Avalanche Forecast

Issued: Dec 17th, 2019 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 Deep Persistent Slabs.

Parks Canada william lawson, Parks Canada

The extent of the new wind slab distribution is uncertain. Where it exist you can expect the new load to be reactive.

Summary

Weather Forecast

The peak wind event will have passed by Tuesday evening but expect moderate to strong values Wednesday. Forecasted temperatures will continue to be warm through the rest of the week. Small inputs of snow are expected Wednesday, Thursday with the intensity increasing by the end of the week. 10-30cm of snow accumulation if forecasted by Saturday.

Snowpack Summary

New wind slab can be found on immediate lees alpine and tree line, the extent of the distribution is uncertain. Beneath the recent 40-60 cm of storm snow, the snowpack structure is generally weak, consisting of facets and depth hoar. The Nov crust is present up to 2500m and ~30 cm up from ground. Snowpack depths at treeline range from 80-160 cm.

Avalanche Summary

No new natural avalanche activity observed for the past two days.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Strong wind values Tuesday have created thin wind slabs predominantly on East aspects directly below ridge top. Expect the new load to be reactive to light loads for the near future.

  • Use caution in lee areas. Recent wind loading has created slabs over weaker snow.
  • Caution on open steep slopes at treeline that have been exposed to wind loading.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 1.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The recent snow sits over weak facet and crust layers. As time goes on the chance of triggering is becoming less likely, but there is lots of uncertainty as to where you could trigger an avalanche and what it will take to get it moving.

  • Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 18th, 2019 4:00PM