Human triggered avalanches are possible in specific terrain. Expect avalanche danger to increase with incoming precipitation and rising freezing levels.
Weather Forecast
Mainly cloudy today with isolated flurries. Expect mild winter temperatures with freezing levels rising to 1600m. Ridge top winds S 12-25km/h. A warm system is moving in for Saturday bringing climbing freezing levels and moderate precipitation. Possible temperature inversion on Saturday. Watch for cold air in the valleys and warm air up high.
Snowpack Summary
Sun crust on steep solar and widespread surface hoar was observed yesterday up to 2000m. Light snow will bury this surface hoar today, forming a new weak layer. November 21 and 9 persistent weak layers are buried down ~100 and ~130cm, and are less reactive. The failure character of these layers is still sudden planer. Breakable crust below ~1600m.
Avalanche Summary
No new avalanches were observed yesterday. Prior to the cold snap, a widespread avalanche cycle occurred. Large avalanches, with wide propagations, demonstrated the potential of buried weak layers. Some areas have not yet avalanched, for example the Frequent Flyer path up the Connaught Drainage.
Confidence
Intensity of incoming weather systems is uncertain
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.