Avalanche Forecast

Archived

Apr 16th, 2024–Apr 17th, 2024

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

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

Watch for variable wind loading as the winds switched from SW to North and back.

Confidence

High

Snowpack Summary

The last 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

Tuesday Evening

Cloudy with clear periods and isolated flurries. Alpine low -13 °C. Ridge winds from NE 15 to 50km/h. Freezing level valley bottom.

Wednesday

A mix of sun & cloud. Alpine high -7 °C. North ridge winds 15-35 km/h

Thursday

Sunny with cloudy periods. Alp Low: -13 °C, High -9 °C. Ridge wind northeast: 15-35 km/h. Freezing level at valley bottom.

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.