Regions
Banff Yoho Kootenay.
Watch locally for heavier snow amounts on Thursday. We still have lowered confidence in most avalanche terrain, especially in thin and variable snowpack areas. SH
Weather Forecast
10-15 cm is possible at upper elevations over the next 24 hours with light gusting moderate NW winds. Watch locally for more amounts as the forecasts are conflicting. Freezing levels will stay at valley bottom.
Snowpack Summary
35cm in the Sunshine area,50cm in the Lake Louise region since March 15th which seems to be bonding well with the previous surfaces. The Feb.10th facet layer is down 80-120cm and is still showing easy to moderate test results in thinner snowpack areas, and harder results in deeper snowpack areas. Areas with buried sun crust are especially touchy.
Avalanche Summary
No avalanches were observed or reported today. A large sz.3 cornice triggered avalanche was reported yesterday in the Sunshine back country. This failed on the Feb.10 interface and stepped to ground in thin areas. We have seen sporadic natural activity like this over the last week.
Confidence
Intensity of incoming weather systems is uncertain on Thursday
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.
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.