Touchy wind slabs will develop with forecast strong winds and snow. Watch for wind slabs Wednesday and more widespread storm slabs on Thursday.
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
WEDNESDAY: Snow starting overnight Tuesday means 10 - 15 cm by Wed evening. Moderate to strong SW wind. Freezing level around 700 m with treeline temperatures well below freezing.THURSDAY: Continued snow with another 15 - 20 cm. Strong SW winds. Continued gradual warming with freezing level around 1100m and temperatures approaching a few degrees below freezing near treeline.FRIDAY: Periods of snow with another 5 - 10 cm. Moderate SW winds. Temperatures starting to cool with freezing level lowering to around 900m.
Avalanche Summary
No new avalanches reported Monday. This will likely change as wind driven snow starts to accumulate Wednesday.
Snowpack Summary
Previous winds have either deposited snow in lee areas, with a few stubborn wind slabs, or scoured down to a mid-February crust. Cold temperatures have faceted the top 20 cm of the snowpack where it wasn't wind hammered. The mid and lower snowpack are well settled and strong. The forecast shift in the weather means new wind slabs and storm slabs will be forming.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.