How a thunderstorm supercell forms and why it’s dangerous

How a thunderstorm supercell forms and why it's dangerous


The persistent heat waves and a set of phenomena that occur in the Po Valley are at the origin of the development of thunderstorm supercells who are scourging Northern Italy these days. The studies of Marcello Miglietta, research manager of the Institute of Atmospheric and Climate Sciences, focus precisely on supercells and tornadoes, as well as on the so-called “Medicanes”, the Mediterranean cyclones similar to tropical ones. The expert helps us to better define the characteristics of supercells.

How a supercell develops

“Let’s start from a normal storm cell – explains Miglietta – which develops because the warm air that rises from the ground collides with the cold air at high altitude. When cumulonimbus saturation is reached, rain occurs. There thunderstorm supercell differs because it has an extra ingredient, the wind is not constant with altitude but tends to intensify. In the normal thunderstorm, in the dissolving phase the warmer air is dragged downwards and cools the colder air, in the supercell this does not happen because the wind has a transversal inclination, called wind shear”.