Visible satellite animation over Europe on November 28, 2012 from 0600 to 1200 UTC.  This loop shows the rotating area of low pressure located over the northern Mediterranean Sea near the Gulf of Genoa. The placement of this strong low pressure was conducive for severe weather to break out across southern Italy. Polar air from the north and west met up with a warm, moist air mass fed by southerly winds tapping into the Mediterranean Sea. The clash of the two air masses triggered the severe weather including the violent Taranto tornado.

The surface analysis near the time of the tornado showed a surface trough (red arrow) in advance of the approaching cold front along the west coast of Italy and slicing through Sicily. It is likely that the surface trough helped to ignite individual supercell t-storms across southeast Italy.  Source: metoffice.uk.gov