Avalanche Forecast
Issued: Mar 18th, 2012 10:23AM
The alpine rating is Storm Slabs, Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
Monday: Mainly sunny with light south-westerly winds. Freezing level rising to around 1300m in the afternoon.Tuesday: Mainly clear in the morning, with clouds and then light (or locally moderate) snow beginning in the afternoon. Winds increasing. Freezing level near 1000m in the afternoon.Wednesday: Light snow continuing. Light to moderate winds. Freezing level near 1000m in the afternoon.
Avalanche Summary
On Sunday, a size 1.5 avalanche released naturally on a north aspect. On Saturday, a recent avalanche was observed on a north aspect in the southern Elk Valley, suspected to have started as a wind slab and ending in moist snow. Evidence of a previous natural cycle was also reported. On Friday, explosives produced size 1-2 avalanches.
Snowpack Summary
Unsettled weather has brought snow and wind through most of the week, creating variable wind slabs and storm slabs. On Saturday, snowpack tests in the Elk Valley, east of Sparwood, showed a couple of shears in the top 20cm of storm snow. A rain crust is buried about 1m down. Two surface hoar layers, buried in February and now 1-2m deep, exhibited sudden planar results, which have been repeated in a number of locations. This means they still have the potential to produce widely-propagating, destructive avalanches if triggered. Most likely triggering mechanisms are a person traveling on a thin snowpack area, or a storm slab, wind slab or cornice stepping down. Basal facets may still exist, particularly in shallow snowpack areas with steep, rocky start zones. Cornices have grown large and threaten slopes below.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 19th, 2012 9:00AM