Perfect snow and weather conditions combine to create “snow rollers” in a Vermont field. Photo by Allon G. Wildgust and courtesy of meteorologist Sharon Meyer, WCAX-TV Burlington, VT.
Weather has some strange ways of making really cool things. One example is snow rollers. They are fairly rare, but given the right conditions they do occur.
Snow rollers form when the snow has just the right combination of sticky snow that is light enough to be moved by wind. If the wind is strong enough, it picks up snow crystals and begins to tumble them over across “downstream” snow cover. Soon a little mini snowball forms. As it grows and increases surface area, the wind gusts push sheets of snow along.
As it grows and rolls along, it picks up more and more snow just like when you build a snowman in your yard. Since there is no compaction going on by pressure from hands, the center can remain open.
Snow rollers can occur anywhere snow and wind conditions are just right. As you can see from the photo, it helps to have a “downhill lie.”
It may not be alien crop circles, but it must be pretty startling to wake up and look out in your field and see snow rollers. Behold the mysteries of weather!