Very strong tornadoes in Italy in late autumn
Late autumn is tornado season in western, central and southern Italy. Warm sea surface of the Mediterranean sea and very moist airmass combine with deep troughs to produce very unstable environments. Additionally, the deep troughs are rounded by strong jetstreams providing strong winds aloft. Secondary cyclogenesis over the northern Mediterranean often results in very strong low level / surface southerlies, providing strong vertical veering wind profiles, conductive for supercells and tornadoes.
In particular, the same setups that produce training cell convective lines, torrential rainfall and major floods in Liguria and Tuscany also tend to produce tornadoes.
Also, as autumn progresses and deep troughs reach further into the central Mediterranean. With remaining high instability in place (2000+ J/kg MLCAPE not unusual in November in S Tyrrhenian sea and central Mediterranean) and very strong deep layer shear, strong tornadoes do occur. Below are two particularly impressive examples.
November 6, 2016 Cesano, Roma (central Italy) F3 tornado
A strong, rapidly moving long-tracked F3 tornado hit the area between Ladispoli and Cesano, central Italy on November 6, 2016. Cesano, where the worst damage was reported, is located approximately 30 km northwest of Rome. The damage track was 41 km long. Two fatalities and one injury ere reported with this tornado.
The forming tornado coming ashore from the Tyrrhenian sea in Ladispoli.
November 28, 2012 Taranto, Puglia (south Italy) tornado
This spectacular big stovepipe/wedge F3 tornado – looking almost like an identical twin to the Tuscaloosa tornado of the 2011 outbreak – hit Taranto in Puglia, southern Italy on November 28, 2012. The tornado produced a 14 km damage track, producing widespread damage. It also caused 1 fatality and 40 injuries.