Regions
Banff Yoho Kootenay.
The cold snap is over with warming occurring today. Of note is the temperature inversion, and tomorrow's high of -5 at higher elevations should cause ice climbers to carefully consider their overhead hazard - it will be a hot afternoon in the sun.
Weather Forecast
The ridge of high pressure has one more day left in it, and Wednesday will be sunny with alpine temperatures reaching -5. Starting Thursday a system embedded in a NW flow will cross the area, but only light amounts of snow are expected. Trace for Thursday, then 4cm each day for Fri and Sat. Temps will be in the -5 to -10 range with light west wind.
Snowpack Summary
70-110 cm of snowpack exists across the region. The main weakness is at the base of the snowpack, where facets and depth hoar produce inconsistent test results 15 cm above the ground. Overall we believe the snowpack is gaining strength, but our confidence in this assessment is low. The Dec 18 layer of SH found further west is not prominent here.
Avalanche Summary
No new avalanches were observed or reported today.
Confidence
Due to the number and quality of field observations
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.