Avalanche Forecast

Archived

Dec 15th, 2022–Dec 16th, 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.

We have switched Jasper's main avalanche problem from a persistent slab to a deep persistent slab. The persistent slab has not gone away but any avalanche triggered in the upper snow pack will likely step down to weak facet crystals on or near the ground.

Confidence

Low

Avalanche Summary

In the past couple of days in the Parker Ridge/Mt. Saskatchewan area there have been a couple of natural avalanches to size 2 that are stepping down to ground in the alpine.

Snowpack Summary

Variable conditions in the alpine from hard wind pressed surfaces to weak faceted snow. A persistent weak layer is down 25-30cm specific to tree line and below in sheltered areas. The snowpack ranges from 40-100cm. Snowpack is unsupportive tree line and below.

Weather Summary

Friday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: High -9 °C.

Ridge wind west: 15 km/h.

Freezing level at valley bottom.

Saturday

Cloudy with sunny periods and isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -27 °C, High -12 °C.

Ridge wind light to 15 km/h.

Freezing level at valley bottom.

Sunday

Mainly cloudy with isolated flurries.

Precipitation: Trace.

Alpine temperature: Low -34 °C, High -25 °C.

Ridge wind east: 10 km/h.

Freezing level at valley bottom.

Terrain and Travel Advice

Uncertainty is best managed through conservative terrain choices at this time.

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.