Avalanche Forecast

Issued: Apr 26th, 2023 4:00PM

The alpine rating is moderate, the treeline rating is considerable, and the below treeline rating is below threshold. Known problems include Deep Persistent Slabs, Loose Wet and Wind Slabs.

MW, Avalanche Canada

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

We will get one more weak overnight freeze on Thursday night before the freezing levels skyrocket Friday afternoon. Watch out for pockets of wind slab as convective flurries can drop vastly different amounts of snow from valley to valley.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were reported and no road patrol on the Icefields Parkway today.

Post avalanche observations to the MIN.

Snowpack Summary

Sun crusts on solar aspects into the alpine and a melt-freeze crust at tree line and below on all aspects. Small wind slabs in the alpine from moderate to strong SW winds with 2-5cm of recent snow available for transport. A layer of sun crust or facets lingers in the mid-pack. The main concern is the depth hoar and basal facets at the bottom causing our deep persistent slab problem.

Weather Summary

Thursday

Sunny with cloudy periods

Alpine temperature: High 1 C

Ridge wind west: 10-25 km/h

Freezing level 2400m

Friday

Sunny with cloudy periods

Alpine temperature: Low -1 C

Ridge wind west: 10-20 km/h

Freezing level 3200 m

Saturday

Mix of sun and cloud

Alpine temperature: Low 4 C

Ridge wind southwest: 10 km/h

Freezing level 3500 m

Terrain and Travel Advice

In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Deep Persistent Slabs

The bottom of the snowpack is inherently weak with well-developed Facets and Depth Hoar. The next few days could see this problem moving into the reactive category with dramatically rising freezing levels.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Loose Wet

Warming temperatures will continue to produce wet loose avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Moderate to strong south west winds and new snow from convective activity will make new wind slabs.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 27th, 2023 4:00PM