Avalanche Forecast

Issued: Feb 15th, 2015 7:14AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Deep Persistent Slabs and Cornices.

triley, Avalanche Canada

South Rockies.

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Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

The freezing level should drop down to the valley bottoms overnight and then rise up to about 1500 metres during the day on Monday. This pattern is expected to continue for Tuesday and Wednesday. The only uncertainty is how much sun we will see over the next few days. There is a chance of valley cloud and high cloud each day.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

I suspect that there was a good re-freeze down to valley bottoms that produced a new surface crust. In the Elk valley north there is 100-160 cm of snow at treeline. The late January crust and surface hoar is down about 30-50 cm and shows moderate results in snow profile tests; this layer was displaying very little propagation in tests. The mid-December buried crust layer is down about 50 cm at 2150 metres elevation and continues to react to hard forces in tests with stubborn results. The snowpack was moist down to the ground on Saturday, and is expected to re-freeze with forecast overnight temperatures. There is not much snow below 1600 metres, and a lot of bare areas below 1200 metres.

Problems

Deep Persistent Slabs

The re-freeze has begun, and the likelihood of triggering a deeply buried weak layer should reduce as the freezing continues. Daytime heating, strong solar radiation, or cornice falls could trigger deep weak layers.

Avoid steep convexities or areas with a thin or variable snowpack.>Be aware of the potential for very large, deep avalanches due to the presence of buried surface hoar or a facet/crust layer.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 5

Cornices

Cornices may not be well anchored after the week of warm weather. Strong solar radiation may result in natural cornice falls.

Extra caution needed around cornices with current conditions.>Cornices become weak with daytime heating. >

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 16th, 2015 2:00PM