Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

More snow and warming temperatures may make triggering large, deadly avalanches easy on Monday. Your best bet will be to avoid steep slopes - especially in the wind drifted areas - until this storm cycle has run its course. Look for very dangerous avalanche conditions to develop during the evening hours. 

 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3

    More precipitation (up to 1 in SWE), continued heavy drifting, and warming temperatures will maintain the threat of large, deadly avalanches. These avalanches will be up 2-4 ft thick and may propagate widely if they rest on weak snow near a crust. With warming temperatures and heavy precipitation rates - we'll likely see a natural avalanche cycle during the evening hours.

    This won't be the avalanche problem to test your luck with. Avoidance will be key. So, use visual clues to help you identify where the problems lurk. 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. Shooting cracks under your feet or machine clearly shows you found an unstable slab. 

    (1/6/2024)

    Any triggered avalanche in wind-drifted snow could be very destructive. 

    This is hard slab debris from the human triggered avalanche on Pea Gravel Ridge on Saturday. 

    Photo: Jack Kuenzle

  • Storm Slabs

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

    New snow will accumulate on warming temperatures, creating upside-down layering and reactive storm slabs. It may be easy for you to trigger soft slabs on any steep convexity, especially during heavy periods of precipitation. The best policy will be to avoid steep slopes greater than 35 degrees until this storm cycle has run its course.

    (12/1/2023)

    An example of a storm slab in the Baker Backcountry. 

    Photo: Irene Henninger

Avalanche Discussion

Wow, the Mt Hood zone went from zero to hero in the matter of 48 hours. As I write this, the Mt Hood Meadows weather station is reporting over 28 inches of new snow (2.85 SWE). 

Over the weekend, backcountry travelers have reported triggering large avalanches, whumping collapses, and propagating test results. Most notably, on Saturday, a group in the Pea Gravel Ridge area had a close call and remotely triggered a D 2.5 hard slab that broke above them while on the descent. It occurred on an east aspect at 6100 ft. The bed surface is unknown but likely failed on old, weak snow from late December. On Sunday, the Meadows Pro Patrol triggered avalanches with explosives in wind drifted snow and one result produced a 2-3 ft crown on the Gods Wall (5500 ft, E aspect). They also reported the debris of a very large avalanche in upper Heather Canyon. This natural avalanche likely occurred during the evening hours on Saturday. And the list goes on, with the USGS reporting a seismic signal in upper White River, which also was a D3 avalanche that  occurred during the heavy precipitation rates on Saturday night. 

The storm cycle is only ramping up on Monday. Look for warming temperatures, increasing precipitation, and likely rain on snow up to 6500 ft on Monday night. This combination will likely create a large natural avalanche cycle. 

If you get out, let us know what you see by submitting a public observation!

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