Avalanche Forecast

Issued: Apr 17th, 2014 4:24PM

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

rupert wedgwood, Parks Canada

Jasper.

Rain events will increase the avalanche danger. On Saturday avalanche control and road closures between Parker Ridge and the Weeping Wall will occur from 4:00-8:00 PM. The Maligne Lake road may also be closed on Saturday.

Summary

Weather Forecast

Warm overnight temps and cloudy skies will prevent the snowpack freezing solid overnight. Temperatures will remain warm on Friday with the freezing level reaching 2,000m. Up to 15mm of rain may arrive in the afternoon with snow at higher elevations. We expect amounts to vary across the range with convective activity.

Snowpack Summary

10-15cm of new snow is sitting on crusts which extend to treeline (TL) on most aspect and higher on sun facing slopes. Beneath the crusts moist snow extends to close to TL where the snowpack depth is 130-180cm. The midpack is well bonded and warm. The base of the snowpack is weak. Loose snow plasters the steep rock faces. Cornices are large.

Avalanche Summary

On the 17th avalanche activity was noted in the Icefields area. Several deep slab avalanche to size 2.5 from the alpine ran close to the valley bottom. These seem to have been triggered by sluffing from rocky terrain above. Below treeline and in the valley bottom there were several size 1-2 moist point release avalanches which scrubbed to ground.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Loose Wet

The snowpack is warming up and the restraining crusts are weakening with the warm weather. Point releases from steep rocks at all elevations are a concern as they can trigger both dry and wet snow avalanches. Rain will increase the activity.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

These events will be of greatest concern with warm temperatures and rain. They may be triggered by smaller surface avalanches such as point releases from steep rocks or cornice failures.

Be aware of thin areas that may propogate to deeper instabilites.Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 18th, 2014 4:00PM