Avalanche Forecast

Issued: Feb 19th, 2016 5:05PM

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

Avalanche Canada snow safety, Avalanche Canada

While some improvement with cold temperatures on Sunday this will be mainly at lower elevations that have been affected by recent warm conditions. Continue to use caution Treeline and above until a trend away from frequent avalanche activity is seen.

Summary

Weather Forecast

Friday saw a the start of a cooling trend.  Moderate SW winds will shift to West and increase to strong overnight before shifting NW and back to the light range as the last of the precip arrives Saturday morning ahead of an approaching ridge. Saturday afternoon the ridge will build, skies should clear and temperatures drop into Sunday.

Snowpack Summary

Fresh windslab and rapid cornice growth is occurring with 30- 50 cm of recent snow and moderate to strong West winds. A 60-130 cm slab overlies the January 6th weak layer of surface hoar (below 2000m), facets and sun crust. This layer is variable in tests, giving mainly hard results in test pits. The lower snowpack is well settled in the region.

Avalanche Summary

Lots of loose wet activity in the size 1-1.5 range Thursday at treeline and below from warm temperatures and rain in the Little Yoho region. Some larger avalanches ( size 2-2.5) were noted on solar aspects when the sun popped out on Mt. Ogden in the Takakkaw falls area. Warm temps and a bit more rain BTL likely induced a bit more activity today.

Confidence

Problems

Persistent Slabs

An icon showing Persistent Slabs

60-130 cm of snow overlies the Jan 6th layer of surface hoar, sun crust and facets and there have been many avalanches on this layer over the last week. Snowpack tests are giving hard sudden planar results and it has been less reactive below treeline

  • Avoid paths that have not avalanched recently.
  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs

Be mindful of cross loaded features and the lees of ridges where fresh windslabs 30-60 cm thick have recently formed. If triggered, there is potential to step down to the persistent weak layer.

  • Use caution in lee areas. Recent wind loading has created wind slabs.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 20th, 2016 4:00PM