Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
It's been 24 hours of post-storm conditions. Large wind slabs that formed during the last storm period from strong southeasterly winds are becoming less widespread and consolidated to steep isolated areas near and above treeline that hold a touch of north and exist along convex trigger points. If you encounter wind-textured snow beneath a cornice, ridgeline, or rock outcropping, consider it loaded.
A switch in weather flow will deliver north and west winds near and above treeline blowing at light to moderate speeds. These speeds are ideal for drifting snow. This will be the next big influencer on the snowpack. These winds will be accompanied by 3-6 inches of new snowfall, giving winds ample ammunition to redistribute old and new storm snow onto E-SE-S-SW-W aspects. This will add stress to previously formed wind slabs and any lingering instabilities within the snowpack. New snowfall may mask any previous signs of wind effect. Investigate under the surface for denser snow above softer snow, as this will help identify areas that have previously experienced wind loading.
An upside-down snowpack structure plagues our forecast region near and below treeline. Remain cautious of steep slopes in consequential terrain, as these may still harbor recent storm instabilities. Although no recent avalanches or obvious signs of instabilities have been observed, stability tests are still resulting in propagation on a crust interface 42 cm (17”) down from the surface. This layer has proven to be very stubborn and would need a large trigger, like a cornice collapse to trigger it. Nevertheless, you don't want to be the straw that breaks the camel's back.
(2/6/2024)
ECTP12 propagating on a crust interface 45 cm (17") down. East aspect and 6,500 feet
Photo: Eric Falconer