Avalanche Forecast

Issued: Feb 18th, 2013 4:00PM

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

garth lemke, Parks Canada

Jasper.

The recent storm snow is still settling in yet evolving into a windslab. Pockets of instability may exist where the snow fell on a smooth surface and is resistant to bonding. Identify and evaluate these features of concern when traveling.

Summary

Weather Forecast

Tuesday to Thursday will be seasonal temperatures, clouds with flurries of 1-3cm accumulation, Northwest switching to Southwest winds, and cold nights. No significant change expected.Â

Snowpack Summary

Saturday's 20cm of snow has settled down to 10-15cm. It is developing into a surface windslab on SE slopes with NW winds. As the winds shift Southerly, slabs will build on NE-NW aspects over the next few days. These new slabs are sitting on previous hard slab and sastrugi surfaces which bridges the weak basal facets near the ground.

Avalanche Summary

Sunday in the Icefields, only two small storm snow slab avalanches were noted from steep NE facing rocky treeline slopes.Â No other avalanches were observed along the Icefields Parkway and visibility was good. Several size 2 avalanches were noted on Sunday in the Whistler creek alpine. No new naturals were noted Monday and visibility was good.

Confidence

Due to the number and quality of field observations

Problems

Storm Slabs

Saturday's 20cm of snow is developing into a surface windslab on SE slopes. As the winds shift Southerly, slabs will build on NE-NW aspects. The new slabs are sitting on previously hard slab and sastrugi surfaces.

Caution in lee and cross-loaded terrain near ridge crests.Assess start zones carefully and use safe travel techniques.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 19th, 2013 4:00PM