Is it normal if it rains heavily for almost 2 hours in a place where the percipation is 780 mm per year? Read!?

I live in Uzice, a small place in the central parts of Serbia. It's normal to have rain here, but it is deffinetly not normal to have to big floods in two days here. There was 40 mm of rain it he past two days and the normal percipation for the whole month is... Well, 56 mm of rainfall! I think that it will rain today exactly the same, 'cause I see some stormy weather moving from the south. Please answer this question!