Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Purcells.
Continued unsettled weather with a gradual cooling.
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
FRIDAY: Cloudy with isolated flurries, light south wind, alpine temperature -5, freezing level 800mSATURDAY: Mainly cloudy, wind light southeast, alpine temperature -4SUNDAY: Cloudy with sunny periods and the chance of isolated flurries, wind light south, alpine temperature -6More details can be found on the Mountain Weather Forecast.
Avalanche Summary
Recent reports indicate some explosives triggered avalanches to size 2 in the alpine on west and north aspects.
Snowpack Summary
10-30 cm of new snow accumulation, wind and warming have built wind slabs on wind-loaded features. In sheltered areas, the new snow has possibly buried a layer of feathery surface hoar. The main concern deeper in the snowpack is a layer of sugary facets from mid-December that can be found between 50 and 100 cm deep. This layer was considered dormant during the recent cold weather, but may still become reactive with the recent warm temperatures.
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.
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.