Lingering wind slabs may still be reactive to human-triggering on Wednesday. Large cornices will become weak with daytime warming and sun so avoid cornice exposed slopes in the afternoon.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain on Thursday
Weather Forecast
Mostly cloudy conditions are for Wednesday with the possibility of light flurries in the morning. Freezing levels are expected to be around valley bottom overnight and 1500m in the afternoon. Alpine winds are forecast to be light to moderate from the southwest. A weak storm front if expected to reach the region Wednesday night and 5-10mm of precipitation can be expected by Thursday afternoon. Alpine winds are expected to be strong from the southwest and freezing levels are forecast to climb to over 2000m during the storm. Clearing is expected for Thursday night and a mix of sun and cloud is expected for Friday.
Avalanche Summary
No new avalanches were reported on Monday. On Sunday, storm slab avalanches up to size 2 were reported from higher elevations. At elevations below around 2000m where it rained, numerous loose wet avalanches were reported as well as one glide avalanche which released on a large planer rock feature below treeline.
Snowpack Summary
Rainfall on Sunday was reported to around 2100m elevation. The snow surface was reported to be soaked below treeline and dense moist storm snow was reported at treeline. With overnight cooling, a melt-freeze crust is expected at some mid-mountain elevations. In the alpine, strong southwest winds have redistributed the recent storm snow into wind slabs on leeward features. Cornices are also reported to be huge and weak. The mid and lower snowpack are generally well settled and there are currently no major weak layers of concern within the snowpack.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.