The next storm makes its way into the region on Wednesday. Be ready to back off from open terrain as winds pick up - there's a ton of loose snow available to form reactive new wind slabs. In recent snowfall hotspots like the MacGregors, it's enough to pose a problem even where slabs haven't formed.
A ramp up in southwest winds will be the first significant impact of the next storm hitting the region on Wednesday. Flurries and loose snow available for transport by these winds will feed into an increasing wind slab problem over the day.
In higher snowfall parts of the region, deep accumulations of new snow that haven't formed into a slab may continue to produce large sluffs with rider traffic in steep areas.
Limited observations since the weekend storm have shown mainly small dry loose avalanches releasing naturally, especially on steep, sunny slopes, as well as with skier traffic. We expect some degree of a slab avalanche cycle also took place at higher, wind affected elevations over the weekend, particularly in areas like Pine Pass and the MacGregors, where up to about 40 cm of new snow accumulated with strong southwest winds.
Earlier in the week there was evidence of deep persistent slab activity that likely occurred during last weekend's storm with avalanches up to size 3.5. While we currently expect the deep weak layer to be dormant, riders should continue to avoid steep, thin, rocky slopes where triggering a deep persistent avalanche would be most likely, particularly near alpine ridgelines.
Looking forward, the next storm hits the region late Wednesday, but with elevated winds leading the charge and expected to be the initial driver of avalanche hazard during the day.
From 20 up to about 40 cm of new snow fell in higher snowfall areas of the region like Pine Pass and the MacGregors over the weekend. Closer to 5-15 cm fell in eastern locations like Tumbler and Kakwa.
These variable storm totals overlie faceted (sugary), heavily wind affected snow from previous cold temperatures and north winds. A switch to southerly winds during the storm means more north-facing aspects are now the primary concern for holding reactive wind slabs at wind-exposed elevations.
The middle of the snowpack is generally strong.
A weak layer of large and weak facets is found near the base of the snowpack. The layer is currently considered dormant, except perhaps in very steep alpine terrain that is inherently shallow. Riders should continue to avoid thin, rocky terrain where the likelihood of triggering this layer is higher.
Tuesday night
Becoming clear. Light northwest winds shifting to strong southwest.
Wednesday
Increasing cloud and flurries with up to about 5 cm of new snow by end of day, increasing overnight. Strong southwest winds. Treeline high temperatures around -11.
Thursday
Cloudy with continuing snowfall bringing 10-20 cm of new snow, including overnight amounts. Strong southwest winds easing over the day. Treeline high temperatures around -9.
Friday
Cloudy with continuing snowfall bringing 5-10 cm of new snow, including overnight amounts. Moderate southwest winds. Treeline high temperatures around -10.
More details can be found in the Mountain Weather Forecast.
