Avalanche Forecast

Issued: Mar 30th, 2016 4:20PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Deep Persistent Slabs, Cornices and Loose Wet.

rupert wedgwood, Parks Canada

Jasper.

Clear skies and warm temperatures are forecast and with them a rapid and dangerous increase in avalanche activity. Stick to shallow angles with no overhead hazard.

Summary

Weather Forecast

The North Westerly flow will continue as a body of warm air from the Pacific approaches. The freezing level (FL) overnight will not drop much below zero at treeline elevation and below allowing the snowpack to keep its heat. On Thursday and Friday FL will increasing to 2700m. With clear skies for Thursday the air and snowpack will rapidly heat up.

Snowpack Summary

Temperature crusts will loose their strength over the next few days with poor overnight recovery. Greater snowpack depths exists closer to the Icefields which offer more support and add strength to the snowpack. Several weaknesses persist in the lower portion of the snowpack and cornices are large. The snow at ground level isÂ very weak.

Avalanche Summary

Avalanche activity will reach dangerous levels by mid afternoon if the weather forecasts holds true.Â Cornices can be expected to collapse and are are of sufficient size to trigger large avalanches.

Confidence

Freezing levels are uncertain on Thursday

Problems

Deep Persistent Slabs

This problem is becoming more active. When triggered, it will be big with serious consequences. Warm and sunny conditions will increase this danger. Steep sun facing rocks, cornice failures, and loose avalanches from above are waking up this problem.

Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Increase occurrence of cornice failures are being noted. It can act as a large trigger initiating deep weaknesses plus their sheer mass, whether or not it initiates an avalanche, would be like being hit by a car.

Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.Cornices become weak with daytime heating.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

This problem will increase with forecasted warm temps and intense solar radiation. The danger rating will rapidly increase particularly on thin snowpack zones and sun facing slopes. Loose avalanches can initiate larger avalanches below.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Be very cautious with gully features.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 31st, 2016 4:00PM