Remember snow can lose strength very quickly on sun exposed slopes. Watch for overhead hazards and stick to supported terrain with low consequence.
Summary
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
SUNDAY: Sunny in the morning then clouding over around noon, moderate south wind, alpine temperature around -5 C.MONDAY: Scattered flurries with 2-4 cm of snow, light southwest wind, alpine temperature around -5 C.TUESDAY: More scattered flurries with another 2-4 cm, strong southwest wind, alpine temperature around -5 C.
Avalanche Summary
On Friday, a natural size 3.5 avalanche was reported southwest of Valemount on a east aspect at 2600 m. It's not certain how old it was, but it was likely triggered by a cornice or ice fall, stepped down to ground, and destroyed some mature timber. A few smaller size 1 storm slabs were triggered on Thursday by skiers on northwest and east aspects at treeline. Earlier last week, several size 2.5-3.5 avalanches were triggered naturally and by explosives. This included a natural cornice triggered size 3 avalanche on a northeast aspect, and explosive triggered size 3.5 deep persistent slab that stepped down to the November crust, and a explosive triggered size 2.5 persistent slab that failed on the mid-February crust layer down 120 cm.On Sunday, morning sun is a potential trigger for cornice falls and deeper weak layers. Read the forecasters blog
(here) for advice on how to manage this low probability, high consequence scenario and check out the accompanying photos
(here). Also expect the recent snow to settle into a slab that will be most reactive at higher elevations, especially in wind loaded terrain and on steep convexities.
Snowpack Summary
15-40 cm of new snow overlies a rain crust at lower elevations or a sun crust on solar aspects at higher elevations. Alpine wind has recently been strong mainly from south through west directions and has loaded leeward slopes in exposed terrain at treeline and in the alpine. Large cornices are also reported and expected to be biggest on northerly aspects in the alpine. The mid-March crust is down 40-60 cm in the south of the region and shallower in the north. The mid-February crust/facet layer is now typically down 100-150 cm and has recently been reactive with many avalanches stepping down to it. The deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack and a few avalanches stepped down to these layers recently resulting in very large avalanches.
shorton,
Avalanche Canada
