Avalanche Forecast
Issued: Mar 23rd, 2013 9:07AM
The alpine rating is Storm Slabs, Cornices and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Good
Weather Forecast
Overnight and Sunday: Some convective energy may cause localised flurries with little accumulation overnight. Convective energy should be reduced on Sunday as the High pressure system moves over the Interior. Expect mostly sunny skies with light Southwest winds and freezing levels rising to about 1300 metres. Strong solar radiation may cause moist snow up to 2100 metres on Southerly aspects.Monday: The surface ridge of High pressure should stay mostly intact as it slides a bit to the East. Expect mostly sunny skies with light Southwest winds and freezing levels rising to about 1400 metres.Tuesday: Some cloud is expected to drift into the interior from a weak disturbance on the coast. There is a chance of flurries that may accumulate a couple of cms.
Avalanche Summary
Very large cornices released naturally and with explosives in several parts of the region. Some cornice falls caused a slab approximately 120 cms deep to release in the track or the fan. Loose dry snow sluffing was reported from shaded aspects in the alpine.
Snowpack Summary
Cornices are reported to be very large and weakly bonded. Natural cornice falls are a concern during daytime warming. Cornices may also be triggered easily by travelling near them. Slopes with corniced entrances, or exposed to cornice falls should be avoided with these conditions. Dry windslabs may be found on Northwest thru Northeast aspects at higher elevations. These wind slabs are reported to be improving their bond to the old surface, but may continue to be triggered by skiers and riders. Loose moist or wet snow may fall naturally out of very steep terrain on sun exposed slopes. Small loose snow avalanches may trigger the recent storm snow slab where it is moist from solar heating and sitting on a planar sliding surface like an old sun or rain crust. The weak layer of buried surface hoar from March 10th is down more than a metre in most places, and is reported to require hard forces to result in resistant failures in snow profile tests. Some shallow snowpack areas in the region report a weak facetted base layer that continues to be a concern for human triggering.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2013 2:00PM