Avalanche Forecast

Issued: Jan 3rd, 2016 6:50PM

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

Ruari Macfarlane, Parks Canada

Waterton Lakes.

Low hazard does not mean no hazard. Although triggering is unlikely, a persistent weak layer of buried Surface Hoar should be on your radar. As always, wear a transceiver, shovel and probe if venturing into avalanche terrain.

Summary

Weather Forecast

An intense upper ridge and associated warm air aloft have moved away to the NE, but a surface ridge persists until midweek, deflecting large systems away. Moderate to strong SW winds for tonight, easing early tomorrow. Mostly mild & cloudy weather this week, with very occasional flurries possible. Temperatures may be above 0 in town Monday night.

Snowpack Summary

Surfaces are affected by sun/wind in exposed areas. Small, difficult-to-trigger wind slabs sit in immediate lees on N and E aspect, and are more of a concern in the far East of the park. A surface hoar layer is down 40-60cm in some treeline & alpine locations, and a weak crust is down 80-100cm. These have produced sudden results in snowpack tests.

Avalanche Summary

Small, isolated Loose Wet avalanches were observed on steep solar aspects on Jan 1, associated with a warm layer of air aloft that has since moved on.

Confidence

Due to the number of field observations

Problems

Persistent Slabs

A buried layer of Surface Hoar will be difficult to trigger, but has potential to propagate widely. Follow good travel techniques, such as spacing out, and regrouping only in safe spots.

Ride slopes one at a time and spot your partners from safe locations.Evaluate unsupported slopes critically.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 3

Wind Slabs

Watch for new wind slabs lee to ridgetops. These may appear as smooth, harder surfaces, amongst more textured surrounding snow.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 6th, 2016 4:00PM