Should the sun peak out of the clouds for a longer period, avalanche activity will increase on the solar aspects in gully features. Also, if the weekend storm comes early it will produce rain at lower elevations with the expected warm temperatures.
Weather Forecast
Overcast skies will begin producing light snowfalls by mid afternoon in the icefields area and it will rain at lower elevations. The weekend will bring steady warm, heavy snow in the south part of the forecast area. The freezing level is expected to go up to 1800m on Saturday afternoon and stay there through the weekend.
Snowpack Summary
A highly variable snowpack exists throughout the forecasting region. Steady strong SW winds have scoured open slopes in the alpine and redistributed that snow lower on the lee aspects. Warming temperatures combined with periodic sun through the clouds could start small slides in the rocks which may step down when they hit a more open slope below.
Avalanche Summary
The sun came out in the afternoon and triggered a size 2 slab avalanche in a shallow alpine gully feature on a west facing aspect indicating that the sun is gaining strength. Below treeline, road cutbanks facing the south are creating snowballing and small loose avalanches.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Friday
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.