bradymk

All forecasts on sites like the weather channel and accuweather are based on the latest GFS output usually so it will just reflect what the latest run shows and that is why the forecasts change so much every time they update.

and the beijing climate centre which is my personal favourite but this hasnt been updated for november yet

Jamstec seasonal model updated and its still going for a below average winter for UK again.

Yes true, but just showing what trend the model has been showing now for several consecutive days, hopefully it will continue to show this, but you never know with the CFS.

I know a lot of people express that the CFS is rubbish but the monthly anomalies it has been chucking out the last few days for December are great. Above are the anomalies from the last 4 day runs, all going for high heights to our NW, i might be completely reading these charts wrong so please correct me if I am Regards, Matthew

http://origin.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk3.wk4_20121113.z500.gif Latest Weekly charts are good for start of December still with high pressure over S Greenland, W of Iceland and in Scandinavia and lower heights to our south. I think it is going to require a few days of waiting as I still think that the period where a change may occur is still in deep FI of the models or even not in the range of the main models yet. The models are showing a cool down at the end of the month looking likely but as a few others have said, it might take a few goes before we get our first real cold of the winter. Hoping for some increase in wave activity and some warming in the stratosphere before I get too optimistic. It is all very exciting nevertheless.

Offerman i take your point however i feel that the cold charts showing in fi are part of a trend rather than one of these "one off fantasy charts". Other models and certain teleconnections i feel back this up. CFS weekly charts agree with GP and show that we should be looking west and not necissarily east. http://origin.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk3.wk4_20121111.z500.gif

Another good run from GFS but the cold coming from the N rather than E this time. Posts about these charts not coming into the reliable frame i feel are invalid because the time period where the cold is potentially going to arrive is not until late FI anyway so there aren't going to be any cold charts showing in reliable timeframe yet. Trends are key and there have been a number of consecutive runs now showing colder weather in FI with northern blocking and a displaced vortex.

GFS 18z control run is not bad either so far to my untrained eye, great run from the GFS, lets hope for a bit more agreement and consistency over the next few days.

http://www.meteociel.fr/modeles/cfse_cartes.php The latest CFS daily is certainly very blocked for December however as we all know this model changes run to run.

http://www.bbc.co.uk/weather/feeds/20297630 a new video by BBC regarding end of month, clearly some uncertainty in the forecast.

But a week or so either side of that chart and the PV is definitely not weaker than what it is now. I would disagree that we are worse off this year, we have had a lot of northern blocking throughout the autumn and there are also signs of it in the last few GFS/GEFS runs returning end of the month.

The CFS week 3 & 4 showing some good HLB blocking to our north

Matt on twitter saying that the ECM 32 day model is sticking with its previous output with "N blocking late Nov/early Dec with cold temps & a likely risk of wintry weather"

Latest EC32 Day model continues to signal N blocking late Nov/early Dec with cold temps & a likely risk of wintry weather given the pattern. Matt on Twitter

Totally agree, the metoffice are normally quite reluctant to say anything until short range but they must have some confidence that this pattern is likely to have published a video this earlier like you both said.

These latter charts of the GFS 12z run aren't too bad at all, correct me if I am wrong. Both OP and control runs above show a return to a more amplified pattern with a weaker vortex again at the end of their runs. I know its deep FI but hopefully following runs will continue to show this. A while off yet I know and I feel the next week will show whether we are more likely to see a milder pattern persist or a change to colder conditions again come end of month.

Hope you don't mind me saying but I disagree with this. Yes the model output isn't great at the moment if your a coldie but I can't see the high pressure building to the south covering all of the UK and most of Europe in this run. I would say that this run is far better with the latter charts alot better than previous runs with a more amplified pattern. I think we have to wait at least a week or so before we can call the end of the month with any confidence but yes next two weeks look unsettled and milder but I don't think anyone can really write off end of the month/beginning of december yet.

Still do not think that the model output is too bad, especially compared to last year with temporary cooler pm outbreaks interspersed with milder periods as the azores high becomes more influential. However, the metoffice 16-30 update is very encouraging with well below temps by the end of the period once again highlighting the end of the month/start of december to be a period of watch.

http://origin.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/ Here we go, z500 for height anomalies

Thank you Phil. Yes very true about the charts changing daily like GFS however if you look at the runs from the last 5/6 days, all show heights to our North and East on the week 4 chart but will continue to monitor them to see if anything changes. What are the links to those ECMWF anomalies charts? Thanks.

The latest CFS forecasts are still showing a mainly blocked atlantic for weeks 1 and 2 and then weeks 3 & 4 are interesting as heights start to build over Greenland again with extensive northern blocking by week 4. This week 4 chart also showing signs of maybe a high to our East linking to the greenland high bringing a cold end to the month/start of december. Wasn't GP saying that something notable could develop end of Nov/beginning of Dec. One of my first posts in the model thread so not sure whether im talking rubbish or not so tell me if I am. Thanks to everyone on here by the way, my basic knowledge has been expanded greatly by some wonderful posts.

The latest CFS forecasts are still showing a mainly blocked atlantic for weeks 1 and 2 and then weeks 3 & 4 are interesting as heights start to build over Greenland again with extensive northern blocking by week 4. This week 4 chart also showing signs of maybe a high to our East linking to the greenland high bringing a cold end to the month/start of december. Wasn't GP saying that something notable could develop end of Nov/beginning of Dec. One of my first posts in the model thread so not sure whether im talking rubbish or not so tell me if I am. Thanks to everyone on here by the way, my basic knowledge has been expanded greatly by some wonderful posts.

Where I live in Pembrokeshire, direct northerlies are the best. 17th December 2010 i think it was when nearly everywhere in Wales had heavy snow, it was a NNW/NW wind so we missed nearly all of the snow, whereas Carmarthen eastwards had plenty. Even though it was very cold here December 2010, we had hardly any snow considering what other places had received but what did fall stayed through Christmas. A direct northerly is perfect for here with irish sea convection or a Pembrokeshire Dangler as it is known.

Updated charts from CFS showing good northern blocking Dec-Feb http://www.cpc.ncep.noaa.gov/products/CFSv2/imagesInd3/glbz700SeaInd3.gif