Avalanche Forecast

Issued: Mar 19th, 2014 8:00AM

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

chris gooliaff, Parks Canada

Glacier.

The complex upper snowpack is still adjusting to the new load. If we receive more than 10cm of snow today, expect the danger rating to bump up at treeline and below treeline.

Summary

Weather Forecast

A cold front should pass through the area today, bringing up to 10cm today, with an additional 5cm tonight. Freezing levels should stay below 1200m, and winds will be moderate from the SW. In the wake of the cold front, unsettled conditions will prevail with light flurries through Thursday.

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 Monday 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

Natural activity in the highway corridor eased yesterday with the cloud cover. A report of a size 2 in the Hospital Knob area of Connaught came in yesterday afternoon. It was suspected to have failed on the more recent, shallower crusts.

Confidence

Forecast snowfall amounts are uncertain

Problems

Wind Slabs

The recent storm snow has been redistributed by winds. The resulting soft slabs sit atop various old surfaces, including crusts on solar aspects and small surface hoar on northerly aspects. The slabs will remain reactive for a couple more days.

Be cautious as you transition into wind affected terrain.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

The early March crusts are buried by over a metre of snow, but are still triggerable by people. They are more likely to fail on steeper S and W aspects.

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

In Rogers Pass, the Feb 10 surface hoar/crust sandwich is buried over 2m deep. We are still seeing hard, sudden test results on this layer. If a very large trigger smacks the slope, there is the potential for a huge avalanche.

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 20th, 2014 8:00AM