I am a little bemused by this as well. I'm not sure how to post yesterday's charts but looking at today's 120 UKMO chart, from memory, it is not too different from yesterday's UKMO 144?
Ok, so the evolution going forward might not what most might be after in terms of deep cold and snow, but this is a constantly evolving situation, and I can see absolutely nothing in the models that suggests that mild southwesterlies are about to become entrenched over the UK.
Indeed, if anything, ECM / GFS et al have been slowly moving towards the UKMO evolution if anything, and I would not be surprised if there are one or two 'white' surprises that pop up in the models at short notice on the next few runs. Time will tell...