Bulletin d’avalanche

Mt Hood

Northwest Avalanche Center
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Danger d’avalanche

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

Points saillants

Sunday will be another heads-up day in the Mt Hood area. The most dangerous areas will be pockets of wind-drifted snow - but still, consider any slopes greater than 35 degrees as a suspect. The best policy is to give the new snow time to settle out. 

UPDATE: Increased danger to CONSIDERABLE at lower elevations due to increased storm totals and expected size of avalanches. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–2.5

    Strong west winds will continue to drift new snow into slabs that could be up to 2-3 ft deep on leeward slopes. These slabs are rapidly growing in depth and will easily be large enough to bury and kill a person on Sunday. This won’t be the avalanche problem to tiptoe around. Some slabs may break wider than expected if they rest on weak, faceted snow sitting over a crust. 

    Fortunately, you’ll likely receive many signs to help you identify where the problem lives. Look for blowing snow, cornice growth, ripples, or rounded pillows of snow to help you identify where the wind has been at work. Due to recent high winds, you may also find these slabs forming further down slope than usual or on mid-slope convexities. Pull back and default to less exposed terrain if you see shooting cracks under your feet or machine. 

    The best policy will be to avoid all wind loaded slopes until this storm has run its course. 

    (3/23/2023)

    Pump the brakes and move to less steep terrain if you observe signs like this.

    Photo: Joe Dellaporta

  • Storm Slabs

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

    The new storm snow will likely stay reactive until precipitation tapers mid-morning. Consider any slope greater than 35 degrees as suspect until the new snow settles. You can use small test slopes or hand pits to check how reactive the storm snow is. The best policy is to give steep slopes some time before jumping into them. 

    Consider fast-moving, dry loose avalanches in any steep terrain. These may be smaller in size but could push you into unwanted terrain features if caught. 

    (12/20/2022)

    An example of a small storm slab. 

    Photo: Public Observation

Avalanche Discussion

Saturday was a stormy day on Mt Hood. As I write this, the telemetry across the mountain is reading over 20 inches of snow (>2 in SWE). Backcountry travelers in the Pea Gravel Ridge area had a close call and remotely triggered a large hard slab (D 2.5) avalanche that broke above them in wind-drifted snow. It occurred on an east aspect at 6100 ft. The bed surface is unknown, but it likely failed on old, weak snow from late December. The Mt Hood Meadows Pro Patrol also reported propagating slab failing up to 18 inches deep in wind-loaded pockets during avalanche mitigation work. They also observed dry loose avalanches running in steeper, more sheltered terrain. 

The winter storm train has officially commenced across the Pacific Northwest. You may be hungry to find the goods, but be sure to temper your stoke as Sunday is shaping up to be another dangerous day for mountain travel. 

We went from zero to hero in a matter of 24 hours. Prior to this storm, lower elevations had little to no snow. So still keep an eye out for hidden hazards such a rocks, trees, and creeks. All of which could easily exacerbate the consequence of even a small avalanche.

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

 

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