Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
3.5 inches of SWE in 12 hours overnight above 9500' is a lot of snow in a short period on the night of 3/12-13/25. In the past 48 hours we've received 5 inches of SWE. The beginning of the storm snow started with an hour downpour of graupel. So that graupel (hail like snow) or ice pellets sits as the interface between the old snow and the new storm snow. Graupel's pellet like shape doesn't bond well with other types of snow and takes a long time to heal and metamorphose.
High winds Above and Near Tree Line during the storm and last night at all elevations have affected the snow pack and likely transported snow drifts up to 3-5x the amount of fallen snow onto leeward slopes. With a mixture of temperatures, snow types and strong wind, the new snow contains a lot of variance and that variance doesn't bode well for avalanche terrain stability.
Cold temperatures, snow flurries and increasing winds today up to 65 mph will add to the already unstable snow conditions. The froth and desire is high to get out into the new snow today, but avoiding avalanche terrain until the snowpack has had time to bond is the safe call.
Snow machines add a lot of stress and weight and easily access the weak interface with its spinning track. Today is not the day to get into those steep slopes. Treed or open slopes both pose a considerable risk to avalanche today in slopes above 30 degrees, both large and small. Once again, avoidance of all avalanche terrain is best until time has passed for the new snow to bond.