I was in a used book store and I saw some of the old blue-cover Hardy Boys books. And this reminded me of a book I read back in my childhood (so around the late sixties or early seventies).
It was not the Hardy Boys. But it was basically a Hardy Boys imitation. There were two teenage brothers who solved mysteries and had adventures. Unlike the blue-themed Hardy Boys books, this book had a yellow cover. I have the impression it was a series but I only read one book. The plot involved a trip to Florida during which a hurricane struck.