Avalanche Forecast

Issued: Apr 29th, 2014 8:11AM

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

danyelle magnan, Parks Canada

Glacier.

Spring melt-freeze cycles are occurring at lower elevations, but in the alpine more winter like problems of new snow and the first kiss of sun exist. Keep your head up and expect danger to rise quickly with today's strong sun.

Summary

Weather Forecast

Today will be sunny with freezing levels rising to 2700m, alpine temps reaching +9'C, and light S winds. Wednesday will see a bit more cloud with freezing levels climbing to 3600m. Alpine temps will reach +14 with a low of +9. Thursday temps will reach +18. During this period there will be strong solar and little overnight freeze and recovery.

Snowpack Summary

Up to 30cm of snow fell over the last 5 days above 1900m. Dry snow can still be found on due north aspects above 2000m. At tree line, the top 50 cm of snow are moist with several crusts in the top meter of the snowpack.

Avalanche Summary

There have been a few natural moist loose avalanches to size 2 occurring daily. Today will be the sunniest day so far and more avalanche activity is expected. In addition, glide cracks are opening up on many slopes. 2 days ago a glide crack failed on the west side of the park, releasing 2 size 3 avalanches.

Confidence

Problems

Loose Wet

The surface crust will break down quickly this morning with strong solar. Over the next few days, temps won't fall below 0 will prevent an overnight recovery. Up to 30cm of snow in the alpine will avalanche easily with the strong sun today.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Start and finish early before the surface crusts melt.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Storm Slabs

Up to 30cm of snow fell in the last 5 days above treeline. With mild temps, and moderate SW winds, this snow may form a soft slab. As you work into the alpine, test to see how cohesive the snow is and how it is bonding to the surface below.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.Plan to be off big slopes before the temperatures rises and the snowpack deteriorates.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Buried weak layers will continue to plague us until the snow is gone. These layers are most likely to release with strong solar radiation, warm temperatures, large triggers or when triggered from a shallow area. Avoid slopes with glide cracks opening

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

3 - 4

Valid until: Apr 30th, 2014 8:00AM