Wintery weather returns with new snow and strong wind on Wednesday. Fresh pockets of wind slab may be reactive on lee slopes in the alpine.
Loose-dry avalanches will may occur from steep slopes and terrain features
Wind slabs will be most likely be isolated to immediate lees of ridgecrests and roll-overs in wind exposed alpine terrain.
Loose-dry sluffing of the new snow can be expected from steeper slopes and terrain features.
Cornices are especially fragile this time of year. Cornice falls are dangerous in their own right and they can also trigger slabs on slopes below.
The higher snow amounts will likely exist in the Northern parts of the region.
Tuesday Night: Clear. Ridgetop wind light to moderate from the South and freezing levels 1200 m.
Wednesday: Snow amounts 5-15 cm. Ridgetop wind moderate from the southwest. Alpine temperatures near -1 and freezing levels 1600 m.
Thursday: Mix of sun and cloud with scattered flurries up to 5 cm. Ridgetop wind light from the southwest. Alpine temperatures near -1 and freezing levels 1400 m.
Friday: Snow 5-10 cm. Ridgetop wind moderate to strong from the South. Alpine temperatures near -5 and freezing levels 1400 m.
On Monday, skier-controlled and natural size 1 slabs were failing within the recent storm snow on solar slopes. The terrain features were steep convex rolls.
Sunday several loose-dry and skier-triggered size 1.5 avalanches were reported. The reactivity mostly occurred during daytime warming from steep slopes within the new snow.
With forecast snow and strong southwest wind on Wednesday, wind slabs may be reactive on leeward slopes, and natural loose-dry sluffing may occur from steep slopes and terrain features.
Winter weather returns with light forecast snow amounts accompanied by moderate wind through the forecast period. Fresh wind slabs may build through the day on Wednesday. The new snow sits above surface hoar crystals on sheltered north facing terrain above 1900 m, a series of melt-freeze crusts on all aspects below 1900 m, and a sun crust on the southerly aspects to mountain top. Below 1500 m a melt-freeze crust exists and the snowpack is quickly diminishing.Loose–dry sluffing will likely occur on steep slopes and terrain features where the new snow has a poor bond to the underlying old surfaces.
At alpine and treeline elevations, a few layers of note are buried 50-100 cm deep including a layer of small surface hoar crystals on shady, wind-sheltered aspects and a series of crusts on solar aspects and below 1800 m. Overall the snow seems to be bonding well to these interfaces, although there have been a few isolated avalanches running on deeper crust layers in the past week.
