Good overnight freeze is occurring; however, the sun packs a punch. The danger will increase in the afternoons at all elevations particularly on South aspects, gullies, and sun affected bowls. Gauge the amount of overnight freeze to start your day.
Weather Forecast
Monday to Wednesday will be clear skies, strong diurnal temperature fluctuation, and light W to NW winds. Freezing level is incrementally increasing each day this week. Monday it will be 1700m, Tuesday 1800m, and clouds on Tuesday evening may prevent a good overnight freeze starting the day off warm for Wednesday.
Snowpack Summary
A variable thick slab exists in alpine and treeline locations on a variety of aspects. It is over a strong midpack except in shallow locations where you could trigger basal facets or depth hoar weakness at the ground. At treeline in south facing terrain, their is a suncrust 80 cm deep. Strong diurnal temperature fluctuations have helped stability.
Avalanche Summary
No Sunday patrol. Nothing new noted on Saturday's Icefield's patrol with good visibility. A size 3 noted on Friday off Indian ridge main peak up Whistler creek scrubbing to ground, cornice fall trigger, and ran far. Thursday in Shangrila a size 3 was triggered by cornice fall in the afternoon heat, scrubbed to ground, 2m crown, and ran full path.
Confidence
Freezing levels are uncertain
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.