Avalanche Forecast

Archived

Feb 2nd, 2019–Feb 3rd, 2019

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

Jasper.

Highway 93N, Icefields Parkway remains Closed from Athabasca Falls to Sask River Crossing. Maligne road is also closed. New expected opening for both: Sunday at 18:00. Check Alberta511 for latest updates

Weather Forecast

Temperatures dropped and will continue to drop overnight; the forecasted high for Sunday, -31°C. Mix of snow and cloud with a significant inversion forecast. May be worth getting out of the valley bottom and into warmer temps above; warm like -20°C, (slightly better than -31)!A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

40cm new snow throughout the forecast region. This puts the Jan18 buried surface hoar, down 50cm. Previous to this storm a strong midpack was bridging the basal weakness. Storm snow may overload that bridging and, large avalanches could be expected to travel full path if triggered. Avoid all avalanche terrain until the new snow has time to settle.

Avalanche Summary

Poor visibility through the forecast region. No new natural avalanches observed in the Icefields. Forecaster's sympathetically triggered multiple sz 1.5 to 2 on the same control route. Highway avalanche control had similar results, up to size 2 and burying the road. Help forecast - share observations HERE, on the Mountain Information Network!

Confidence

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

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.