SAINT- The only tiresome thing IMO is your persistent attacks on me (both last winter and this).
Originally Posted by: Quantum
You've brought this up before, but I think in all the time I've been on TWO, I've mentioned you three times. Hardly 'persistent'.
As I said, of course you're entitled to your interpretation of the MO. But, as I also said, your constant crowing about it being mild is tiresome & verging on trolling IMO (see, I'm also entitled to have an opinion...)
Originally Posted by: Saint Snow
I do think Jacko does have a point about milder weather. This is my take on it. The only model really showing any significantly cold runs is the ECMWF; all the other models seem to indicate that although things could turn colder around the 20th; certainly colder than of late, there is no real support for a significant cold spell.
The ECMWF has a different take on things, and should not be dismissed as on average it has the highest verification stats for all models (although not significantly higher, and inter model means do even better than the ECM alone).
Anyway the ECMOP has a period where blocking tries to be established at 168h
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/ECH1-192.GIF?06-12
we can see a section of the PV moving into SE Europe and some modest height rises over Scandanavia (I always look for the 552 500mb isopleth as a good guide for decent height rises and in this case its borderline with 552dm being reached by 192h. However these modest height rises are dwarfed compared to blocking in southern europe and the azors. This combined with a still moderately active atlantic quickly flattens the jet and absorbs the high pressure from scandanavia into a southerly position.
There are still a few runs that manage to resist this and fully amplify the ridge over scandi but these are in the minority, it would not be a good bet to plump for that situ.
By 240h we have a developed southern block
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/ECH1-240.GIF?06-12
Meanwhile in the north the PV shrinks and strenghens. The surface heigh over the arctic retreats further away so its influence on us weakens.
Also note the ECMOP has another cold shot in progress over canada at this point, suggesting the dwindling of the atlntic may be tempory, this would prevent any WAA getting heights risen over greenland for instance.
What about the EPS?
People have been posting surface temp esembles forecasts, I don't have verification figures for surface temps but I am skeptical how high they are. 500mb heights however, I know do very well on all models and have a higher verification than SLP for instance. Also surface temps as we all know are subject to inversions, meseoclimates, dirunal variation e.c.t. that is too specific to easily get at such a long range. Better imo to look at overall longwave patterns.
Speaking of which the EPS mean shows the same blocking attempt at 168h over scandi
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/EDH1-168.GIF?06-12
But also the same collapse
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/EDH1-240.GIF?06-12
Here the PV over canada is particularly prominent and agrees with the OP that another cold shot is in progress. There is still some small amount of height rise over scandi but its influence does not extend over the UK. Middle europe should do well out of it though. The anomoly charts do show this blocking quite well
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/EDH101-240.GIF?06-12
The UK is very much under the influence of LP despite what looks like the right sort of 'dipole', it reminds me of the winter of 2011/2012 where all the cold air stayed out east:
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/EDH100-240.GIF?06-12
And although the uncertainty for middle europe is high, for our part of the world it seems we are firmly in the mild airmass.
http://www.meteociel.fr/modeles/ecmwf/runs/2014010600/EEH0-240.GIF?06-12
This corresponds to the -6C 850hpa isotherm skirting the SE of england in the absolute best case scenrio.
Originally Posted by: JACKO4EVER