Avalanche Forecast

Issued: Jan 1st, 2016 5:05PM

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

Ruari Macfarlane, Parks Canada

Waterton Lakes.

An above-freezing air layer currently in the alpine spreads to all elevations by Saturday, before a welcome cooling trend kicks in Saturday night. Enjoy the sunshine, and consider leaving your bigger objectives for Sunday once the snowpack cools off.

Summary

Weather Forecast

A strong ridge is anchored over interior BC. A layer of unseasonably warm air covers the Rockies, with temperatures around or even above 0 expected at all elevations on Saturday, which is also forecast to be clear and calm. Sunday-Monday promise a mix of sun and cloud, andcooler temperatures. Moderate SW winds develop on Sunday night.

Snowpack Summary

Surfaces are sun affected on steep solar slopes. 10cm of recent snow has formed small stubborn wind slabs in isolated lees, and buried larger old windslabs. A layer of surface hoar down 40-60cm exists in some Treeline & Alpine locations, and a weakening crust is down 80-100cm. These have produced Moderate - Hard, Sudden results in snowpack tests.

Avalanche Summary

One small loose wet avalanche observed this afternoon from solar aspect Alpine terrain. Also, a few small wind slabs occurred yesterday in Alpine terrain. These were on North facing slopes loaded by downslope winds / light spindrift from steeper terrain above.

Confidence

Freezing levels are uncertain

Problems

Loose Wet

Watch for warm temperatures and clear skies on Saturday to destabilize the surface snow on sunny slopes.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Small surface wind slabs are still visible in isolated locations, while older large wind slabs are buried under a skiff of recent snow.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

A buried surface hoar layer has produced sudden results in snowpack tests at treeline. This layer is now a concern due to rapid warming of the snowpack and strong solar radiation.

Be aware of the potential for wide propagations.Small avalanches may trigger deeper instabilities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 3

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