Объясните использование структуры "Be going to".Look at those dark clouds. The wind is...

Question

Объясните использование структуры "Be going to".Look at those dark clouds. The wind is getting strong. There are lightnings in the sky. It is going to rain.

Answer 1

В данном случае использование конструкции "Be going to" обусловлено следующим: Because I can see the reasons of the future rain now.