A better GFS 18z which ties in with Helen Willets forecast, I don't know how up to date data she was using so I would reserve judgement on that forecast for time being, also though the met office map graphic shows a slight NE ward correction again, also - don't be concerned that the medium range prognosis has been compromised for a quick snow to rain event - it wouldnt, you need the low to sink but you need it to dig south East rather than end up just to the south, you can see on the 18z that a tiny correction has now meant the Easterly lasting far longer than on the 12z, if the low just barrelled through from West to East only clipping Northern UK as it would in a mobile set up then it would be the end but there is no chance of this happening, ideally we would want the low to dive SE but then Stall over France but elongate towards the Low countries and the Icelandic High to link up with the Russian high with the really severe uppers coming around the back of the high with the surface isobars tracing all the way to Eastern Russia / Siberia, that isn't going to happen but the 18z is still far better than the 12z.