This looks like drops hitting glass (but then disappearing, as if they vaporized). Or perhaps "heat shimmer" of another type, if we can call it that: what you might see in your field of vision if you've been running a long distance along that road, without drinking water.

Heat shimmer has to be sort of stringy due to the currents of different air densities that move as aggregates. It's mostly vertical as the plumes of hot air rise from the ground, so most of the distortion is horizontal displacement (side-to-side jitter).