Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Today will be the last hurrah in a potent series of storms that began Monday night. Another 2-6" of dense snow is expected today, bringing storm totals to a solid 1-3' of snow (1-3" SWE) by the end of the day. Snowfall in this zone has heavily favored the Smoky mountain crest near Dollarhide Summit. Despite lower snow totals around the Wood River Valley, small, natural, and skier-triggered avalanches were reported above the Wood River Valley in the last two days.
Strong wind blew throughout each storm, blowing from the S on Monday before switching to the SW-W-WNW. Today's wind will blow moderate to strong from the SW, switching to the W by the afternoon.
Expect to find wind slabs, large drifts, and cornices in upper elevation and exposed middle elevation terrain. Triggering a wind slab is most likely near ridgelines, beneath cornices, and on the sides of cross-loaded gullies. Strong wind has mixed down into valley locations as well, so don't be surprised to find stiffer, wind-drifted snow near the mouths of main drainages, along Highway 75 and near prominent terrain features lower on slopes and on aprons at the bottom of chutes.
Some of the wind slabs may have formed above weak snow in the upper part of the snowpack and could be more sensitive to triggering than you would expect. Cracks shooting out in front of you are a clear sign you could trigger wind slab avalanches. Pay attention to how the snow feels beneath your boards or sled. If you feel the snow stiffen or notice you're staying closer to the surface instead of sinking deep into the snowpack, you've found wind-affected snow and should avoid steep slopes.
Additional Discussion:Yesterday, high temperatures in Ketchum and Hailey reached near 38 F. Similar temperatures are expected again today. This warming has caused rapid settlement in recent storm snow enhancing your chance of triggering a slab avalanche on even wind-sheltered slopes at low elevations. These avalanches should be small but can have big consequences if they drag you into a terrain trap like a road cut or a creek bottom. If the snow surface is wet, expect to be able to trigger small wet loose avalanches, particularly on very steep S-SW facing slopes where recent snow sits above stout crusts.
(1/5/2022) These small drifts were observed Wednesday in out-of-bounds terrain near Baldy.