http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=19299&oPark=100092We have a very touchy avalanche conditions and have seen some very large full path avalanches in the last 24 hrs. Stick to low angle terrain away from large overhead slopes.
Weather Forecast
Daytime temperatures will cool on Sunday with good overnight freezes possible by Monday. Dry sunny conditions are forecast into the week. Light SW winds will accompany these stable conditions.
Snowpack Summary
Heavy rain that changed to snow overnight has created a saturated snowpack extending into tree line. Limited overnight freeze created a weak melt freeze crust that broke down quickly with daytime heating and solar radiation. At higher elevations, a 40-80 cm deep persistent slab is sitting over multiple touchy interfaces on all aspects.
Avalanche Summary
There has been an avalanche cycle with numerous size 2 slab avalanches ranging form 1700 m to 2600 m on all aspects, many stepping down to the basal facets/November rain crust. Several larger avalanches also observed including a full path size 3.5 on the South Churchill Slide path (East Aspect 2400 m)
Confidence
The weather pattern is stable on Sunday
Problems
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.
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.