Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Mar 30th, 2021 4:00PM

Tue Mar 30th Current Conditions
Alpine Moderate Treeline Moderate Below Treeline Moderate
Wed Mar 31st 2 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Moderate
Thu Apr 1st 3 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low

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

Warm temperatures are forecast for Wednesday and Thursday. The effects will be strongest on steep, rocky solar terrain in the front ranges east of the divide. Start and finish your trips early if you plan to be in this type of terrain

Summary

Weather Forecast

A ridge will keep skies clear on Wed. Temps will be warm with ~ 2000m freezing levels, but alpine winds will be strong. The sun's affect will be strongest on steep solar, rocky aspects and the warming looks most significant in the front ranges east of the divide. Thurs looks similar but with skies clouding over and snow starting in the afternoon.

Snowpack Summary

15-35cm of snow fell on Sunday night, with the most around Sunshine and Bow Summit. Wind slabs exist in alpine and exposed treeline areas from strong winds during the storm. The March 19 interface of crust on solar aspects and facets on north aspects is below this, now down 20-50 cm. Basal facets exist in shallow areas east of the divide.

Avalanche Summary

Good visibility into the alpine today revealed evidence of the avalanche cycle that occurred with Sunday nights storm. Themes seemed to be alpine and treeline features failing as windslabs up to size 2.5. There was a third hand report of a small, potentially skier triggered windslab in the Bow Summit area today, but no other details were obtained.

Confidence

Timing or intensity of solar radiation is uncertain on Wednesday

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible - Unlikely

Expected Size

1 - 2.5

Wind slabs exist in alpine and exposed treeline areas from variable strong winds and 15 to 35cm of new snow. Use caution in any steep or loaded terrain until you have a sense for how reactive the new snow is.

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

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Loose Wet

An icon showing Loose Wet

Likelihood

Likely

Expected Size

1 - 2

Sun and warm temperatures will cause the recent snow to slide. The warming will be most significant in low elevation steep, rocky, solar terrain in the front ranges east of the divide. Alpine winds will help to cool temperatures

  • Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.
  • Avoid ice climbs that are exposed to steep rocky terrain on solar aspects.

Aspects:

South East, South, South West, West.

Elevations:

Treeline, Below Treeline.

Cornices

An icon showing Cornices

Likelihood

Likely - Possible

Expected Size

1 - 2.5

Cornices are big and the springtime is when they fall off more frequently. Recent wind combined with the forecasted warmup may make them more likely to fall. Don't be nearby when they do!

  • Cornices become weak with daytime heating, so travel early on exposed slopes.
  • Minimize exposure to overhead hazard from cornices.

Aspects:

North, North East, East, South East.

Elevations:

Alpine.

Valid until: Mar 31st, 2021 4:00PM

Forecast Trend

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