Isolated supercells in a potentially tornadic setup in NE Italy – October 10, 2013
Several isolated supercells formed prefrontally in NE Veneto, Italy in the late afternoon and evening of October 10, 2013. The storms formed on a surface convergence just south of the southern Alpine flank
Photographs from storm chaser Fabio Veneziano clearly show supercellular structure of the storm with a distinct RFD cut/clear slot.
Isolated supercell north of Treviso, Oct 10, 18:40 CEST. Image credit: Fabio Veneziano
Conditions in E Veneto and Friuli were favourable for formation of tornadic supercells, particularly in the southern part where (backing) surface winds reached 40 – 50 km/h, sustained, and CAPE reached 1500 – 2000 J/kg, dropping off quite sharply towards the north. High low level lapse rates were present and LCLs in 300 – 500 m range. A 30 – 40 kt mid level SW jet was present. Any supercell that formed in the south of the region was expected to have a high tornadic potential.
Surface wind in Friuli, Oct 10, 19:00 CEST. Source: OSMER FVG. OSMER Fossalon radar image, Oct 10, 19:00 CEST. Two isolated supercells in NE Veneto. Source: OSMER FVG. ARPAV-CMT Monte Grande radar image, Oct 10, 19:00 CEST. Two isolated supercells in NE Veneto. Supercell photographed by Fabio Veneziano is marked by the circle. Source: ARPAV-CMT / Fabio Veneziano.No supercells formed in the south, all development remained confined to the less favourable area in the north, near the Alpine flank. No reports of possible tornadoes have appeared.