Avalanche Forecast

Issued: Mar 18th, 2014 8:11AM

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

ali haeri, Parks Canada

Glacier.

The solar affect will be strong until it clouds over later today, this may cause loose avalanches on sunny aspects or trigger a storm slab instability.

Summary

Weather Forecast

Brief ridge of high pressure will maintain dry conditions until this evening when a Pacific frontal system approaches the interior. Expect increasing cloudiness throughout the day and light snow to begin tonight. Light to moderate snow amounts are forecast for tomorrow into Thursday morning.

Snowpack Summary

80 to 90cm of recent storm snow overlies the Mar 13 and 14 crusts that are within 10cm of each other on solar aspects. The 13th being a lot thicker. Snowpack tests yesterday on this layer produced a Rutschblock 3 whole block . Below this the Mar 2 crust is down 110-130cm and below that the Feb 10 layer is down around 2 to 2.25m.

Avalanche Summary

Several natural avalanches from size 2.0 to 2.5 within the highway corridor from early yesterday.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

Lingering storm slabs instabilities may exist from the last storm two days ago and the associated wind. 2 crusts have been recently buried by this. Caution in more exposed areas where the wind had a chance to stiffen the snow.

Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

A weak layer from early March within the range of rider triggering may catch you by surprise. Triggering this layer is more likely on steep south and west aspects where the crust had a chance to fully form.

Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

The deep instability from mid February , down around 2m will need a large trigger to be initiated like a cornice fall or shallower avalanche. It should not be overlooked by backcountry users due to the large consequences should it be triggered.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Mar 19th, 2014 8:00AM