Archive for December, 2011

Wind Driven Snow Rollers

Saturday, December 17th, 2011

My tips for witnessing unusual, interesting or simply beautiful weather phenomena have always included spending as much time as possible outdoors and keeping your eyes up, as in looking up at the sky often. A couple days ago I found some unusual weather down at my feet. Snow rollers! My other advice is to always have your camera with you, which I did not, but it was close and I was able to fetch it before the mid afternoon dusk turned to complete darkness. Between the duskiness, the falling snow and the flat light, my photos turned out pretty rough, but by the next morning, after a few hours of rain, the snow rollers were history…you would not have suspected a thing. (Please click on the photos to see larger versions.)

snow rollers, Haines, Alaska, Jim Green

Snow rollers form when the snow possesses a certain layered tackiness that allows the top layer to peel off the underlying layer (or sometimes the ground) and stay together as it gets rolled into a ball or tube. The rolling can be bone by either gravity or the wind. No elves or gremlins are needed. If by gravity, a pretty steep slope is usually needed. If wind, then you can guess that a pretty strong wind is needed. (more…)