Wet Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Likely
- Taille
- 1–2
With another inch of rain expected through Friday, wet snow avalanches need to be on your mind. Especially at higher elevations, continued rain will work its way further down into a previously dry snowpack, increasing the possibility of large and powerful wet slab avalanches. We've already seen a cycle of glide avalanches (wet snow avalanches that run to ground) and while this AR event may not be as wet or prolonged as what we saw around the Christmas period, you'll want to avoid traveling in or below steep slopes with smooth underlying bed surfaces, like the 20th of June path for example.
Wet slab and glide avalanches are notoriously unpredictable, with changes happening out of sight in the snowpack over time. They typically cannot be directly correlated to the most intense part of a storm cycle. Generally avoid stepping out onto steep open slopes near and above treeline capable of producing large avalanches. Let the storm play out and allow the wet weak upper snowpack to stabilize over the next few days as temperatures drop.
Human and natural wet loose avalanches will also be possible on Friday. You may see evidence of a natural wet loose cycle from earlier in the storm as temperatures rose and snow changed to rain. The travel advice is simple; if you see natural wet loose avalanches or find yourself sinking into wet surface snow of more than a few inches, avoid steep slopes. Small wet loose avalanches may gouge down to older weaker wet snow, becoming larger and more powerful. Use extra care near terrain traps like cliffs, rocks, and other hazards that would amplify the consequences of a small avalanche.
(12/26/2022)
Just a few weeks ago the 20th of June slide path avalanched to the ground. This glide avalanche occurred during the prolonged mild and rainy period preceding the 26th of Dec.
Photo: Sam siemens-luthy