Ben_Cambs

Yep, general agreement between UKMO, GFS and ECM up to T+120 now...

GFS 12z T+120: http://modeles.meteociel.fr/modeles/gfs/runs/2013010812/gfs-0-120.png?12 GFS 06z T+126: http://176.31.229.228/modeles/gfs/archives/2013010806/gfs-0-126. Stronger easterly flow on the 12z, helping to drag -10 850's to the region. Liking the potential for snow on Saturday!

A few model comparisons of the three main models between 96-144hrs : T+96: UKMO: http://www.wetterzentrale.de/pics/Rukm961.gif GFS: http://www.wetterzentrale.de/pics/Rtavn961.png ECM: http://www.wetterzentrale.de/pics/Recm961.gif The main three are all broadly similar at this timeframe with regards to the positioning of the Scandinavian High and activity in the Atlantic. T+120: UKMO: http://www.wetterzentrale.de/pics/Rukm1201.gif GFS: http://www.wetterzentrale.de/pics/Rtavn1201.png ECM: http://www.wetterzentrale.de/pics/Recm1201.gif Perhaps more similarity between the main three models at this timeframe compared to last night's model set - they send the energy south at this timeframe whereas a couple of the models did not last night. This a key component in advecting the colder air from the continent, as well as the HP cell over the Scandinavia region. T+144: UKMO: http://www.wetterzentrale.de/pics/Rukm1441.gif GFS: http://www.wetterzentrale.de/pics/Rtavn1441.png ECM: http://www.wetterzentrale.de/pics/Recm1441.gif With the energy from the previous timeframe pushed south of the UK, all three models do bring some form of a ENE'ly/NE'ly component to the weather. ECM and GFS are slightly different to UKMO which builds links the Scandinavian HP to the Azores HP at T+144, however unlike last night's model set which offered totally different solutions at this timeframe, some form of agreement of an easterly component to our weather by the end of the week. After this timeframe, the models diverge significantly, which is to be expected. So from what I gather from tonight's models including the ensembles, is that an incursion of colder air from the continent is increasingly likely at the weekend, with much colder temperatures than of late and even the risk of wintry precipitation and frosts. How long this lasts for is still up in the air. It must be stressed that as demonstrated by today's output again is that nothing is set in stone (between 0z and 12z output) and that the model output is still volatile. It wouldn't be suprising to see more changes to how the weekend is modelled over the next couple of days.

Thankyou! Just got to hope in the end, that we'll be the beneficiary of these changes!

GFS 12z T+144: http://176.31.229.22...2/gfs-0-144.png GFS 18z T+138: http://modeles.meteo...fs-0-138.png?18 Small differences between the two this time around but this equals two different scenarios - 18z advects cold air from the continent to the region due to the positioning of the trough over France however this didn't occur on the 12z. Small differences but huge consequences. Undoubtedly, this will be different in the morning. Edit: First link wasn't working so had to replace both links.

Judging by today's differing and volatile output, I'd put F.I at T+96. Beyond this time, the models begin to diverge significantly. UKMO, GFS and ECM at T+96: UKMO: http://www.wetterzentrale.de/pics/Rukm961.gif GFS: http://www.wetterzentrale.de/pics/Rtavn961.png ECM: http://www.wetterzentrale.de/pics/Recm961.gif A few differences at this timeframe, though nothing too significant. Then compare the models at T+120, where the differences begin to increase between the main three models: UKMO: http://www.wetterzentrale.de/pics/Rukm1201.gif GFS: http://www.wetterzentrale.de/pics/Rtavn1201.png ECM: http://www.wetterzentrale.de/pics/Recm1201.gif For example, UKMO handles the Azores high much differently compared to ECM and GFS. Then go out to T+144 where the UKMO ends: UKMO: http://www.wetterzentrale.de/pics/Rukm1441.gif GFS: http://www.wetterzentrale.de/pics/Rtavn1441.png ECM: http://www.wetterzentrale.de/pics/Recm1441.gif Plenty of differences between the models at this timeframe. Some examples include much increased heights to the south of the UK on UKMO compared to GFS and ECM. Then for example, ECM has the area of HP originally over Scandinavia over the north of the UK, while GFS and UKMO maintain it over or to the west of Norway. Just a couple of examples but I'm sure I could list at least a few more! The point of this post is effectively to say not to get too down-heartened by tonight's output. Even within today's two model sets there have been big changes. The volatile nature of the output in the past few days suggests to me that this volatility will continue for a while yet. Best to keep an open mind about the output in the next few days I feel.

Morning all, foggy here too this morning. Some lovely charts, namely from the ECM for next weekend, we could finally see our first decent wintry spell next weekend. GFS is not as good but would still deliver cold and some snow. Looking forward to the output over the next couple of days!

Morning all, currently 8C and mostly cloudy here at the moment. A few more mild days to come though turning cooler as next week progresses, and we may see frosts again! Models continue to look good for cold again this morning, good times ahead I feel. Have a great day!

Fingers crossed for the next few days of model output!

A member posted this in the MOD thread, so I thought it would be worthwhile posting this in this thread - an 8-14 day anomaly chart from NOAA: http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif Very much liking the look of this chart; the signal of above average pressure over the Greenland area and below average pressure out in the Azores. Cold trend growing pace...

A continuing theme for cold in the model output today, though still a long way off from knowing what will happen. A wide scatter on the GFS ensembles portraying the uncertainty of the situation. The period between the 10th-12th Jan still of main interest however for the appearance of cold weather, though I would of thought it would be at least 3 days until we have a much clearer picture of where we are heading.

Your post in the other thread sums up the situation very nicely! Nothing to change my mind about the next 7 days at least maintaining a dry theme, from today's/tonight's output, with little to note weather-wise over the next week or so. As John Pike's post illustrates, some very interesting GFS ensemble runs appearing. Wouldn't be suprised if a GFS operational run throws up a 'stella' run, such as the ensemble member JP posted, within the next couple of days. A growing signal for cold from the model output for sure.

I haven't done one of these for a while, but here's a model summary based on today's output: The next few days herald in a quieter period of weather, with an area of HP building in from the south. http://www.wetterzen...ics/Rukm721.gif However, plenty of cloud will be trapped in the HP cell as well as plenty of mild air: http://www.wetterzen...ics/Rukm722.gif For the majority of the time conditions will be cloudy, mild but dry with light winds. Temperatures generally between 9-11C during the day and not falling by much at night. These conditions are likely to last into the new week. Further ahead, it does appear that Atlantic driven weather will struggle to return to the scene, and it's likely that the region may not recieve any meaningful rainfall again until the middle of next week at the very earliest. For example, this UKMO chart at T+144 would give wetter conditions to the NW of the UK but our region would remain dry: http://www.wetterzen...cs/Rukm1441.gif Judging from the ensemble means of the GFS, ECM and NAEFS, I believe the drier theme than of late will continue for the next 10 days at least. Though some rain can't be ruled out, drier weather appears more likely: NAEFS: http://176.31.229.22...-0-0-240.png?12 Suggestive of higher than average pressure around and just to the south of the UK, with the main Atlantic trough further west towards Greenland. ECM 0z ens : http://www.wetterzen...cs/Reem2401.gif Mean for >1025mb pressure at T+240, suggesting drier weather. GFS ens 12z London: http://www.wetterzen..._London_ens.png Not many precipitation spikes on that graph. Also to note gradually cooling temperatures in the longer term. So to conclude, remaining mainly dry over the next 10 days with the risk of rain only increasing to the end of the 10 days, temperatures dropping off slightly towards the average by the end of the period too. Lastly, I'd like to apologise for not doing any updates for a while, the run-up to Christmas was very hectic and unfortunately didn't have enough time to post model updates. Hopefully, I'll be able to start doing them a lot more regularly again.

Of course! At least the lighter winds will allow for less frustrating cycle rides for myself too! Can feel like this on a windy day..

A poor afternoon of weather with drizzly rain and feeling cool in the rain. Not much to talk about weather-wise in the next few days, the general theme will be cloudy, mild and dry, though a break from the rain will be most welcomed I'm sure!

Sorry for the late entry, I'll punt for 3.5C please.

Glad we're on the same wave-length GTLTW! . I'd be suprised if the second half of this meterological winter is not snowier and colder than the first half, particularly between mid-Jan and mid-Feb. It's a waiting game I suppose, to see what lies in store for us in the longer term.

Morning all, Terrific start to the new year weather-wise with clear blue sky though breezy, currently 4.8C. Going ahead to the next few days, some rain likely for most tomorrow afternoon then turning drier and less windy thereafter, however it will be mainly cloudy, but mild. A definite cooling trend in the longer term on the GFS ensembles: http://www.wetterzentrale.de/pics/MT8_London_ens.png Perhaps a sign of something brewing in the longer term?

I'd like to wish everyone a very happy new year, and hopefully moving into a snowy 2013! Welcome to the forum and this thread (and also a happy new year!) Please could you place your location onto your profile (click on your profile, 'my settings'), many thanks! As for your question, I'd say the risk of a cold spell increases from around the 10-12th January onwards after a quieter spell of HP dominated weather, hopefully leading us into a snowy second half of winter!

Morning all, hope you had a fantastic Christmas Day and Boxing Day! Not too suprisingly it's raining here, currently 6C. And not too suprisingly, there's more rain on the way in the next few days! Interesting trend from the models however, with a big area of HP now likely to build in just after the New Year: http://www.wetterzentrale.de/pics/Rtavn1681.png Positioning and orientation of the High will be key in determining if the weather is cloudy, mild or cold and sunny. Happy birthday to Floatylight and Chris!

Some showers around tomorrow with temperatures around 7-9C and a similar picture also on Boxing Day. If I don't get the chance to say later, I'd like to wish everyone a very merry Christmas! Christmas Eve was too long to wait for me!

Morning all. 5.4mm of rain fell during the night, currently 6.4C. This morning's models continue to maintain a broadly unsettled theme over the next 7-10 days at least, however some drier days are likely. Cooler than of late over the next few days aswell. Have a lovely Christmas Eve!

Ah yes forgot that! Maybe all the uninspiring weather this year made me forget some of the better moments!

Judging by the GFS and NAE charts, I'd say up to 20mm, mainly falling tomorrow is possible around your area Surrey, with a low risk of a greater total than that. Not helpful at all for the rivers etc around the region at all.

Jan: Pretty mundane, not much action weatherwise. Feb: Very cold and snowy first half countered by a mild second half, though the most interesting month of winter overall by far. March: Very dry but rather uneventful. April: Relentless rainfall and cool temperatures. May: Same as April. June: The same.. July: A slight improvement on the past months though not particularly warm or dry. August: By far the best month of the summer, plenty of warm and sunny weather which included a couple of cracking thunderstorms. September: Nothing too spectacular. October: Mundane. Nov: Not too eventful. Dec: Some decent frosts and one snowfall, though not great now that the wet weather has returned! August was the most interesting month this year...