Avalanche Forecast

Issued: Feb 12th, 2014 8:54AM

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

Avalanche Canada mhalik, Avalanche Canada

The danger ratings are based on areas that will receive larger snowfall amounts. Areas that receive less snow will have lower danger ratings than posted.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Tonight and Thursday: Cloudy with precipitation starting overnight and carrying into the day, most accumulations will be along the western slopes of the Rockies. Between 2-10cm expected across the region. Freezing levels between 1300-1500m. Highs around -3 in the alpine. Strong to extreme south west winds at ridgetop.Friday: Moderate amounts of precipitation are forecasted, in the 10-15 cm range with moderate south west winds. Freezing levels rising to 1200m.Saturday: A brief break between systems, mostly cloudy with precipitation starting again in the evening. Mild temperatures with light to moderate northerly winds.

Avalanche Summary

Several natural, snowmobile and skier triggered avalanches up to size 2 running in the the recent storm snow were reported yesterday and today.

Snowpack Summary

Precipitation amounts will vary across the region. Expect between 2-10 cm to fall on Thursday, with possibly more (up to 15cm) near Fernie and the Flathead adding to the 20-30cm of recent storm snow. This new storm snow has formed a slab due to warming temperatures and variable strong to extreme winds. This slab is likely to have poor bonds with underlying hard slabs in the alpine and facets or surface hoar in sheltered areas at treeline and below. At treeline, approximately 40 - 60 cm below the surface exists another surface hoar and/or sun crust layer, that was buried late in January which could become active. The mid snowpack is strong and supportive. Deeper persistent layers have been dormant, however they could wake-up with a heavy load such as a cornice drop or large slab avalanche. The recent avalanche activity is a sign of the unstable snowpack conditions. With more load from forecasted precipitation and wind, expect avalanche sizes and occurrences to increase.

Problems

Storm Slabs

An icon showing Storm Slabs
Touchy new storm slabs have formed on various aspects especially in lee areas. Expect natural avalanches with increased loading from precipitation and wind. Loose snow avalanches remain a concern.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>For sledders boondocking through low angle terrain and avoiding avalanche slopes is a great option.>Choose regroup spots carefully and avoid runout zones.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 4

Valid until: Feb 13th, 2014 2:00PM