Avalanche Forecast

Issued: Mar 15th, 2018 4:49PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada cgarritty, Avalanche Canada

Lingering wind slabs remain a concern on high elevation north aspects. Exercise increasing caution around solar aspects and lower elevations as loose wet avalanche conditions develop over the day.

Summary

Confidence

Moderate -

Weather Forecast

Friday: Mainly cloudy with light flurries beginning in the evening. Light northeast winds. Freezing level to 1600 metres with alpine high temperatures of -2.Saturday: Cloudy with continuing scattered flurries bringing about 5-8 cm of accumulated new snow by end of day.. Light northeast winds. Freezing level to 1600 metres with alpine high temperatures around -1.Sunday: Cloudy with isolated flurries and a trace of new snow. Light northwest winds. Freezing level to 1500 metres with alpine high temperatures of -3.

Avalanche Summary

Several more loose wet avalanches were reported on Tuesday. Explosives control in the Kootenay Pass area produced eight results from size 2-2.5. Another natural size 2 was noted for releasing two hours after the sun had left the slope.Avalanche activity through the end of the weekend into Monday focused on a natural solar induced loose wet avalanche cycle on south and west aspects in the alpine an treeline to size 2. On Friday reports indicate numerous size 2-2.5 natural and explosive controlled storm snow avalanches running on all aspects in the alpine and at tree line. There were also several skier triggered storm slab avalanche size 1.5-2 both Friday and Saturday on north aspects in the alpine and tree line.

Snowpack Summary

A mix of light rain and wet flurries brought about 7 cm of new snow to the region on Wednesday. Where it arrived as snow, this precipitation buried a moist crust on solar aspects and a new layer of surface hoar on sheltered north aspects.Last week's snow was redistributed by predominantly west and southwest wind, forming wind slabs at high elevations. On north aspects these older slabs may be sitting on a layer of surface hoar about 25-40 cm below the surface.A mix of weak layers exists 50-100 cm below the surface, including small surface hoar on shady aspects and a crust on solar aspects. These layers are expected to have gained strength from recent cycles of warming and cooling. Like other deeper weak layers that formed in January and December, they are considered dormant at this time. These deeper layers include several surface hoar and facet layers 1 to 2 m below the surface and a crust/ facet interface near the base of the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind loaded pockets on high north aspects remain a concern for Thursday. Old and new slabs that formed here may overlie weak layers of surface hoar. Loose wet avalanche conditions increase with daytime warmth at lower elevations and on south aspects.
Be careful around wind loaded pockets near ridge crests and roll-overs.Extra caution needed around cornices with current conditions.Use extra caution on solar slopes, or if the snow is moist or wet.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 16th, 2018 2:00PM