Domanda multiple-vortex tornado

[Tornado1977]

Riassumendo quindi non c'è una sola causa ben precisa per cui il tornado si suddivide in sotto vortici o rimane un blocco unico...Giusto? Ci sono svariati fattori da tenere di conto, e non è quindi possibile, immagino, prevedere con anticipo l'insorgenza di un tornado multi-vortex o meno!

Si in linea di massimo è esatto, anche se la tipologia Multivortex si manifesta per valori di scala superiori alla EF2 (scala EF). Giusto per completezza didattica d'informazione:

Multivortex (a.k.a. multiple-vortex) tornadoes contain two or more small, intense subvortices orbiting the center of the larger tornado circulation. When a tornado doesn't contain too much dust and debris, they can sometimes be spectacularly visible. These vortices may form and die within a few seconds, sometimes appearing to train through the same part of the tornado one after another. They can happen in all sorts of tornado sizes, from huge "wedge" tornadoes to narrow "rope" tornadoes. Subvortices are the cause of most of the narrow, short, extreme swaths of damage that sometimes arc through tornado tracks. From the air, they can preferentially mow down crops and stack the stubble, leaving cycloidal marks in fields. Multivortex tornadoes are the source of most of the old stories from newspapers and other media before the late 20th century which told of several tornadoes seen together at once.

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