Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Mar 22nd, 2022 4:00PM

Tue Mar 22nd Current Conditions
Alpine Considerable Treeline Considerable Below Treeline Considerable
Wed Mar 23rd 2 Day Outlook
Alpine Moderate Treeline Low Below Treeline Low
Thu Mar 24th 3 Day Outlook
Alpine Moderate Treeline Low Below Treeline Low

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

Extensive avalanche control is planned in the Yoho and Highway 93 North areas on Wednesday, March 23.

Mount Stephen, Mount Field, Mount Hector, Noseeum Peak and Silverhorn/Observation Peak Closure Zones are in effect Wednesday, March 23.

Summary

Weather Forecast

Wednesday will be mainly cloudy with isolated flurries and moderate winds out of the west, freezing levels could reach as high as 2500m. A cold front will arrive in the area on Wednesday evening, freezing levels will lower back to valley bottom. Thursday will be a mix of sun and cloud with alpine temps up to -6.

Snowpack Summary

5-10cm of recent snow overlies old wind slabs in alpine and isolated areas at treeline. The recent snow has formed new soft wind slabs in lee alpine features. Surface snow is moist on sheltered solar aspects at all elevations, and below 1700m on all aspects. Several buried crusts exist on solar aspects and are found 30 to 80 cm deep.

Avalanche Summary

Natural cornice releases up to size 2.5 on all aspects and a skier triggered size 2 wind slab on an east aspect were reported on Monday. On Sunday, Bourgeau-Left waterfall (next to Sunshine gondola) released a large natural avalanche that ran over the waterfall and hit Healy Creek. This may have been triggered by a cornice or strong solar effect.

Confidence

Freezing levels are uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely

Expected Size

1 - 2

Last week's slabs are 30-50cm thick but are likely to only be reactive in steep features. Sunday's new slabs are thin, soft and isolated to immediate lees but will be sensitive. Expect all of these slabs to become more reactive with warming.

  • Pay attention to cornices which may fail as they are heated and could trigger larger avalanches.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Persistent Slabs

An icon showing Persistent Slabs

Likelihood

Possible

Expected Size

1.5 - 3

Buried crust/facet layers exist in the upper snowpack on solar aspects and all aspects below 1800m. As the slabs overlying all of these crusts becomes heated, they will become much more sensitive to triggering. Wet slab activity may become possible.

  • Be aware of the potential for wide propagations.
  • Avoid travel on slopes where a crust is buried once the surface snow has become moist.

Aspects:

South East, South, South West, West.

Elevations:

All elevations.

Loose Wet

An icon showing Loose Wet

Likelihood

Likely

Expected Size

1 - 2

As freezing levels rise, expect loose wet sluffs to become active first in lower elevation steep terrain, then progress higher. Depending on cloud cover and solar inputs, this may be intensified on steep solar slopes and solar cliffy terrain.

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

Aspects:

All aspects.

Elevations:

Treeline, Below Treeline.

Valid until: Mar 23rd, 2022 4:00PM

Forecast Trend

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