Avalanche Forecast

Issued: Feb 8th, 2018 5:07PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Storm Slabs, Persistent Slabs and Wind Slabs.

deryl kelly, Parks Canada

Jasper.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=30731&oPark=100244Highway 93N from Athabasca Falls to Saskatchewan River Crossing and the Maligne Lake road will remain closed for Friday. Check Alberta 511 for updated opening times.

Summary

Weather Forecast

Storm to ease overnight on Thursday, clearing Friday morning and sunny with cloudy periods over the day. Light northerly winds and alpine temperatures near -10.

Snowpack Summary

Varied HST amounts building soft storm slabs through the forecast region, up to 45cm in the southern region on Mount Wilson; 10-15cm in the Icefields. This storm slab is sitting on the weak facetted persistent slab and is running far and fast to valley bottom. Reverse loading from north to south on ridge tops and open areas.

Avalanche Summary

Epic avalanche cycle through the forecasted region up to size 3.5. Most active at 2400m to 2600m (TL elevation). Expect the same carnage in the alpine but unable to confirm due to poor visability.

Confidence

Problems

Storm Slabs

Up to 45cm of HST fell through the forecast area, over-loading the already weak persistent slab and running far and fast.

Avoid all avalanche terrain

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Persistent Slabs

Field teams observed widespread whumpfing and moderate test results at TL during the past week. Shallow areas are the most likely triggering locations in the alpine.

Watch for whumpfing, hollow sounds, and shooting cracks.Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3.5

Wind Slabs

Windslabs were created over the last week with 40cm of snow and West winds. The incoming snow coupled with moderate West winds may build sensitive new storm / windslabs.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Feb 9th, 2018 4:00PM