Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Feb 15th, 2021 4:00PM

Mon Feb 15th Current Conditions
Alpine Moderate Treeline Moderate Below Treeline Low
Tue Feb 16th 2 Day Outlook
Alpine Moderate Treeline Low Below Treeline Low
Wed Feb 17th 3 Day Outlook
Alpine Low Treeline Low Below Treeline Low

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

We have observed several cornice failures over the last few days. The recent cold snap has facetted and weakened them.  Some of these failures have triggered slabs on the slopes below, others have not.

Give cornices an even wider berth than normal.

Summary

Weather Forecast

The drought continues!  Skies will cloud over on Tuesday and we may see a dusting of snow and increasing alpine winds to moderate from the west. Winds will die down on Wednesday as light flurries taper off. Thursday will be clear and cold with lows in the -25 range and highs -10 to -15. But don't worry, they are calling for -1 on Friday ;)

Snowpack Summary

Isolated small wind slabs exist in exposed alpine and treeline areas. In sheltered areas, the surface snow is facetted and is starting to sluff more easily in steep terrain. A facet layer from Jan 27th is present at treeline and in the alpine down 30-40. On steep south this layer may consist of a thin sun crust as well.

Avalanche Summary

Several cornice failures have been observed over the past few days including one on Fatigue Mountain on Sunday that triggered a size 3 to ground reminding us that there is still a deep layer. Forecasters ski cut a size 2 in the Simpson area at 2100 m on the persistent layer Saturday. SSV reports working with small stubborn windslabs in the alpine

Confidence

The weather pattern is stable

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Unlikely

Expected Size

1 - 2

Recent variable winds have built slabs. These are mainly small in size but would be of concern in steep alpine terrain. There have also been several examples of cornice failures over the last few days creating larger events that involve these slabs.

  • Pay attention to overhead hazards like cornices which could trigger slabs.
  • Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects:

All aspects.

Elevations:

Alpine.

Persistent Slabs

An icon showing Persistent Slabs

Likelihood

Possible - Unlikely

Expected Size

1 - 2

Sporadic observations of avalanches over the last two weeks, mainly centered around the Kootenay region. These are 30-40 cm soft slabs over the Jan. 27 layer : facets, or facets over a thin sun crust on steep south aspects

  • Dig down to find and test weak layers before committing to a line.
  • Consider that avalanches may run further than expected as they entrain this loose surface snow.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Loose Dry

An icon showing Loose Dry

Likelihood

Possible

Expected Size

1 - 1.5

As the surface snow facets and weakens, it is starting to sluff more easily in steep terrain. This is mostly a problem in narrow confined terrain like gullies or couloirs.

  • Consider that avalanches may run further than expected as they entrain this loose surface snow.
  • On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Valid until: Feb 16th, 2021 4:00PM

Forecast Trend

The latest forecast danger ratings, broken down to elevation. See how an elevation is trending.