Avalanche Forecast

Archived

Jan 23rd, 2024–Jan 24th, 2024

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, human triggered possible.

Regions

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

Travel in the Icefields will require you to ride on some version of a slab, (windslab, temp crust, and settlement) overlying the Jan PWL.

Dig down and test the reactivity of the new snowpack before you commit to a line or feature.

Confidence

High

Avalanche Summary

The road survey team was in Medicine Lake and the Icefields on Tuesday. Lower elevations below 1800m has snowballing and small loose dry, point releases. Recent natural slab activity in the forecast region has been associated with the Jan PWL.

Snowpack Summary

As a general observation, the snowpack continues to be weak and largely unsupportive, though recent storm snow has improved travel. HS at tree-line is 45-75cm. Ski penetration is down ~30cm which shows that while shallow, there is some structure (slab) in the mid-pack. An interface down ~25cm shows up in snowpack tests; while in the field, reactivity will be subject to the strength of the slab over the PWL layer.

Weather Summary

Icefields Overnight: Cloudy with clear periods and isolated flurries. Low -7 °C. Mostly light SW winds.

Wednesday: A mix of sun and cloud. High -5 °C. Light SW wind. Freezing level: 1500 metres.

The Mountain Weather Forecast is available at Avalanche Canada https://avalanche.ca/weather/forecast

Terrain and Travel Advice

Be carefull around freshly wind loaded features.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Problems

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.

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.