Avalanche Forecast

Issued: Nov 28th, 2024 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Deep Persistent Slabs and Wind Slabs.

Avalanche Canada Parks Canada/Parcs Canada, Avalanche Canada

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The winds have increased and are forecasted to get stronger, we are a little uncertain as to the extent and reactivity of the fresh windslabs. We also may see some loose dry activity with the increased wind in extreme terrain.

The Oct crust deep persistent problem remains the layer of greatest concern on large alpine slopes.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were observed or reported today. In the Sunshine region, a natural size 2 avalanche on the deep persistent layer was observed on Thursday on an alpine North aspect in extreme terrain and two days prior on Scarab Peak. Over the past few days, there have been reports of deep slab avalanches with explosives at both Sunshine and Lake Louise ski hills.

Snowpack Summary

10-20 cm of snow from last week lies on an early-season snowpack measuring 50-90 cm at treeline. Two weak layers are present: the November 9 crust, found 25-40 cm above the ground, and an October crust near the ground, where facets and depth hoar are developing. Observations of the October layer are limited, but it appears most prominent on northerly aspects at treeline and above.

Weather Summary

Low of -13C and highs of -7C Friday. Westerly winds increase to strong by mid-day Friday and continue into Saturday with very light flurries. See image below for tables.

Terrain and Travel Advice

  • Be aware of the possibility for full depth avalanches due to deeply buried weak layers.
  • Wind slabs are most reactive during their formation.
  • Avoid freshly wind-loaded terrain features.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The crust/facet layer from October 23, located just above the ground, is capped by a 50-80 cm slab. This layer has caused avalanches over the past week. The extent of the problem remains uncertain, but we advise exercising extra caution on steep, open alpine features.

Aspects: North, North East, East, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

We expect new windslab development in the lees of terrain features. Since the snowfall last week, the winds have been light. Tuesday night the westerly winds increased to moderate and are forecasted to increase to strong Friday through Saturday.

Aspects: North, North East, East, South East, South, North West.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Nov 29th, 2024 4:00PM

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