Saturday night's storm will elevate the hazard to HIGH on Sunday. Conservative terrain choices will be critical in the days to come.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A series of storm systems will continue to impact the region during the forecast period. The next storm front should arrive Saturday evening and is expected to yield 20-30cm of snow by Sunday evening. Freezing levels are expected to be 1000-1400m during this period with strong SW winds in the alpine. On Sunday overnight and Monday, another 15-25cm of snow is expected in the highest snowfall areas. Winds will continue to be moderate to strong from the SW and freezing levels should be around 1500m or lower. On Tuesday, similar amounts of precipitation are being forecast but freezing levels could rise to around 2000m.
Avalanche Summary
On Friday, numerous natural and human-triggered avalanches were reported up to size 2. Most of this activity was below treeline on a variety of aspects. Natural and human triggered avalanche activity is expected to increase Sunday with the incoming storm Saturday night.
Snowpack Summary
Saturday night's snowfall will add to the existing 30-40 cm of recent storm snow that overlays a variety of old surfaces which include wind scoured north aspects, sugary facets, sun crusts, and/or large-sized surface hoar. The primary concern is the surface hoar which sits on top of a sun crust on solar aspects. Reports suggest that the surface hoar exists up to approximately 1800 m on all aspects.
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.