Loose Wet
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
The threat of natural and human-triggered wet loose avalanches will increase through the day with clear skies and above freezing temperatures. As temperatures warm, snow surfaces may destabilize causing avalanches on solar aspects - particularly below 9000'. The largest of these will occur on very steep, rocky slopes directly facing the sun, where solar input is greatest. This problem will follow the sun, starting with east aspects and wrapping around to south, then west aspects as the sun moves across the sky. These avalanches often initiate as a 'point release' near exposed rocks, the base of trees, or at your feet, and grow in size as they travel downhill entraining snow. Watch for early indications of a warming snow surface such as rollerballs, pinwheels, or wet surface snow. Even a small wet loose avalanche can quickly knock you off your feet and drag you downhill. Give yourself options, including low-angled routes and exits not threatened by steep sunny slopes above. Seek cooler, shaded terrain if you find snow becoming wet and unstable.
Additional Discussion: Isolated lingering wind slabs and large cornices may be found on upper elevation ridgelines. Wind slabs may be difficult to trigger but remain consequential in very steep, complex terrain. As temperatures warm, cornices will weaken, and could release naturally. Limit time beneath these features and remember that cornices can break further back than expected on ridgelines.
(2/3/2025)
D2 natural wet loose avalanche from a previous cycle in the Snake River Canyon
Photo: Bridger-Teton Avalanche Center