If there is anything sophisticated available, I would expect to find it on a big Boeing or Airbus, as it must cost money to heat the leading edges for anti-ice purposes. Knowing the RH might allow less anti-icing.
Incidentally, even at +15C OAT you could still get airframe icing, eg if you had a sub-zero airframe following a descent, or if you were flying below clouds dropping super-cooled rain on you.