Avalanche Forecast

Issued: Jan 15th, 2013 4:24PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs, Deep Persistent Slabs and Loose Dry.

max darrah, Parks Canada

Jasper.

Warm temperatures with possibility of rain on Thursday means that we don't anticipate any decrease in avalanche danger in the short term. Conservative terrain choices are advised.

Summary

Weather Forecast

Warming trend continues, accompanied by intense NW winds at ridgetop for next 48 hours. Rain is forecast for Thursday (5mm). Freezing levels rising to 1400m.

Snowpack Summary

Snowpack remains thin and facetted at lower elevations, but is supportive above treeline. Last week's storm snow has buried a surface hoar layer (Jan6) down approx 30cm. Windslabs forming on Southerly alpine aspects and significant snow transport by intense winds.

Avalanche Summary

Numerous size 2 natural soft and hard slab avalanches observed in the alpine and several size 3. Many of these slides are stepping to ground and running to valley bottom. Widespread natural loose dry and spindrift avalanches originating from steep rocky terrain at all elevations. These observations were made in the Columbia Icefield Area.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Thursday

Problems

Wind Slabs

Significant new windslab formation and loading observed today with the arrival of intense NW winds at upper elevations. Once triggered, these events are stepping down to ground.

Avoid alpine terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 3

Deep Persistent Slabs

Surface instabilities such as loose snow and new windslabs are stepping down to ground, which means a small avalanche has the ability to become large very quickly.

Sluffs may trigger deeper instabilities.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Loose Dry

Wind transported snow is triggering point releases, most commonly out of steep and rocky terrain.

Watch for terrain traps where small amounts of snow will acumulate into deep deposits.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 16th, 2013 4:00PM