Avalanche Forecast

Issued: Dec 28th, 2022 4:00PM

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

DK, Avalanche Canada

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

The highway is open to Parkers Summer for recreational use.

Avalanche Control on Highway 93 was stymied by poor visibility Wednesday. Anticipating full opening Thursday at 17:00.

Be very cautious in open areas where a stiffer slab will propagate widely. The few shots we could take showed a 4F soft slab, reactive to light loads, down 20 cm.

Summary

Confidence

Moderate

Avalanche Summary

Avalanche Control was delayed due to poor visibility. Observed natural activity is limited to the alpine. The few charges deployed today all produced storm slab results on low-elevation targets up to sz 1.5.

Snowpack Summary

20-30 cm of storm snow has developed into a soft slab over very airy facets. The storm interface is mostly made up of facets and small surface hoar making it quite reactive. Facets and depth hoar make up the deep persistent base, to ground. Snow height ranges from 50-120cm.

Weather Summary

Overnight Wednesday and through the day Thursday, the forecast calls for mainly cloudy skies with very light flurries. Light to Moderate winds from the southwest. Temperatures steady at -10.

Terrain and Travel Advice

In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Problems

Storm Slabs

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Very Likely

Expected Size

1 - 2.5

Wind Slabs

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

This problem includes a buried facet-surface hoar layer buried 30-40cm down as well as the bottom of the snow pack is inherently weak with well developed Facets and Depth hoar particularly in shallow locations. An avalanche initiating in the upper snowpack has the potential to step down to this deeper layer. This problem may extend below tree line in isolated, steep, open slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 29th, 2022 4:00PM