Aaah, them good old "плоква" tiles.
Well it's not an official name, but it makes sence, since плочка(/плоча) is a tile and локва is a puddle. Beware their treachery, for when their powers combine, noone is safe.


It's not so much "pray it won't rain" as "Man, I really hope it won't rain". The inevitability of the incoming rain is subtly implied  in the phrase, yet stoically accepted as a part of life. For such is the bulgarian way of dealing with nature's unwanted gifts. And плокваs.