Avalanche Forecast

Issued: Nov 17th, 2020 4:00PM

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

Ian Jackson,

Avalanche control will be conducted in the Simpson Avalanche Paths on Wednesday Nov. 18th.  No access to this area on that day.

Summary

Weather Forecast

Tuesday was warm and windy, but temperatures will cool and winds will decrease Wednesday - Friday.  Forecasts are calling for 5-20 cm overnight Tuesday with higher amounts to the north. Winds will decrease but remain in the moderate to strong range at 3000m from the SW.  Another pulse of precip is forecast for Wednesday evening.

Snowpack Summary

20-40 cm of settled snow overlies the Nov 5th crust with the higher amounts around Sunshine. Windslabs exist in alpine and at treeline. The crust is 1-10 cm thick and generally thickest around Sunshine. It extends up to 2400m on polar aspects and slightly higher around Sunshine and on solar aspects. Total snow depths at treeline are 50-100 cm

Avalanche Summary

A size 2 natural out of the "Goat's Eye" feature near Sunshine ran ~ 300m on a NW aspect.  Otherwise, local ski hills generally triggering small soft windslabs within the overnight storm snow. Small sluffs were noted out of steep rocky terrain on a field trip in "Guiness Gully" as temperatures warmed on Tuesday.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs exist in the alpine and at treeline and more forecasted wind and snow will create new ones. So far, we haven't seen too many stepping down to the Nov. 5th crust, but the potential is there.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Dry

An icon showing Loose Dry

With up to 20 cm forecasted overnight, watch for sluffing in steep terrain. This will be less of a problem in areas that don't receive as much snow.

  • Use caution above cliffs where small avalanches may have severe consequences.
  • Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Nov 18th, 2020 4:00PM