、。
I wish it would rain tomorrow.
Literal
Tomorrow, rain [subject-が] fall [if-ば] good [yet-のに].
The pattern ~ばいいのに expresses counterfactual wishing — 'if only X.' The のに here carries regret or wistful contrast, suggesting the speaker knows it probably won't rain but wishes it would — a more pessimistic flavor than a simple 'I hope it rains.'