Danger ratings may be higher and progress quicker than what is currently forecasted for the storm. Models do not agree on amounts and timing but it looks like an atmospheric river is coming with potentially 75cm of new snow by Thursday and rain at lower elevations. Expect Highway 93 to be closed Monday at 1600hrs and opening TBD.
A 40-80cm slab sitting atop the Jan 24th weak layer of facets & surface hoar. It has produced large avalanches across the range. It will likely be overwhelmed by the new storm load Tuesday to Thursday.
Expect a storm slab problem to develop as the storm progresses Monday night through Thursday,
With the potential for rising freezing levels and lower elevation rain on Tuesday, wet loose problem can rapidly develop with natural activity.
Sunday's field patrol Mount Morden Long near Sunwapta station observed nothing notable with excellent visibility. They noted whoomphing up to 1800m. Avalanche control at Parker Ridge on March 12th produced a few surface wind slabs up to size 2.
Strong winds last week have scoured fetches and formed and maintained wind slabs on leeward features. A persistent weak layer of surface hoar and facets is buried 20-80 cm. Below, the snowpack is generally well consolidated facets to ground. Average snow depths for Icefields is 130-200 cm and Maligne is 60-140 cm.
Monday is forecasted to be 15cm of snow by the end of the day, -3 °C, and 25-35 km/h SW winds. Tuesday could bring 25cm of more snow, -1 °C, 25 gusting 70 km/h SW winds. Wednesday will be potentially another 20cm of snow, 0 °C, 15 gusting 65 km/h winds. Thursday might be another 14cm of snow and 0 °C. Monday to Thursday could amass 75cm of snow.
