Avalanche Forecast

Archived

Feb 6th, 2024–Feb 7th, 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.

Regions

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

Recent spring-like conditions didn't improve the overall quality of the snowpack. It remains a cold, mid-winter snowpack with active persistent and deep persistent problems!

Continue to use caution on any large slopes in the alpine or at treeline.

Confidence

High

Avalanche Summary

The field team on Monday triggered a sz 1.5 persistent slab on a south asp. at TL in Boundary Lake on the Parkway. Triggered with a whumph and was slow to initiate.

No new avalanches were reported by Field Teams on Tuesday.

Snowpack Summary

A light dusting of recent snow sits over a variable, almost always breakable crust. This crust can seen as a 1-3 temp crust over facets on shaded aspects, up to a 15-20cm melt freeze crust observed on solar asps, over the DPL, especially at TL.

Persistent and deep persistent weak layers remain ever-present and active. Do not put your trust in either of these layers. Both are showing some potential to propagate in snowpit tests.

Weather Summary

Tuesday Overnight: Low in the Icefields: -13°C

Wednesday: Mainly cloudy. Alpine High -5 °C; Light right top winds. Freezing level: 1500m

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

Terrain and Travel Advice

Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.

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.