From March 27-April 2, An ACMG TAP Apprentice Ski Guide Exam was based out of Lake Louise. We skied a variety of objectives on the 93 N, Little Yoho, Kananaskis, and Lake Louise area.

Weather:

The week started off with a major storm that brought up to 40cm of snow accompanied by moderate to strong SW winds. Larger snowfall amounts fell on the 93 N than other areas during this storm. A cold front swept through the next day with lows dropping to -20C in the alpine and continued strong to extreme winds. After the short lived cold snap, a significant warming event occurred on Wednesday afternoon bringing freezing levels up to 2000m and strong solar effect on S to W aspects. Strong to extreme SW winds, cloudy skies, and warmer temperatures bringing freezing levels up to 1700m continued on Thursday and Friday.

Snowpack:

15-40cm of storm snow from the March 28-29 storm has been redistributed by strong southwest winds, leaving variable wind-affected surfaces at upper elevations with slabs persisting in immediate leeward features. Scoured surfaces are evident along windward ridge crests. Variable surface crusts exist at low elevations.
The March 19th interface is down 30-60cm across the range and consists of a crust up to ridgetop on southerly aspects. On northerly aspects this surface is a crust below 2100m and old wind slab/facets above.
Persistent weak layers from January and February are visible in the snowpack but remain dormant. The November crust/facet interface persists near the base of the snowpack, being weakest in shallow areas.

Avalanche Activity:

There was a large avalanche cycle up to size 3 during the storm on March 28th, and we observed evidence of this cycle on subsequent days in most areas visited. Most avalanches observed were combinations of wind slabs and cornices.

Cornices are very large and we saw continued evidence of cornice failures during the week, some of which triggered slabs on the slopes below.
On Wednesday, a loose wet cycle was initiated from steep rocky terrain below treeline on S to W aspects in the afternoon from warm temperatures and rising freezing levels.
Despite recent strong winds, we didn’t observe significant wind slab reactivity.

Other Notable Hazards:

Spring travel conditions and variable surfaces are starting to force creative management. Ski crampons were necessary most days.
Lower elevation snow surfaces changing from melt-freeze crusts to moist snow throughout the day, requiring extra caution.

Careful downhill skiing was required in wind exposed and thin snowpack areas where rocks are barely covered.

Glacier coverage in general is quite deep in sheltered areas (2 to 3m) but we also saw bare ice in wind exposed areas around Mt.Hector and Mt.Victoria

Submitted by: Jeff Relph on behalf of the TAP ASG candidiates