Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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In sintesi

The most dangerous places on Saturday will be in areas that hold pockets of wind-drifted snow. These avalanches could be large enough to bury or kill you, especially in heavily loaded alpine terrain. As you travel, look for blowing snow and textured pillows to help you identify problematic slopes. 

Problemi valanghivi

  • Wind Slabs

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

    Wind slabs will stay fresh and reactive to your weight on Saturday. Increasing south and east winds will continue to drift snow into cohesive slabs. Due to recent east winds, don't be surprised if you find these slabs all over the compass on Saturday. Look for these slabs as you change aspects, especially in areas that promote drifting, such as the downwind sides of ridges, beneath rock and cliff bands, or on the breakover of unsupported features. 

    Recent observations have illustrated weak snow grains about 1-2 ft below the snow surface and sometimes sitting over a crust. These grains are also responsible for propagating test results along with recent natural and explosive-triggered slabs. If a wind slab rests over this structure, the resulting avalanche  could break widely. To avoid this problem, stick to more sheltered slopes and avoid travel on terrain steeper than 35 degrees if the surface snow appears textured and rounded. Take a big step back if you notice shooting cracks or audible whumphs. 

    Storm slabs should settle out by Saturday, but still look for hard over soft layering and signs of instability before committing to steeper terrain in more sheltered areas. You can use small test slopes to gauge the reactivity of this storm snow. 

    (2/16/2024)

    You could trigger similar-sized avalanches on Saturday.

    An explosive triggered soft slab in the A zone in upper Heather Canyon.

    SS-AA-R2-D2-U

    NE, 7500 ft

    Photo: Joe Dellaporta

Avalanche Discussion

An incoming system will bring a strong dose of east winds along with increasing chances for precipitation as the day progresses. This storm won’t be a big snow producer for Mt Hood, but maybe just enough to freshen up some old tracks by Sunday morning. What it will do is maintain the likelihood of avalanches in exposed, wind-loaded areas. 

Backcountry travelers and avalanche professionals reported numerous avalanches on Friday. Most of the large avalanches occurred in heavily wind-loaded terrain above 6000 ft. The Mt Hood Meadows Pro Patrol even reported an artillery-triggered D 2.5 just beneath the Newton Clark Headwall at roughly 8500 ft, E aspect. Another observer in the Goverment Camp area saw a large, natural slab near West Crater Rim on the south side (photo in gallery). However, avalanches were not just limited to exposed terrain,  travelers still reported triggering small storm slabs failing on a crust below treeline. 

So far, we've received nearly 20 inches of low-density new snow, which has improved riding conditions immensely across the Mt Hood zone. On Friday, I went out to track this new snow and a couple notable layers of concern in the upper snowpack: the EFC & the 2/14 (new/old snow interface). In my travels, I found the 2/14, producing consistent propagation on E- NE aspects above 6000 ft. This layer sat about 15-20 inches below the surface and consisted of mixed forms in this location. However, other observers reported finding buried surface hoar at similar depths. We’re not sure how long this layer of mixed forms will persist since they aren't straight facets, but it's worth keeping on your radar as you move through terrain. The best strategy will be to dig down and use snowpack tests to gauge the sensitivity of this potential weak layer before trusting steeper terrain features. 

 Your avalanche, snowpack, or weather observations are extremely valuable to the avalanche community. Help create a more accurate avalanche forecast by submitting your observations here. 

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