Avalanche Forecast

Issued: Apr 16th, 2018 4:00PM

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

jonas hoke, Parks Canada

Jasper.

Current avalanche problems have been reactive to light loads recently - the hazard may increase quickly if forecast snowfall amounts are exceeded.

Summary

Weather Forecast

Flurries continue for the next 24 hours. Accumulations and loading may vary significantly. Forecasted snow amounts are up to 7 cm in the Icefields area, with much less in the North. Freezing levels will fall to valley bottom overnight and rise to 1800m mid-day. Ridge winds will be mainly light and variable, with gusts into the moderate range.

Snowpack Summary

Up to 20cm of snowfall since Thursday and moderate SW winds have built windslabs in open areas at treeline and in the alpine, and continue to add to the cornice problem. Persistent instabilities (down 40-100cm) remain sensitive to triggering, especially on N slopes at treeline and in the alpine. The mid and lower snowpack remain weak and facetted.

Avalanche Summary

No new avalanches reported today. Check Avalanche Canada's MIN Reports for several recent reports of large avalanches, both natural and skier triggered.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

New snow will bury windslabs in the Alpine and TL, these are overloaded and under tension, and remain sensitive to light loads.

If triggered the wind slabs may step down to deeper facet layers resulting in larger avalanches.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Large cornices in all areas of the bulletin region. When failing these are triggering persistent instabilities and the subsequent avalanches are proving large and destructive.

Minimize overhead exposure during periods of heavy loading from new snow, wind.Avoid travel on slopes that are exposed to cornices overhead.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Persistent Slabs

A slab up to 1m thick overlies: weak faceted crystals, and sun crusts (on steep S and W aspects). This problem has been reactive recently in North facing terrain.

Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.Be aware of the potential for wide propagations which could result in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 17th, 2018 4:00PM