Avalanche Forecast

Issued: Apr 15th, 2019 4:00PM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Loose Wet and Deep Persistent Slabs.

adam greenberg, Parks Canada

Waterton Lakes.

Though the snowpack is mainly in the grips of daily spring temperature swings, a recent large avalanche failing on basal weaknesses on Mt Blackiston is a good reminder that winter remains on high north faces.

Summary

Weather Forecast

Tuesday: A mix of sun and cloud with a high of 8 in the alpine, freezing levels to 2300m and light west wind increasing overnight.Wednesday: Cloudy with sunny periods. Alpine high of 6 with freezing levels to 2100m with strong west winds.Thursday: Showers, with 6cm or snow expected in the high alpine. Freezing level of 2800m and strong west winds.

Snowpack Summary

In most areas we are seeing a typical spring snowpack with crusts breaking down in the heat of the day. The exception is high North facing terrain where temperatures have stayed cold and a winter snowpack remains, with facets continuing to linger at the base. The midpack is generally well settled.

Avalanche Summary

Forecaster observed a large avalanche on a high north facing bowl on Mount Blackiston that occurred sometime in the last week. It was triggered by cornice fall, and ran on basal weaknesses. Otherwise, no recent avalanches were observed.

Confidence

Problems

Loose Wet

Recent snow may begin to slide on solar aspects as the sun makes an appearance and temperatures rise.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Deep Persistent Slabs

Deep layers are still responsive to large triggers (think cornices or rain) on high north faces. Though triggering this layer is unlikely, it's not impossible as evidenced by a recent large avalanche on Mt. Blackiston

Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.

Aspects: North.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Apr 18th, 2019 4:00PM