Confidence
Fair - Intensity of incoming weather is uncertain on Friday
Weather Forecast
Thursday: Fairly benign, cloudy in the morning with scattered flurries, broken skies with possible sunshine in the afternoon. Ridgetop winds light from the North. Treeline temperatures near -6. Freezing levels may rise to 900 m. Friday: A series of systems will arrive, with a decent moisture feed from the SW. The morning brings light snow amounts, with moderate amounts in the afternoon. Ridgetop winds moderate-strong from the SW. Treeline temperatures near -6. Freezing levels near 800 m. Saturday: Continued moderate precipitation possibly up to 15 cm by the afternoon. Ridgetop winds strong from the West. Freezing levels could rise to 1500m.
Avalanche Summary
Reports of natural activity seemed to dwindle. Rider triggered avalanches are still occurring up to size 2. The reactive aspects mainly being N-NE, but some reports have included SE-SW, with elevation bands being 14-2000 m. The layers triggered are preserved stellars that seem to be down near 20cm, and the mid-February interface. With forecast snow and wind, avalanche conditions will remain touchy, and susceptible to rider triggers through the forecast period.
Snowpack Summary
Due to changing winds, wind slabs can be found on N-NE aspects and S-SW aspects in the alpine on exposed slopes at treeline. Reports indicate the new wind slabs are not bonding well to the southerly scoured, sun crust surfaces. The total settled storm snow is near 60cm and sits over a variety of old surfaces. These include melt-freeze crusts at lower elevations, old sun crusts on Southerly aspects into alpine elevations and spotty areas of surface hoar in sheltered treeline areas. Where they exist, they may act as sliding layers. Easy shears persist in the new storm snow down 25-40 cm with sudden planar results. The mid and lower snowpack is well bonded and strong.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
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.