Wind Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Possible
- Größe
- 1–2
Yesterday (Friday), new snow and shifting winds formed slabs of wind-drifted snow on various aspects. WMR snow safety reported slabs 8-12 inches thick that ran full path. My partner and I saw less action in the Swan Lake area, where thin, isolated pockets of wind-drifted snow cracked but were reluctant to slide. Slabs will be thickest and most sensitive at upper elevations or in places favored by the recent snowfall, like Tunnel Ridge in the Flathead Range. Look for wind-drifted snow along ridgelines and mid-slope terrain features like ribs and gullies.
Use small, inconsequential terrain features to assess this hazard. You'll know you've found a wind slab if the soft, light snow you're moving through suddenly feels heavier or becomes stiff enough that it supports your weight. Cracks shooting out from your skis or sled and collapsing the snowpack indicate the slab's instability. Slabs formed above weak, faceted snow can break above you and wider than expected. Choose terrain sheltered from the winds for a safer, more enjoyable experience.
Additional Discussion: Loose-dry snow may sluff and run long distances in steep terrain sheltered from the wind. These may travel further than expected where the new snow rests on a crust. These slides can be dangerous if they knock you off your feet, over a cliff, or into a spot where debris can pile up deep–like a creek bed or gully. Where new snow fell on surface hoar, it may be possible to trigger small slabs of storm snow. These could be problematic when you find 8 or more inches of new snow.
(3/6/2023)
very small drifts produced isolated cracking.
Photo: sw