Watch out for wind slabs at upper elevations. Avoid lingering in the runout of avalanche paths as wind loading and cornice fall could trigger large avalanches.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
We're looking at a series of small systems moving through the region during the forecast period. The winter weather train keeps rolling into town!MONDAY: Flurries Sunday overnight into Monday (5-10cm possible). Moderate southwest wind, freezing level around 1900m.TUESDAY: Cloudy with isolated flurries. Moderate southwest wind, freezing levels 1700m.WEDNESDAY: Snow (5-10cm possible) moderate south wind, freezing levels 1900m, alpine temperature around -1 C.
Avalanche Summary
On Sunday several loose wet natural avalanches to Size 1.5 were reported on solar (southerly) aspects at all elevations.On Saturday a pair of Size 2 storm slabs were reported on north(east) aspects near 2100m elevation, possibly triggered by cornice fall. Ski cutting on Saturday also produced several storm slab releases to Size 1.5.Field reports from the Elkford area had widespread evidence of persistent slabs pulling out from the recent cycle.
See here for more information.Evidence of a large natural avalanche cycle during last week's storm has been reported around the Crowsnest Pass / Sparwood area as well as around Waterton (typically size 2.5 deep persistent slabs). Widespread natural activity in the neighboring Kananaskis region suggest conditions may be touchier north of Elkford (see above).Looking ahead, the primary concern is the potential for large deep persistent slab avalanches triggered by natural triggers such as a cornice fall. See the forecaster blog for advice on managing a low probability - high consequence problem (
here) and the accompanying photos (
here).
Snowpack Summary
Over the past few days we've had 10-30 cm of heavy snow at higher elevations, which sits on a thick hard crust that is quite solid above 1700m. In some locations winds have been strong from the southwest, creating wind slabs 10-50cm thick on northerly aspects, and isolated features at treeline.Rain from last week soaked the snow below about 2000 m. Recent rain and sun have left a variety of crusts that are thicker and most supportive in open south facing terrain.Below the new snow and crusts, roughly 50-90 cm of snow sits above the February crust and facet interfaces. In some areas there may still be a poor bond to these interfaces. The bottom third of the snowpack is composed of weak facets and full-depth avalanches over this basal weakness remain a concern.
mgrist,
Avalanche Canada
