Northeastern part of Italy hit by strange shapes of hail grains

In the hours between Monday, July 9th and Tuesday, July 10th, 2007 a heavy and long hailstorm fell down in the North-Easter part of Italy, it hit especially the region of Friuli Venezia Giulia in the areas of Udine and Gorizia.

The weather phenomenon is not unusual for the zone, but the shocking facet of the event is that the hail had very strange shapes; in fact the experts of the Osmer, the Osservatorio Meteorologico Regionale (which can be translated as Regional Weather Observatory) has obtained data which revealed the hail grains had a diameter of the size of about 6 centimeters and which were incredibly disk-shaped, such as a sort of doughnuts and flapjacks.

The experts of the Italian Observatory explained that a mix of three contemporaneous  decisive factors caused this strange phenomenon: the abundance of water vapour in the lower atmosphere, a lot of wind in altitude and the range (large variance of temperatures) between the lower and the upper atmospheric layers.

All these components favoured the formation of big hail grains which ruined a wide area of harvest-fields.