Snow-Rollers

Regarding the “snow-rollers” of 50 cm in diameter generated at Takada in January 1968, the results of observation about their form and rolling trace, together with the meteorological conditions at the time of occurrence are described. It is presumed that the snow-rollers may be caused probably by turning-up of a part of the surface layer of snow drifts due to negative pressure induced on the snow surface by a gust of wind that changes its direction violently. Further, the observation records of snow-rollers in the past are introduced, and the difference between the snow-rollers and the snow ball produced on a slope is discussed.