Avalanche Forecast

Archived

Dec 6th, 2023–Dec 7th, 2023

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

From one extreme to another! Avoid any activity in avalanche terrain on Thursday as we're expecting our first real storm of the year.

Confidence

Low

Avalanche Summary

Clouds prevented any views of the hills today, but there's likely an avalanche cycle under way.

Snowpack Summary

We have a largely wet and warm snowpack at the moment. Rain up to 2100m has saturated low elevation snowpacks and likely a moist, soon-to-be crust from 2100-2200m. Above that, weather stations aren't showing much accumulation yet, but it appears we've had 10-20cm at peak height by this evening. The interface between the old and new snow will be slow to develop because of the wide temperature spread. As the snow temperatures average out, the bond will improve, This is a rapid loading situation, which typically means an avalanche cycle is on the way.

Weather Summary

Snow?? Apparently there is some on the way. The rain will be pushed out by cold air overnight tonight with moderate snow to follow. Forecasts vary on timing, but amounts seem to more or less agree with 30-40cm being the average number. Surface light winds will shift to the north and temperatures will fall to -7 by morning.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Approach lee and cross-loaded slopes with caution.
Watch for changing conditions today, storm slabs may become increasingly reactive.

Problems

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.

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.

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.