EFFINGHAM, Kan. — A snow shower on February 12 has resulted in a rare and strange weather phenomenon: wind-rolled snowballs.
Viewer Lou Helmick sent in photos of the bizarre scene, a snow-covered field speckled with clumpy snowballs. In an email, Helmick said one of the snowballs measured 12 inches in diameter.
These snowballs are called “snow rollers,” according to the National Weather Service.
Snow rollers are “extremely rare because of the unique combination of snow, wind, temperature and moisture needed to create them,” according to a post on the NWS website.
The snow must be wet and sticky, but also light enough to be moved by the wind. The wind also must be strong enough to pick up the snow, but not too strong as to cause drifting. As they gather mass, they get harder to roll, so the bigger the roller, the more rare the situation.
A man driving home from work in 2009 in Idaho came across snow rollers that were up to 2 feet tall.