Avalanche Forecast

Issued: Jan 18th, 2017 4:08PM

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

Avalanche Canada triley, Avalanche Canada

There is a lot of uncertainty surrounding the intensity of precipitation amounts in the region. Rising temperatures combined with new snow and wind are pushing the avalanche danger to HIGH.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Strong southwest winds and 10-15 cm of new snow expected overnight with freezing levels dropping to about 1000 metres by morning. Overcast with moderate southwest winds and 5-10 cm of new snow during the day on Thursday as the freezing levels rise to about 1300 metres. Clearing and cooler with light winds on Friday and freezing levels at valley bottom by morning. Mostly clear on Saturday with light winds and temperatures near -10 in the alpine.

Avalanche Summary

Explosive control released storm slabs up to size 2.0 in the alpine that were 10-20 cm deep on Wednesday. Natural avalanches were heard during the day on Wednesday but poor visibility limited observations. Natural wind slabs and natural cornice falls were reported up to size 1.5 on Tuesday. Several natural and human triggered size 1 wind slabs were reported on Monday.

Snowpack Summary

10 cm overnight combined with another 10 cm during the day on Wednesday has developed storm slabs at higher elevations. Recent winds have caused widespread wind affect in exposed alpine and tree line terrain forming touchy wind slabs on lee features. These are now buried by a blanket of new snow. Last week's 20 cm of low density snow buried a variety of old surfaces (wind scoured, old wind slabs, surface hoar up to 20 mm in sheltered terrain, and/or faceted old snow). Deeper in the snowpack, the mid-December persistent weak layer of facets has been more prominent and reactive in the Corbin area than areas closer to Fernie. The layer is generally considered dormant at the moment in deeper snowpack areas, but its status may change as the temperatures warm throughout the week.

Problems

Storm Slabs

An icon showing Storm Slabs
Forecast wind and snow continue to develop storm slabs in the alpine and at treeline.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.The new snow will requires several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet
Rain at lower elevations may result in loose wet avalanches in steep terrain.
Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 19th, 2017 2:00PM

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