Here is more about snow rollers with a few pictures.
QUOTE(Information and Educational Technology
Weather Data Library
)
Snow Rollers Appear in Kansas
Russell Countians saw an unusual winter weather phenomenon Dec. 18, 2000. Strong winds coupled with just the right snow conditions to produce nature-generated snowballs. These "snow rollers" ranged in size from baseballs to 30-gallon drums. They were seen on city streets, golf courses, and other smooth surfaces throughout the county, including the towns of Lucas, Wilson, Luray and Russell.
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