Mediterranean tropical-like cyclones, often referred to as Mediterranean cyclones or Mediterranean hurricanes, and shortened as medicanes, are meteorological phenomena occasionally observed over the Mediterranean Sea. On a few rare occasions, some storms have been observed reaching the strength of a Category 1 hurricane on the Saffir–Simpson scale, and Medicane Ianos in 2020 was recorded reaching Category 2 intensity. The main societal hazard posed by medicanes is not usually from destructive winds, but through life-threatening torrential rains and flash floods.
The occurrence of medicanes has been described as not particularly rare. Tropical-like systems were first identified in the Mediterranean basin in the 1980s, when widespread satellite coverage showing tropical-looking low pressures which formed a cyclonic eye in the center were identified. Due to the dry nature of the Mediterranean region, the formation of tropical, subtropical cyclones and tropical-like cyclones is infrequent and also hard to detect, in particular with the reanalysis of past data. Depending on the search algorithms used, different long-term surveys of satellite era and pre-satellite era data came up with 67 tropical-like cyclones of tropical storm intensity or higher between 1947 and 2014, and around 100 recorded tropical-like storms between 1947 and 2011. More consensus exists about the long term temporal and spatial distribution of tropical-like cyclones: they form predominantly over the western and central Mediterranean Sea while the area east of Crete is almost devoid of tropical-like cyclones. The development of tropical-like cyclones can occur year-round, with activity historically peaking between the months of September and January, while the counts for the summer months of June and July are the lowest, being within the peak dry season of the Mediterranean with stable air.
Meteorological classification and history Historically, the term tropical-like cyclone was coined in the 1980s to unofficially distinguish tropical cyclones developing outside the tropics (like in the Mediterranean Basin) from those developing inside the tropics. The term tropical-like was in no way meant to indicate a hybrid cyclone exhibiting characteristics not usually seen in "true" tropical cyclones. In their matured stages, Mediterranean tropical cyclones show no difference from other tropical storms. Mediterranean hurricanes or medicanes are therefore not different from hurricanes elsewhere.
Mediterranean tropical-like cyclones are not considered to be formally classified tropical cyclones and their region of formation is not officially monitored by any agency with meteorological tasks. However, the NOAA subsidiary Satellite Analysis Branch released information related to a medicane in November 2011 while it was active, which they dubbed as "Tropical Storm 01M", though they ceased services in the Mediterranean on 16 December 2011 for undisclosed reasons. However, in 2015, the NOAA resumed services in the Mediterranean region; by 2016, the NOAA was issuing advisories on a new tropical system, Tropical Storm 90M. Since 2005, ESTOFEX has been issuing bulletins that can include tropical-like cyclones, among others. No agency with meteorological tasks, however, is officially responsible for monitoring the formation and development of medicanes, as well as for their naming.
Despite all this, the whole Mediterranean Sea lies within the Greek area of responsibility with the Hellenic National Meteorological Service (HNMS) as the governing agency, while France's Météo-France serves as a "preparation service" for the western part of the Mediterranean as well. As the only official agency covering the whole Mediterranean Sea, HNMS publications are of particular interest for the classification of medicanes. HNMS calls the meteorological phenomenon Mediterranean tropical-like Hurricane in its annual bulletin and – by also using the respective portmanteau word medicane – makes the term medicane quasi-official. In a joint article with the Laboratory of Climatology and Atmospheric Environment of the University of Athens, the Hellenic National Meteorological Service outlines conditions to consider a cyclone over the Mediterranean Sea a Medicane:
In the same article, a survey of 37 medicanes revealed that medicanes could have a well-defined cyclone eye at estimated maximum sustained winds between , with the lower end being exceptionally low for warm core cyclones. Medicanes can indeed develop well-defined eyes at such low maximum sustained winds of around as could be seen for a 22 October 2015 medicane near the Albanian coast. This is much lower than the lower threshold for eye development in tropical systems in the Atlantic Ocean which seems to be close to , well below hurricane-force winds.
Several notable and damaging medicanes are known to have occurred. In September 1969, a North African Mediterranean tropical cyclone produced flooding that killed nearly 600 individuals, left 250,000 homeless, and crippled local economies. A medicane in September 1996 that developed in the Balearic Islands region spawned six tornadoes, and inundated parts of the islands. Several medicanes have also been subject to extensive study, such as those of January 1982, January 1995, September 2006, November 2011, and November 2014. The January 1995 storm is one of the best-studied Mediterranean tropical cyclones, with its close resemblance to tropical cyclones elsewhere and availability of observations. The medicane of September 2006, meanwhile, is well-studied, due to the availability of existing observations and data.
Given the low profile of HNMS in forecasting and classifying tropical-like systems in the Mediterranean, a proper classification system for Mediterranean tropical-like cyclones does not exist. The HNMS criterion of a cyclonic eye for considering a system a medicane is usually valid for a system at peak strength, often only hours before landfall, which is not suitable at least for forecasts and warnings.
Unofficially, Deutscher Wetterdienst (DWD, the German meteorological service) proposed a system to forecast and classify tropical-like cyclones based on the NHC classification for the northern Atlantic Ocean. To account for the broader wind field and the larger radius of maximum winds of tropical-like systems in the Mediterranean (see the section Development and characteristics below), DWD is suggesting a lower threshold of for the use of the term medicane in the Mediterranean instead of as suggested by the Saffir–Simpson scale for Atlantic hurricanes. The DWD proposal and also US-based forecasts (NHC, NOAA, NRL etc.) use one-minute sustained winds while European-based forecasts use ten-minute sustained winds which makes a difference of roughly 14% in measurements. The distinction is also of direct practical use (for example for a comparison of NOAA bulletins with EUMETSAT, ESTOFEX and HNMS bulletins). To account for the difference, the DWD proposal is shown below for both one-minute and deduced ten-minute sustained winds (see tropical cyclone scales for conversions):
maximum sustained winds Mediterranean Tropical Depression Mediterranean Tropical Storm Medicane 1-minute average ≤ 62 km/h (≤ 17 m/s; ≤ 38 mph; ≤ 33 knots) 63–111 km/h (18–30 m/s; 39–69 mph; 34–60 knots) ≥ 112 km/h (≥ 31 m/s; ≥ 70 mph; ≥ 61 knots) 10-minute average ≤ 54 km/h (≤ 14 m/s; ≤ 33 mph; ≤ 29 knots) 56–98 km/h (15–27 m/s; 35–61 mph; 30–53 knots) ≥ 99 km/h (≥ 28 m/s; ≥ 62 mph; ≥ 54 knots)
Another proposal uses roughly the same scale but suggests to use the term medicane for tropical storm force cyclones and major medicane for hurricane force cyclones. Both proposals would fit the observation, that half of the 37 cyclones surveyed by HNMS with a clearly observable hurricane-like eye, as the major criterion for assigning the medicane status, showed maximum sustained winds between , while another quarter of the medicanes peaked at lower wind speeds.
Due to the lack of a proper definition and discrepancies over the classification of a Mediterranean tropical-like cyclone, most commonly accepted to be a relative area of vorticity with satellite-observed characteristics typical of tropical cyclones, the lack of a proper definition has caused confusion among those in the scientific and operational community. To better define and describe the definition of a Medicane, a paper published by European experts from the American Meteorological Society on 1 September, 2025 aimed to reconcile inconsistent Medicane phenomena and structural criteria that has been applied amongst a multitude of past studies and papers, with this definition stating;
This definition provided by the paper assures consistency upon solving confusion in the scientific community and in operational weather services in regards to the classification of a Mediterranean tropical-like cyclone, as well as being used as a reference for future scientific research or operational application.
Climatology
A majority of Mediterranean tropical cyclones (tropical cyclogenesis) form over two separate regions. The first, more conducive for development than the other, encompasses an area of the western Mediterranean bordered by the Balearic Islands, southern France, and the shorelines of the islands of Corsica and Sardinia. The second identified region of development, in the Ionian Sea between Sicily and Greece and stretching south to Libya, is less favorable for tropical cyclogenesis. An additional two regions, in the Aegean and Adriatic seas, produce fewer medicanes, while activity is minimal in the Levantine region. The geographical distribution of Mediterranean tropical-like cyclones is markedly different from that of other cyclones, with the formation of regular cyclones centering on the Pyrenees and Atlas mountain ranges, the Gulf of Genoa, and in the Ionian Sea. Although meteorological factors are most advantageous in the Adriatic and Aegean seas, the closed nature of the region's geography, bordered by land, allows little time for further evolution.
The geography of mountain ranges bordering the Mediterranean are conducive for severe weather and thunderstorms, with the sloped nature of mountainous regions permitting the development of convective activity. Although the geography of the Mediterranean region, as well as its dry air, typically prevent the formation of tropical cyclones, when certain meteorological circumstances arise, difficulties influenced by the region's geography are overcome. The occurrence of tropical cyclones in the Mediterranean Sea is generally extremely rare, with an average of 1.57 forming annually and merely 99 recorded occurrences of tropical-like storms discovered between 1948 and 2011 in a modern study, with no definitive trend in activity in that period. Few medicanes form during the summer season, though activity typically rises in autumn, peaks in January, and gradually decreases from February to May. In the western Mediterranean region of development, approximately 0.75 such systems form each year, compared with 0.32 in the Ionian Sea region. However, on very rare occasions, similar tropical-like storms may also develop in the Black Sea.