JetA181, are you for real? or perhaps just a troll or flight sim expert?
What would you expect the guy to read back? "ummm yes tower it's currently a bit warm here in the cockpit plus I can't see anything outside cos it's cloudy.
IMC is a perfectly adequate description of inflight conditions....unless of course there is some dumbarse Oz rule that mandates otherwise, in which case the said Virgin flightcrew have probably been fined..censured, and CASA will be pressing charges with the full backing of Air circus australia.