Low hazard Below Treeline does not mean you can't be hit by a Large avalanche that started higher up. Minimize time in avalanche runout zones (these cross many Waterton trails). While not likely, any natural avalanches may reach runouts.
Summary
Weather Forecast
Saturday: Snowfall overnight, and in squalls throughout the day(5-15cm forecast). Ridge winds: Strong-Extreme SW. Freezing Level at valley floor. Treeline high -4.Sunday: Sun & cloud. W winds becoming light. Freezing Level at valley floor. Treeline Low -8, High -4.Monday: Mainly cloudy, flurries possible. Light winds. Treeline High -2.5
Snowpack Summary
A thick crust overlies a Moist snowpack Below Treeline. Wind exposed terrain is scoured and slick, but pockets of Wind Slab 5-30cm deep sit in sheltered lee terrain. These will grow with snow and wind forecast. A crust from Mid Feb, down 1m, is giving some sudden results in tests. The bottom of the snowpack is faceted, and still weak in places.
Avalanche Summary
On Friday, a small cornice fell into a steep lee slope at treeline. This triggered a relatively deep slab in the steep, rocky slope, which stepped down multiple times to deeply buried Persistent Weak Layers, and to Ground lower down. This ended up as a Large (Size 2.5) avalanche. No new avalanches were observed on Thursday with good visibility.
Confidence
Forecast snowfall amounts are uncertain on Saturday