Avalanche Forecast

Issued: Apr 25th, 2014 8:00AM

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

danyelle magnan, Parks Canada

Glacier.

An unsettled forecast could bring intense periods of sun and periods of rain, both of which will increase danger.

Summary

Weather Forecast

Today should be cloudy with sunny periods and some convective flurries. Freezing levels will rise to 1800m, and light winds won't do much to help keep things cool. A system moving in on Saturday will bring up to 10cm of snow above 1700m with light to moderate SW winds. Sunday will be similar with lighter precipitation amounts.

Snowpack Summary

Below treeline, warm temperatures overnight prevented a freeze. Above 1900m ~20cm of moist snow sits on a crust. Mod SW winds loaded immediate lees. Several crusts in the top meter of the snowpack provide potential failure layers and sliding surfaces for avalanches.

Avalanche Summary

Cooler temps and high cloud kept things quiet yesterday avalanche wise. Wind loaded pockets in the immediate lees were reactive to ski cuts on steep slopes yesterday. These size 1 avalanches were loose, as the new snow had no slab properties. As it settles it may develop more propagation potential as it fails on a crust.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

Thin wind loaded pockets were reactive to ski cuts on steep slopes in the immediate lees of ridgelines yesterday. These windslabs overlie various surfaces; at treeline they will likely bond poorly to crusts or wet snow below them.

Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

At lower elevations there was no overnight freeze, and at higher elevations new snow overlies wet snow and crusts. Loose wet avalanches are possible during periods of strong solar.

Make your travel plans to take advantage of overnight freezing.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Persistent Slabs

Deeply buried layers like the various March sun crusts and deeply buried surface hoar from February may be triggered by warm temps, heavy rain, or large triggers like a cornice failure of other avalanches.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Pay attention to overhead hazards like cornices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Valid until: Apr 26th, 2014 8:00AM