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.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Little Yoho.
Another day of temperature inversions and solar heating will keep slabs sensitive to failure on Tuesday. While some areas in this region have a deeper snowpack that is gaining strength, others do not: treat thin areas with increased caution.
Weather Forecast
Continued warm temperatures and sun are expected Tuesday as the temperature inversion continues . Winds that have been in the moderate range out of the West are forecast to diminish through to Wednesday. Cooling is expected on Wednesday increasing cloud. Trace amounts of snow can be expected Thursday.
Snowpack Summary
New solar crusts steep South and West slopes. Extensive wind effect in the alpine, less so at treeline. In thick snowpack areas, the Dec 10th weak layer of facets is now down 100-150cm with a stronger snowpack below. In thin snowpack areas, there is little separation between Dec 10 and the weak depth hoar/ facets sitting just above the ground.
Avalanche Summary
A size 3 slab failed on the south aspect of Mt Fairview sometime during the last couple days of temperature inversions and clear skies. The crown was 70cm to 1m deep and over 1000m wide. The slide ran up the other side of the valley below Sheol. There were 2 sz 2 loose wet avalanches observed on a field trip to Hamilton Lake at 2400m west aspect.
Confidence
Due to the number of field observations
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.