Avalanche Forecast

Issued: Dec 4th, 2019 8:13AM

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

Parks Canada ross campbell, Parks Canada

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All Winter Restricted Areas are closed for Avalanche Control today. Avalanches have been running full path, this trend will continue today!

Summary

Weather Forecast

Today we will receive another 5-10cm, moderate to strong winds and seasonally warm temperatures. Clearing tonight, temperatures will cool, and winds will decrease to light values. Tomorrow a mix of sun and cloud, with flurries.  Friday, Saturday's forecast is for another 30cm!

Snowpack Summary

Approximately 60-70cm of storm snow overlies a variety of facetted surfaces, crusts or old wind slabs depending on aspect and elevation. The two main interfaces to watch for are the storm slab interface and the Nov 23rd surface hoar/ crust buried 40-60cm.

Avalanche Summary

Yesterday's Natural avalanche cycle produced numerous avalanches to size 3! With last night's additional 30cm of new snow + more snow today, warm temps, and wind, the natural cycle will continue with larger/more destructive slides running full path! Public reports of natural avalanches yesterday in the Connaught drainage burying the skin track!

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs

Approximately 50cm + of new snow in the last 36 hours, warm temperatures and strong winds formed storm slabs on all aspects and elevations. Loose dry avalanches are also problematic with this much new snow!

  • If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
  • Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 3.5

Persistent Slabs

An icon showing Persistent Slabs

Storm slabs have the potential to step down to a buried weak layer (Nov 23 Surface Hoar) now down 40-60cm. It consists of surface hoar at treeline and below, and a crust on steep solar aspects into the alpine.

  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3.5

Valid until: Dec 5th, 2019 8:00AM