It’s something we see a lot - a random snowball, person, or object(s) start rolling down a long snowy hill. They accumulate snow along the way, and by the bottom of the hill, it’s a giant ball of snow, a killer snow boulder.
Does anything remotely like this happen in real life?
I’ve seen pictures of ‘snow wheels’ which I would think would require some sort of similar process, but that’s not quite the same thing.
We often see depictions of kids making snowmen by continually rolling balls of snow in snow patches to get them to grow, but my memories of the actual process involve just digging up and packing on snow to make it bigger, and then rolling it later just to make it round.
If the snow is wet and sticky it will roll. I always try this first before shoveling my driveway. But it doesn’t do it by itself, even though my driveway is by no means flat. Of course, neither is it really a serious hill.
Anyway, if there’s enough snow to have to shovel the driveway, it’s usually too dry to roll like this.
We used to make them as children, our town is almost surrounded by hills so we had plenty of opportunities when it snowed. Our favourite was Scot’s hill, it’s just barely walk-able in good weather, but there’s a track through the woods that’s normally passable. We’d get to the top, roll snowballs around until they were a foot or so across, then all roll them down the hill to see who’s snowball got the furthest.
They would generally break up once they got to about 3 feet across, or when they bounced down a rabbit hole, but now and then one would make it to the bottom and wind up stuck in the hedge, occasionally going through. The biggest couldn’t have been more than maybe 7 feet, probably not even that.
Given a long enough, steep enough, smooth-ish slope, with a deep covering of the right kind of snow, I can see how the OP’s scenario might enter the realms of plausibility.
They are possible, but there’s usually a limit where they break apart all by themselves, if they haven’t already due to bumps.
I’m wagging it’s because the packing of the snow gets denser and denser as you go outwards, which means the center is soft and compressible, which leads to deformation and breakup.
Also you won’t get the cartoon sphere ball, you’ll get a wheel with vaguely conic indentations on each side and a propensity to tip over and break.
I was the opposite as a child. I would roll, often changing direction, and then when I was done add some snow by hand to make it round. I ended up with some large snowmen, and the front lawn looked like it had stripes because the rolling picked up all the snow.
I love this image. Big burly guy out shoveling snow, huffing and puffing. Nerd or nerdette comes out, and just rolls away the snow like rolling up a sleeping bag.
Yeah, that’s pretty much how I remember it as a kid. You needed at least 5-6 inches of snow, and it couldn’t be the bone-dry powdery stuff, but it worked just like the movies. You’d occasionally see smaller “streaks” in ditches and such where a small patch had started sliding naturally and picked up snow as it “rolled” (or slid, usually only few feet).