Avalanche Forecast

Archived

Mar 14th, 2023–Mar 15th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

North Rockies, Kakwa, McGregor, Pine Pass, Tumbler.

15-25 cm of recent snow and moderate south wind formed wind slabs on lee aspects that may remain reactive in the alpine.

Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Confidence

Moderate

Avalanche Summary

No new avalanches were reported in this region on Monday.

Snowpack Summary

15-25 cm of recent snow and moderate south wind formed wind slabs on lee aspects that may remain reactive in the alpine.

Below the new snow, is generally hard surfaces from extensive wind effect or a thin sun crust on steep, sunny slopes.

The middle of the snowpack is generally well settled and strong.

A weak layer of large and weak facets is found near the base of the snowpack. This layer is of greatest concern in shallow snowpack areas in the north and east of the region.

Weather Summary

Tuesday Night

Clear skies / 30 km/h south ridgetop wind / Low temperature at treeline around -10 C

Wednesday

Mix of sun and cloud with isolated flurries; 0-3 cm / 40 km/h southwest ridgetop wind / High temperature at treeline around -9 C

Thursday

Sunny / 20 km/h southwest ridgetop wind / High temperature at treeline around -7 C

Friday

Sunny / 20 km/h southwest ridgetop wind / High temperature at treeline around -3 C

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

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.

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.