Avalanche Forecast

Issued: Mar 26th, 2018 4:54PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs.

Avalanche Canada cgarritty, Avalanche Canada

Another round of overnight snowfall and strong wind will keep avalanche danger elevated on Tuesday. Keep selecting conservative terrain and watch for signs of instability as you travel.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Monday night: Continuing flurries bringing 10-20 cm of new snow. Strong to extreme southwest winds.Tuesday: Mainly cloudy with isolated flurries and a trace to 5 cm of new snow. Strong west winds. Freezing level to 900 metres with alpine high temperatures around -4Wednesday: Mainly cloudy with isolated flurries and a trace of new snow. Light to moderate west winds. Freezing level to 800 metres with alpine high temperatures around -5.Thursday: Mainly sunny. Light variable winds. Freezing level to 1000 metres with alpine high temperatures around -2.

Avalanche Summary

Reports from Saturday showed ski cutting in the Bear Pass area producing both slab and loose dry avalanches to size 1.5. Slabs failed all the way down to the melt-freeze crust buried 60 cm deep at treeline on north aspects. No new avalanches were reported in the south of the region. Poor visibility has been limiting observations throughout the region.On Saturday, the strong westerly winds were responsible for triggering a couple of wind slabs up to size 1.5 from north-easterly aspects in the alpine. On Friday and MIN reported a rider triggered wind slab avalanche size 1.5 from a southwest aspect. The person rode out of the avalanche and the crown was reportedly 35 cm deep. Friday also saw a natural cycle up to size 2.5 in the recent storm snow.

Snowpack Summary

Ongoing snowfall is building new storm slabs on the surface under the influence of strong southwest winds at high elevations. The new snow is adding to existing storm totals of 40-60 cm from the past week. Beneath the surface wind effect, the new snow overlies a plethora of old snow surfaces, including a layer of surface hoar existing on high shaded aspects as well as a melt-freeze crust on all aspects at treeline and below.Deeper in the mid-pack, layers of crusts, facets, and isolated surface hoar buried 50 to 100 cm exist from mid- and late-February and a surface hoar/ crust layer from January is buried around 150 to 200 cm. Near the bottom of the snowpack, sugary facets exist in colder and dryer parts of the region, such as the far north. These buried layers are currently dormant.

Problems

Storm Slabs

An icon showing Storm Slabs
A final storm pulse of snowfall and strong winds will add to existing storm slabs over Monday night. Very large avalanches may result if shallower storm slabs step down to the melt-freeze crust or surface hoar that is already 40-80 cm deep.
Use conservative route selection, choose moderate angled and supported terrain with low consequence.Be especially careful with wind loaded pockets near ridge crests and roll-overs.Watch for signs of instability such as shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Valid until: Mar 27th, 2018 2:00PM