Massive storms over Italy and the Mediterranean Sea

Massive storms over Italy & the Med

3 September 2015 00:00 UTC–5 September 10:00 UTC

Massive storms over Italy and the Mediterranean Sea
Massive storms over Italy and the Mediterranean Sea

A large convective system brought severe storms to Naples and the Balearics in early September.

Last Updated

09 March 2021

Published on

03 September 2015

Between 3–5 September several convective cells developed along a relatively weak airmass boundary. One of the most severe cells brought tennis ball-sized hail to parts of Naples. Figure 1 shows the supercell over the Italian city on 5 September.

 

by HansPeter Roesli (Switzerland) and Jochen Kerkmann and Sancha Lancaster (EUMETSAT)

 Meteosat-10 IR10.8, 5 Sept 09:00 UTC.
Figure 1: Meteosat-10 IR10.8, 5 Sept 09:00 UTC.

The Meteosat-10 infrared imagery, animation from 3 Sept 00:00 UTC–5 Sept 10:00 UTC and Figure 1, shows the series of cells developing over the Mediterranean Sea. The severe storms were caused by a combination of instability (high moisture), lift (the trough can be clearly seen on the imagery) and wind shear (there was a jet over the area during the period).

 
 Suomi-NPP VIIRS infrared and visible sandwich product, 4 Sept 12:35 UTC
Figure 2: Suomi-NPP VIIRS infrared and visible sandwich product, 4 Sept 12:35 UTC

Figure 2: Sandwich product, 4 September

On 4 September storms in Menorca, Mallorca and Malaga caused flash flooding and severe lightning — some planes had to make emergency diversions. Local papers in Menorca reported it was the worst storm for 33 years.

The YouTube video Inundacion en calas fons menorca es castell shows flood water sweeping through the streets.

The Suomi-NPP VIIRS infrared and visible sandwich product, 4 Sept 12:35 UTC, shows one of the intense cells over the Mediterranean Sea, to the east of Menorca.

 
 Hailstone, Naples. Credit: Federica Urzo
Figure 3: Hailstone, Naples. Credit: Federica Urzo

The Meteosat-10 infrared imagery, animation from 5 Sept 00:00–10:00 UTC and Figure 1 (top right), shows the convection that brought massive, damaging hailstones to parts of Naples (Figure 3).

It was reported that several people and animals were injured, and vehicles and crops were badly damaged.

On Figure 1 a well-defined cold ring-shape cloud top can be seen, signifying a severe storm. The coldest cloud-top IR brightness temperature was -73.5º C at 09:00 UTC.

 
 Meteosat-10 High Resolution Visible, 5 Sept 05:30–09:00 UTC
Figure 4: Meteosat-10 High Resolution Visible, 5 Sept 05:30–09:00 UTC

On the animated gif of the Meteosat-10 High Resolution Visible, 5 Sept 05:30–09:00 UTC (Figure 4), overshooting tops, ship-wave like plumes and gravity waves can be seen.

 

Related Content

Supercell thunderstorm producing large hail in the Naples, Italy area (CIMSS Blog)
Three Jet2 planes declare emergencies as fierce storm rages over Ibiza, Majorca and Malaga (Mail Online)
Flash flood hits Menorca and egg-sized hailstones strike Aragon, Spain (sott.net)
Incredible Large Hail Stones (Grandine) hit Napoli, Italy | 05 09 2015 (YouTube/Nature Reporter)

Previous case studies

Spain hit by severe hailstorms twice in three days (1/2/3 July 2014)
Thunderstorm in Mallorca (29 Oct 2013)
Storms over Southern Italy (2 Sept 2010)