Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
4 · Forte
Limite del bosco
4 · Forte
Sotto il limite
3 · Marcato
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In sintesi

Wet snow avalanches are very likely as warm temperatures and rain continue Wednesday. Avoid steep slopes and lower angle areas beneath large, steep open slopes as well. 

Problemi valanghivi

  • Wet Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1.5–2.5

    Fellow NWAC forecaster Lee Lazarra traveled into the Baker backcountry Tuesday, where he encountered wet loose avalanches, glide cracks, a very small glide avalanche, and sagging cornices (see photos). You can read his observation HERE.  Another OBSERVATION came in from a hiker who reported a wet slab avalanche, probably failing naturally in the early morning hours, near Excelsior Peak. 

    We've got a myriad of wet snow problems that we're encountering- at earlier stages in the rain event wet loose avalanches were more common, but as more water is added to the snowpack and temperatures continue to increase, the problem could shift more towards wet slab avalanches. 

    By Wednesday morning 3-4 inches of rain will have fallen in the West North zone over the last 36 hours. Snowlines started around 5000ft and are only increasing in elevation.  It is alarming to see this much water falling on a snowpack that was previously mostly dry, low density snow.

    Wet snow avalanches tend to be less predictable than dry snow avalanches, and the chances of a human triggering one are very likely. Natural avalanches are likely. For this reason, stay off of steep slopes, and avoid traveling beneath large, steep slopes as well.

    (1/11/2022) Public Field Observation: A wet slab avalanche near Excelsior Peak. This probably occurred Tuesday morning. Around 5100 ft, S facing.  : NWAC Public Obs

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    3

    Infrequent very large avalanches occurred on a deeper buried weak layer since around Christmas. Not much is known about these avalanches, or how widespread the weakness is. The added weight of rain on the snowpack, and warmer temperatures, makes for a good test to determine whether any more large, alpine slopes could slide on this layer. Chances that one of these very large avalanches could occur are unlikely, but keep it in the back of your mind as more weight is added to the snowpack if you're out on Wednesday. Consider that large deep slab avalanches from higher terrain could run into lower elevations.

Avalanche Discussion

If you make it up to the highest reaches of the forecast zone, you may still encounter slab avalanches. Strong winds are redistributing snow, and you could trigger a slab avalanche in freshly deposited areas. At this point, the elevations where you might encounter dry snow are probably above where we forecast for, an impressive feat for Wednesday. 

Temperatures shifted from cooler to warm since the New Year, several feet of snow fell and now we've got rain on top. A lone clear day on Sunday (1/9) initiated even warmer temperatures and gave us one good day to get out into the mountains, glimpse recent avalanches, and the chance to quickly check out what's been going on in the snowpack before unsettled weather regained its grasp. There are a lot of uncertainties right now, it's a good day to stay aware of your surroundings and travel very carefully if you head into the backcountry. 

Regioni coperte