Avalanche Forecast

Issued: Apr 16th, 2023 4:00PM

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

Avalanche Canada MM, Avalanche Canada

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If only the weather could make up its mind! With forecasted precip amounts jumping around the total snowfall amounts are uncertain.

Regardless, with new snow and strong winds the recipe for slab formation is prime!

Summary

Confidence

Moderate

Avalanche Summary

A field team was able to easily trigger size 1-1.5 slow moving loose wet avalanches on a North aspect below treeline yesterday.

Several natural avalanches from all aspects were observed in the park Thursday through Saturday.

On Wednesday, numerous solar triggered storm slab and loose wet avalanches up to size 3 were observed with wide propagation over the March 31 layer.

Snowpack Summary

13cm of new snow (Sunday night @ ALP & TL) will cover 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 (dn 5-20 BTL) and the Mar 31 crust (dn 50cm) 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 low pressure system arrives tonight bringing light to moderate precipitation and strong gusty winds.

Tonight: 13cm. Alpine Low -11 °C, FZL 500m, S-SW winds 20-45km/hr

Mon: Mix of sun & cloud. Alpine High -5 °C, FZL 1500m. Light gusting strong S winds.

Tues: Trace. Low -8 °C, High -4 °C, FZL 1700m. West wind 10-25km/hr

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 active, and have shown wide propagation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Storm Slabs

An icon showing Storm Slabs

With new snow available for transport and forecasted strong winds, this problem could be amplified in immediate lee and cross-loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 17th, 2023 4:00PM