"Storm in a tea-cup."?

Not quite; more sort of Tornado in a bottle.
Elder Sheffield sprog got a weather science/meteorology kit off Santa.
I didn't see any of the others, I'd have loved to see his Volcano.
;¬)
This was a neat little example:-
Two bottles joined by a "Double-female" connector, to use Fire-speak. There was a quite significantly reduced orifice twixt the two such that complete inversion did not easily allow fluid to flow, if at all, when held steady.
Impart, however, a swirl and behold - instant Tornado.