Avalanche Forecast

Issued: Dec 6th, 2024 4:00PM

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

Parks Canada, Avalanche Canada

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

The Icefields Parkway will be closed from Parkers to Big Bend for avalanche control on Saturday December 7th from noon until 4pm. Check for updates on 511.alberta.ca

Incoming snowfall combined with strong winds will create wind slabs in leeward areas. Avalanches may have the potential to step down to deep persistent instabilities

Summary

Confidence

Moderate

Avalanche Summary

At Marmot Basin size 2 avalanches failing on the facets above the October 18 MFcr have been produced by large explosives in the alpine on E-S aspects.

Snowpack Summary

Up to 20cm of new snow will sit on a thin melt freeze crust that developed from the previous warm temperatures up to 2200m. The Nov 8th crust and facets are down 30-40 cm at tree-line and below. We have also found surface hoar (6mm) down 70cm at 2500m. The October crust is widespread and is found near the base of the snow pack with facets above and below. Snow depth is roughly 80 cm at treeline and tapers rapidly below.

Weather Summary

Saturday

Cloudy with flurries accumulating up to 15 cm.

Alpine high of -3 Â°C.

Southwest winds of 15 km/h gusting to 65 km/h at ridgetop.

Freezing level: 1500 metres.

Sunday

A mix of sun and cloud with isolated flurries.

Trace of precipitation.

Low -11 Â°C, High -8 Â°C in the alpine.

Mostly light ridge wind occasionally gusting to 55 km/h.

Freezing level at valley bottom.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.

Problems

Deep Persistent Slabs

This layer is most reactive where it has been loaded by wind transported snow. This problem includes the Oct 18 crust and the Nov 8th crust and surface hoar. There’s uncertainty around its distribution and sensitivity.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Wind Slabs

Incoming snow and increased southwest winds will develop a windslab in leeward features over the next 24 hours.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Dec 7th, 2024 4:00PM