Avalanche Forecast

Issued: Mar 10th, 2018 4:02PM

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

Avalanche Canada mbender, Avalanche Canada

As the day warms up and the surface snow starts to melt, the avalanche danger will gradually rise.

Summary

Confidence

High -

Weather Forecast

SUNDAY: Mix of sun and cloud / Light south wind / Alpine temperature 3 / Freezing level 2000m MONDAY: Mix of sun and cloud / Light southeast wind / Alpine temperature 5 / Freezing level 2200m TUESDAY: Cloudy with flurries or rain showers / light to moderate south wind / Alpine temperature 4 / Freezing level 2100m

Avalanche Summary

On Saturday there were several size 2.5 natural persistent slab avalanches reported. These were suspected to have run in the previous 24hours and were observed on northwest to east aspects between 1900 and 2000m. On Friday there were reports of a several explosives and naturally triggered storm slab avalanches size 1.5-2 on a variety of aspects that entrained the storm snow only. There were also a few skier triggered size 1-1.5 storm slab avalanches on northeast aspects and a few explosives controlled cornice releases to size 1.5.

Snowpack Summary

Recent new snow has been redistributed by by strong west and south winds. This new snow sits on a sun crust on steep south-facing slopes, cold dry snow on northerly aspects, and wind affected snow at upper elevations. The surface snow is reported to be moist on all aspects to 1800m and to mountain top on solar aspects.Last week's storms buried a weak layer composed of soft facets, surface hoar, and/or crust that is roughly 50-100 cm below the surface. This layer has produced whumpfing, sudden results in snowpack tests, and some remotely triggered avalanches. Lots of the activity has been on buried surface hoar on north aspects at upper treeline elevations. The snowpack is well settled and strong beneath this interface. Variable winds in the past month have produced cornices on many ridgelines. They will become touchier as they grow in size, as temperatures rise, and when they are subject to the strong late-winter sun on clear days.

Problems

Persistent Slabs

An icon showing Persistent Slabs
A layer of surface hoar, sugary facets, and/or crust is buried 50-100 cm deep and has produced widespread whumpfing, concerning snowpack test results, and a few large remotely triggered avalanches. Upper treeline elevations are the greatest concern.
Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.Use conservative route selection while travelling at treeline elevations.If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2.5

Storm Slabs

An icon showing Storm Slabs
Recent snow and southwest winds have built storm and wind slabs. Expect to see loose wet avalanches as the sun comes out and the freezing level rises.
Be cautious as you transition into wind affected terrain.Extra caution needed around cornices with current conditions.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Mar 11th, 2018 3:00PM