Natural avalanches are likely with the continuing strong, gusty winds and additional snowfall onto a complex, upper snowpack.
Until cooler, calmer weather arrives and the snowpack has time to adjust to the new load, danger levels will remain elevated.
The new snow overlays a buried persistent weak layer (PWL). This weak layer consists of surface hoar, facets and/or a suncrust. The storm snow has overloaded this PWL, producing large avalanches where it is present in the start zone or within the track of the path.
Fresh snow, strong winds and warm temperatures have created a storm slab. This sits on (yet another) weak layer of facets. Expect this to be most reactive in immediate lee features, such as along ridge-lines and cross-loaded gullies.
A natural avalanche cycle started Sat night and continues into the Sunday. Numerous avalanches to sz 3 have been detected within the highway corridor.
Low elevation areas (below 1000m) with a thin, faceted snowpack (ie Beaver Valley) seem to be failing to ground under the new weight of heavy slop/rain.
Artillery control late Saturday night produced avalanches with nearly every shot, some up to sz 3.5, with far-reaching powder clouds hitting the valley floor and beyond.
30-40cm of heavy storm snow sits on a faceted upper snowpack. Strong, gusty SW winds are creating windslabs at Alpine and Tree-line elevations.
A weak layer of surface hoar, facets and/or suncrust (Jan 30th) is 50-80cm down. This layer is easy to pick out in the snowpack and is reactive in tests.
Low elevation zones with a thin snowpack should be treated with caution. The cold, weak facets at the base are now overloaded by the heavy, warm storm snow.
Windy and warm, with uncertainty on snowfall amounts the next couple of days.
Tonight 10-15cm. Alpine low -7°C. Ridge winds SW 40km/h gusting to 85. Freezing Level (FZL) 1100m
Mon 5-10cm. Alp high -6°C. Ridge wind SW 30km/h gusting 60. FZL 1400m
Tues 5-10cm. Alp high -6°C. Ridge wind SW 30-40km/h. FZL 1500m
Wed Cloudy, isolated flurries. Trace snowfall. Alp high -4°C. Ridge wind SW 20km/h. FZL 1600m
