BC Zone Observation Report
Thursday, February 21, 2013 at 12:00 AM
Tour to steep below treeline gladed terrain
Toured to 10,700 ft on a variety of aspects--NE,E,SE,S and skied slopes up to 45 degrees.
Tour in East River Valley under broken to overcast skies with high thin clouds. Light to moderate northwest winds with very light and isolated scattered snow showers. I did not observe any blowing snow below treeline while touring, but at the trailhead and on the drive home I noticed light blowing snow in exposed terrain below treeline.
Found about 2-5" of new snow on a variety of surfaces--melt-freeze crusts, wind crusts and DFs. Skied slopes up to mid-40 degrees. Triggered a small loose-dry snow avalanche--L-ASc-R1-D1-O--on a hard ski cut over a steep convex roll. The sluff ran close to 250 vertical feet and was about 20 feet wide. It did not step down into older faceted layers but did entrain older storm snow. Steep E-NE slopes were weak and variable with each turn bringing a surprise.
Steep poorly supported convex roll
Average Slope Angle:
O - Within Old Snow
Slow moving sluff. After triggering it I continued to ski the slope and beat it down to the flats.