Avalanche Forecast

Issued: Mar 7th, 2017 8:04AM

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

Parks Canada percy woods, Parks Canada

The storm snow requires time to bond well to old snow surfaces. Be alert to signs of snowpack instability.

Summary

Weather Forecast

A mix of sun and cloud today with convective cells possibly bringing localized flurries. Ridgetop temperatures should reach -11C. Southerly winds should reach the low end of moderate today. Tonight brings another pulse of snow up to 10cm accompanied by gusty S winds. Unsettled weather for the remainder of the week.

Snowpack Summary

50cm recent storm snow continues to settle. Strong S'ly winds during the storm formed sensitive windslab on all aspects in the alpine. Weak layers within the storm snow have been failing and occasionally digging down and releasing on persistent sliding layers such as crusts and surface hoar. Steep S aspects may become reactive this afternoon.

Avalanche Summary

Six avalanches to size 2.5 were observed in the highway corridor. Our field team was able to shear off the top 30cm of storm snow off of convex unsupported features at below treeline elevation in the west end of the forecast area.

Confidence

Due to the number of field observations

Problems

Storm Slabs

An icon showing Storm Slabs
Widespread storm slabs were observed to fail at all elevations Sunday.  The storm slab needs time to bond to the old snow surface. Features that have not failed should be given a very cautious approach. 
The new snow will require several days to settle and stabilize.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Strong S winds during the storm created widespread wind slab in the alpine and fresh cornice at ridge top. Be vigilant when approaching ridgelines and avoid convex features.
Watch for whumpfing, hollow sounds, and shooting cracks.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 8th, 2017 8:00AM