Avalanche Forecast

Issued: Apr 15th, 2017 4:30PM

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

mgrist, Avalanche Canada

Kootenay Boundary.

The next big change is on Sunday: Sunny, warm weather will be driving avalanche problems.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Sunday

Weather Forecast

The clouds will clear out Saturday afternoon, giving way to pleasant weather on Easter Sunday. Back to moist spring weather on Monday afternoon/eveningSUNDAY: Clearing with some good sunshine. Freezing level rising to 2100 m in the afternoon. Winds light southerly. MONDAY: Snow late in the day (5-10cm) above 1900m. Winds 10-25 km/h from the south. TUESDAY: Snow, heavy at times (10-25cm possible by late Tuesday). Freezing level around 2000 m. Winds light-moderate westerly.

Avalanche Summary

On Thursday, we had reports of touchy conditions in the Rossland Range with upwards of 35cm of new snow falling at treeline and above, running easily on a temperature crust. Several loose wet avalanches to Size 2 were reported near Kootenay Pass, running on all aspects between 1800m and 2100m elevation.

Snowpack Summary

This region experienced a wide variation in snowfall amounts on Thursday - most areas saw 5-10 cm of wet heavy snow above 1600m; however, the Rossland Range was the 'bulls eye' for enhanced convective snowfall and received upwards of 35cm! An additional 5-10cm of snow fell above 1500m on Friday. The snow and shifting wind directions created fresh wind slabs on a variety of aspects at Treeline and above. The new snow will be prone to sliding in steep terrain where it is sitting on a crust. Cornices are large in some areas and could trigger large avalanches when they fail.

Problems

Loose Wet

Warm temperatures and sunshine will make the snow heavy, wet and cohesionless on Sunday. Even small slides can have serious consequences.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

Shifting wind directions have created fresh wind slabs on a variety of aspects.

Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.The new snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 16th, 2017 2:00PM