Be cautious on steep features at lower elevations. where a persistent slab problem lingers. A weak storm will bring more low density snow on Wednesday night.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
TUESDAY NIGHT: Clear with cloudy periods, light northeast wind, alpine temperatures drop to -15 C.WEDNESDAY: Cloudy with isolated flurries, trace accumulations, 20-40 km/h southeast wind, alpine high temperatures near -10 C.THURSDAY: Scattered flurries easing throughout the day with 5-15 cm of snow, 40-60 km/h southwest wind, alpine high temperatures near -5 C.FRIDAY: Cloudy with sunny breaks and isolated flurries, 30-50 km/h southwest wind, alpine high temperatures near -7 C.
Avalanche Summary
A few small loose dry avalanches were reported on Tuesday. On Monday, one small (size 1) skier triggered slab avalanche was reported on an east aspect at 1850 m.
Snowpack Summary
A mix of hard and soft wind slabs can be found in open alpine terrain, while pockets of soft snow can be found in sheltered and shaded areas. Sun crusts can also be found on south-facing slopes. There are potentially three layers of surface hoar in the upper snowpack. One is down 30-50 cm, another is down 40-80 cm, and the last one is down 80-120 cm. These layers have been most prominent and reactive between 1600 and 1900 m over the past month. The lower portion of the snowpack is generally strong.
Problems
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.
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.