Fair-weather friend

Elmo rearranged his bouquet nervously, tucked the chocolates under his arm and adjusted his clip-on tie. One big sigh, then ring the doorbell, he thought. Ding dong! To his surprise, Elma’s mother answered. “Good evening, Mrs. Cumulo-Nimbus,” he said.
“Hello, Elmo. I’m sorry. Elma won’t be able to see you tonight. She thinks it will rain. In case you don’t know, it’ll be mostly cloudy today with light rain and a high of 60.”
“Well could you tell her I’ll stop by tomorrow?”
“I don’t think that’s a good idea. It’ll be cloudy Saturday as well, with highs in the upper 50s and a 40 percent chance of rain.” Elmo hung his head, said “Thank you,” and started back off the porch.