Avalanche Forecast

Issued: Mar 3rd, 2015 7:16AM

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

Peter, Avalanche Canada

South Rockies.

Snow quality should be slightly improved, but be wary of touchy thin wind slabs and loose snow sluffing in steep exposed terrain.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

A very persistent ridge of high pressure will maintain dry and mainly sunny conditions forâ€¦ a long time (at least a week, but probably longer). Temperatures should slowly rise with a freezing level near 1200-1400 m on Wednesday, 1500-1600 m on Thursday, and around 2000 m heading into the weekend. Ridge winds should be light or moderate from the NW-SW.

Avalanche Summary

No new avalanches have been reported recently but observations are limited.

Snowpack Summary

Up to 10 cm of new snow sits on the previous snow surface, which was a mix of surface hoar, crusts, wind affected surfaces, or dry powder. Periods of moderate northerly winds have produced pockets of wind slab in exposed lee terrain. The most prominent snowpack features is a thick supportive crust around 10-30 cm below the surface. It extends up to around 2200m. Below this elevation the crust is effectively capping the snowpack, preventing riders from tickling deeper persistent weak layers. In alpine areas, where the crust is not present or is less thick, it could still be possible to trigger a deep avalanche from sparsely covered rocky slopes or with a heavy load (i.e. cornice fall).

Problems

Wind Slabs

New snow amounts vary from only a few centimetres to around 10 cm. This snow arrived with moderate N-NE winds, which should switch to W-NW winds. Watch for pockets of wind slab on a variety of slopes in exposed terrain.

Use ridges or ribs to avoid pockets of wind loaded snow.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Deeper weaknesses still exist and remain a concern in shallow rocky areas and anywhere the thick near-surface crust is weakening. For example, steep sunny slopes or higher north aspects.

Be aware of thin areas and rock outcroppings where it may be possible to initiate an avalanche that fails on one of the deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

3 - 6

Valid until: Mar 4th, 2015 2:00PM