Avalanche Forecast

Issued: Dec 29th, 2014 8:00AM

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

ali haeri, Parks Canada

Glacier.

http://www.pc.gc.ca/apps/links/goto_e.asp?destination=http://www.facebook.com/MRGnationalparks/posts/608542575941919We're in a pattern of stable clear weather but the weakness in our snowpack is still present. Certain areas may not indicate this instability but rest assured that this weak layer is reactive and that cautious route selection is required.

Summary

Weather Forecast

High pressure ridge and a northerly flow is settled in over the Province. Cold temperatures, clear skies and moderate northerly winds will be par for the course for the next few days.

Snowpack Summary

Upper snowpack is settling snow. The widespread and highly reactive Dec 17 surface hoar layer is down beneath a ~50-70cm slab and on top of a thick rain crust up to 2100m. The Dec 9 surface hoar is down ~ 70-90cm but is more spotty in distribution. The Nov 9 crust sits 30cm above the ground.

Avalanche Summary

Yesterday, several ski cuts, size 1 and whumphs observed by the field team on Mt Abbott between 1800-2000m. Backcountry report from Hospital Knob area in Connaught of several skier triggered and remote avalanches to size 1.5. Daily reports of rider triggered avalanches to size 2.0 over the last week all down ~50cm on the Dec 17 surface hoar.

Confidence

Due to the number and quality of field observations

Problems

Persistent Slabs

Rider triggered and remote avalanches are happening daily on a widespread surface hoar layer down ~50cm. The overlying slab has gained enough strength to propagate widely which means bigger consequences. This problem will persist for a while.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Use conservative route selection, stick to moderate angled terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

Winds have been steady in the 40-50km/h range from the north overnight. There's lots of snow available to move around to form slabs on lee features which is on south and west aspects.

Use caution in lee areas. Recent wind loading have created wind slabs.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 30th, 2014 8:00AM