We had snow rollers in Feb of 2003 here in Central Illinois.
http://www.crh.noaa.gov/ilx/events/roller/roller.php
They were in a band from western Illinois to Cincinnati. We had an inch or two of powder snow that I think fell on Monday and they were predicting strong winds for overnight. My prediction was that we would have 3' drifts with vast bare areas as we had one time years ago. Monday evening the temperature went up to the high 30s or low 40s and the wind came. My prediction was that the now soft snow would freeze and form a crust with little or no drifting. This seemed to be the case and I did not notice anything unusual during my morning run or drive to work. That evening, however, the weather babe mentioned snow rollers & may have had a picture. The next morning upon closer examination the snow rollers appeared. There were thousands of them, the largest being about 6" - 11" in diameter. They had formed where ever the northwest wind had an open shot.
I normally consider myself reasonably observant about nature stuff, but certainly missed the rollers the first day. They all melted the second day.