That's what I was thinking also. Layer with long underwear, then a not-too-heavy fleece shirt and pants, then rainwear like the Precip or REI ultralight jacket and pants. Then for extreme rain/storm conditions, a USGI poncho.

In my opinion, that should cover any weather I'll ever encounter in Alabama or most of America as long as I carry a pair of shorts and a t-shirt in my bag too.