Avalanche Forecast

Issued: Nov 24th, 2019 8:03AM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs, Persistent Slabs and Loose Dry.

jonas hoke, Parks Canada

Glacier.

As natural activity tappers later today, human triggering will remain very likely.

The new Winter Permit System is in effect.

A permit is required to enter restricted areas when they are open.

Summary

Weather Forecast

Ongoing strong winds and flurries in the wake of the frontal system that passed to our north last night.

Today: Flurries (2-3cm). Treeline High -8 C. Ridge wind light W (gusting strong). Frzlvl 1000m.

Tonight: Isolated flurries. TL Low -10 C. Wind mod SW. Frzlvl 600m.

Monday: Cloudy with sunny periods. TL High -10 C. Wind light NW. Frzlvl 700m.

Snowpack Summary

Up to 35cm of new snow and mod-strong southerly winds continues to build fresh storm slabs, these overly a suncrust on steep solar aspects into the alpine (widespread below 1600m), and up to 10mm surface hoar below treeline. The new snow may also trigger the persistent slab (now buried down 60-90cm) that sits on a crust/surface hoar/stellar layer.

Avalanche Summary

A natural cycle of large avalanches is underway. Do not let the thin snow cover in valley bottoms fool you in to being complacent about overhead hazard - large avalanches have the potential to reach valley bottom.

Confidence

Due to the number and quality of field observations

Problems

Storm Slabs

Up to 35cm of new snow and strong Southerly winds continue to build fresh storm slabs.

Minimize exposure to terrain traps where the consequences of an avalanche could be serious.
Avoid avalanche terrain during periods of heavy loading from new snow and wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1.5 - 2.5

Persistent Slabs

The persistent slab sits atop a crust/surface hoar/stellar layer.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Loose Dry

These could run far and fast where the new snow sits on a crust (below 1600m and on steep solar aspects in to the alpine).

Be very cautious with gully features.
Be increasingly cautious on sun exposed slopes.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Nov 25th, 2019 8:00AM