Regions
Banff Yoho Kootenay.
The period of fine weather and good spring conditions is ending as the weather pattern is breaking down and will allow for some frontal systems with cloud and possibly significant snow by the end of the week. JBW
Weather Forecast
The blocking pattern i breaking down and we will see the first in a series of weak storms Tuesday night. By Friday the pattern will have changed and snowfall is likely.
Snowpack Summary
Another hard freeze overnight made for excellent travel. True corn is forming on low to mid elevation solar aspects with a thinner crust in the high alpine. Due north slopes have a mixture of wind effect and thin facetted snow with low penetration.
Avalanche Summary
A widespread spring cycle up to size three has been occurring on solar aspects starting mid afternoons. Deep wet slabs have been coming out in isolated locations on steep solar aspects late in the day., and some slabs have been observed failing at the bottom of the snowpack in shallow snowpack areas.. Cornices have been falling off also.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Wednesday
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.