Wind is the horizontal movement of air, and predictions of the wind's speed and direction are routinely included in weather forecasts. But there's a different kind of air movement that's also going on: up-and-down motions that meteorologists call "vertical motions." These vertical motions are even more important in determining our weather.

That's because the vast majority of clouds form when air cools, and the primary way that air cools in the atmosphere is by rising. So if we know exactly where air is rising, predicting where clouds and precipitation form is a lot easier. Or, if we know exactly where air is sinking, we're better able to pinpoint where skies are cloud-free, or where clouds will tend to dissipate.

So the next time you feel the wind in your face, realize that there's another type of air movement - up and down - that's just as busy shaping the weather.