Avalanche Forecast

Issued: Nov 23rd, 2017 4:00PM

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

Parks Canada jonas hoke, Parks Canada

While the likelihood of triggering persistent slabs is being reduced by cooling temps, the consequences remain the same. A cautious approach is recommended for the foreseeable future.

Summary

Weather Forecast

Tonight: flurries with trace amounts, freezing level 1300m, Alpine temps lows  -7 °C, wind moderate west. Friday: flurries giving up to 5cm, freezing level to valley bottom, and similar winds.Forecast: Sat and Sun freezing level between 1500m-2000m. 6cm Sat and Sun 26cm. Winds SW mod gusting strong.

Snowpack Summary

Cooling temperatures forming a new surface crust on the saturated upper snowpack below 2300m.  A persistent slab of between 40cm - 200cm sits over the Halloween Crust. This crust can be found up to 2,700m in the Icefields and depending on its location is between 20cm - 40cm above the ground. Wind slabs likely exist in the upper alpine.

Avalanche Summary

Numerous persistent slab avalanches to size 2.5 observed from field teams today. These were failing at treeline and in the lower alpine as a result of warm temperatures, rain and additional snow loading. On Nov. 22nd a field team remote triggered 3 simultaneous size 2 persistent slabs 60-150m away.

Confidence

Due to the number and quality of field observations

Problems

Persistent Slabs

An icon showing Persistent Slabs
Be aware of the potential for wide propagations.Be wary of slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Nov 24th, 2017 4:00PM