Regions
Kootenay Boundary.
Daytime warming and solar radiation will be driving the avalanche danger over the next few days. Watch for conditions that change with aspect, elevation and time of day.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Generally sunny skies are expected for the forecast period as a dry ridge sets up over the region. Increased cloud and light snowfall is possible on Friday evening. Ridgetop winds should remain light for Wednesday and Thursday, and then become strong from the southwest on Friday night. Daytime freezing levels should hover around 2000m.
Avalanche Summary
Observations are becoming more limited as we enter into spring. If you're out in the mountains, please consider posting your observations to our webpage using the Mountain Information Network. With freezing levels rising and lots of sun expected on Wednesday, lots of natural sluffing is expected from steep sun-exposed slopes, especially in areas where cold, dry snow is exposed to solar radiation for the first time. Cornices will become weaker than they have been for the last week and may fail naturally. Wind slabs in the alpine may be sensitive to human-triggering. Reverse loading may have occurred and wind slabs should be expected on a variety of aspects.
Snowpack Summary
Melt-freeze surface conditions exist on sun-exposed slopes. On shaded slopes, 10-30cm of recent snow overlies a thick supportive melt-freeze crust. At higher elevations these accumulations have been blown around by variable winds and thin wind slabs may exist on a variety of aspects. The mid-March crust/facet complex is buried around 50cm below the surface. This layer is generally considered dormant, although it could be reactivated in isolated terrain by warm temperatures forecast for the week. The mid and lower snowpack are strong and well settled.
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.