Well, in fairness, 24-36 is a ludicrous range. Generally speaking, forecasting that 24"+ of snow will fall in any given storm is usually on the safer end of the betting spectrum. This one certainly has duration on its side in certain areas, but beyond that it's really difficult to set 24" as the "at least" part of your range. 18"-24"? Sure.
I mean, down by me, I don't think I belong in the 24-36 shading either. I should get 48+, if for no other reason than how good I look in that particular shade of purple.