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The incredible thing is that the precipitation has been generated by a single MCS, classifiable as "V-shape", that formed upstream the Apennines in a warm and humid south-westerly blowing from the Gulf of Genova. It started ad 18 UTC and it lasted approximately up to 6 UTC, just changing shape and moving a little bit, but substantially remained almost stationary. See the picture below taken at 00UTC 14/09/2015. This has generated more than 300mm, recorded by many stations on the upper part of those basins. The precipitation intensity was also striking with 4 stations recording more than 110mm per hour and almost 10 stations recording more than 80 mm per hour. See the map of the total precipitation fallen during the event between 13 and 14/09 over the station network of Emilia-Romagna
3-hour precipitation from RADAR accumulation:
3-hourly precipitation from 1 km COSMO model (from Suisse):
The plot below shows the radar data from Veneto 1440 on 14 September, with the supercell that caused the hailstorm (thanks to Massimo Enrico Ferrario):
Observed precipitation Saturday (12 Sept 06- 13 Sept 06z)
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