Flew from ASI to Stanley, at least that was the plan, and just before PNR we got a authenticated coded message to turn around and head back from whence we came. Upon landing at ASI the next day after about 20 hours airborne, we shut down and not a word was said. Eventually we wandered up to Ops and made some enquiries only to find that newly arrived OC Phantom Det had made a unilateral decision that the weather was unfit for the F4 and therefore also unfit for Albert which was of course total bollocks !