This region lies on the margin of where heavy precipitation is expected with the incoming storm on Thursday. If the storm track turns north, snow amounts and corresponding avalanche danger will be higher.
Confidence
Moderate - Track of incoming weather systems is uncertain on Thursday
Weather Forecast
Thursday: 5-10 cm new snow expected (possibly a little more in the south) with strong southwest winds up to 80 km/h expected at ridgetop. Freezing levels expected to rise to 1700 m near noon. Friday: Dry with some clear spells. Moderate southeasterly winds. Freezing level around 1600 m. Saturday: 5-10 cm new snow, with moderate southwesterly winds and freezing level around 1700 m.
Avalanche Summary
A size 1.5 human-triggered avalanche was reported on Tuesday on a north aspect at 2500 m. On Sunday and Monday, size 2-2.5 natural avalanches ran in recent storm snow with crown depths averaging 40 cm on west through northeast aspects.
Snowpack Summary
At elevations above around 1600 m, approximately 50-80 cm recent storm snow now rests above a prominent weak layer buried on or around Feb-27. This weak layer comprises surface hoar sitting on a crust and is reported to be most prominent at sheltered treeline elevations. Thicker and touchier wind slabs are lurking throughout exposed terrain in the alpine and at treeline. A couple of sun crusts might exist in the upper 50-70cm on southerly 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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.