PHOTOS: Giant Snowballs Mystify Onlookers in Ohio

Giant nature-made snowballs have been spotted across Ohio this week, mystifying onlookers unfamiliar with the meteorological phenomenon.

The rare snowballs, called snow rollers, are formed when gusty winds roll snow along the ground, similar to how snow might be rolled to create a snowman. The result, however, is typically cylindrical and hollow.

Snow rollers do not form after every winter storm because they require specific winter conditions.

First, the ground must be covered by a layer of ice, then have wet, loose snow on top, with a temperature near freezing. Next, winds need to be strong enough to get the snow rolling, but not too strong that they dismantle the weak inner layers of the roller.