Can you help me

It's a film about a boy and a girl and their grandad can turn into a bird/owl and he has
A dream about it and there's a evil tornado guy and they run away from him in a truck and then it turns out he can turn into a bird everyone can and he finds this place where there's grass and a waterfall.. Thats all I remember can you help me

And it was a cartoonish like film not a real life one and it was placed in the desert Caribbean where the cracks are in the ground..