Avalanche Forecast

Issued: Dec 24th, 2016 8:02AM

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

percy woods, Parks Canada

Glacier.

Take the time to gather information, assess the snowpack before committing to your line.

Summary

Weather Forecast

Mainly cloudy today with light flurries and a chance of sunny breaks this afternoon. Christmas day calls for a mix of sun and cloud as well. Alpine temperatures should remain cool in the -12C to -13C range and winds will be light. Snow is in the forecast once again Monday, with a shift to a SW flow aloft.

Snowpack Summary

Upwards of 100cm of snow has fallen at our Fidelity station (1900m, west end of Glacier Park) since December 19. The storm snow is slowly settling into a slab over the Dec 18th facet/surface hoar layer down 60cm. In many areas the storm snow remains loose and soft. Watch for wind effected snow.

Avalanche Summary

The last couple days of avalanche activity in the highway corridor has been limited to very steep terrain off Mt Tupper and Mt MacDonald. Info from Avalanche Crest area reported small convex rolls were shearing off 50cm down from the surface which would link to the December 18th facet/surface hoar being the weak layer.

Confidence

Due to the number of field observations

Problems

Storm Slabs

Recent storm snow has been slow to form a slab in part due to cold temps. Slab properties are starting to form. The slab rests on the Dec 18 facet/surface hoar layer down 50-60cm. Stability tests show that the storm slab is reactive to skier loads.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

Moderate to strong SW winds during this past week's storm formed soft slabs on lee features. Field tests Thursday confirmed the slabs were reactive to skier loads around ridges. These slabs may be hidden by Friday's snowfall.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 25th, 2016 8:00AM