Taking a quick look at some of the HI Res charts there is still some quite big differences between them (as to be expected) below are a quick sample of said charts. Hirlam goes initially for a south east event edging into the midlands were as at the same time the arpege takes the main band sightly more North and West giving the midlands and east anglia more in the way of rain. Later on in the day hirlam gives most rain to the midlands ,northern england, towards the north east whilst the arpege takes it more towards yorkshire. Then again we could get nothing clear as mud.