AVOID ALL AVALANCHE TERRAIN and stay clear of overhead hazards. A natural avalanche cycle is expected in the region over the coming days. Conditions will become increasingly dangerous over the day Tuesday.
Heavy snowfall, strong wind, and rising freezing levels will bring a natural avalanche cycle to the region over the coming days. Storm slab reactivity and destructive potential will increase over the day.
Monday night: Increasing flurries bringing 10-20 cm of new snow. Strong to extreme southwest winds.
Tuesday: Cloudy with increasing snowfall bringing another 20-40 cm of new snow, continuing overnight. Strong to extreme southwest wind. Treeline high temperatures around 0C with freezing levels rising to 1800 metres.
Wednesday: Clearing over the day. Clouding over again in evening and light flurries overnight. Storm totals of 40-80 cm. Light southwest winds. Treeline high temperatures around -6.
Thursday: A mix of sun and cloud with isolated flurries. Moderate southwest winds. Treeline high temperatures around -10.
A fatal avalanche involvement occurred in the Hasler riding area on Saturday. We have preliminary information that indicates a party of four snowmobilers were in the area when one person triggered and was caught in an avalanche and did not survive. This section will be updated as we receive additional information.
A Mountain Information Network report from Sunday provides valuable information about conditions in the region ahead of this week's storm. A steady storm pattern has given the snowpack little time to stabilize between snowfalls. Forecast weather will push the region's snowpack into yet another natural avalanche cycle over the coming days.
Forecast snowfall should bring 30-60 cm of new snow to the region by end of day Tuesday. Strong to extreme wind will accompany the snowfall and contribute to increasingly touchy slabs forming in most areas. This will be a widespread event but the greatest accumulations are expected on the west slope of the region.
In exposed areas, the new snow will bury wind-affected surfaces and recent wind slab formations. In sheltered areas it will add to storm slabs that have been building on all aspects during recent stormy weather. Both the new snow interface and more deeply buried recent storm interfaces have potential to act as failure planes during forecast avalanche activity.
At elevations below treeline that saw rain earlier in the week, the new storm snow will continue burying the crust that formed overnight on Friday. Rising and falling freezing levels could cause a new surface crust to form as high as 1700 metres over Tuesday night.
Recent observations suggest snow depths below treeline are around 75-100 cm. The alpine snowpack should approach two metres by Wednesday.
Expect to find a deeper snowpack in the Pine Pass area than in the rest of the region. It's expected to be a focal point for this storm as well.
The lower snowpack mostly consists of a series of early season crusts. These appear to be strong, but shallow alpine slopes along the eastern side of the Rockies towards Jasper may have weaker, faceted snow near the ground. Anywhere this type of basal snowpack condition exists is a serious concern with forecast weather. (think thin snowpack areas in the alpine) Potential for storm slab releases to trigger deeper snowpack layers will be increasing through the storm.
