This is weird, and I can't explain what I saw. I was looking out a window while at work. I was looking down at a shallow rain puddle that had developed from the light rain we are having. It was in a kind of shallow valley of pavement that had been created to funnel rainwater down a drain in the center, but the drain must be plugged, because the big puddle had formed that was probably about a half inch deep and 6 feet across. I'd say the incline of the "sides" of the valley was only 5 degrees or less. Anyway, I was watching the ripples from the raindrops, when I noticed a little swirling funnel of water traveling along near the edge of the pool that was nowhere near the drain. I though it may have been caused by the wind, but there was no noticeable wind. I watched it for a while, perplexed, and then it moved all the way to the edge of the pool. I thought it would disappear when it hit the edge of the water. Here's the part I can't understand. It didn't stop - it kept moving up the incline of wet pavement, all the while creating the swirling ripple effect. It's hard to explain, it's like I watched a living, spinning water ripple move up a hill on it's own. It traveled about a foot up the incline before it dissipated. WTF was it? All I can think of is a slight breeze that, due to the right conditions, had enough power to carry swirling water up wet pavement - yet there was no wind. I would think a strong gust would be needed to pull something like that off. I don't get it.