The world’s largest storms occur in its two biggest oceans, the Pacific and Atlantic. Tropical cyclones are massive dynamos that produce swirling destruction on unparalleled levels. We call storms that transpire in the Atlantic or Northeastern Pacific hurricanes, while those in the Northwestern Pacific go by typhoons. In the Indian Ocean and the extreme southern portion of the Pacific, they are simply referred to as cyclones or cyclonic storms.

No matter where they occur, the tempests are the same phenomenon. Why did we end up with different names? The origins of hurricanes and typhoons as nomenclature are settled in etymology, but it’s a bit odd that the same form of storm isn’t universally denoted. Both “hurricane” and “typhoon” are fantastic words, though, so perhaps the world is better for it.

Despite the various names, these cyclones are strictly defined. They originate in the tropics or subtropics, spin around a tight eye, and sustain winds of at least 74 miles per hour. They form largely due to the evaporation of warm water, usually in oceans with surface temperatures above 80 degrees Fahrenheit. They can last in open seas for more than a month but rapidly dissipate over land.

2018's Hurricane Florence from space - NASA

Other oceans, such as the Arctic and Southern, don’t currently spawn cyclones because they’re too cold. Some waters – notably the Southern Atlantic – that would otherwise be rife with hurricanes feature conditions that typically prevent them. In this case, the region sports too much wind shear for the storms to arise.

As it turns out, just a few regions become hotspots for the baddest storms on the planet. The Caribbean and Gulf of Mexico portions of the Atlantic. The Australasia and Indian sections of the Pacific/Indian.

You’ve no doubt put the pieces together, based on the title of the article and our penchant for loving oddballs in the natural world, that one spot outside of the Atlantic and Pacific (and sometimes the Indian) manages to produce “tropical-like cyclones.”

The globe’s only remaining body that is big enough with the proper conditions for massive storms is the Mediterranean Sea!

A map of the Mediterranean - graphic by O H 237
Medicane Ianos approaching Greece in 2020 - NOAA

The storm above is technically called a Mediterranean tropical-like cyclone. This designation is somewhat confusing, as it could imply two different things based on the reading of the term “tropical-like.” Meteorologists dubbed the storms “tropical-like” because they are similar to regular cyclones but do not originate in the tropics or sub-tropics. However, one could also read the term as “sort of like a tropical cyclone.” Despite the fact that they do not develop in lower latitudes, these storms are essentially the same type of disturbance.

In order to tidy up the moniker, many scientists now dub them medicanes.

Though the anatomy of medicanes and hurricanes are similar, a few key differences exist between the two. Medicanes are rarer than typhoons; they tend to happen during the cooler months; they are usually less intense; they peter out more quickly; and they form not because of warm surface water but because of warm air temperatures and temperature gradients.

Because the Mediterranean is not as large as the Atlantic or Pacific, the size and duration of a medicane tends to be much smaller than the typical cyclone. The storms run into land much more quickly. Because of these factors, medicanes usually top out at Category 1 on the Saffir-Simpson scale that quantifies hurricanes. This puts the maximum winds somewhere in the range of 74-95 miles per hour. In 2020, a medicane did reach Category 2, but anything higher is currently unlikely to occur.

Medicane Daniel in 2023 - NOAA

Though medicanes do not reach the peak winds of the most destructive cyclones, their effects can be rather striking.

We focus on the winds of the major hurricanes, but often the worst parts relate to water: rain and storm surge. Medicanes can pack in the rain just as heavily as a typhoon. Further, sometimes a natural disaster’s impact is directly related to how ready a region is to resist it. Medicanes are more uncommon, so many people on the coasts of the Mediterranean do not properly plan to be hit by a superstorm.

Medicane Daniel, pictured above, displayed this point in September 2023.

On 5 September, Daniel unleashed torrents on Greece. One village received nearly 30 inches of rain in 24 hours. Dozens of people died in Greece, Turkey, and Bulgaria due to flooding. As bad as the situation became in Europe, Daniel had far a far worse plan in store for Africa.

Daniel's track - graphic by Supportstorm

Daniel made landfall in Libya on 10 September. The arid nation received upwards of 10 inches of rain, in addition to 70-80 miles per hour winds. To say the least, Libya was not ready for this type of storm.

In the city of Derna, two dams were built in the 1970s to control flooding. They had never faced a deluge like Daniel before.

Here is how the city appeared in 2020; one of the dams is visible in the left portion of this image:

Derna in 2020 - photo by Maherlink

On the night of September 10-11, the dams failed.

The obliteration of the town and the people who lived there is nothing short of the word “Biblical.”

According to some estimates, 25% of the city was wiped off the map. The nation’s aviation minister said it looked as if it had been hit by a tsunami. Buildings and entire residential neighborhoods were swept to the sea. Where a thriving city had been previously, a mud-caked wasteland emerged.

More than 4,000 people are confirmed to be dead, but this number is expected to rise greatly. More than 10,000 humans remain missing. Already, Daniel is the deadliest storm to ever hit Africa.

Satellite view of Derna on August 25, 2023 - NASA
Scoured landscape on 18 September - NASA

All from a medicane that would have been labeled as a Category 1 hurricane in the Atlantic or Pacific.

Though Category 1 storms are undoubtedly mighty, we have become slightly desensitized to the mega storms that ravage North America and Asia. As sea and air temperatures continue to rise, the potency and reach of storms will likely continue to increase. Cuba, Florida, and the Philippines are used to major tropical cyclones. Just recently, Maine, Newfoundland, and Libya felt Mother Nature’s tropical wrath, an unusual punishment for those regions.

The future might require us to weather-proof our habitations in ways we’ve never imagined.

Further Reading and Exploration

What are medicanes? The ‘supercharged’ Mediterranean storms that could become more frequent – The Guardian

Medicanes – European Union Aviation Safety Agency

Mediterranean cyclones – The European Organisation for the Exploitation of Meteorological Satellites

Libya flood: Satellite images and aerial photographs show destruction – BBC

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