[Lenka]

I was told that weather forecast is told with using WILL:
e.g. It will rain tomorrow.
Tomorrow's weather will be warm and sunny.

We can't say "Tomorrow's weather is going to be warm", can we? I read it in Headway...


If it's the truth that it's not possible to say "Tomorrow's weather is going to...", why is the sentence below right?

- 'What a beautiful day! Not a cloud in the sky!'
- 'Ah, but the weather forecast says it's going to rain." <= why not only WILL?