We are coming up to the period where there was a lot of discussion re: GFS vs ECM outcomes which were very different. All the models, particularly GFS, predicted this current cold outbreak very well. In fact the most unusual thing was how much more snow there was in the East and South/South East, not forecast by anyone. It yet again proved the futility in trying to look at snow predictions more than a couple of days out whoever is saying it. So soon we will see if we get the (then) forecast GFS NW/W dominated HP across the UK next week or the ECM (then) forecast Easterly. I suspect it will be something with an easterly element, but not quite how ECM envisaged it then.
Really? My recollection is that ECM picked up the northerly and sustained it whilst GFS had the high flattening to the west as early as tomorrow. As for the easterly/south-easterly flow next week, GFS didn't show that at all for several days after ECM picked it up.
Your point about precipitation is well made. I posted in the other thread that this morning's snow wasn't correctly predicted even by the 06z, i.e. it was wrong at 3-4 hours out. Actually the trough was far more active than even the Met Office were expecting as recently as last night, with a larger area of precipitation extending further west than expected.
Meanwhile, here's the 00z ECM ensemble for London:
Still the same trend to less cold in the 10-15 day period but less marked that in yesterday's 12z. I commented last night that it seemed it was around uncertainties over the possible repositioning of the block or its demise. It's only a guess but I wonder if more perturbations are showing the block moving towards the north Atlantic - as hinted at in several operational runs recently (and this morning's GFS).
Probably the kiss of death but worth remembering that, if you look at historical charts, in most sustained cold periods there are switches in pattern that must have looked at the time like an imminent breakdown.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E