Spring conditions. While the freezing level remains high, wet slabs will be the primary concern.
Summary
Weather Forecast
On Saturday, light snow is forecast above about 1600 m, with light SW winds. A cold front arriving on Sunday brings 10-20 cm snow, with the freezing level falling to around 1100 m by afternoon. Clouds and a few showers may linger on Monday.
Avalanche Summary
No new avalanches have been reported. On Tuesday, explosives triggered a size 3 wet slab avalanche in the Duffey Lake area. The avalanche released at ground on a NW aspect at 2200 m and ran to valley bottom. A MIN report from Monday describes a close call with a size 2.5 wet slab avalanche on a NE aspect in the alpine on Hour Peak on the McBride Range traverse. A skier triggered the large avalanche that released down 30 cm on an old melt-freeze crust and propagated a fracture about 50 m wide. Most commercial operations in the region have finished their season and information is becoming sparse.
Snowpack Summary
As temperatures gradually cool through the weekend, loose wet and wet slab avalanches will become less likely. Storm slabs may develop at alpine elevations as the cold front passes through. At lower elevations, monitor the overnight freeze of the snow surface. If the snow surface does not freeze overnight or if the crust is only a few cm thick, the effect of daytime heating or rain will weaken the snowpack much more quickly than it would if there is a well frozen thick crust. Low elevation and thin snowpack areas have become isothermal.
Problems
Wet Slabs
Wet slabs remain possible until temperatures drop significantly.
Travel early before the heat of the day, and avoid big slopes in the afternoon.>Avoid rocky, shallow or steep slopes during the heat of the day.>
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Rain can weaken snow surface layers and lead to loose wet avalanches in steep terrain.
Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >Avoid exposed avalanche terrain during periods of rain.>
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 23rd, 2016 2:00PM
