PB22

GFS now tending to bring the Atlantic more into play on the 06Z by T+126: http://www.wzkarten.de/pics/Rtavn1261.html http://www.wzkarten.de/pics/Rtavn1262.html

Excellent post. There's a lot of other weather types to be experienced in winter and it looks like it may soon be time for one of those other types to come along. The 06Z GFS is now coming out and the weekend is still looking a lot milder than recent weeks, with many areas seeing temperatures back up to normal, and even above normal in some places: http://www.wzkarten.de/pics/Rtavn601.html http://www.wzkarten.de/pics/Rtavn602.html http://www.wzkarten.de/pics/Rtavn6017.html Although these milder conditions also means a band of wet weather will cross the country on Saturday: http://www.wzkarten.de/pics/Rtavn604.html P.S. I thought you might like the outlook Mushy!

A very poor set of 00Z runs if you are looking for a return to cold and potential snow next week. The GFS 00Z brings in a brief east/south-easterly next week: http://www.wzkarten.de/pics/Rtavn1201.html http://www.wzkarten.de/pics/Rtavn1441.html http://www.wzkarten.de/pics/Rtavn1681.html But its a pretty tame affair, and a quick look at the ensembles shows it to be one of the coldest options whilst the ensemble set as a whole has drifted away from a potential colder scenario: http://www.wzkarten.de/pics/MT8_London_ens.png http://www.wzkarten.de/pics/MT8_Manchester_ens.png http://www.wzkarten.de/pics/MT8_Aberdeen_ens.png UKMO 00Z is even worse: http://www.wzkarten.de/pics/Rukm961.html http://www.wzkarten.de/pics/Rukm1201.html http://www.wzkarten.de/pics/Rukm1441.html ECM does bring a continental influence in, but again its a tame affair and wouldn't bring much more than rather cold and bright weather: http://www.wzkarten.de/pics/Recm1201.html http://www.wzkarten.de/pics/Recm1441.html http://www.wzkarten.de/pics/Recm1681.html GEM says no as well: http://www.wzkarten.de/pics/Rgem1201.html http://www.wzkarten.de/pics/Rgem1441.html http://www.wzkarten.de/pics/Rgem1681.html As does NOGAPS: http://91.121.94.83/modeles/nogaps/run/nogaps-0-120.png?14-06 http://91.121.94.83/modeles/nogaps/run/nogaps-0-144.png?14-06 http://91.121.94.83/modeles/nogaps/run/nogaps-0-168.png?14-06 Finally, GME offers no hope either: http://91.121.94.83/modeles/gme/run/gme-0-108.png http://91.121.94.83/modeles/gme/run/gme-0-132.png We may have a monster block to the east, but we also have an active Atlantic to our west now, and the Atlantic is increasingly looking like it will come out on top. I still maintain that unless heights to our northwest drop, the high to the east will struggle to exert its influence across us.

18Z GFS sticks to its guns with the easterly theme for next week: http://www.wzkarten.de/pics/Rtavn1261.html http://www.wzkarten.de/pics/Rtavn1262.html

The extended ECM ensembles have trended colder for Holland tonight: http://www.weerplaza...im.asp?r=midden I wonder what the London ones will show later?

ECM ensembles for Holland show the operational to be one of the warmest runs, along with the control: http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

Hi John, Are you saying that comparing today's 12z run to yesterday's 12z run is more reliable than comparing today's 12Z run to the earlier 06Z run although that 06Z run would have more up to date data available rather than yesterday's 12z run? Wouldn't the more up to date data outweigh the advantages of comparing one run to the previous run or is it because different data types are fed in for the different runs?

Personally I think its all to play for overall. The ECM ensembles will tell us more later, but it is just one run and at the end of the day, no-one knows for sure what the outcome will be. We will just have to see what future runs bring.

Well that's me told! Sorry! OK, to compare to last night's ECM, then tonight's has definitely backed away from the easterly. Last night's ECM had us under an easterly by T+168, tonight's T+144 hasn't.

Perhaps, but compared to the 00Z run, the evolution on this 12z run is seriously delayed if it does end up in a easterly later. ECM basically brings back the Atlantic influence this weekend, and keeps us under the Atlantic influence right out to T+168 and is a poor run for coldies. To compare, UKMO and GFS have us in a easterly by T+144. Hi CV, I would tend to agree with your sentiments...after all, we don't often see a 1060mb Siberian High on the charts! Looks like ECM is going to have another go with the high at T+192: Nope, ECM not interested tonight: T+216: Will be interesting to see the ensembles later.

ECM 12Z isn't off to the best of starts, as it makes more of the Atlantic trough coming through this weekend. Will be interesting to see where it heads beyond T+120. T+96: T+120: ECM T+144: Shows that the outcome next week is far from certain. Wonder why its gone quiet in here? ECM says NO to the easterly:

The GFS Control run gives us the shortest easterly ever and once again on the ensembles there is good support for a quick return to southwesterlies in FI. This trend is almost as consistent as the trend for a renewed colder slot next week. All subject to change though.

The extended forecasts do change regularly, but to be honest it would be more of a surprise if they didn't because we all know that medium to long range forecasting is very difficult and subject to big changes. (FWIW I still maintain the 6-15 day forecasts are a day behind the latest developments and today's release merely reinforces my opinion) In terms of short to mid range forecasts though, the Met Office rule. Here's the 12Z GFS mean charts from the ensembles for T+138: http://91.121.94.83/modeles/gens/run/gens-21-1-138.png?12 http://91.121.94.83/modeles/gens/run/gens-21-0-138.png?12

I agree 100% OON. The Met Office are the professionals at this game, and I would bet that their accuracy rates are a lot higher than anyone else's. Sadly, most people here and elsewhere only tend to focus on cold and snow, thus failing to take into account all the millions of forecasts that, shock horror, don't include cold and snow! Met Office forecasts aren't scrutinised in spring, summer and autumn to the extent that they are in winter and thus a lot of their work is by and large un-noticed. Anyway, back to models... The 12Z GFS is a good run for the cold lovers as we are soon back into a colder easterly flow next week after a milder weekend: http://www.wzkarten....s/Rtavn661.html http://www.wzkarten....s/Rtavn662.html By midweek there are some reasonable cold uppers across the country: http://www.wzkarten..../Rtavn1621.html http://www.wzkarten..../Rtavn1622.html UKMO 12Z isn't too dis-similar to the GFS at T+120, although it still has us under a SW'ly: http://www.meteociel...20-21.GIF?13-17 By T+144 its very much game on: http://www.meteociel...44-21.GIF?13-17 Once we get into GFS FI, we soon lose the easterly again, and this is another trend that the GFS ensembles have been hinting at so far. http://www.wzkarten.de/pics/Rtavn2401.html

Try an Ctrl+F5 refresh? I have the 12:00 12/01/2010 set on my screen! http://www.meteogroup.co.uk/meteo/eps/ensemble-tt6-london.gif

The ECM 12z ensembles for London are just out: http://www.meteogroup.co.uk/uk/home/weather/services/ensemble_forecast.html Not particularly inspiring to be honest, with the ECM one of the colder options. They look nice for Berlin though! http://www.meteogroup.co.uk/uk/home/weather/services/ensemble_forecast.html?eps=berlin

ECM FI shows the problem that the high to the east has to deal with, an active Atlantic and jet stream, with low heights towards Greenland and Iceland. Plus there's no real deep cold on offer: http://www.wzkarten.de/pics/Recm1921.html http://www.wzkarten.de/pics/Recm2161.html

Back to the models, and a look at the GFS ensembles shows the operational was a mild outlier towards the end of the high resolution run (up to T+180), whilst the control run was the coldest option on the table for T+180! The ensemble graphs show the operational was a mild outlier early in FI, with most going for a return to cold conditions by the 20th towards the south: http://www.wzkarten...._London_ens.png http://www.wzkarten.de/pics/MT8_Manchester_ens.png Not so keen further north, which suggests an easterly incursion for the south on most of the ensemble members: http://www.wzkarten....berdeen_ens.png

Thanks for your thoughts John, an excellent read as always. Would definitely agree that the trend is edging further and further away from a potential colder end to January. Perhaps we have just had winter! (That's a joke before I get lynched!)

UKMO 12Z slightly different to the GFS for the same time, but not much joy for cold lovers with the Atlantic looking more dominant and the high to the east retreating: All a long way off though. GFS FI offers little joy in the early stages, but will the ensembles offer some later?

No deep cold anywhere near us by T+156: http://www.wzkarten.de/pics/Rtavn1561.html http://www.wzkarten.de/pics/Rtavn1562.html http://www.wzkarten.de/pics/Rtavn15617.html Settled in the south and a touch of frost by night, but nothing compared to recently.

Sunday a little cooler again, but generally most places are near to normal: http://www.wzkarten.de/pics/Rtavn1261.html http://www.wzkarten.de/pics/Rtavn1262.html http://www.wzkarten.de/pics/Rtavn12617.html I expect the Met Office extended outlook will catch up tomorrow as it seems somewhat at odds with the output. UKMO 12Z very similar to GFS 12Z at T+96: And not too different at T+120: Those low heights over Greenland will certainly not help future prospects for cold weather returning. 10C or above is mild in January regardless of location IMO. 6 or 7C is around normal for the south, and 4 or 5C in the north.

I really wouldn't hold my breath for anything exciting tomorrow. Some snow may fall inland, but no great quantities, and rain or sleet is likely in the east of the area. The front will be dying, and losing intensity which won't help matters.

Saturday is mild in the west, and back to near normal values in the north and east: http://www.wzkarten.de/pics/Rtavn1021.html http://www.wzkarten.de/pics/Rtavn1022.html http://www.wzkarten.de/pics/Rtavn10217.html

Wow, this will feel very different across Ireland and south-western Britain on Friday if the 12Z GFS is to be believed: http://www.wzkarten....s/Rtavn781.html http://www.wzkarten....s/Rtavn782.html http://www.wzkarten..../Rtavn7817.html