New snow and wind Thursday night and Friday will add to recent storm slabs that sit on a touchy crust/facet/surface hoar layer. Choose conservative terrain and be especially wary of wind-loaded areas and solar aspects.
Weather Forecast
TONIGHT: Flurries. Accumulation 10-15 cm. Ridge wind moderate to strong, west. Alpine temperature near -6. Freezing level valley bottom.FRIDAY: Flurries. Accumulation 5-10 cm. Ridge wind moderate to strong, northwest. Alpine temperature near -10. Freezing level valley bottom.SATURDAY: Mostly sunny. Ridge wind light, west. Alpine temperature near -8. Freezing level 800 m.SUNDAY: Cloudy, flurries. Accumulation 2-4 cm. Ridge wind light, southwest. Alpine temperature near -8. Freezing level 700 m.
Avalanche Summary
A widespread natural avalanche cycle up to size 3.5 was reported on Tuesday and Wednesday following the storm on Tuesday. Storm slabs from 50 to 100 cm deep were reported on all aspects between 1700-2500 m. Southerly aspects were the most reactive with numerous large and very large (size 2.5 - 3.5) avalanches running on a recently buried crust. While the natural cycle has tapered off, human triggered avalanches remain likely at treeline and above where the touchy late-March crust/surface hoar layer exists.
Snowpack Summary
Approximately 60 to 100 cm of recent storm snow has fallen with moderate to strong winds from the south / west. The storm snow sits on a variety of old snow surfaces buried late-March that consist of: sun crusts at lower elevations and on south aspects, and older storm snow or wind slabs up high. Surface hoar layers have been reported on shaded aspects at higher elevations. Persistent weak layers from early January and mid-December are still being reported by local operators but are generally considered dormant.
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.