Avalanche Forecast

Archived

Apr 15th, 2025–Apr 18th, 2025

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.

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.

Start and end your day early. Solar radiation and daytime warming can rapidly increase the avalanche hazard.

The deep persistent layers are still in the snowpack. Be careful on high north aspects where there are no crusts above these layers.

Confidence

High

Avalanche Summary

Recently large cornice failures and small wind slabs have been observed at alpine elevations.

On Sunday a size 3.5 deep persistent avalanche was observed on the subpeak to the east of Mt. Saskatchewan.

Snowpack Summary

5-20 cm of recent new snow exists in sheltered areas at the icefields. Wind slabs exist in lee features. The upper snowpack at tree line and below is a series of melt-freeze crusts and moist snow. The mid-pack and lower snowpack is dry, faceted and weak. High north aspects do not have any of crusts in the upper snowpack which may make it easier to trigger the deep persistent layer.

Average treeline snow depth is around 100-150cm at the icefields area.

Weather Summary

Tuesday Night

Cloudy with clear periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -10 °C.

Ridge wind northwest: 15-30 km/h.

Freezing level at valley bottom.

Wednesday

A mix of sun and cloud with isolated flurries.

Precipitation: Trace.

Alpine temperature: High -5 °C.

Ridge wind north: 15 km/h gusting to 40 km/h.

Freezing level: 1600 metres.

Thursday

A mix of sun and cloud with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -10 °C, High -3 °C.

Mostly light ridge wind occasionally gusting to 35 km/h.

Terrain and Travel Advice

Pay attention to cornices and give them a wide berth when traveling on or below ridges.
A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.

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 Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.