Avalanche Forecast

Issued: Mar 26th, 2018 4:56PM

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

cgarritty, Avalanche Canada

South Rockies.

Strong winds are forecast to peak on Tuesday. Rising freezing levels are likely to make widespread new wind slabs increasingly touchy.

Summary

Confidence

Moderate -

Weather Forecast

Tuesday: Mainly cloudy with isolated flurries and a trace to 5 cm of new snow. Strong to extreme southwest winds. Freezing level to 1800 metres after weak overnight cooling with alpine high temperatures around -3.Wednesday: A mix of sun and cloud. Moderate northwest winds. Freezing level to 1600 metres after weak overnight cooling with alpine high temperatures around -5.Thursday: Mainly cloudy with cloud increasing and flurries beginning in the afternoon. Light west winds. Freezing level to 1600 metres with alpine high temperatures around -4

Avalanche Summary

Reports from Saturday in the Castle area showed a couple of storm slabs that released to size 1.5 and 2. The smaller avalanche occurred naturally while the size 2 was explosives-triggered.

Snowpack Summary

Up to 35 cm of new snow fell over the region over the past few days. This new snow was initially redistributed by strong easterly winds before winds switched to the southwest. As a result, wind slabs are now likely to be found on a variety of aspects. Below the wind effect, this recent snow will take some time to form a reliable bond to the old snow surface, which consist of crusts up to 2100 metres and dry snow or surface hoar on north aspects above 2100 m. Below this layer the mid-pack is is well consolidated. Deeper in the snowpack (50-80 cm down) the surface hoar buried in mid-February is now considered dormant. At the bottom of the snowpack you'll find a combination of crusts and facets that is reportedly widespread.

Problems

Wind Slabs

Ongoing strong southwest winds will continue to redistribute loose storm snow into wind slabs in the lee of wind-exposed terrain. Rising freezing levels mean that loose wet avalanches could become a hazard in steeper terrain at lower elevations

Use caution around wind-loaded areas in the alpine and at tree line.Avoid large slopes with thin-to-thick snow coverage and convex features.Use extra caution on slopes if the snow becomes moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

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