Avalanche Forecast

Archived

Apr 15th, 2024–Apr 16th, 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.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

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

Spring is on hold for a few days with cooler temperatures and incoming snow making it feel more like winter.

Watch for variable wind loading as the winds switch from SW to North.

Forecasted snowfall amounts vary from 2cm to 13cm.

Carefully assess how well the new snow is bonding to old hard surfaces.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed or reported on Monday.

A loose dry size one was reported on Sunday in the Icefields area as well as serac falls off of Kitchener and snowdome.

Neighbouring forecast areas reported numerous dry loose and wet loose avalanches to size 1.5 from the heat and sun over the weekend. Cornice failures have also been observed producing avalanches stepping down to deeper layers or even to ground.

Snowpack Summary

The weekend heat has formed a crust to 2600m on all aspects and up to mountain top on solar slopes. Solar slopes at treeline and below have a plethora of crusts in the upper snow pack.

On shaded slopes 10-20cm of recent snow has been redistributed by South to SW winds forming windslabs in the alpine. The Feb 3 PWL is down 40-100cm and remains a concern on shaded aspects and shallow areas, above 2400m.

The basal depth hoar/facets are gaining strength in deeper snowpack areas.

Weather Summary

Mountain Weather Forecast is available at Avalanche Canada

Monday Evening

Flurries with up to 13 cm. Alpine low -8 °C. Ridge winds from east 10-30 km/h. Freezing level valley bottom.

Tuesday

A mix of sun & cloud with isolated flurries. Alpine high of -7 °C. Northeast ridge wind 20 km/h gusting to 45 km/h. Freezing level valley bottom

Wednesday

A mix of sun & cloud. Alpine high -9 °C. North ridge winds 15-30 km/h

Terrain and Travel Advice

Closely monitor how the new snow is bonding to the crust.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.