Avalanche Forecast
Issued: Dec 20th, 2017 4:09PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jfloyer,
Avalanche Canada
Watch for small wind slabs in exposed terrain.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Thursday: Flurries in the morning, then clearing. Winds moderate northwesterly becoming light northeasterly. Treeline temperatures around -15C.Friday: Clear and sunny. Generally light northeasterly winds. Temperatures around -22C.Saturday: Clear and sunny. Generally light easterly winds. Temperatures around -25C.
Avalanche Summary
Some natural and skier-triggered avalanche activity was noted from the weekend - it appears as though it can be characterized as small wind slab activity. If you're out in the mountains and see recent avalanches please snap a photo and submit your information to the Mountain Information Network.
Snowpack Summary
The inland region picked up 5 to 15cm of new snow over the weekend accompanied by wind that was initially out of the west, but has since switched to being out of the southeast. This new snow rests on a wide variety of old surfaces including small facets, crusts on solar aspects and stubborn old wind slabs near ridge crest. In protected areas below 1500m the new snow may be sitting on previously formed feathery surface hoar.Two crusts formed near the end of November are found approximately 30 to 50cm below the surface. These crusts are widespread and extend into the alpine. Previous snowpack tests produced hard results on these crusts, but we have not seen any recent information about their sensitivity to triggering. Below these crusts, a well settled mid-pack overlies the late October crust which is down near the ground. The October crust is widespread and has not been reactive to human triggering since the end of November. Average snowpack depths in the region are between 80 and 140cm at treeline, with up to 160cm in the alpine.
Problems
Wind Slabs
Wind slabs are most likely to be found immediately lee of ridge crest in exposed terrain. While relatively small, they could be problematic in complex terrain.
Use ridges or ribs to avoid pockets of wind loaded snow.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Avoid steep convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 21st, 2017 2:00PM
