What is so special about the weather on the day that Nick goes to lunch at Daisy’s? What is the symbolism in this?

In my opinion, the rain speaks to the impossibility of Gatsby's dream. He made his plans, insured that their afternoon tea would be perfect in every way, and yet.... things don't go quite as planned. We might see the rain as the rain as a kind of foreshadowing..... possibly all of Gatsby's well laid plans with come to naught.