Avalanche Forecast

Moderate

• Uncertainty is due to the timing, track, & intensity of the incoming weather system.

A natural avalanche cycle continues with slab avalanches up to size 3 in Alpine and Treeline terrain. These slabs are anywhere between 20 and 100cm thick, including many that are stepping down to the Nov crust layer. Explosives control work on EEOR today also produced several size 2 avalanches. With the incoming storm Tuesday night and Wednesday morning, a natural avalanche cycle is expected to continue.

Incoming new snow and strong winds will add to existing wind slabs at Treeline and above. There is already a 25-40cm thick surface wind slab, and this will grow. Unfortunately, this is sitting on a softer layer of decomposed particles that is very reactive to field tests. If this layer is triggered, there is a strong likelihood that it will step down to the November crust (now buried 90-120cm), creating large avalanches. At 2200m and below the incoming snow will land on a rain/temperature crust from the last few days. The bond at this interface will be important to watch, as the crust could form a good sliding layer.

Wednesday is expected to be overcast and snowy. Total accumulations should be in the neighbourhood of 25cm. With the passing of a cold front, the winds will be strong from the SW switching to the NW, and temperatures will drop from -4C in the morning to -12C in the evening.

More details can be found in the Mountain Weather Forecast.

• Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
• Avoid areas with overhead hazard.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.