Well, I guess it's possible, but afaik it's much harder than making static strings translatable. As you said yourself, they are stored in the track files because these define what weather states are available. Simply making that string editable is a no no because it would have to be saved into the track files too, therefore modifying and invalidating them for online play.
So, a possibility would maybe be to store the standard strings in the track files, and if loading a translation there are extra text files for each track which contain the names of the weather states.
PS: It may be a language thing, but atleast I consider this "I don't care if it's in track file. Make it translatable" pretty rude.