Avalanche Forecast

Issued: Apr 4th, 2015 8:02AM

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

andrew jones, Parks Canada

Glacier.

Although temperatures have dropped, a couple more cold nights are needed to neutralize instabilities in the upper snowpack.

Summary

Weather Forecast

An unstable weather pattern will bring flurries and up to 9cm of snow this morning. Freezing levels rise to 1500m this afternoon with an alpine high of -3. Ridge winds west 10-30km/h. A clearing trend begins early this evening with cold temperatures and clear periods overnight. A mix of sun and cloud forecast for Sunday.

Snowpack Summary

Cold temps overnight have cooled surface snow and formed a 10cm crust at lower elevations. The middle snowpack is still warm, with moist snow down to 70cm at treeline. Rapidly settling storm snow (30-40cm) is sitting atop 6cm wet layer that is showing weakness in stability tests. Lower snowpack is well settled. Suspect wind slabs near ridges.

Avalanche Summary

No new natural avalanches were observed in Glacier National Park yesterday.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Storm Slabs

30-40cm of rapidly settling storm snow sits over a weak wet layer below 2300m. Stability tests indicate that this layer is triggerable by light loads. At higher elevations moderate winds have created pockets of wind slab and fragile cornices.

The new snow will require several days to settle and stabilize.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

A series of weak layers in the top 1.5m of the snowpack are more easily triggered due to the load added by the new snow and rain over the past week. They may be triggered by the added load of a person, another avalanche or a cornice falling.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Pay attention to overhead hazards like cornices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 5th, 2015 8:00AM