Posting at Weekend Reflections.
May 2004 - Venice Italy
Piazza San Marco is at the lowest point in Venice and consequently it is flooded during Acqua Alta the "high water" from storm surges from the Adriatic. In order for Acqua Alta to occur certain events must coincide:
A very high tide (usually during a full or new moon)
Low atmospheric pressure
A scirocco wind blowing up the narrow, shallow Adriatic Sea, which forces water into the Venetian Lagoon.
It is most likely to happen in late September and April, and especially in the months of October, November,
Walking along the temporary walkways they erect
Policman surveying San Marco Square