easy digging and cool stuff to observe). 

It is also notable that there are variable crusts in our upper snowpack based upon elevation.  Today I heard a lot of "crackly and crunchy" sounds associated with my skis breaking through upper crust layers.  I didn't consider these to be the whumphing sounds that we associate with weak layer failure and avalanche activity.  If it's hard to tell, ask your friend, "did you hear/feel that?", and play it safe when in doubt.  There might be a bit of both: crunchy sounds and genuine whumphs out there.

Régions couvertes