Avalanche Forecast
Issued: Apr 18th, 2013 10:54AM
The alpine rating is Persistent Slabs, Wind Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
Thursday night and Friday: Moderate snowfall tapering to light on Friday (higher amounts are more likely in the South end of the region) / Moderate southwest winds becoming light on Friday / Freezing levels at about 1500mSaturday: Cloudy with isolated flurries / Moderate west winds / Freezing level at 1500mSunday: Ridging will develop resulting in clearing skies and rising freezing levels
Avalanche Summary
Numerous rider triggered and isolated remote/sympathetic events have been reported in high (2300-2700m) north and northeast facing slopes up to size 2.5, all associated with preserved surface hoar. Much of the reported activity on buried surface hoar seems to be occurring in the north of the region in the Duffey Lake/ Birkenhead areas, through the Hurley and up towards Bralorne/Goldbridge.
Snowpack Summary
North and Northeast aspects above 2000m continue to hold dry snow; otherwise, the surface condition is crusts. The carrying strength of the crusts varies depending on aspect and elevation as well as proximity to rocks, etc.... Generally speaking, the crusts have been going moist in the afternoon and then refreezing at night in all but the lowest terrain. Recent storm snow has settled into a cohesive slab between 30-60cm deep. At the interface of this storm snow lies the April 05 layers. On solar aspects, the layer is a strong melt-freeze crust, with some faceting observed above and below. Reactivity on this layer has been inconsistent, with occasional sudden results and some whumphing. On North and Northeast aspects above about 2300m, this interface may be preserved surface hoar (up to 15mm). Where the surface hoar is present we have reports of sudden results in stability tests and have seen rider triggered, sympathetic and remote events up to size 2.5. Professional operators express consistent concern for triggering this layer.Cornices are huge and will continue to grow with the forecasted precipitation.
Problems
Persistent Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 19th, 2013 2:00PM