Avalanche Forecast

Issued: Apr 11th, 2016 9:00AM

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. Forecast cloud cover, cooler air temperatures, and dropping freezing levels will all contribute to decrease the likelihood and size of avalanches. Avoid slopes that do not develop a solid crust overnight.

Summary

Weather Forecast

High cloud developing overnight with freezing levels dipping down to 2000 metres by morning. Mix of sun and cloud on Tuesday morning, becoming cloudy with moderate southwest winds in the afternoon. Freezing levels dropping to 1500 metres by Wednesday morning with moderate southwest winds and 3-5 cm of new snow above 1500 metres. Cloudy with light winds during the day on Wednesday. Mix of sun and cloud on Thursday with overnight freezing down to 1300 metres.

Avalanche Summary

Natural avalanches up to size 3.0 were reported from Sunday in the central Purcells on alpine features with solar exposed aspects. Some glide cracks were also reported releasing up to size 2.5 during the heat of the day.

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. A moist/wet, isothermal, and rapidly melting snowpack exists on all aspects below around 1500 m and probably even higher on solar aspects. The strength (thickness) of the surface crust and how quickly it breaks down during the day are important factors to focus on.

Problems

Loose Wet

Loose wet avalanche activity is expected to decrease with forecast cloud cover and descending freezing levels. Watch for slopes that do not re-freeze overnight.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Cornices

The likelihood of natural cornice falls will drop as the cloud cover increases and the freezing levels drop.

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

Unlikely - Possible

Expected Size

2 - 5

Wet Slabs

Wet slab avalanche activity is expected to decrease with forecast cloud cover and descending freezing levels. Watch for slopes that do not re-freeze overnight.

Be aware of the potential for large, deep avalanches.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 6

Valid until: Apr 12th, 2016 2:00PM