Avalanche Forecast
Issued: Apr 1st, 2017 3:50PM
The alpine rating is Storm Slabs, Persistent Slabs and Loose Wet.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
Saturday night: Isolated flurries with a trace to 5 cm of new snow. Light to moderate southwest winds. Sunday: Cloudy with sunny periods and isolated flurries with a trace of new snow. Light northwest winds. Freezing level to 1500 metres with alpine temperatures around -6.Monday: A mix of sun and cloud. Light northwest winds. Freezing level to 1700 metres with alpine temperatures around -5.Tuesday: Cloudy with sunny periods. Light south winds. Freezing level to 1800 metres with alpine temperatures around -4.
Avalanche Summary
Reports from Friday showed several recent (12-36 hour old) persistent slab releases to Size 3 with natural storm slab and cornice triggers. Two of these occurred on southeast aspects. Improved visibility also revealed evidence of numerous storm slabs and wind slabs having released from Size 2-3 over the same time period. Natural loose wet slides were also observed running up to Size 2.5 from steep, solar terrain.Reports from Thursday include numerous observations of storm slabs and wind slabs releasing naturally, with natural cornice falls, skier traffic as well as with ski cutting and explosives control as triggers. Sizes ranged from 1-2.5 and crown fractures generally from 30-60 cm in depth. Northeast to northwest aspects were the most active.On Wednesday, storm slabs proved reactive and ran naturally up to Size 2.5 with a couple larger Size 3 and 3.5. Storm slabs were also reportedly reactive to skier triggers up to size 1.5 at treeline elevations.
Snowpack Summary
About 10 cm of new snow fell over Friday night and Saturday morning, burying a temperature crust at about 1900 metres and below as well as sun crust all the way into the alpine on most solar aspects. The new snow brings recent storm snow totals at upper elevations to 40-60 cm. This storm snow is dry up high and moist at 1800 m and below. 90-130 cm of accumulated snow now overlies a rain crust below 2000 m and sun crust on solar aspects at higher elevations. New wind slabs are developing on leeward slopes and behind terrain features and large, fragile cornices exist along ridgelines. At higher elevations, the February weak layers are down 150-190 cm and woke up during last week's storm with many avalanches stepping down to them. The deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack and a few avalanches and cornice falls have also stepped down to these layers last week resulting in some very large full depth avalanches. These layers remain a real concern while touchier wind slabs, storm slabs, and cornices continue to present the risk of acting as triggers for deeper weaknesses.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 2nd, 2017 2:00PM