Avalanche Forecast

Archived

Apr 18th, 2024–Apr 20th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

Still good skiing on at higher elevations on the northern aspects. The crusts and cool temperatures are making for fast travel! Be cautious of windslabs along ridgelines and at the entrances to runs.

Confidence

High

Avalanche Summary

A few loose dry avalanches up to sz 1.

Snowpack Summary

Recent storm snow totals are highly variable depending on drainage and elevation. The farther east you are, the more snow there is! While Burstall Pass area saw 10-13cm, on the eastern side there was closer to 20cm. This recent snow overlies a strong crust and is bonding well except at higher elevations where it is sluffing easily. Wind slabs are evident at 2400m and above, and could be sensitive to human triggering in specific locations such as along ridgelines. The deeper persistent weak layers are still a concern where the snowpack is thin or when the crusts break down with direct solar radiation and/or daytime heating. Moist snow was observed by 1300m at 2200m on Thursday on solar aspects.

Weather Summary

Friday will start off rather chilly with temps around -14C. Throughout the day there will be a warm up to around -4C but it will feel much warmer than that with the mix of sun and cloud forecast. Winds will continue out of the east and there may be a few cm of snow that falls overnight on Thursday. The sun has lots of intensity at this time of year so pay attention to aspect and whats overhead as you travel. Stability will decrease throughout the day as temperatures warm up.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.