Bulletin d’avalanche

Mt Hood

Northwest Avalanche Center
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Danger d’avalanche

Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 2 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Pay attention to changing conditions with the avalanche danger ticking upwards on Thursday, and becoming dangerous quickly Thursday night.  Avalanches may be easier to trigger in areas where new snow builds over recently buried weak snow.  Be prepared to pivot to lower angle and wind-sheltered slopes if conditions warrant. 

Problèmes avalancheux

  • Wind Slabs

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

    Freshly formed wind slabs should be easy to find on lee slopes on Thursday.  While most will be small, some could be deep enough to produce large, consquential avalanches on large open slopes, or near terrain traps at lower elevations.  Where denser snow builds over recently buried weak snow (surface hoar and near surface facts), these avalanches may be easier to trigger and break more widely than the garden variety wind slab that you're used to in the Mt Hood area.   Shooting cracks, hollow-sounding snow, and snowpack collapses are obvious signs of instability that you should not ignore. Sheltered terrain with lower slope angles will offer safer riding opportunities.

    There's also uncertainity how quickly the 2nd serving of wind and snow will arrive on Thursday.  If storm conditons ramp up more quickly than forecast, you may be able to trigger storm slab avalanches on steep slopes even in lower elevation/wind-sheltered terrain. 

    (12/30/2024)

    Use small test slopes or quick hand pits to help you identify how the new snow is bonding to the old surface. Cracking like this is a good reason to dial it back. 

    Photo: Joe Dellaporta

Avalanche Discussion

A period of high pressure earlier in the week led to widespread surface hoar in many areas, including up to 7000' in the Mt Hood Meadows area.  We don't know how this weak layer survived following a few inches of fresh snow and strong ridgeline winds Tuesday night into Wednesday morning, but we're going to find out more about the snow stability as we enter an active storm cycle that lasts through the weekend.  A few public observations from 12/31 reported cracking in stiffer wind drifted snow but no new avalanches. It's unlikely that the larger wind slab avalanches in alpine terrain featured in the gallery below could be triggered by a human moving forward.   

Riding conditions and the overall snowpack coverage has improved rapidly over the last few weeks, especially compared to last year!

Let us know what you see by submitting a public observation. 

Régions couvertes