Mediterranean cyclones are infrequent to rare with debate concerning their typology (tropical cyclones, subtropical cyclones or polar lows). They develop over open waters under strong, initially cold-core cyclones, similar to subtropical cyclones in the Atlantic Basin with typically non-tropical origins (source: http://en.wikipedia.org/wiki/Mediterranean_tropical_cyclone).
While Mediterranean sea surface temperatures in late-August and early-September range between +24 to +28°C, research indicates water temperatures of 20 °C are normally required for cyclone development and it appears that elevated cold air may bebe the main trigger for instability in the development of these systems.
It has been suggsted that a “hurricane season in the Mediterranean would be June – November ( similar to the North Atlantic hurricane season).
Recent US National Academy of Sciences study has shown powerful links between rising ocean temperatures in the key hurricane breeding grounds of the Atlantic and Pacific and an increase in the intensity of such storms.(source: http://www.theaustralian.news.com.au/story/0,25197,22080458-30417,00.html). For example:
- 2004, Cyclone Catarina, South Atlantic
- 2005 Hurricane Vince, Madeira in Portugal, an area that had never before produced such storms. It even struck Spain – another first.
- 2005, New Orleans overwhelmed by Hurricane Katrina.
- 2005: US Gulf coast, Hurricane Rita, the 4th most intense Atlantic hurricane ever recorded.
It has been further suggested that climate change induced warming in the Mediterranean may be enabling it to store enough heat to trigger the formation of its own hurricanes.
Mediterranean tropical cyclone – October 6-10, 1996 which resulted in serious flooding in the Balearic Islands, Sardinia, and south Italy. Winds of up to 145 km/h were reported over the Eolian Islands, causing infrastructural damage and four deaths. (source: http://en.wikipedia.org/wiki/Mediterranean_tropical_cyclone)