Avalanche Control will take place in the highway corridor commencing early this afternoon.
Weather Forecast
A ridge of high pressure dominates the weather pattern over B.C. with clear skies for the whole province. With a strong southerly flow of air, freezing levels rise to 3700m. Alpine temp will reach 8.0. Conditions stay warm until a pulse of moisture arrives Sunday with 16mm of rain by Tuesday morning.
Snowpack Summary
Typical spring melt freeze conditions. This morning we had a minimal recovery with temperatures just below zero at valley bottom and likely less of a recovery higher with an overnight inversion. There may be some dry snow on North aspects above 2400m. Cornices are large and will weaken with the rising temperatures.
Avalanche Summary
There was a widespread loose wet avalanche cycle yesterday corresponding to daytime warming. Average size 2.5 with several size 3.5 observed. Avalanche control is planed for this afternoon in the highway corridor.
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.