This is a serious, but all too common, misconception. It is PILOT induced oscillations. Not WEATHER induced.
PIO are actually quite common in perfectly smooth conditions.
Example. You were told to fly finals with the bar into your guts. You turn finals, but not quite lined up on the runway. You turn slightly, to line up. Because you are too fast, your turn extends past the intended angle, you then try to turn it back.
Because the aircraft has already begun the turn back to level, and you are too fast for what you are used to, your input actually increases the turn into the opposite direction (over-correcting, easier when flying fast, and depending on the roll stability of the trike!)
You then try to correct the turn in the opposite direction, again too late or two slow or two long, and your oscillations become increasingly severe. A very frightning place to be!
Solution: Ease of the bar, go with the turn, and get it under control. On finals, do go-around. It is though, something which can feel a lot like turbulence, and this is where it is imporant to see what your airspeed is, too fast, chances are its PIO.