Avalanche Forecast

Issued: Jan 20th, 2017 4:00PM

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

Ruari Macfarlane, Parks Canada

Waterton Lakes.

Ski conditions are very poor below 1900m, and reasonable above. Treat big open slopes at Treeline elevations the same as you would in the Alpine - the current problem lurks in big features with areas of variable snowpack depths.

Summary

Weather Forecast

A stationary Low equals Status Quo.Â Temperatures have cooled since midweek, and will fluctuate with daytime warming between -13 and -3 . Light winds and a mix of sun and cloud will dominate the forecast period, other than overcast skies late Saturday. A light Upslope event with overcast skies and flurries may arrive late Sunday or Monday.

Snowpack Summary

A few Cm of recent snowfall is well bonded to harder, wind affected snow below. A thin, breakable rain crust on the surface extends up to 1900m, with Moist snow below. Faceted layers in the mid and lower snowpack remain a concern, particularly in shallow snowpack areas where facetting is more pronounced and triggering is more likely.

Avalanche Summary

A few small avalanches Size 1 were noted from extreme terrain Below Treeline on Thursday and Friday. No large avalanches have been observed since a natural Deep Persistent Slab avalanche a week ago. This initiated in a shallow area in a wind-affected Alpine basin, when a small windslab from above stepped down to a faceted crust near ground.

Confidence

Due to the number of field observations

Problems

Deep Persistent Slabs

Due to the depth of the weak layers, trigger points are isolated but the consequence would be high. Shallow areas, rocky areas, and areas with Variable snowpack depth should be avoided. This problem may also exist Below Treeline in the Front Ranges.

Avoid shallow snowpack areas where triggering is more likely.Use caution on wide-open slopes - these are the most suspect.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 23rd, 2017 4:00PM