What exactly is a medicane and why storm Jolina matters for the entire Mediterranean
The term medicane, created by combining the words Mediterranean and hurricane, is often used in public as an attractive label for unusually strong storms over the Mediterranean Sea. But behind that name stands a real and serious meteorological problem. It refers to rare cyclones that in some characteristics resemble tropical cyclones, although they form in a completely different geographical and atmospheric environment. That is precisely why they have long represented a challenge both for science and for operational meteorology: they are difficult to define unambiguously, even harder to compare across different studies, and because of their rarity the number of cases on which forecast models can be tested is also limited.
The recent case of storm Jolina, which developed over the Mediterranean in mid-March 2026 and then affected the area of Libya, has once again raised the question of how well we understand such systems and how prepared the countries on the southern and central Mediterranean coasts are for their consequences. According to data and analyses from the European Space Agency, EUMETSAT, CNR-ISAC and the American Meteorological Society, Jolina has become one of the most important recent examples for tracking the formation and evolution of medicanes in near real time. Its value lies not only in the fact that it brought dangerous weather, but also in the fact that it served scientists as an almost textbook case for testing the new, standardized definition of this type of storm.
For the wider public, this has very concrete importance. The Mediterranean is not a region in which the population, infrastructure and civil protection systems are traditionally prepared for storms that resemble hurricanes. Nevertheless, that is exactly what a series of extreme events in recent years shows: even systems that are not frequent, nor necessarily the strongest in the sense of tropical cyclones, can cause very serious consequences. In that sense, Jolina is not only a meteorological story but also a warning about the vulnerability of coastal areas, cities, transport systems and emergency services in a region where more than 500 million people live.
A new definition of medicane should reduce confusion in forecasts and warnings
One of the biggest problems in the monitoring of such storms so far was the absence of a single and generally accepted definition. In professional papers and in operational practice, the term medicane was used inconsistently. Some authors placed the emphasis on similarity to tropical cyclones, others on the warm core of the system, others on the satellite-visible structure with an eye and spiral cloud bands. The result was that different types of cyclones were sometimes understood under the same name, which made both scientific comparison and public communication more difficult.
That is precisely why a group of European experts, with the leading role of the Italian Institute of Atmospheric Sciences and Climate CNR-ISAC and with the support of the ESA-funded MEDICANES project, proposed a standardized definition based on observations that can be monitored by satellites. As the authors of the paper published in the Bulletin of the American Meteorological Society state, a medicane is defined as a mesoscale cyclone that develops over the Mediterranean Sea and shows characteristics similar to a tropical cyclone: a warm core extending into the upper troposphere, a central eye-like area with surrounding spiral cloud bands, and an almost windless center surrounded by an almost symmetrical circulation of wind at the sea surface, with the maximum wind speed reached at a distance of several tens of kilometers from the center.
That definition is important for several reasons. First, it gives meteorological services clearer criteria for when a storm should truly be regarded as a medicane, and when it is another type of Mediterranean cyclone. Second, it enables the comparability of research, which is crucial for understanding trends, physical mechanisms and possible changes in the future. Third, it relies on satellite observations, so it is applicable in near real time as well, and not only in subsequent scientific analyses.
How Jolina formed and why it first had a different name
According to the available analyses, the system began as a cold-core low-pressure field over the western Mediterranean on March 14, 2026. At that stage it did not show all the characteristics of a medicane, but rather resembled a strong extratropical cyclone. During its further movement toward the central Mediterranean, it gradually changed structure. In meteorological monitoring, the name Samuel was initially mentioned, but after the transition to a warm core and the development of characteristics corresponding to the new definition, the system was reclassified as a medicane on March 17 and designated with the name Jolina.
That very transition from a cold to a warm core is one of the most interesting elements of the entire event. Scientists point out that not all medicanes form in the same way. Some rely more strongly on processes typical of tropical cyclones, while in others strong influences of mechanisms characteristic of the mid-latitudes remain visible. Jolina is therefore important because it shows that hybrid systems can develop over the Mediterranean that begin as a classic cyclone and then acquire a structure increasingly similar to a tropical storm.
Unlike the popular notion according to which such systems are simply “small hurricanes,” reality is more complex. The Mediterranean is a confined basin, with a different distribution of land and sea, a shorter storm lifetime and a special relationship between the sea, relief and atmospheric flows. Because of that, even relatively cooler sea-surface temperatures do not exclude the possibility of the development of a deep warm core if other favorable conditions are met. Jolina itself, according to available satellite analyses, showed that the transition to a warm core can occur even in an environment that at first glance is not typical of a classic tropical cyclone.
Satellites were crucial for confirming that it was a medicane
Most of the scientific value of the Jolina case arises from the fact that the system was tracked using a larger number of satellite instruments of different purposes. The geostationary meteorological missions Meteosat Third Generation and Meteosat Second Generation enabled continuous observation of cloud structure above Europe and North Africa. Visible and infrared channels showed the spiral organization of cloudiness and the development of a central eye-like area, especially as the system approached the Libyan coast.
Even more important for the physical diagnosis were the microwave instruments on the MetOp-C, NOAA-20 and NOAA-21 satellites. According to the researchers’ interpretation, it was precisely these data that made it possible to detect the development of the warm core in the higher layers of the troposphere. In other words, the satellites did not only capture an impressive image of the storm, but also helped confirm its internal thermodynamic structure, which is one of the fundamental criteria of the new medicane definition.
Data from the ASCAT instruments on the MetOp satellites and radar data from the Copernicus Sentinel-1 satellite were used to estimate wind at the sea surface. These data showed an almost closed ring of stronger winds around the center, as well as a relatively calmer, eye-like area in the very center. Such a combination of observations is especially important because it allows an assessment of the maximum sustained wind and the radius of maximum wind speed, two parameters that are important for determining the intensity of the cyclone and for understanding the transition from the development phase to the mature phase.
This also shows the broader value of new European and international Earth observation systems. According to EUMETSAT, Meteosat Third Generation was conceived precisely to improve short-term warnings and the monitoring of rapidly developing dangerous weather phenomena. Jolina showed how such technology can in practice help not only scientists but also the services responsible for forecasting and protecting the population.
Why Jolina is important to scientists, and not only to forecasters
The Jolina case is of particular interest to researchers because it opens up room for a better understanding of how certain Mediterranean cyclones transform into warm-core systems. In atmospheric science this is not merely a terminological question. The way a cyclone forms directly affects its track, intensity, wind distribution, precipitation amount and ability to generate dangerous storm surges. If it is not clear to which group a system belongs, it is harder to assess what consequences it will leave on the ground.
Authors associated with the MEDICANES project emphasize that the standardized definition does not start from the assumption that all medicanes form according to one single pattern. On the contrary, the new definition acknowledges that these systems can have different developmental pathways while still sharing recognizable structural characteristics. This is important because it connects two approaches that for years were viewed almost separately: the operational one, based on what is seen from satellites, and the structural one, which relies on the diagnostics of numerical models.
For future research, this means that individual cases will be able to be compared on a firmer basis. Scientists will more easily distinguish storms that only partially resemble tropical systems from those that truly develop a deep warm core, an eye and an almost symmetrical wind circulation. They will also more easily assess how rare such events are, whether their frequency is changing, whether there is seasonality, and what the connection is with changes in sea temperature, the arrangement of atmospheric flows and thermal contrasts over the Mediterranean.
Consequences in Italy: warnings, closures and transport disruptions
Although Jolina left its strongest impact on the southern side of the Mediterranean, its effects were also visible in Italy. The Italian civil protection system issued warnings in mid-March because of heavy precipitation, severe weather and strong wind in several southern regions, including Calabria and Sicily. Media reports from Italy recorded school closures in a number of cities and damage associated with strong wind gusts and heavy rain.
According to Sky TG24 reports, for March 17 an orange warning level had been declared for parts of Calabria, Basilicata and northeastern Sicily. In Calabria, damage was recorded in the Catanzaro area, while in Cosenza strong wind gusts damaged structures and fair infrastructure. At the same time, schools, parks and part of public facilities were closed in Catania, and because of bad weather some flights were redirected to Palermo. Such disruptions may not look as spectacular as images of flooded neighborhoods, but they clearly show how great an operational burden even a moderately strong but well-organized cyclone can create for cities, transport and local services.
This is an important part of the story of medicanes that is often underestimated. It is not necessary for a storm to reach the extreme wind values recorded in the Atlantic in order to cause significant disruptions. In densely populated coastal areas, it is enough for strong wind gusts, heavy precipitation, local flash floods, high waves and transport exposure to coincide for the total social and economic damage to become serious.
Libya once again showed how vulnerable coastal cities are
After crossing the central Mediterranean, Jolina weakened only after landfall in Libya on March 19, and the most severe consequences were recorded precisely in that country. Libyan media and official responses spoke of heavy rain, flooded roads and urban flooding in several areas of western Libya, including Tajoura and Zawiya. Libya Herald reported that after the severe rainstorm an emergency meeting of the government’s emergency team was held and that a young man lost his life in Tajoura during volunteer activities connected with the severe weather.
Although the scale of damage in this case is not comparable with the catastrophe caused in Libya by Daniel in 2023, the context is extremely important. Libya has already shown how the combination of intense precipitation, vulnerable infrastructure, urban constraints and insufficient protection can turn dangerous weather into a major humanitarian tragedy. That is why every new storm with medicane characteristics also carries additional political and social weight: it is no longer only a meteorological curiosity but a question of the preparedness of cities and risk-management systems.
In that sense, Jolina served as a reminder that even systems of more moderate intensity can produce serious consequences when they hit highly exposed coastal areas. Urban flooding, traffic interruptions, pressure on emergency services and the need for rapid mobilization of resources often unfold within a very short time. If the forecast and classification of the storm are not sufficiently clear, the room for timely response narrows even further.
From the satellite image to the assessment of risk on the ground
Modern Earth observation systems are changing precisely that part of the story. Instead of a storm being declared a medicane only afterwards, after the entire event has been processed, it is now increasingly possible to follow the physical processes in almost real time. This includes cloud development, the warm core, the organization of wind at the sea surface and the position of the system’s center. For meteorologists this means better diagnostics, and for protection and rescue services potentially earlier and more precise warning.
But satellite technology alone is not enough. The key is how these data will be translated into understandable warnings and clear operational decisions. That is exactly why the new medicane definition also has practical weight: it reduces the space for terminological improvisation at the moment when the public and institutions need a clear assessment of risk. If it is known what exactly makes a medicane, it is easier to build monitoring protocols, comparisons with previous cases and models for assessing possible consequences.
This is especially important for Mediterranean countries that do not have the same level of experience with tropical cyclones as Atlantic or Pacific regions. In them, risk communication often relies on classic categories of cyclones, severe weather and heavy rain, while the term medicane can sound to the public either overly alarming or insufficiently precise. Standardization is therefore not only a scientific luxury, but a prerequisite for better public communication.
What Jolina says about the future monitoring of storms over the Mediterranean
Although it is not possible to draw far-reaching conclusions about long-term trends from a single case, Jolina shows that the quality of observation of Mediterranean cyclones has significantly improved. The combination of geostationary satellites, microwave instruments and radar measurements of wind over the sea allows a more detailed insight into the entire life cycle of such storms than was possible ten or fifteen years ago. This does not mean that the forecasting problem has been solved, but it does mean that the diagnostic tools are considerably stronger.
The broader scientific framework is also important. The MEDICANES project, led by CNR-ISAC with ESA support, is aimed precisely at making observations from space the foundation for understanding, modeling and risk assessment associated with medicanes. In that context, Jolina becomes more than one episode of bad weather. It is an example of how satellite images, thermodynamic diagnostics, analysis of surface wind and assessment of social consequences can now be connected into a single picture of the event.
For Mediterranean countries this matters because the real risk is not measured only by the maximum wind gust. Coastal flooding, high waves, disruptions of air and maritime traffic, strain on power and municipal infrastructure, and consequences for the local economy are often decisive elements of the total damage. In regions that are extremely densely populated, important for tourism and infrastructurally burdened, even rare events can have a disproportionate effect.
Jolina therefore entered the professional literature and public debates at a time when an attempt is being made to introduce more order into a term that had long been used insufficiently precisely. At the same time, it showed that medicane is not only a popular label for an unusual storm over the sea, but a concrete category of atmospheric system with measurable characteristics and very real consequences. If the new definition truly comes to life in operational practice, every next similar event could be better recognized, more clearly explained to the public and more precisely incorporated into early-warning systems throughout the Mediterranean.
Sources:- American Meteorological Society – overview of the new medicane definition and explanation of why it was needed (link)- Bulletin of the American Meteorological Society – scientific paper on the standardized medicane definition (link)- CNR-ISAC – announcement of the accepted medicane definition and its entry into the AMS professional glossary (link)- ESA EO Science for Society – description of the MEDICANES project and the goals of research and socioeconomic impact assessment (link)- MEDICANES Project – official website of the project under the leadership of CNR-ISAC (link)- EUMETSAT – overview of the capabilities of the Meteosat Third Generation system for monitoring strong and rapidly developing storms (link)- CIMSS Satellite Blog – satellite analysis of a strong cyclone north of Libya on March 17, 2026, and presentation of the system’s development (link)- Dipartimento della Protezione Civile – official meteorological bulletin and warnings for Italy in mid-March 2026 (link)- Sky TG24 – report on warnings, school closures and transport disruptions in Calabria and Sicily on March 16 and 17, 2026 (link)- Libya Herald – report on flooding, an emergency government meeting and a young man killed in Tajoura after a severe rainstorm (link)
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