Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Mar 28th, 2021 4:11PM

Sun Mar 28th Current Conditions
Alpine Considerable Treeline Considerable Below Treeline Low
Mon Mar 29th 2 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low
Tue Mar 30th 3 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low

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

Cooler temps and lighter winds will start to lower the hazard Monday, however we are uncertain about the extent of the wind effect at treeline, and how the new snow will react to triggers in areas that saw 25+ cm. Use caution as you gather more info.

Summary

Weather Forecast

Another 10 cm of snow at treeline is forecast for most areas Sunday night with alpine winds dropping down to the moderate range and switching from SW to North. Treeline temperatures will fall to the -12 C to -18 C range overnight and stay cool on Monday. Some light flurries and light to moderate NW winds are expected on Monday.

Snowpack Summary

5 to 25 cm of snow at treeline on Sunday with the most in the 93N. New wind slabs in alpine and exposed treeline areas with strong to extreme S-SW winds. Moist snow below 1500 m. 20-50+ cm now sits over the March 19 interface of crust on solar aspects and facets on north aspects. Nov basal facets still prominent in shallow areas east of the divide.

Avalanche Summary

One natural size 2.5-3 came down the Mt Stephen path into the berm near Field. Small loose wet avalanches reported in the Field area below 1500 m. Some small wind slabs above treeline reported by local ski areas, and some sluffing in steep terrain reported on the 93N. Limited visibility in the alpine all day.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely

Expected Size

1 - 2.5

Widespread wind slab development in alpine and some exposed treeline areas is expected from strong to extreme SW winds and 10 to 35 cm of new snow. Use caution in any steep or loaded terrain until you have a sense for how reactive the new snow is.

  • Use caution in lee areas. Recent wind loading have created wind slabs.
  • Be careful with wind loaded pockets, especially in steep confined alpine terrain.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Loose Dry

An icon showing Loose Dry

Likelihood

Likely - Possible

Expected Size

1 - 1.5

The new snow will sluff easily in steep terrain, especially in areas that received the largest amounts over the past 24 hours.

  • Be careful of loose dry power sluffing in steep, confined or exposed terrain.
  • On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects:

North, North East, East, South East.

Elevations:

Alpine, Treeline.

Valid until: Mar 29th, 2021 4:00PM

Forecast Trend

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