A few small-ish natural wind slab avalanches occurred Wednesday in alpine terrain. Similar conditions can be expected over the next few days with ongoing light snow amounts, but strong southwesterly winds.
Recent storm snow is being blown into wind slabs in the alpine. Natural activity up to size 2 was observed on Wednesday in steep alpine terrain. Human triggering remains a possibility in steep, unsupported terrain.
Wednesday night: Flurries. Moderate southwesterly winds. Freezing level around 1000 m.
Thursday: Flurries. Strong southwesterly winds. Freezing level rising to around 1500 m in the afternoon.
Friday: Around 5 cm new snow. Moderate southwesterly winds. Freezing level around 1700 m.
Saturday: Around 5 cm new snow. Moderate southwesterly winds. Freezing level around 1600 m.
On Wednesday, three natural storm slab avalanches were reported size 1.5-2 on northeast aspects at 1850 m.
On Monday, natural storm slabs up to size 1.5 were observed in steep alpine terrain below cliffy headwalls in the Lizard range. One was triggered by a cornice fall.
Thin surface crusts may be found on a variety of aspects and elevations. Wind loaded pockets are forming in lee features in the alpine. After over 1 m of steady snowfall last week, the stout upper snowpack continues to settle in the mild temperatures.
Several crust layers exist in the mid snowpack as a result of previous warming and rain events. These have not been identified as bed surfaces or failure planes in recent avalanche activity.
The bottom 10-20 cm of the snowpack consists of faceted snow and decomposing crusts. Although inherently weak, this basal layer has not been an active avalanche problem in our region since 2019.
