One a day, plus iron

I'm not sure it's an official term. I just... you know how ocean waves break and the top falls over the bottom in a circle-y sort of way? That's what it looks like when snow is coming off of a plow, at least when there's a good layer of snow on the road and the plow is making decent time. It's a very rotary affair, plowing is. Plow roll suits and most people understand what I mean when I say it. You might ask around and see if other people use a different word for the stuff. (And possibly there are people who live where it does not snow or who do not get their driveways plowed shut by the local DoT. Those people would not need a word for "bump of snow left by the plow across the end of your driveway")