Regions
Banff Yoho Kootenay.
Current forecasts predict 20-25cm over the next 48 hours at treeline and above. If this holds true ski quality will improve, but sensitivity to triggering will increase. We have low confidence in the overall weak snowpack. SH
Weather Forecast
Mainly light East winds with gusts into the moderate range for Sunday. Current forecasts are showing 6-8cm Saturday night, 6-8cm Sunday, and 7-9 cm Monday. There is still quite a bit of uncertainty around snow amounts for this time period. Alpine highs will be in the -15C range for Sunday, and into the -20's for Monday.
Snowpack Summary
5 - 15cm in the last 24 hours. This sits on harder wind pressed surfaces from previous strong W/SW winds at treeline and above. Surface hoar may be found buried in sheltered locations. Generally the midpack is weak at TL and above, and the entire snowpack is weak BTL. Near the divide, deeper snow-packs are a bit stronger and more supportive.
Avalanche Summary
No new avalanches were seen or observed in the last 48 hours.
Confidence
Forecast snowfall amounts are uncertain on Sunday
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.
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.