Archived

Avalanche Forecast

Apr 18th, 2018–Apr 19th, 2018

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Kananaskis.

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.

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.

Avalanche Problems

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

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

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