Severe thunderstorm outbreak south of the Alps

Severe thunderstorms have caused extensive damage on Sunday 6th of July and Monday 7th of July. The episode started with the development of intense supercells across the southern flanks of the Alps in northern Italy Sunday afternoon. The updated ESTOFEX forecast for this day can be found here: link. Large hailstones up to 6 cm in diameter and tornadoes have been reported to the ESWD database of the European Severe Storms Laboratory, the organization that keeps track of severe weather in Europe. The reports of both days can be retrieved here. Among the people affected were tourists who were camping close to Lake Garda. A video at Youtube shows the large hailstones: link. Later in the day, the cells progressed southeastward through the level 2 area while continuing to produce large hail. A timelapse video of the rotating storm by Cristiano Corte can be found here: link. This storm continued to produce several tornadoes near Padova. A video of an impressive tornado over water can be found here: link. Several images and video's of the storms and the damage they have caused are presented on the website of Andrea Colombo link.

On Monday, the severe weather continued. The latest forecast update on Monday looked like this: link. During the afternoon strong storms moved eastward over the southern Italian Alps again, before even more intense supercell storms developed over the regions of Veneto and Friuli Venezia Giulia. One particularly intense supercell storm crossed the northern Adriatic Sea and produced serious tornado damage north of the city of Rijeka in Croatia. In the towns of Lisac and Pozega, houses were damaged and the nearby forests partly flattened, see: link. Damage also occurred in the areas of Klenovnik and Lipovnik: link. Slovenia was hard hit as well as damaging winds swept through the country after the supercells had clustered into a linear system. At the same time, more isolated convective storms, also including supercells had developed over parts of Hungary, where widespread large hail occurred.