Avalanche Forecast

Issued: Jan 23rd, 2013 8:06AM

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

catherine brown, Parks Canada

Glacier.

Danger levels will rise today as we finally start seeing new snow accumulate. Keep your trip plan flexible and incorporate all evidence of unstable snow (avalanche activity, cracking, whumphing, etc.) in your decision making.

Summary

Weather Forecast

5 to 15cm on snow are forecast for the park this afternoon and evening as a fast moving westerly flow brings seasonal temperatures and southwest ridge top winds 30 to 50km/h. Another system is expected to bring more snow overnight Thursday into Friday. Exact timing and amounts are uncertain. Temperatures will remain seasonal (-10 to -5)

Snowpack Summary

New snow overnight has covered a variety of surfaces including, small surface hoar and sun crust on steep south through west slopes. Widespread wind effect is present in open areas at treeline and in the alpine, though stubborn to rider triggering.Jan 4th SH/CR down 45-65 cm reacting in stab tests (moderate to hard range) yesterday at TL, SE asp.

Avalanche Summary

We have observed few natural avalanches in the park recently. These avalanches have been small and triggered by wind deposited snow or solar radiation inputs.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Wind Slabs

Evidence of wind slabs still lingers in the alpine. Caution at ridge crests and on cross loaded features.

Be cautious as you transition into wind affected terrain.Minimize exposure during periods of heavy loading from new snow, wind.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

A weak layer down around 50 cm remains a concern. It has been most reactive to rider triggering on steep slopes where a sun crust is present.

Dig down to find and test weak layers before committing to a line.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 24th, 2013 8:00AM