Soaring alpine temperatures will test the snowpack this week. Be extra cautious around sun exposed slopes.
Confidence
Low - Due to the number and quality of field observations
Weather Forecast
WEDNESDAY: Sunny with valley cloud in the morning, light northwest wind, inversion forming with alpine temperatures possibly reaching above 0 C.THURSDAY: Sunny with valley cloud, light wind, inversion with freezing level up to 3000 m.FRIDAY: Sunny with valley cloud, light wind, inversion with freezing level up to 2700 m.
Avalanche Summary
No recent avalanches have been reported. On the weekend, small loose dry avalanches were reported in steep terrain around Valemount and Blue River, but no human-triggered avalanches were reported. Please submit your observations to the Mountain Information Network (MIN).
Snowpack Summary
The snowpack is about to experience a big change with a week of warm sunny weather ahead. Widespread melting is expected, with the most intense warming on steep south-facing slopes. Warming could potentially impact deeper layers including a combination of crusts that formed during rain events in November. Little is known about the depth, distribution, or reactivity of these crusts. Wind slabs formed at higher elevations over the past week and will likely continue to be reactive. Snow depths decrease rapidly below treeline, where the primary hazards are rocks, stumps, and open creeks.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.