Isolated supercell over the Italian region of Emilia-Romagna, producing tennis ball-sized hail and a tornado near Castelfranco.
05 May 2023
03 May 2013
By Martin Setvak (CHMI) and HansPeter Roesli (Switzerland)
On 3 May 2013, several severe convective storms occurred above Emilia-Romagna region (north Italy), causing heavy damage in the area between Modena, Bologna and Ferrara. The storms were accompanied by large hail, heavy rain and even several tornadoes, causing major damage and injuring at least 13 people.
From the satellite perspective, the storms were accompanied by several cloud-top features, which are typical for severe storms. Besides many overshooting tops, bubbling-up and disappearing on very short time scales (of the order of several minutes), the storms formed in IR bands distinct cold ring and cold-U features with embedded warm areas, and above-anvil ice plumes.
The most pronounced and longest-lived plume formed above the south-eastern storm; similar split-like appearance of the plume was observed for example above the 18 August 1986 storm above Czech Republic (Setvák and Doswell, 1991; Levizzani and Setvák, 1995), and is believed to form due to ship-wave like processes at tops of convective storms (Wang et al., 2010).
The loops below show evolution of these storms as captured by Meteosat-9 at 5-minute intervals (RSS), and the still images from NOAA-15 show storm-top details in 1km AVHRR imagery.
Colour-enhanced IR10.8–BT (212K–240K) loop
Sandwich product of HRV and colour-enhanced IR10.8–BT images loop
Band 2 image
Colour-enhanced band 4 image — Full resolution
RGB image product of bands 1, 2 and 4 — Full resolution
Sandwich product of the RGB124 and color-enhanced band 4 images above
Setvák M., Doswell III C.A., 1991: The AVHRR Channel 3 Cloud Top Reflectivity of Convective Storms. Mon. Wea. Rev. 119, 842‑847.
Levizzani V., Setvák M., 1996: Multispectral, High‑Resolution Satellite Observations of Plumes on Top of Convective Storms. J. Atmos. Sci., 53, 361‑369.
Wang P. K., Su S-H., Setvák M., Lin H-M., Rabin R. M., 2010: Ship wave signature at the cloud top of deep convective storms. Atmos. Research, 97, 294-302, DOI: 10.1016/j.atmosres.2010.03.015 .