Avalanche Forecast

Issued: Dec 27th, 2018 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Deep Persistent Slabs.

grant statham, Parks Canada

Banff Yoho Kootenay.

Although the snowpack continues to stabilize, the Deep Persistent Slab Problem has a significant amount of uncertainty. Deep snowpack areas to the west have a stronger snowpack (eg: Pulpit, Little Yoho). Conditions will deteriorate on Saturday.

Summary

Weather Forecast

One more day of high pressure with a light Northwest flow brings mostly sunny skies for Friday with temperatures remaining cool (-10 to -20), but this changes on Saturday as an intense 1-day system will cross the area and deposits 10-20 cm of snow with extreme winds in the forecast (>100 km/hr).

Snowpack Summary

The majority of the BYK region is a 40-50cm slab of stiff snow overlying 40-50cm of weak facets and depth hoar. This nasty combination has been stabilizing over the past few days but continues to produce whumphing and easy test results. Deeper snowpack areas are stronger, but have a 60-80cm slab over top of the Dec10 surface hoar/facet layer.

Avalanche Summary

No new avalanches observed or reported in the Banff, Yoho and Kootenay region on Thursday.

Confidence

Problems

Deep Persistent Slabs

This problem dominates the central and eastern part of the forecast region and will continue to do so for some time. Natural activity on this layer has decreased but human triggered avalanches on this layer are still possible.

Be wary of large slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Dec 28th, 2018 4:00PM