In the same way modern Greece is disposed towards climatic conditions like tornados/cyclones, waterspouts and funnel clouds, particularly over Crete and Corfu, Greek Natural Philosophy is much given to discussion about the wind, storm seasons, and the dangers of these. It is important to remember that the ancients were far more at the mercy of Nature than we generally tend to perceive ourselves in daily life today. (Global warming is changing this again) They carefully considered wind in works on city planning. (Hippocrates comes to mind). Their very strong awareness of the wind led ancient Greeks to mythologise them, so we have, for example, Hesiod’s discussion in Theogony of the birth of the Anemoi from Typhoeus, described as “boisterous winds that blow damply”. While some are seen as benevolent, the others “blow fitfully upon the seas. Some rush upon the misty sea and work great havoc among men with their evil, raging blasts; for varying with the season they blow, scattering ships and destroying sailors. And men who meet these upon the sea have no help against the mischief. Others again over the boundless, flowering earth spoil the fair fields of men who dwell below, filling them with dust and cruel uproar.”
By far the best example I can think to give you though is Aristotle’s Meterologica Book II and III ( I used an online translation by E.W Webster) where he specifically sets about explaining how whirlwinds and firewind is caused. In part 9 of book II he begins by describing that there are two types of “exhalations” moist and dry in the atmosphere. These condense into cloud and he posits that the density is higher the higher you go, which he feels explains why hurricanes “move downwards in spite of the fact that everything hot has a natural tendency upwards. Just as the pips that we squeeze between our fingers are heavy but often jump upwards: so these things are necessarily squeezed out away from the densest part of the cloud” He continues in Book III part 1 to say that this squeezing out, or exhalation is the precursor condition to thunder and lightning but where this exhalation is denser and being pushed in greater volume it results in hurricanes. In more specialised conditions this exhalation might collide with other exhalations and get forces down an unyielding path of resistance, to create a whirlwind or cyclone.
“It often happens in such cases that the first part of the moving body is deflected because of the resistance due either to the narrowness or to a contrary current, and so the wind forms a circle and eddy. It is prevented from advancing in a straight line: at the same time it is pushed on from behind; so it is compelled to move sideways in the direction of least resistance.”
He posits that each following part gets forces in the same manner until a circle is formed and if it doesn’t break free to expand as a hurricane - that is if it fails “to break away from the cloud because of its density” – it will circle and then descend “because clouds are always densest on the side where the heat escapes. This phenomenon is called a whirlwind when it is colourless; and it is a sort of undigested hurricane.” Further “So the whirlwind originates in the failure of an incipient hurricane to escape from its cloud: it is due to the resistance which generates the eddy, and it consists in the spiral which descends to the earth and drags with it the cloud which it cannot shake off. It moves things by its wind in the direction in which it is blowing in a straight line, and whirls round by its circular motion and forcibly snatches up whatever it meets.”
He goes on to say whirlwinds never happen when there is snow or prevailing winds are northerly.