Steam Devils

[Andrew Pritchard]

I ventured up north for an early fall weekend get-away to my family's lake house in Wisconsin this past weekend. With the first freeze of the season forecast as temperatures plunged to at or just below 30F and the lake temperature still in the lower 60s I figured photogenic morning steam would be a sure thing. I ended up with that and more, as steam devils, or little vortices in the steam started sprouting up around sunrise. Essentially these guys form under the same conditions that drive dust devils, as well as water spouts and land spout tornadoes, on a much much smaller scale of course.

Little areas of vorticity would be present as the very light winds roll the steam across the lake surface, while little updrafts due to the instability in the lowest of levels stretches the vorticity into at times tight little circulations in the steam. Pretty mesmerizing stuff to watch as they really do resemble little water spouts. I ended up almost core punching one on the row boat just after sunrise and noticed they even created little "swirl" regions at the surface of the water and base of the vortex, exactly as water spouts do. Unfortunately this was too difficult to actually document visually.

I managed a few decent photos, and composed a short video with some clips of some of the more interesting circulations. Unfortunately I hadn't planned on documenting anything interesting video-wise over the weekend so I left the HD camera at home and just had the little back up SD video camera. Better than nothing, I suppose.

For the video, I recommend actually clicking the link and opening in a new, larger window to be able to see some of the more subtle circulations.

http://www.youtube.com/watch?v=DuXK_tTq2lg

There are several circulations in a line in this photo:

 

[BHastings]

Andrew, that's really amazing -- I'd never heard of that before. What part of Wisconsin were you in?

 

[Andrew Pritchard]

Andrew, that's really amazing -- I'd never heard of that before. What part of Wisconsin were you in?

This was on Deep Lake, west of Oxford, WI on Highway 82 in Adams County. South-central Wisconsin, I guess.

 

[Dave Kaplow]

That's pretty cool. I find it interesting that most of the more defined devils in the video appear to form on or very near the sunlight/shade boundary... If this is really what is happening and not just a trick of perspective and camera angle, I would guess that it represents yet another instance of boundary-induced vorticity in a naturally occurring atmospheric process.

 

[Andrew Pritchard]

That's pretty cool. I find it interesting that most of the more defined devils in the video appear to form on or very near the sunlight/shade boundary... If this is really what is happening and not just a trick of perspective and camera angle, I would guess that it represents yet another instance of boundary-induced vorticity in a naturally occurring atmospheric process.

I actually noticed this as I was shooting them, so you aren't alone. There might be something to that.

 

[Paul Hadfield]

A day after Andrew published his amazing video, conditions here in C IL were similar to what he experienced so I headed out to a local park hoping to find the same. At first there wasn't much happening but once the sun crested the tree line, it was on. I put together a brief time lapse video with a few of the best spouts appearing at :30 and 1:30.

http://www.youtube.com/watch?v=DouPN_uZLy8

 

[John Farley]

I also got inspired by Andrew and Paul's work with steam devils. So, yesterday morning (Oct 5), I got up early and was on the shore of Dunlap Lake (located in Edwardsville, IL) at sunrise in hopes of getting some steam devils. No full-fledged steam devils, but I did get some interesting eddies along convergence boundaries created when the offshore breeze came back together after going around shoreline obstacles. Not quite enough temperature difference to stretch them into real steam devils, though. Video is at:

http://www.youtube.com/watch?v=66Yuh6RFy

The best eddies appear between about 1:45 and 3:00 minutes into the video, if you don't want to watch the whole thing.