It's undoubtedly a disappointing outlook for cold weather fans this morning - a clear case of so near but so far!
ECM shows something which a few days ago wasn't shown by any model at all... a mildish spell:
http://oi43.tinypic.com/2j27312.jpg GEFS is slightly colder, with near-normal conditions on its ensembles:
http://www.meteociel.com/cartes_obs/gens_display.php?x=306&y=141&run=0&ville=Londres&runpara=0&type=3&ext=1 So, what happened? 2 or 3 days ago cold weather was looking more likely than not and it was sustained over several runs too. The handling of the upper blocking high (and the jet over the Atlantic) has subtly changed and as a result the heights are more likely to sink away SE'wards, meaning that low pressure stalls close to the UK and we get unsettled conditions. The only consolation of this pattern is at least it's not stormy in the way we saw over and around Christmas.
It goes to show that the most likely option doesn't always happen, but sod's law it should be when cold is showing as likely - it does of course happen the other way sometimes (as recently as last year) but it's the let-downs that stick in the mind more than sudden upgrades. FWIW MOGREPS was the least keen model on things turning colder (reaching at most 50%, whereas ECM-15 had it at 70% for a couple of runs and over 50% for a couple more).
It's not entirely game over for a colder outlook but at the moment the odds are lower than they've been for the past week, only 10% or so.
In the meantime it looks like more rain (but nowhere near as much as we've had recently) and average or even slightly mild daytime highs.