Loose Wet
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Possible
- Taille
- 1–2
Observers reported a moderate freeze and supportable crusts yesterday morning, but very warm mountain temperatures led to wet, mushy snow surfaces by the afternoon. I saw numerous fresh wet loose slides yesterday afternoon in the Boulders, Smokys, and Sawtooths. Most of these were small, but I observed one medium-sized wet slide in the southern Sawtooths (photo above/right).
Temperatures remained in the mid to upper-30s F last night. With mostly clear skies, the snowpack surface probably received a weak re-freeze this morning. But several days of very warm temperatures are leading to increasing meltwater within the snowpack. As a result, expect the chance of both natural and triggered wet slides to increase quickly today. The potential for larger wet slides will also increase through the weekend—some avalanches may gouge deeper into the snowpack.
As the hottest weather of the winter continues, we need to step back and take a more conservative approach. If you're hunting for corn, plan to be off of—and out from beneath—steep slopes before the surface turns to wet mush. If you're finding that the weak overnight freeze produced a crust that is thin and barely supportable, it may be a good idea to pull the plug on your objective. Expect wet snow problems to wrap into shadier terrain, especially at mid-elevations.
ADDITIONAL DISCUSSION - WET SLABS: Wet slab avalanches are tough to predict, but we do know they are more likely when 1) Well-defined weak layers exist in the snowpack, and 2) During prolonged warm weather with little to no overnight freezing. Sound familiar? Spring doesn't always lead to a predictably stable snowpack (watch video from Galena Summit on Friday). Although triggering a wet slab isn't likely, they should factor into your plans during this and subsequent warming events this spring. This isn't the year to be playing in steep, consequential avalanche terrain with only a weak re-freeze and thin surface crust, and make sure to give yourself an extra margin of safety to be out of harm's way before the surface gets wet and mushy.
4/2/2021) Expect wet slides to increase in size this weekend as the snowpack becomes wetter and weaker. This medium-sized wet slide ran Friday afternoon near McDonald Peak in the southern Sawtooths. 9800', E.