Avalanche Forecast

Issued: Jan 12th, 2017 4:00PM

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

Avalanche Canada Lisa Paulson, Avalanche Canada

Steady winds from the north have blown most of the recent snow into hard slabs in unusual locations (reverse loading).  With moderate winds aloft on Friday ice climbers should be mindful of overhead terrain. Extreme cold warning for Yoho in effect.

Summary

Weather Forecast

Environment Canada has an extreme cold warning for Yoho - with windchill temps will feel like -40 frostbite may occur in minutes for Friday.  Moderate west wind at ridge top tomorrow, highs of -19 under sunny skies. After Friday temperatures will climb to seasonal norms over the weekend with sunny skies. No snow is in the forecast.

Snowpack Summary

Up to 20 cm of low density snow has been blown into hard wind slabs from north winds, so expect locally deep pockets of dense wind drifts in unusual areas (reverse loading). These slabs overlie a some facet layers with the main problem being the Dec 19 interface of facets, now buried down about 50-70 cm.

Avalanche Summary

No avalanche activity reported or observed in Little Yoho today, but we have minimal observations from this area - so low confidence.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Winds from the north have created hard wind slabs in many areas, and these are reverse from normal locations. These slabs are hard to trigger, with a single person, but if they go it will be a dense piece of snow to ride.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Facets buried on Dec 19 are down 50-70 cm in some locations. This is a concern wherever a more cohesive slab of snow sits on top of this weakness. Tree line or wind loaded areas seem to be the primary concern.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 13th, 2017 4:00PM