Avalanche Forecast

Archived

Dec 7th, 2022–Dec 8th, 2022

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

There is a persistent weak layer buried 25-35 cm below the surface. Sensitivity of this layer may increase with rising temperatures and increasing winds. Also watch out for building wind slabs in the alpine and down into tree line.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed on a road patrol to the Parker Ridge area on Wednesday.

Snowpack Summary

Up to 10cm of new snow in the Maligne and townsite area; up to 5cm in the Icefields area in the last two days. Strong south west winds are creating wind slabs in the alpine and tree line with this new snow. Tree line and below there is a buried layer down 30-35cm that consists of surface hoar, facets, and sun crust depending on aspect and location. Snow depth ranges from 45-110cm.

Weather Summary

Thursday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: High -10 °C.

Ridge wind southwest: 20 km/h gusting to 45 km/h.

Freezing level at valley bottom.

Friday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -15 °C, High -11 °C.

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

Freezing level at valley bottom.

Saturday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -16 °C, High -9 °C.

Ridge wind south: 10-20 km/h.

Freezing level at valley bottom.

Terrain and Travel Advice

Watch for signs of slab formation throughout the day.

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.