Avalanche Forecast

Issued: Mar 25th, 2018 4:51PM

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

Avalanche Canada cgarritty, Avalanche Canada

Strong winds are expected to maintain touchy conditions on Monday. Keep seeking out supported lines in sheltered areas while the storm snow settles and bonds.

Summary

Confidence

Moderate -

Weather Forecast

Monday: A mix of sun and cloud. Strong southwest winds. Freezing level to 1400 metres with alpine high temperatures around -6.Tuesday: A mix of sun and cloud with increasing cloud and flurries beginning in the afternoon. Strong to extreme west winds. Freezing level to 1900 metres after a poor overnight refreeze. Alpine high temperatures around -1.Wednesday: A mix of sun and cloud with continuingflurries and a trace to 5 cm of new snow. Moderate northwest winds. Freezing level to 1600 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 over the past few days. This new snow was initially redistributed by strong easterly winds in the beginning of the storm before winds switched to the southwest. As a result, and with southwest winds forecast to increase again, wind slabs are now likely to be found on a variety of aspects. The 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. Recent snowpack testing on the March 15th surface hoar interface (down 20-40 cm on sheltered north aspects) has shown no significant results in the Barnes area. Below this interface the mid-pack is is well consolidated. Deeper in the snowpack (50-80 cm down) a surface hoar buried in mid-February may exist. This interface is considered dormant. Digging towards the bottom of the snowpack you'll find a combination of crusts and facets that are reportedly widespread.

Problems

Wind Slabs

An icon showing Wind Slabs
Another bout of strong southwest wind will continue to redistribute loose storm snow into wind slabs in the lee of wind-exposed terrain. Loose dry or loose wet avalanches may occur from steeper, sheltered slopes - especially if they see sunshine.
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.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 26th, 2018 2:00PM