Avalanche Forecast

Archived

Apr 12th, 2024–Apr 13th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

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

Day time warming is a major consideration for avalanche hazard right now. If the temperatures spike, the moderate rating could easily jump to considerable with wet loose avalanches being the additional concern. Keep those thermometers handy.

Confidence

High

Avalanche Summary

No new avalanches observed or reported today.

Snowpack Summary

Below treeline is basically in full spring with a steadily shrinking, near isothermal snowpack. At about 2000m the snow still feels wintery with several layers being apparent. All solar aspects have a 10cm surface crust with a very slight dusting of recent, dry snow. Starting at treeline, the polar aspects still have dry snow. There has been some wind transport near ridges in the last 48 hours that's built new windslabs in immediate lee areas. Cornices are continuing to grow as these winds continue.

Weather Summary

Beautiful day in store for Saturday. Some thin cloud will hopefully limit the solar input and buy some time before the snow starts to soften. Overnight low of -6, with a mid morning warm up to above zero. Daytime high of +3. No snow is expected in the next few days. Light winds all day, except for some gusts near alpine ridges.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.