> #2
...
> "There is an index.html and a hts-cache folder ...
> A site may have been mirrored here, that could mean
> that you want to update it
> Be sure parameters are ok
> 
> Press <Y><Enter> to confirm, <N><Enter> to abort"
> 
> Is there a parameter I can add so it knows not ask
> me this- I always want to do it, since we plan on
> scheduling a daily job for this process.


(From the help) Tack this onto your command line:

--update
update a mirror, without confirmation (-iC2)