I remember i think it was feb/march 2005 here in north kent, there was a system moving down from the north which gave sleet further north and west from here but gave us continuous wet heavy snow which laid on the ground for two weeks. Its was meant to turn to rain every time but for some reason it stayed as snow, sometimes dry powder others huge wet chunks... between falls in those two weeks we had thaws but we had four falls of 4-6 inches, one morning we had 6inches of powder!!!! I hope we get a bit, i think you could be right white lightening...... it may linger over here and im hoping the fax/meto charts prog this low that 50-100 miles further south keeping us in the colder air . may not need to as if the precip is heavy cooling the air...... I remember quite a few occassions this occurred in the isle of man when i lived there in the 90's.