bluearmy

Extended eps show the jet running out of some oomph as it crosses the Atlantic compared with previous runs - this co incides with the vortex pulling back west towards Alaska and lowering the gradient of uppers Newfoundland/be Canada - a more gentle spread becoming ever more convinced that we see a scandi ridge setting up in the 10/15 day period - surface conditions over here will depend on whether this is sceuro or we manage to get some low heights to our south

swings and roundabouts MWB. overall, the 12z's thus far are a swing away from the coldies ……… ecm still to go as the Siberian high builds sw in week 2, the atlantic is going to have a job pushing through - hence i expect week 2 output to trend towards some split flow and we know how good gfs is at deciphering that conundrum! im also hoping/expecting that the Canadian vortex will begin to run out of energy and retreat nw away from being the driver of the atlantic lows and their strength as the cold uppers are pushed se with each cycle

Anyone hoping for much guidance from the eps clusters ...... forget it 6 of them out to day 10 and then three beyond whilst the extended show a strong Atlantic upper trough across all three, they also show two clusters keen on ScEuro or Scandinavian height rises .... we can’t see how deep any central euro trough/low heights are in these scenarios so uncertain in any case Plenty (well pretty much everything post day 7) still to be resolved but given the background signals thus far, a renewed Scandinavian ridge wouldn’t be any surprise apart from those who feel we are in an unending phase of zonality .....

The forecast for zonal flow high up in deep fi is fraught with operational inconsistencies- especially CFSv2 predictions however - better to see it predicted to fall than to rise ....... (it is currently going through a drop which will be followed by a recovery towards normal values .... and then .....)

Mulzys chart shows a Euro trough when you click on it but a ridge if you don’t ..... the trough is correct

Extended eps are more ridgy n of scandi which helps explain the more southerly aspect of the jet - clusters will be worth looking at to see how the mean has been arrived at and if we are approaching a point where two clear directions of travel appear rather than the many we currently have .......still that rise in heights over Europe at day 14/15. The gems not interested in any absence of euro heights in contrast to the gefs and eps

Surprising how the earlier ops imprinted to at least 30hpa re upper ridges .....

low res on the gfs op may be unreliable but going to be fun to see what tha5 developing monster Siberian high does late on .....

As an through the eps clusters reveals plenty of interest in the 9/13 day period re developments ...... the day began poorly but has swung back ...... still 50/50 ..............

18z slower again upstream......less defined upper ridge but higher heights spread around in general via some wedges ........Asian upper ridging looking more interesting in general ..... time for the clusters .......will that small one which the 12z control resembled somewhat have grown ......

Dutch ens are the eps control Tom ......

The extended eps mean looks very mobile with a strong Atlantic low anomaly and flat pattern - no sign of high slp over Europe though so cool zonal more likely than mild - the clusters could still be numerous - the control is very cold and quite snowy in the extended with a big sceuro trough and griceland high

The day 10 spread says that Europe in general is going to be much more troughy than the mean shows

yes but it should be knocking on the door of day 8 by this time

ecm 12z slow out again ………..

the pendulum swings back a little with the 12z gfs and gefs ……...up to ecm fi to set the tone for the remainder of the evening...………….. hopefully some balance restored after the 00z/06z suites …….

Wonder what would have happened in low res gfs timeframe if it wasn’t low res and didn’t blow up that Atlantic low ....... hopefully the gfsp will be in a similar place at day 10 and we can see what a lack of resolution drop off does for the run not taking much from the op runs at that range other than they are inconsistent re amplification and zonality

One run one model 5th dec (you said 7/8th) fwiw - thats as likely to verity as anything else I’ve seen but why does it mean we will still be zonal a week later ???

December doesn’t require below -8c to bring deep cold (or snowfall) on a continental feed @feb1991blizzard - I am being realistic - 12/18 days is a long time - even Exeter are actually talking about possibilities of snow showers back end week 2 - low probability but then they would say that ........ give it until the back end of the week until we see the polar profile settle down somewhat - then my percentages will be re assessed.

The gets continue to show plenty of upstream energy to interfere with the repeated attempts to amplify - add in the polar high and it’s unpredictable nature and you have a recipe for chaotic nwp i still maintain we are at 50/50 re proper cold by mid December - no way will the low res gefs be getting things right as week two progresses - the mean anomaly’s will give a loose indication but nothing more than that ..... the eps running at a resolution similar to gfs op are clearly struggling

Standard net weather over reaction to a couple of less promising suites ..... still six eps clusters post day 10 says it all ......

Frustrating isn’t it! Until the modelling get the polar field right, then the rest of the NH is also going to be wrong as a consequence (due to the splitting of the vortex and subsequent behaviour of those two parts). Add in some meandering discarded chunks and fi phasing will be modelled where it won’t occur etc etc ...... a couple more days of patience required .....hopefully not too many more before we ge some weeek 2 consistency ...... still 50/50 imo

6 eps clusters right out to day 15 .......maybe the mean is more useful than some might think .........

Encouraging to see ec mean taking the mean ridge west out of Europe by day 10 ...... that allows for it to ridge a little to our west and for the sceuro trough to back further west

note that the gfsp and gfs are not so far apart at day 10 …. the gfsp gets mote amplitude on the ridge and doesn't blow up the atlantic low approaching T300 - result is undercutting rather than blowing away the block - i would like to see ec op picking up the ridging north as per gfs - ec is progressive with the Atlantic and fails to split the jet as much