Why is the word wind sometimes plural?
Why can it be counted when there is no fixed shape?

See a translation

@mari369

Culturally, many places still have an idea of there being multiple winds which come from multiple different places – the four winds, particularly, indicating the different qualities of air which come from the different cardinal directions – north, south, east, west.

Also, in mythology, the winds have sometimes been represented as a collection of forces, or even animals – types of invisible horses which bring strong winds, as if they were galloping.

Anyway, it is very common in English to talk about the wind as a plurality of forces.