Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
Continued wind transport was observed yesterday in the alpine terrain of the Greys River and Teton zones. These wind slabs are becoming less sensitive to the weight of a skier or rider, but some are sitting atop weak snow surfaces (facets and/or crusts) and remain touchy. Recognize that wind-loading also adds stress to the weak layers buried in the snowpack (described in Problem 2 below). Any wind slab you trigger could step down to deeper layers, producing a much larger, more dangerous avalanche. While the slabs you encounter today are less likely to be large, they may produce slides large enough to knock you off your feet and send you downslope. Look for evidence of wind drifting such as dune-like drifts and ripples on the snow surface. Cracks shooting out from your skis or board are a sure sign that you've found a sensitive wind drift.
ADDITIONAL DISCUSSIONDirect sunshine on fresh snow is a recipe for loose snow avalanches. Variable cloud cover and winds blowing out of the SE will both help to keep the snow surface cool, but the intense March sunshine will quickly melt the snow when it breaks free from the clouds. Be aware of prolonged periods of sunshine and how that is altering the snow surrounding you. Moving forward into March, you're most likely to encounter this problem on very steep, rocky slopes that directly face the sun.