Snowfall through Thursday night and Friday combined with wind and warm temperatures will keep the avalanche danger at High on Friday.
There is still concern for heavy loads (storm slab avalanches running) to step down and trigger deeper weak layers buried in December.
Snowfall continues to accumulate above a recently buried layer of weak surface hoar. Expect storm slabs to remain reactive as the load builds and temperatures rise.
Thursday Night: Snow, accumulation 10-20 cm . Alpine temperature -10 C. Moderate northwest wind.
Friday: Snow, accumulation 10-15 cm. Alpine temperature -5 C. Moderate to strong west wind. Freezing level 1400 m.
Saturday: Snow, accumulation 10-15 cm. Alpine temperature -6 C. Moderate to strong southwest wind. Freezing level 1200 m.
Sunday: Flurries. Alpine temperature -6 C. Moderate southwest wind. Freezing level 1000m.
There was a widespread natural storm slab avalanche cycle to size 2.5 on Wednesday. Avalanches were 30-60 cm deep and were reported on all aspects and elevations. Additionally there were several human triggered avalanches reported up to size 2. Some of these were remotely (from a distance) triggered.
Expect another 10-20 cm of new snow overnight Thursday to add to the 40-70 cm that fell through the New Year's period. All this recent snow has buried a layer of surface hoar found at all elevations. In some places the surface hoar may be combined with sun crust on steep sun-exposed aspects.
A weak layer that was buried at the end of December is now approximately 100 cm deep and may present as surface hoar in sheltered areas, sun crust on steep solar aspects and/or a melt freeze crust below 1700 m.
An additional layer of surface hoar buried mid December is 110-180 cm deep. Avalanche activity on this layer has tapered off, but there is still concern for heavy loads to step down to this layer. A crust from late November is now over 180 cm deep. Concern for this layer is limited to rocky or variable snowpack depth areas in the alpine where it most likely exists as a combination of facets and crust.
