Precipitation occurs when water condenses in the atmosphere and forms droplets (or ice crystals, if the air is below freezing), and falls to the Earth. Precipitation occurs as rain (liquid water), sleet (frozen rain which freezes prior to the ground), snow (ice crystals at point of condensation), or hail (balls of ice formed during updrafts in large thunderstorms). Other variations of these have various names; drizzle, graupel, ice pellets etc. but all refer to water falling post-condensation from the sky in some form. In this experiment we simulate the condensation of warm water on a layer of cold air (plastic!) and it's dripping back down onto the Earth's surface.
Click HERE for a precipitation experiment.