Avalanche Forecast

Issued: Feb 13th, 2018 4:00PM

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

Jonas Hoke, Parks Canada

Jasper.

Strong winds and new snow are building fresh windslabs and burying evidence of previous activity. Human triggering remains a serious concern in avalanche start zones that have not had activity in the past week.

Summary

Weather Forecast

An upper level northwest (Aleutian) flow is pushing a couple of cold fronts through our area on Wednesday.Â Up to 10-15cm of snow is forecast, with strong SW switching to light NE winds and seasonal temperatures.Â Thursday we will see a bit of a break in the precip, and possibly some sun.Â On Friday more snow is forecast.

Snowpack Summary

5-10cm of new snow has been blown in to fresh slabs by moderate to strong SW winds. These wind slabs overlie a settled upper snowpack which is sitting on the persistent weak layers in the mid snowpack. Many slopes had avalanche activity on these weak layers during last weeks storm, slopes without previous activity remain suspect.

Avalanche Summary

A couple of fresh slab avalanches (likely failing on a persistent mid snowpack weakness, and up to size 2) were observed by field teams at treeline elevations on Tuesday - likely triggered by significant wind transport and warming temperatures.

Confidence

Forecast snowfall amounts are uncertain

Problems

Wind Slabs

Up to 15cm of new snow is being blown in to fresh windslabs.

Variable winds have created pockets of wind slab on all aspects.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

Persistent slabs remain a problem. The main concern is for areas exposed to large triggers such as cornices and large South facing alpine terrain exposed to the sun.

Be wary of large alpine slopes that did not previously avalanche.Minimize overhead exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Feb 14th, 2018 4:00PM