Snow rollers

check this out, they are really neat

Snow Rollers - Camas Prairie
http://www.wrh.noaa.gov/otx/photo_gallery/snow_rollers.php
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 usual 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. These snow rollers formed during the day as they weren't present in the morning on Tim's drive to work.