Purcells

Expect natural avalanche activity if there are few clouds and the sun starts baking the storm slab.

Fair - Timing or intensity of solar radiation is uncertain on Friday

Strong southerly winds combined with moderate snowfall are expected to continue until around midnight. The wind should clock to the west and lighten by morning as mostly clear skies show the sun for a couple of hours. Cloud and convective flurries with light southwest wind are forecast for the afternoon as the freezing level rises to about 900 metres. More cloud is expected to move in from the southwest in the morning on Saturday. The North Columbia may have scattered cloud until the afternoon when it is forecast to become overcast. The South Columbia and Purcell should cloud over by early morning. The south and west of the region could see up to 15cm and the north and east may get 5-10 cm on Saturday. Sunday may be mostly clear with only scattered clouds and light winds. Periods of strong solar radiation are possible.

Avalanches continue to be reported from various aspects and all elevations. Large avalanches are reported from explosive control work in the west and north of the region where the snowpack is a bit deeper. A skier remotely triggered a size 3.0 avalanche from about 50 metres away on Wednesday in Canyon Creek. The slide was reported to be from a west aspect below treeline at about 2000 metres. Expect natural and easily triggered avalanches to continue. If the sun comes out, expect natural activity in the storm slab that may step down to the PWL once it is in motion.

Another 10 cm on Thursday, 80-160 cm storm snow now overlies the prominent surface hoar layer of mid-February. There is 55 cm of foot penetration, which means that there is a lot of snow available for transport by the wind. The storm snow is reacting readily to both natural and human triggers. The mid-February surface hoar layer is more stubborn and not reacting everywhere, but has regularly been producing large avalanches up to size 3.5, which indicates it is very much still alive and needs to be treated with the utmost respect. This layer is widespread, so defining safe zones based on elevation or aspect may not be the best idea right now. Of course, shallower snowpack areas are those where you are more likely to trigger it, as well as convex rolls, and rocky or uneven terrain features. If you know that a slope has already avalanched on that layer, it may be a better bet, although you still need to factor in the effect of recent storm snow amounts and whether reloading is an issue. Operators continue to monitor basal facets, especially in shallow, rocky areas, but with all the recent storm snow, the basal weakness has not been of undue concern recently.