Avalanche Forecast

Issued: Mar 13th, 2013 4:25PM

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

rupert wedgwood, Parks Canada

Jasper.

Avalanches can be expected from the alpine over the next 24 hours. The best powder snow can be found in the Icefields on low angle terrain at treeline.

Summary

Weather Forecast

Up to 15cm of new snow is forecast for upper elevation in the next 24 hours. At lower elevations this will fall as rain up to midnight then turning to snow. Freezing levels will increase to treeline. Winds will be highly variable ranging from light and NE in the East to strong and Westerly in the Icefields area.

Snowpack Summary

Soft slabs are forming in the Alpine under the influence of moderate to strong Westerly winds.Â 30cm of new snow has fallen in the past 24 hours in the Columbia Icefields area. At Treeline soft slabs exist in isolated terrain near ridges. On solar slopes, at Treeline and below thisÂ snow is sitting over a crust which is up to 5cm thick.

Avalanche Summary

Poor visibility and flat light has obscured observations from the alpine but numerous piles of avalanche debris have been observed in runouts along highway 93. This indicates that an avalanche cycle is underway with numerous size 2 or 2.5 avalanches occurring in the alpine. At lower elevations loose point releases of size 1 were observed.

Confidence

Freezing levels are uncertain on Friday

Problems

Storm Slabs

30cm of new snow has fallen in the Icefields area in the past 24hrs. This snow has formed stiffer wind slabs in the alpine than at treeline. Near treeline the slabs are softer and less sensitive to triggering. Moderate shears were recorded at 2350m.

Avoid open slopes with any steepness over 30 degrees.Space out and travel quickly through runout zones of avalanche paths.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Dry

Quantities of loose snow plasters steep cliffy terrain which is often encountered in and around ice climbs. With sufficient volume there currently to produce sizable avalanches, and more on the way, you would do well to avoid this terrain.

Avoid travelling on ledges and cliffs where sluffing may have severe consequences.Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

Warm temperatures and rain at lower elevations are creating moist point release avalanches from steep terrain. Solar radiation will rapidly destabilize the snowpack in the valley bottom and near treeline.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Be very cautious with gully features.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 14th, 2013 4:00PM