Okay, if you have a depth of 18" right now, then you had 20.5". That makes sense from my Wilmington measurements, as the depth when I left was 17" at 1am.
I have a current depth of 14" in Methuen, and had a 16.5" snowfall.
15" depth in Methuen....15.5" snowfall. 2" less than Wilmington, and its apparent that it never got above 29 here....all drifted powder. There was zero drifting in Wilmington.