Sicily, October 29th 2021: Medicane Apollo [1] approached the coast of Sicily and released torrential rains east of the island, especially over the cities of Augusta and Syracuse that received half of its annual rainfall amount [2].This event occurred right after a series of severe thunderstorms between the 24thand the 26th of October that dropped vast amount of rainfall (Figure 1) over the metropolitan city of Catania [3]. These cities are one of the largest in Sicily with a total population of over 0.4 million. Many countries on the Mediterranean coast also suffered from Medicane Apollo…. The storm killed at least 5 people and left 2 others missing due to flooding from the cyclone, in Tunisia, Algeria, Malta.
Three systems have formed so far this season [4]: Apollo, followed by Blas in November 2021 and Diomedes in January 2022. The risk is still ongoing until the end of the season in April.
What are medicanes and what are their associated risks?
Medicane is the short name for Mediterranean hurricanes or Mediterranean tropical-like cyclones. Just like tropical cyclones, they can develop spiraling clouds and an ‘eye’ feature free of clouds. However they are typically smaller in diameter than tropical cyclones, have lower wind speeds and shorter lifespan. They also form over the western and central Mediterranean Sea, above waters with surface temperatures much lower than tropical oceans. Medicane season starts usually in autumn and lasts until spring. Their formation requires the presence of cold air in the upper atmosphere associated with a cutoff low. This configuration enhances the atmospheric instability responsible for thunderstorms that can then organize into medicanes.
In addition to strong winds, medicanes generate storm surge and large amounts of rainfall that lead to flooding and landslides. In the case of Apollo, flood maps displaying such as JBA flood map highlighted the regions susceptible to flooding in Sicily.
Is climate change impacting medicanes ?
Recent research indicates that the medicanes are likely to become more intense but occur less often. The latest IPCC AR6 report states that “It is likely that medicanes will decrease in frequency, while the strongest medicanes become stronger under warming scenario projections”.
Romero and Emanuel (2017) found that in the future on average the total frequency of Medicanes does not vary, but results show a higher number of moderate and violent medicanes at the expense of weak storms. Future extreme events (winds > 110km/h) become more probable in all Mediterranean subbasins. 1-in-100 year will show an increase in intensity of about 10kts (from 95kts to 105kts) under RCP8.5 scenario by the end of the century (2081—2100 compared to 1986—2005).
patially, Romero and Emanuel (2017) projects an increased occurrence of medicanes in the western Mediterranean and Black Sea that is balanced by a reduction of storm tracks in contiguous areas, particularly in the central Mediterranean.
A study by Cavicchia et al. (2014) also found that the frequency of Medicanes is projected to decrease in future climate scenarios, as a consequence of the lower frequency of environmental configurations favorable for their formation. The projected intensity of simulated Medicanes shows on the other hand a tendency to a moderate increase.
A paper from Gonzalez-Aleman et al. (2019) found that under a RCP4.5 (middle road) emission scenario, the frequency of medicanes is expected to decrease, but become more intense towards the end of the century, bringing longer lasting stronger winds and heavier rainfall. Medicanes might also become more vigorous in autumn relative to spring and winter.
Another study by Pytharoulis (2018) found that warmer sea surface temperatures in the Mediterranean (1.73 to 2.97°C by the end of the century) can allow storms to become stronger and longer lasting.
Medicanes can impact vulnerable businesses and operations
Corporate companies with physical footprint around the Mediterranean are not prepared for cyclonic events in this geographical area. Two years ago, the word “medicane” itself was unknown to most European risk managers. And yet today, this natural hazard does deserve to be better known, especially if one wants to foster its business resilience in this area.
Because science tells us that the intensity of medicanes is definitely increasing, corporate companies with exposed assets will be impacted by new type of natural hazards, leading to:
- More physical vulnerability to flash flooding, (medicanes will bring a significant amount of excess rainfall)
- Vulnerability to coastal flooding, (due to strong wind and wave propagation)
- And more extreme wind damages (as roof structures in this area are not yet prepared to medicane wind gusts of 100 kt or 185 km/h).
Flooding will induce material damages, challenge business continuity, put at risk employees and overthrow operational resilience with supply chain disruption, potentially over days or weeks.
Extreme winds will require building and roof reinforcement on physical assets to minimize the impact of medicanes, especially against projectiles in the vicinity, and to properly address duty of care for business activities and employee safety.
A good illustration of how businesses could respond to this new climate risk is the case of this industrial company with assets in Southern Italy. After gathering data confirming its exposure to medicane, this company is organizing in 2022 climate adaptation field visits to audit not only the prevention plan of its major industrial plant against these new climate conditions due to medicanes, but also the public mitigation plans of local authorities due its dependencies on public investments for expanded levees or dykes.
Assessing the exposure to a rising threat
Title: Mediterranean Sea | Medicane Cassilda | from 14th September 2020 through 20th October 2020
Source: Meteosat-11
To put a story short, medicanes are a new and raising climate hazard in Europe. Most companies have no or very little records of exposure and vulnerability to such a treat. Corporate companies should collect qualitative and quantitative data about their exposure to climate change, and to medicanes specifically.
Once data is collected from a reliable climate data provider, specific climate adaptation plans should be considered (and implemented!) to reduce physical vulnerability to excess rainfall and extreme winds related to medicane events.
For example, before conducting a field visit dedicated to climate adaptation, companies should collect quantitative data about the intensity and frequency of such extreme events like medicanes for their assets, especially those located on the Northern coastline of Mediterranean Sea (Southern Italy, Greece, Turkey, Cyprus, Malta). And then, during field visits, companies should include interviews with local teams and also local authorities about mitigation plans set or planned or… sometimes long-time forgotten for their respective locations or their vinicity.
As a matter of fact, IPCC Working Group 2 assessment report, published in February 2022 focuses on the impact of global warming, our vulnerabilities, and outlines adaptation measures to cope with it. This report explicitly mentions that adaptation is a local topic *: recent studies have emerged that explore how indigenous knowledge can become part of a shared learning effort to address climate-change impacts and adaptation, and its links with sustainability.
* https://archive.ipcc.ch/publications_and_data/ar4/wg2/en/xccsc4.html
Finally, a specific focus should be made locally on prevention plans against more severe flash and coastal flooding and a stress test of the buildings and roof structures should be performed, for example with wind tunnel simulation of digital twins of the physical assets, as medicanes (such as other cyclones) can impact a business both with extreme winds and flooding, hence threatening employees’ safety, physical assets, and also business continuity of operations.
