Avalanche Forecast

Issued: Apr 18th, 2018 3:00PM

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

Alberta Parks matt.mueller, Alberta Parks

Solar radiation is a concern even under cloudy skies. If the cloud layer is thin, it may even create a "greenhouse" effect and cause the snow to weaken faster than if it was clear.

Summary

Confidence

High -

Weather Forecast

Overnight low of -6 and cloudy skies. Tomorrow has a freezing level of 2400m and a high of -1C. Expect thin clouds and strong solar input. Winds will remain light. No snow.

Avalanche Summary

2 notable avalanches today:-A cornice triggered slab on an east aspect. Sz2.5, ran full path and had a crown up to 1.5m thick. Near Ranger Creek.-Another cornice triggered pocket on a north aspect, possibly a sz 2.5(seen from a distance) and a consistent crown of 1m. Near Commonwealth Pk. We had a report of an avalanche in this area yesterday, so it is possible that this one is older.

Snowpack Summary

A freeze overnight and cloudy skies kept the snowpack reasonably cool for most of the day. By mid afternoon, the solar radiation began and the snow softened up on any solar aspect. Only polar aspects above 2200m are holding dry snow. The April 13th melt/freeze crust is still concerning as the bond appears to variable depending on aspect and elevation. Areas with consistently cool temperatures will be slower to improve.

Problems

Storm Slabs

An icon showing Storm Slabs
30-40cm slab sitting on top of the April 13 melt/freeze crust. These storm slabs could also be triggered by solar radiation.
Watch for signs of instability such as whumpfing, or cracking. Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Loose Wet

An icon showing Loose Wet
Expect the solar radiation to have a rapid, negative effect on the snowpack and ski conditions.
Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Use extra caution on slopes if the snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 2.5

Cornices

An icon showing Cornices
Keep a safe distance from overhead cornices. These avalanches will be deep and run far.
Cornices become weak with daytime heating, so travel early on exposed slopes.Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Valid until: Apr 19th, 2018 2:00PM