I largely agree - I think the special thing about the forthcoming cold spell is that it is going to be prolonged. I am sure we will see freezing canals as the winds and clouds drop away and we need to watch for the possibility of snow developing. Apart from the possible long duration of the cold spell, I however see nothing particularly unusual. Lows of -9C are not that rare when we get these conditions but I don't think we will see a repeat of 1981 when we had ice floes on some of the major rivers, despite looking like that might happen a few days ago.
A question - does the GFS always try to turn anything into a south westerly flow eventually? I wonder if it is biased to do ?
R