Avalanche Forecast

Archived

Apr 11th, 2024–Apr 12th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

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, human triggered possible.

Below Treeline

Below Threshold.

Regions

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

Recent snow and strong wind have formed wind slabs on lee features in the alpine.

If the sun pokes out beware of warming on solar slopes.

Confidence

High

Avalanche Summary

On April 10, a size 2 Deep Persistent Slab was observed on the NW bowl of Andromeda, pulling a slab to ice above the bergschrund.

Snowpack Summary

Up to 10cm of recent snow has been redistributed by South to SW winds in the Alpine. Solar slopes and all aspects at tree line and below have a plethora of crusts in the upper snow pack. The Feb 3 PWL is down 40-100cm and remains a concern on shaded aspects above 2400m. The basal depth hoar/facets are gaining strength in deeper snowpack areas.

Weather Summary

Mountain Weather Forecast is available at Avalanche Canada

Friday

Cloudy with sunny periods. Ridge wind west: 15-30 km/h. Freezing level: 2100m.

Saturday

Cloudy with sunny periods. Ridge wind west: 15 km/h gusting to 40 km/h. Freezing level: 2300m.

Sunday

Cloudy with sunny periods and isolated flurries. Mostly light ridge wind occasionally gusting to 35 km/h. Freezing level: 2400m.

Terrain and Travel Advice

Be carefull around freshly wind loaded features.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

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.