DAVOS, Switzerland — It may be tempting fate to try to gather 60 heads of state and hundreds of global business leaders in the dead of winter in a Swiss mountain valley. This year, the World Economic Forum’s luck seems to have run out.

Fat, damp snowflakes have been tumbling down for the past six days, burying the town in six feet of snow, three feet of it in the last two days alone. Snow was still falling fast on Monday night, and the steep, pine-dotted slopes were so heavily laden that some neighborhoods here in Davos had to be evacuated for fear of avalanches.

Head-high snow drifts quickly piled up along the roads, leaving no place for street plows to push more snow. Sidewalks completely disappeared. Pedestrians slipped and slid in traffic between huge trucks and luxury minivans on streets carpeted with compacted ice several inches thick.