Last September we wrote about the rare undulatus asperatus clouds over Gloucester Harbor. According to WBZ-TV chief meterologist Eric Fisher, they were recognized by the Wold Meteorological Organization in March as an official cloud formation. The clouds could be seen over Boston the past few days. You can see a photos of the wavy formations here: Good Morning Gloucester Undulatus Asperitus.
Undulatus asperatus clouds over Gloucester Harbor from Rocky Neck Railways