Avalanche Forecast

Archived

Jan 16th, 2023–Jan 17th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

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, Churchill, Cirrus-Wilson, Fryatt, Icefields, Miette Lake.

Natural avalanche activity has slowed down but human triggering remains possible. A continued, conservative attitude is warranted as the snowpack is generally weak with a faceted base keeping deep persistent slabs on the problem list for the foreseeable future.

Confidence

Moderate

Avalanche Summary

There were no new avalanches observed on over the weekend on the icefields parkway. There was evidence of a natural cycle up to Size 3 on Friday. Some avalanches initiated with cornice failures or in a surface Wind Slab stepping down to the basal facets.

If you're out in the hills, don't forget to post to the MIN. Every bit of information helps

Snowpack Summary

5cm of new snow since Friday has been redistributed by SW wind creating wind slab in the alpine and on exposed features at tree line. There is a weak temperature crust below 1800m. A layer of surface hoar and facets is down 20-40cm in sheltered areas. Large facets and depth hoar comprise the bottom portion of the snowpack. Snowpack depths vary from 40-100cm.

Weather Summary

Tuesday - Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: High -9 °C.

Ridge wind southwest: 15 km/h.

Freezing level at valley bottom.

Wednesday - Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -11 °C, High -9 °C.

Ridge wind southwest: 10 km/h.

Freezing level at valley bottom.

Thursday - A mix of sun and cloud.

Precipitation: Nil.

Alpine temperature: Low -14 °C, High -10 °C.

Ridge wind west: 10 km/h.

Freezing level at valley bottom.

Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

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.