Tuesday, January 28, 2014

Snow Rollers! Snow Rollers!

Just when you think you've seen it all...

Yesterday, while heading out to lunch, I passed as usual a small lake near my office. Glancing over at its smooth, snow-covered surface, I did a double-take. What in the bejeesus were all of those lumps dotting the otherwise unbroken plain?! It looked like kids had gone haywire, tossing giant marshmallows onto the snow.

As I progressed with my short drive to retrieve lunch, I noticed more of the snowy marshmallows anywhere there was a smooth unbroken surface of any size: lawns, roadsides, parking lots, etc.

I'm no stranger to the outdoors, and might even make a claim of being a keen observer of natural history phenomenon, but these miniature round haybales of snow were a new one on me. Upon return to my office and access to The Google and other online resources, it didn't take long to figure out what these circular lumps of frozen water were.

Snow Rollers!

By now, I was desperately wanting to make photos of this ephemeral phenomenon, but didn't have my trusty Canon along. When I got home yesterday evening, there were even Snow Rollers in and around my yard, but it was too dark by that time to make any images.

Fortunately, last night's frigid temperatures worked to preserve the Snow Rollers pretty much as they were yesterday, and I tossed the camera gear in the car before setting off to the office today. Around 9 am, I begged out of the office for a short while, and headed out into the -8 F temperature to make Snow Roller photos. The grassy expanse above is the yard of a school only a few minutes from work, and I headed there to photo-document Snow Rollers.

An obvious question: how do Snow Rollers form? Well, the brew of ingredients apparently must be just so - their formation is nearly magical and very rare, at least in this part of the world.

First, the ground must be slick and icy - a surface to which snow will not adhere very well. Two, the ice must then be blanketed by snow of just the right consistency - not too dry nor wet, and of just the right fluffiness. Three, a fairly forceful but not overly powerful wind must whip up and start moving chunks of snow. As the nucleus of the Snow Roller begins to gain momentum, it collects more snow and eventually forms a near perfect roll. Too much wind, and the snow rolls will disintegrate.

They remind me of those scrumptious cinnamon rolls, where you can see the various layers of dough spiraling into layers. Some of the Snow Rollers are hollow, like a tire. This one nearly is - you can see a small hole that goes right through its center.

Snow Roller tracks. Many fail to reach maturity, as it were, and peter out before attaining true magnificence. But plenty do build to a magnificent size, and a field or lawn dotted with Snow Rollers suggests a hayfield full of those round bales. A big one might be a foot and a half in height.

I got a call earlier today from a reporter with a TV station in Cincinnati about - what else - Snowy Owls. It turns out that she is also a meterologist, so I grilled her about Snow Rollers. According to her, they are indeed a rarity and I probably hadn't just been overlooking them every winter. Most of the people that I've talked to today had never seen any, either. I spoke to my 87 year-old father today (after he finished shoveling 4 inches of snow off his driveway, the dynamo) and he didn't recall ever seeing Snow Rollers either.

So if you happen across any Snow Rollers, take a moment to drink them in. It may be a long time before you see any again.


Katie (Nature ID) said...

Very cool! If you're going to have cold temps, might as well have some fun stuff, too.

Jim McCormac said...

Thank you Katie. Yes, the opportunity to photo and admire these curious snow formations made laying in the snow in subzero temps well worthwhile!

Ron Gamble said...

Very interesting! I've not seen these before. What is the approximate diameter across your "cinnamon roll" photos you've posted?

Jim McCormac said...

Biggest were probably a foot and a half across, Ron

Lisa at Greenbow said...

I have only seen this one time before. It is eerie to watch. Another odd thing happened here in Southern IN, a tumble weed came streaking across a field and smashed into our truck the other day. Don't see that often either. I don't know what kind of plant it was but it looked like the plants I have seen in Westerns.

Unknown said...

Great photos. I posted some on my blog today that I took at work.