Avalanche Forecast

Issued: Feb 18th, 2016 4:00PM

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 stephen holeczi, Avalanche Canada

Avalanche sightings and/or close calls are still occurring on a daily basis. Cooling temperatures will take some time to start settling down the avalanche activity. We still have low confidence in the current snowpack. SH

Summary

Weather Forecast

5-10cm expected overnight with moderate to strong west winds and cooling temperatures.  Freezing levels are forecast to stay at valley bottom with alpine temperatures in the -10 to -12 range with diminishing winds.  Only light snow and winds with cooler temps in the current 3 day forecast.

Snowpack Summary

Fresh windslab and rapid cornice growth is occurring with 20- 40 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. 

Confidence

Freezing levels are uncertain on Friday

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

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

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 and to ground in thin areas.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 19th, 2016 4:00PM