Jeff,
Guess I am really confused now. "Predicted rain fade?" I have no idea how you want them to predict the weather. (That's a joke I know that's not what you meant.) If you are saying that the DirecTV or Dish signal is not as strong in various parts of the Country that kind of info is pretty well documented. It's up to the antenna owner to see what their signal strength numbers are and if they are dropping a call to DirecTV or Dish would be in order. The auto pointing dishes take care of that automatically every time they deploy but a home installation or a manual portable setup can change with time.
Assuming I am completely off-base, please let me know what you are referring to.