Avalanche Forecast

An outlier of an avalanche was reported on Thursday: a size 3 slab on a SE aspect at 2800m above Bow Lake. We're unclear on the failure plane but assume this was a large windslab that released on a suncrust. Perhaps a cornice trigger.

We continue to monitor the Feb 3rd persistent weak layer as there have been three avalanches involving this layer in the last two weeks: a natural near Bow Summit, a skier remote in Purple Bowl and a skier accidental at the Cathedral Glades.

Surface crusts exist on solar aspects, and up to ~2000 m on north aspects. Above this the snow surface is dry, wind-affected snow. The upper snowpack contains several buried crusts.

The midpack is generally well settled down to the February 3 persistent weak layer which remains a concern in shallow snowpack areas on northerly alpine aspects. In these areas, no crusts are found in the upper snowpack and the midpack remains thin and weak.

A short-lived weather system will cross the region this evening, depositing up to 2-5 cm over higher elevation terrain before it clears early Friday morning. In its wake, expect scattered flurries on Friday and a mix of sun and clouds on Saturday. Freezing levels will reach the 2100-2400 range on both days with moderate westerly winds at the ridge crests.

The longer-term models show a good dump of snow on Monday.

• Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.