Avalanche Forecast

Issued: Apr 15th, 2016 8:57AM

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

triley, Avalanche Canada

Purcells.

Spring Conditions. Sunny skies and very high freezing levels will increase the avalanche danger this weekend. The surface crust may break down rapidly if there is no re-freeze overnight.

Summary

Weather Forecast

Cloud overnight decreasing as moderate southwest winds develop as the ridge of high pressure builds. Clearing during the day on Saturday with light southerly winds and freezing levels at 2500 metres. Clear on Sunday with freezing levels rising up to at least 3000 metres and treeline temperatures around plus 10 degrees. Monday should be the warmest day with freezing levels at 3500 metres.

Avalanche Summary

Several size 1.0 loose dry avalanches were reported on Thursday from high alpine north aspects.

Snowpack Summary

The snow surface is currently going through a typical spring melt-freeze cycle on all aspects and at all elevations, except possibly high true-north slopes which could be holding onto cold snow. The strength (thickness) of the surface crust and how quickly it breaks down during the day are important factors to focus on. Forecast very warm weather with high freezing levels and strong solar radiation is expected to start to effect high alpine north aspects over the next few days. In some areas this may be the first real heat that the snowpack in these areas has received. Watch for clues that the snowpack is warming up, and stay off big slopes in the afternoon.

Problems

Loose Wet

Forecast sunny skies and high freezing levels may rapidly weaken the surface snow on solar aspects. Shaded aspects in the alpine may warm up enough to release as loose wet avalanches.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Strong solar radiation and high freezing levels will be another test for remaining cornices in the alpine and at treeline. Avoid travelling beneath corniced ridges.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Avoid steep slopes below cornices.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Wet Slabs

The likelihood of wet slab avalanches will increase over the next few days due to forecast high freezing levels and strong solar radiation.

Be aware of the potential for large, deep avalanches.>Travel early before the heat of the day, and avoid big slopes in the afternoon.>

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 5

Valid until: Apr 16th, 2016 2:00PM