Avalanche Forecast

Issued: Mar 27th, 2018 4:53PM

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

cgarritty, Avalanche Canada

South Rockies.

Watch for any prolonged sunshine to destabilize wind slabs and create loose wet avalanche conditions on sun-exposed slopes.

Summary

Confidence

Moderate -

Weather Forecast

Wednesday: A mix of sun and cloud. Moderate northwest winds. Freezing level to 1500 metres with alpine high temperatures around -6.Thursday: A mix of sun and cloud. Light west winds. Freezing level to 1600 metres with alpine high temperatures around -5.Friday: Mainly cloudy with scattered flurries and a trace to 5 cm of new snow, continuing overnight. Moderate to strong southwest winds. Freezing level to 1400 metres with alpine high temperatures around -5.

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 on the weekend. This new snow was initially redistributed by strong easterly winds before winds switched to the southwest. As a result, a mix of old and new wind slabs can now be found on a variety of aspects and at lower elevations as well.Below the wind effect, this recent snow has buried and old snow surface that consists 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

Strong southwest winds have redistributed storm snow into wind slabs on a wide range of aspects and elevations. Newer slabs may become touchy if they see prolonged solar exposure on Wednesday.

Avoid large slopes with thin-to-thick snow coverage and convex features.Use caution around wind-loaded areas in the alpine and at tree line.Keep your guard up at lower elevations. Wind slab formation has been extensive.

Aspects: North, North East, East, South East, South.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

The chance for loose wet avalanches will increase with the duration of sunshine on steep, sunny slopes. Loose wet activity may occur naturally or with a human trigger.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.

Aspects: North, North East, East, South East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 28th, 2018 2:00PM