Avalanche in Radar Bowl

Route: Montana alpine and trees; up Roscoes onto Kokanee Peak; Almost Heli and down to Catchers. Skiing Conditions: Solar-affected aspects really crusty, skied terribly. Pockets of workable conditions in shaded areas. Windswept on Kokanee ridge as you'd expect. N facing slopes in Montana incl. Almost Heli skied wonderfully. Avalanche and snowpack: Whilst on Kokanee Peak summit we heard and then saw the immediate aftermath of a size 2.5-3 slab released on the eastern face off Kokanee Peak. It had a significant run off (~400m) into Radar Bowl. Propagation perhaps ~200m and crown depth of perhaps 60cm. We think remote triggered, most likely by a group further SE past Kokanee peak. One solo skier caught in the runoff (approx 300m below the crown) and carried approx 100m. Partially buried, self-rescued. The guide we were with conducted a transceiver clearance of the debris (nothing found). The caught skier was extracted via heli. Otherwise: no whumphs or cracking on the route we took; nothing released on Roscoes, Almost Heli or the lower down N-facing aspects of Kokanee ridge into Montana. Weather: Sunny and clear in the morning, overcast in the afternoon. Moderate S/SW winds.

Unable to answer all questions - based on observations in immediate aftermath