Future Forms (will vs. be going to)
1. To express a prediction: Use either WILL or BE GOING TO.
a) According to the weather report, it will be cloudy tomorrow.
b) According to the weather report, it is going to be cloudy tomorrow.
c) Be careful! You’ll hurt yourself!
d) Watch out! You’re going to hurt yourself!
**When the speaker is making a prediction (a statement about something he/she thinks will be true or will occur in the future), either will or being going to is possible.
There is no difference in meaning between a) and b), and c) and d).