Avalanche Forecast

Archived

Nov 14th, 2023–Nov 16th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Early Season

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Early Season

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Early Season

Regions

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

Ice climbers be aware for overhead avalanche hazard and choose conservative routes. For you skiers out there, there is just not enough snow yet.

Confidence

Low

Avalanche Summary

No new avalanches have been reported on Tuesday. There is likely some activity with the most recent snow and continued strong winds.

Of note is the numerous avalanches that occurred over the weekend, both naturally and controlled with explosives. Most of these were noted on N and E aspects up to size 2.

A fatal avalanche occurred on Saturday involving ice climbers on the Spray Road. A size 2.0 naturally trigged slab avalanche failed in alpine terrain, ran over a cliff and caught two people in a terrain trap. Ice climbers should take extra caution on route selection for overhead avalanche hazard.

Snowpack Summary

We now have a persistent weak layer (Nov 10) that is down about 20-40cm in the alpine, 10cm at treeline. Very little is known about this Nov 10th temperature crust, but it appears to be spotty aspect wise, very reactive(slippery) and estimated to be up to 2400m. Wind slabs are the theme for this early season. We have had 2 snow events with strong winds in the last 5 days:

Saturday: 15-20cm with extreme winds that created wind slabs in a very short period of time. This is the cause for all of the avalanches over last weekend.

Monday/Tuesday: 10-15cm with strong SW winds have created another wind slab problem. Strong winds will continue until Wednesday morning moving snow around some more.

Overall snowpack depth and character is largely unknown as it is early season. From what we have seen and heard, total snow depth varies from 20-60cm. Coverage is very inconsistent with LOTS of hidden hazards.

Weather Summary

Strong SW winds will continue through Tuesday night until Wednesday morning and then diminish to 30km/h from the West. Wednesday will see a daytime alpine high temp of -5c with flurries developing in the late afternoon with up to 5cm of snow.

Thursday

Mainly sunny on Thursday with 40-60km/hr West winds and freezing levels rising to 1500m. Temperatures will begin to rise during the late afternoon.

Friday

Stay tuned for Friday as a warming trend is looking likely.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
Avoid lee and cross-loaded terrain.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Avoid terrain traps where the consequence of any avalanche could be serious.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.