Forecast warm temperatures and strong solar radiation may result in easy triggering of storm slabs.
Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
Cloudy overnight with alpine temperatures around -5 and freezing levels dropping down to about 1400 metres. Expect a mix of sun and cloud on Tuesday with freezing levels rising up to about 2200 metres and moderate southwest winds. Cloudy with light precipitation on Wednesday combined with strong southwest winds and freezing levels around 2000 metres. Thursday should be mostly cloudy with strong southwest winds and 2000 metre freezing levels.
Avalanche Summary
Several windslab avalanches up to size 2.0 were reported on Sunday that were 20-30 cm deep on northerly aspects in the alpine and at treeline. I suspect that the size and likelihood of windslab and new storm snow avalanches has increased with the new snow.
Snowpack Summary
New snow and strong winds have developed wind slabs that have been reported to be 40-60 cm deep. The new snow is sitting on various old surfaces that includes dry new snow, loose facetted snow, wind slabs, and sun crusts. The mid-February crust is down around 10-30 cm below the new snow. The late-Jan crust/surface hoar layer (up to 100 cm deep) and the mid-January surface hoar (80-120 cm deep) are generally dormant, and chances of triggering these weaknesses have decreased.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.