What Causes These Strange Clear Stripes on the Lake When it Rains?

It's funny how you can wonder something your whole life and never look into it.

Maybe because it's been raining for 817 days in a row, I've found myself looking out the window pretty often lately, with a question in my mind. Maybe I'll look out and see something, or I'll even just be daydreaming and become struck with the idea of researching something that's been bugging me. It's not like there's been anything to do.

As it was raining (again) yesterday, I was staring at the lake out at my camp and got to wondering what made all the strange clear bands in the water. You really only ever see them when it rains. So I figured there must be some correlation between them and the rain. Here's what they look like:

How do these lines happen?

I've learned that when I was a kid, I'd obviously been the victim of a misinformation campaign. Not on purpose, but I took what adults told me to be the truth about these lines. I was told once that they were currents, and told once that they were fish schooling. The latter made me excited when I was a kid, but could never understand why I never caught any fish when I casted into them when it rained.

It turns out, according to the National Institute of Environmental Health Sciences, initial assessment was more correct. the lines are caused specifically when there is little to no wind. Wind typically causes ripples, but when the ripples are caused by rainwater, those ripples can interact with the various currents in a lake. Lakes aren't like rivers where water generally moves in one direction.

But anything can interact with the surface, and cause these variations in the surface. If there's simple junk floating on the water like debris or even pollen, it can affect the surface tension. All the factors can contribute to different patterns in the flow. This is at least my interpretation of all the science-y poindexter stuff. I'm probably kinda wrong. Check it out for yourself. But in short... currents, no wind, and rainfall make these lines.

Check out this sweet spot on the water downeast...