Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Apr 29th, 2021 4:00PM

Thu Apr 29th Current Conditions
Alpine Below Threshold Treeline Below Threshold Below Treeline Below Threshold
Fri Apr 30th 2 Day Outlook
Alpine Below Threshold Treeline Below Threshold Below Treeline Below Threshold
Sat May 1st 3 Day Outlook
Alpine Below Threshold Treeline Below Threshold Below Treeline Below Threshold

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Loose Wet, Wet Slabs and Cornices.

A poor freeze overnight Thursday extending above tree line elevations will place us in the  'All Melt, No Freeze' Spring conditions scenario through Friday.

Click the "More Spring Conditions details" link for more info.

Summary

Weather Forecast

Freezing levels area approaching 2600m Thursday afternoon and are expected to remain at a similar level through the night as SW winds increase to strong. Clearing, with some associated cooling, early Friday morning holds the best potential for a weak freeze at treeline elevations. Light snowfall at treeline elevations is expected Friday afternoon .

Snowpack Summary

Poor overnight crust recovery, weak crusts on all aspects up to 2000m with moist snow up to 2500m with light rain in some areas Thursday. 10-20cm of settled dry snow in high Northerly terrain. Isolated pockets of wind slab may exist in the alpine.

Avalanche Summary

No new avalanche activity observed or reported for the past few days however temperatures are climbing higher than they have been for a week. We had limited observations today with limited visibility and no field trip.

Confidence

Problems

Loose Wet

An icon showing Loose Wet

Likelihood

Likely - Possible

Expected Size

1 - 2

A poor surface crust recovery and the potential for afternoon showers up to treeline Friday will allow surface snow to become reactive over buried crusts. Deeper wet snow can be expected at lower elevations where buried crusts may break down as well.

  • Use extra caution on solar slopes if the snow is moist or wet.

Aspects:

All aspects.

Elevations:

Treeline, Below Treeline.

Wet Slabs

An icon showing Wet Slabs

Likelihood

Possible

Expected Size

2 - 3

As temperatures rise, the snowpack becomes more sensitive and brings concern for slab avalanches. While the main concern is for wet snow to react as slabs over crusts at lower elevations, there is also  potential for dry slabs on shaded alpine slopes

  • If triggered loose wet sluffs may step down to deeper layers resulting in larger avalanches.

Aspects:

All aspects.

Elevations:

All elevations.

Cornices

An icon showing Cornices

Likelihood

Possible

Expected Size

1 - 2.5

Winds and temperatures will both remain elevated into Friday and with this there is some added concern for cornice failure. While these have their own destructive potential, perhaps the greater concern here is that they trigger deeper slabs as well.

Aspects:

All aspects.

Elevations:

Alpine.

Valid until: Apr 30th, 2021 4:00PM

Forecast Trend

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