Avalanche Forecast

Issued: Apr 17th, 2023 4:00PM

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

Avalanche Canada MM, Avalanche Canada

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Keep in mind that even though the hazard is moderate and natural avalanche activity has tapered, human triggered avalanches are still possible.

Summary

Confidence

High

Avalanche Summary

A remotely triggered size 2 persistent slab was reported to Parks staff Monday afternoon, running on the March 31st layer. A few Na avalanches were observed in the park from the extreme winds overnight on Sun.

On Sat, field teams easily triggered sz1 loose wet avalanches below TL with daytime warming. Naturals up to sz3 were seen earlier in the week and were also associated with warming events.

Snowpack Summary

10cm of new snow covers a surface crust on all aspects, except due North where dry snow still exists.

In the upper snowpack, two main layers remain a concern, the Apr 9 crust (down 5-30 BTL) and the Mar 31 crust (down 30-50cm) which both remain reactive to tests.

The mid and lower snowpack are generally strong and the Nov 17 basal weakness can still be found 20-40cm off the ground.

Weather Summary

A band of convective flurries will start to move to the region on Tuesday morning

Tonight: Alpine Low -5°C, FZL 600m, SE winds 20-30km/hr

Tues: Flurries. Alpine High -5°C, FZL 1600m. Light westerly winds

Wed: 6cm. Low -9 °C, High -6 °C, FZL 1600m. Light NW winds

Terrain and Travel Advice

  • Approach lee and cross-loaded slopes with caution.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Recently formed slabs have been slow to bond to the previous surfaces of suncrust, surface hoar and/or facets. These slabs remain a concern and have shown wide propagation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Storm Slabs

An icon showing Storm Slabs

With recent snow being transported by strong winds, this problem could be amplified in immediate lee and cross-loaded features and take a few days to settle out.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 18th, 2023 4:00PM

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