I’m not a real fan of weather that’s so bitter-cold it’ll freeze your eyeballs, so I’ve never seen these in real life:
On the evening of March 31st, 2009, Tim Tevebaugh was driving home from work east of Craigmont in the southern Idaho Panhandle (see map below). Across the rolling hay fields, Tim saw a very unusual phenomenon. The snow rollers that he took pictures of are extremely rare because of the unique combination of snow, wind, temperature and moisture needed to create them. They form with light but sticky snow and strong (but not too strong) winds. Some snow rollers are formed by gravity (i.e. rolling down a hill), but in this case, the snow rollers were generated by the wind.
These snow rollers formed during the day as they weren’t present in the morning on Tim’s drive to work.
Based on estimations from Tim as well as the blades of grass in the picture, most of the snow rollers were about 18″ in height, while the largest rollers were about 2 feet tall.
Link thanks to Seablogger