Avalanche Forecast

Issued: Dec 10th, 2014 4:00PM

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

grant statham, Parks Canada

Banff Yoho Kootenay.

The current storm has mostly petered out in the Rockies, with minimal new snow in the last 24 hours. However, heavy rain in Yoho Park has produced several large avalanches over the Field ice climbs. Ice climbers should should consider heading east.

Summary

Weather Forecast

A strong SW flow aloft is streaming moisture onto the west coast, but the punch is mostly gone from these storms by the time they reach the Continental Divide. Regardless, expect heavy rain in Yoho Park on Thursday, with light rain or flurries further east, possibility of up to 10 cm at Bow Summit. Cooling is expected to arrive on Saturday.

Snowpack Summary

Although these warm daytime temperatures are promoting overall snowpack settlement, the lower half of the snowpack remains poorly structured, with a weak based comprised entirely of facets and depth hoar. This problem is most pronounced in rocky, windswept terrain at treeline and higher where human triggering of full depth avalanches is possible.

Avalanche Summary

Good observations today in Kootenay Park and highway 93 N revealed a distinct lack of avalanche activity. Sunshine ski area reports a similar lack of avalanches. However, the low elevation rainfall resulted in widespread avalanche activity in the ice climbing gullies down in Field (on Mt. Dennis).

Confidence

Timing of incoming weather systems is uncertain on Friday

Problems

Deep Persistent Slabs

Snowpack tests continue to show collapse at several levels of weak facets near the base of the snowpack. Avoid large slopes during this warm spell; wait for future cooling when the snowpack will stabilize and conditions will improve.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Loose Wet

The low elevation snowpack has lost all strength as a result of the warm temperatures and rain. Ice climbers in particular should be wary of steep gullies at and below treeline.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 11th, 2014 4:00PM