Severe weather with supercells, large hail and excessive precipitation in Sicily – October 11, 2013

Intense supercell thunderstorms hit Sicily two days ago. The storm system formed in the early morning on a strong, nearly stationary surface convergence zone just north of Sicily, ahead of the approaching cold front. Conditions were very favourable for formation of supercells with high CAPE (2000-3500 J/kg), strong 40-45 kt mid level jet and veering wind profile with backing surface E-SE winds. A MDT risk was assigned to this area in the updated Day 1 Outlook for 11/10/2013.

Supercell over Sicily. Source:

Shelf cloud on one of the storms. Source:

Storm structure with shelf cloud and roll cloud in Brolo, Sicily. Source:

Multiple severe hailstorms hit the region, with large hail up to ~5 cm diameter being reported.

Large hail from one of the supercells. Source:

Large hail in Pomeriggio from one of the supercells. Source:

Radar Italia Sud showed multiple isolated supercells within the system, tracking east as the system slowly pushed ESE.

Composite radar Italia Sud showing several supercells over Italy during early afternoon. Source:

Satellite imagery showed impressive storm structure with multiple overshooting tops and a strong flanking line.

EUMETSAT VIS images 08:00 and 09:00 UTC. Source: EUMETSAT.