Avalanche Forecast

Issued: Feb 28th, 2012 9:39AM

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

Avalanche Canada swerner, Avalanche Canada

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday: Snow amounts up to 15 cm arriving by the am. Light snow near 5 cm before noon. Ridgetop winds 30km/hr from the South. Treeline temperatures near -11. Thursday: Snow amounts 5-10 cm. Ridgetop winds moderate from the West. Treeline temperatures near -8. Possible solar influence in the afternoon if clouds break. Friday: A strong westerly flow brings light snow amounts. Strong ridgetop winds from the West. Freezing levels at valley bottom.

Avalanche Summary

Reports of natural activity seemed to dwindle on Monday. One natural size 2 occurred on a SW aspect @2400m. The crown was 40-50 cm deep, 40 m wide, and ran 300 m in length. Few, small size 1 skier triggered, and explosive triggered avalanches were reported on steeper, convex terrain features, and gully features. With forecast snow and wind, I suspect avalanche conditions will remain touchy, and susceptible to rider triggers through the forecast period.

Snowpack Summary

Due to switching winds, wind slabs can be found mainly on N-NE aspects and S-SW aspects in the alpine on exposed slopes at treeline. Reports indicate the new wind slabs are not bonding well to the southerly scoured, sun crust surfaces. The total settled storm snow is near 60cm and sits over a variety of old surfaces. These include melt-freeze crusts at lower elevations and spotty areas of surface hoar in sheltered treeline areas. Where they exist, they may act as sliding layers. Easy shears persist in the new storm snow down 25-40 cm with sudden planar results. The mid and lower snowpack is well bonded and strong.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and moderate SW winds may form new wind slabs Tuesday night though Wednesday on Northerly aspects.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Storm Slabs

An icon showing Storm Slabs
The region may receive 15 cm of new snow overnight. This will add to the current storm slab instabilities; especially in areas where they overlie buried crusts, facetted snow, and/or sheltered areas with buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Feb 29th, 2012 8:00AM