Avalanche Forecast

Issued: Apr 8th, 2014 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

The biggest question is the amount of heat input that the snowpack will receive over the next few days. It is generally a good habit to start your day a bit earlier this time of year so you can be back in town by early afternoon.

Summary

Weather Forecast

The temperature is supposed to drop over the next few days (-4@ 1500m). Strong wind and very little precip (amounting to no more than 7cm over the next 3 days) will keep the danger ratings where they presently are until Friday.

Snowpack Summary

Moist snow to 2000m on all aspects and to ridge top on solar aspects. Thin wind slabs in open areas. Western areas such as Emerald and Field have a deep and stable snowpack. The Lake Louise, Hwy 93 N, & Sunshine areas have a weaker snowpack and we are still getting easy to moderate sudden collapse results on the basal depth hoar in some areas.

Avalanche Summary

Cascade Waterfall and Rogans gulley both produced avalanches size three this afternoon. Also, we have a reliable report that many avalanches occurred on Mt. Rundle between Banff and Canmore. All of these slides were due to rapid warming in the afternoon. Additionally, a small wet slide came down to the ditch on the Field Back Road.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Friday

Problems

Deep Persistent Slabs

The warmer temperatures have the potential to wake this layer up, as demonstrated today on Cascade Waterfall (size 3).

Avoid shallow snowpack areas where triggering is more likely.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Loose Wet

Low elevation south aspects will be particularly susceptible to loose wet avalanches. This problem will be most active in the warm afternoons.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Cornices

Cornices are quite large at the moment. Try to minimize your exposure to these features, especially with the warmer temps in the afternoon.

Cornices become weak with daytime heating, so travel early on exposed slopes.Extra caution needed around cornices with current conditions.

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 9th, 2014 4:00PM