Avalanche Forecast

Issued: Jan 17th, 2019 4:00PM

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

Marcus Waring, Parks Canada

Waterton Lakes.

New wind slabs from the incoming storm on Saturday will likely be forming on a recently buried crust and surface hoar layer, creating the potential for touchy conditions. Keep an eye on snowfall amounts and evaluate the bond of the new snow.

Summary

Weather Forecast

FRIDAY Isolated Flurries. Light SW wind.SATURDAY Snowfall amounts are uncertain. Estimating between 5-20cm. Strong SW Wind. SUNDAY Cloudy with sunny periods. Moderate W Wind.

Snowpack Summary

5-10cm off storm snow on Thursday has fallen over a variety of hard bed surfaces including newly buried Surface Hoar 1600-1900m and a supportive temperature crust up to 2000m. A strong Midpack sits on top of a faceted base.

Avalanche Summary

No new avalanches observed. Limited Alpine observations.

Confidence

Forecast snowfall amounts are uncertain on Saturday

Problems

Wind Slabs

Regardless of snowfall amounts, Wind Slabs will continue to build over a crust / surface hoar layer during the forecast period.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

This layer likely requires a large trigger. New wind slabs may step down causing large avalanches.

Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 20th, 2019 4:00PM