Dynamics of Etna's "hat of the Countess's"

When strong wind blows over Mount Etna volcano in Sicily, the gas plume emitted from the summit craters is pushed down the slope and once it enters into the wind shadow of the mountain, it starts rising. Since most of this gas plume consists of water vapor, once the plume rises and enters into colder air, it condensates, forming a dense white cloud that often has an oval shape and hangs somewhat detached from Etna's summit, sometimes obliquely, resembling the hat of a noble lady. The locals call it "contessa", which means countess, or "contesa", which means competed or disputed. Often people also call the cloud an "UFO", a visit from another civilization ... and this cloud moves constantly as it is sculplted by the strong wind and the gas from Etna feeding into the base of the cloud. On 10 January 2016, I filmed this movement over a long period, and here is a timelapse of that movie footage, showing the whole thing, then the clouds drifting over Etna with the roaring wind, the gas plume trailing out from underneath those clouds and rising in the wind shadow until they reach the "contessa" cloud, and the constantly changing shapes of this cloud. The view is from my home town Tremestieri Etneo, 20 km south of Etna's summit.
The music is Jerry Martin's "Shape Shifter" out of the SimCity music collection.

[@KdEtna]

Sapevo che ti sarebbe stata utile e con questo contesto (uno dei possibili) è perfetta :)

[@hreader]

This phenomenon was a nuisance when I visited last Thursday (13th) as part of an organised excursion - the mist rather restricted our tour, but I'll never forget looking into the Bocca Nuova at the aftermath of the explosion on the previous Monday (10/10).