Warming at higher elevations is expected, but how warm is uncertain. Best to use cautious route-selection, observe for signs of snowpack warming, and manage your adventure expecting rapid changes to the snowpack over the day.
Summary
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
FRIDAY NIGHT: Partly cloudy, inversion conditions with above freezing layer between 2000 m and 2500 m.SATURDAY: Partly cloudy, light southwest winds, alpine temperature variable between -1 and 3 C, inversion conditions with above freezing layer between 2000 m and 2600 m.SUNDAY: Clear skies, light southwest winds, alpine temperature 3 C, inversion conditions with above freezing layer between 1600 m and 2800 m.MONDAY: Clear skies, light southwest winds, alpine temperature 3 C, inversion conditions with above freezing layer between 1600 m and 2800 m.
Avalanche Summary
Numerous storm and wind slab avalanches were observed in the region on Thursday. Most of them were small (size 1 to 1.5), between 1600 m and 2300 m, and on all aspects. They were triggered naturally, by skiers, and explosives.For the weekend, the likelihood of triggering storm slabs may increase due to the substantial amount of warming expected around upper below treeline, treeline, and alpine elevations. The likelihood of triggering deeper weak layers may also increase too. Watch out in thin snowpack areas, where the likelihood of triggering deeper layers is the highest.
See here for an example.Snowpack Summary
Warm upper-level air temperatures may be impacting the snow surface. You may find dry snow, moist snow, or possibly a frozen melt-freeze crust, depending on how warm the air temperatures are. The warm air may produce touchy storm slabs at all elevations. At the highest of elevations, wind slabs may still linger in lee and cross-loaded terrain features.The middle and lower portions of the snowpack are generally well-settled and strong. However, there still remain a few deeper weaknesses in the snowpack around treeline and alpine elevations. Professionals are still tracking a layer around 150 to 200 cm deep, composed of sugary faceted grains, feathery surface hoar, and a sun crust. The base of the snowpack may also still be composed of weak faceted grains. The likelihood of triggering these layers may increase with the warm air incoming this weekend. These layers would most likely be triggered by humans in areas where the snowpack is shallow.
mconlan,
Avalanche Canada
