Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2
With strong winds overnight and fresh snow, sensitive slabs of wind-drifted snow are likely to be encountered on all upper-elevation slopes and mid-elevation terrain features that allow for drifting snow accumulation. These drifts could be 6-24 inches deep and up to 150 feet wide. Watch out for signs of wind-drifted snow, such as pillow-shaped deposits, and avoid those slopes. Give cornices a wide berth. Any avalanches, wind-drifted snow, or new snow may be sensitive today due to weak grains at the interface between the new snow and old snow. The Valentine's Day storm buried facets, weak stellars, and surface hoar on many slopes. While this layer is not as prevalent in the Ogden area, it does exist. A skier-triggered avalanche occurred on a southeast-facing aspect in the Toilet Bowl region of Hell's Canyon. This avalanche was triggered by a skier at 7700 feet. It ran on small-grained facets above a melt-freeze crust, breaking above the skier. This avalanche is similar to others we've seen recently in wind-protected areas, where there was enough time before the last storm for small facets to develop and be preserved on top of the crust. This avalanche, along with the overwhelming avalanche activity south of Ogden, indicates that southeasterly and easterly facing terrain are currently the focal points for this issue. Due to this weak interface, remote triggering of an avalanche from a distance remains possible.
It's expected that this layering will settle in a few days but could remain active under any stress, whether from wind or snow today. If this layer does not settle out, we would expect to see it transitioning away from an interface issue and into a more traditional persistent weak layer instability.