This animated graphic shows a rare tropical storm known as a a "medicane" forming in the Mediterranean Sea. Tropical storms in the Mediterranean Sea are uncommon because the region is too far north to produce these "warm" storms. But as sea surface temperatures increase, medicanes could become more common. (EUMETSAT/SSEC/CIMSS)

A rare, ostensibly bizarre storm formed in the Mediterranean over the weekend. It was a tropical storm, which is uncommon for that region simply because the Mediterranean Sea is usually too cold.

This odd storm started as an average low-pressure system on Saturday, east of Malta. What made it different was the exceptionally warm water in the Mediterranean Sea. The water temperature there is running 5 to 6 degrees above average for this time of year, which means it was around the special 80-degree mark that tropical storms usually need to develop.

Strong thunderstorms bubbled up in the system on Saturday and Sunday, and the pressure dropped. The atmosphere was moist and warm enough for the storm to become “warm core” — the signature difference between something like a hurricane and the day-to-day storms we get in the mid-latitudes.

Scott Bachmeier, a research meteorologist at the University of Wisconsin, has been tracking the storm since the weekend. He said “it developed over the Ionian Sea between Italy and Greece, initially moved southwestward, and then turned to the east where it eventually produced a wind gust to [60 mph] and caused some damage on the Greek island of Crete on 31 October. A wind gust to [57 mph] was also seen from a ship report at [1 p.m. local time Friday].”

The storm didn’t have a name because the National Hurricane Center doesn’t cover the Mediterranean Sea. However, it did reach tropical storm status, according to the Weather Channel.

The last time a storm like this occurred in the Mediterranean was in November 2011. The satellite division of NOAA designated it “Rolf.”


(NASA/Capital Weather Gang)

The storm dissipated on Monday — though not before it slammed Malta with strong winds. Giant waves crashed on the shoreline in St. Julian’s Bay and other east-coast locations, which experienced the strongest winds. The waves stopped traffic and damaged hotels, according to the Times of Malta:

Vicious winds are lashing the Maltese islands leaving a trail of damage, especially at the Radisson Hotel in St Julian’s which was flooded after strong waves smashed through its windows.

The police today issued a warning advising the public to avoid coastal areas and seafronts such as Triq Borg Olivier in St Julian’s due to high waves crashing onto land. Seawater had flooded one side of the Strand in Sliema.

A resident said the strong sea waves even smashed cars into the Park Towers Mall in St Julian’s.

The Times of Malta even reported a strange slimy substance washing ashore. People blamed local fish farms, which denied responsibility:

Meanwhile, a glutinous slime was washed into Portomaso but fish farms have categorically denied it had anything to do with them.

Joseph Caruana, Fish & Fish director, said: “This slime has absolutely nothing to do with us. We have asked the government to carry out an investigation to establish this once and for all, and we’re going to keep putting pressure until it’s resolved.”

Still, a reader reported seeing amounts of “strange slime like big snowflakes or foam from a washing machine being washed up by the waves” along the Coast Road, making the roads slippery and dangerous to drivers.