Uncle_Barty

Exactly.. bit of a roller-coaster thing going on ion here last day or two! The reality*, looking at the trends (rather from the run-to-run/good run /disappointing run ) of the models over the last 3 days or so, is that we are looking at a less mild, more unsettled spell of weather in the reliable/semi reliable time frame. As is often the case with a definite pattern shift, there is no point in looking beyond 5-6 days until the pattern change has happened and the new upper pattern settles in a bit. Anything beyond 5-6 days will flip-flop to a certain extent, leading to the roller-coaster atmosphere in this thread. *yes i know it's not reality till it happens, but you know what I am getting at......

Is it me or is the ECM on NW still 00z Friday's??

Are you talking about solar activity/solar flux? If so, it's as high as it has been in nearly 10 years!

Well explained and that is the conclusion I have been coming to over the past 2 weeks or so. Average to mild, perhaps if the pattern flattens out more we may get some short-lived shots of PM air. Why? Just wondering what your rationale is behind that, because I can't see any exciting prospects for coldies as things stand right now.

Signs of change starting 6-7 days away, though not that solid in the ensembles and the models diverge 6-7 days out anyway. I think we will have a much better idea of where we are going after the weekend, but it looks to be a change to more unsettled and temps around normal in the main, and zonal as pressure is progged to remain high to the south. Still not a great deal there for coldies I'm afraid.

Groundhog day. Strong agreement across the models up to T144 The overall H500 pattern remains the same. GFS tries to, and then does eventually bring in the Atlantic proper in deep bonkers-land but that's it. Yes an intense high appears to form over Greenland but as it is not backed up with strong heights or a change in the upper air pattern, I don't see it becoming much of a player if it forms at all. I've not had to scrape ice off the car yet this autumn/winter period for my 0645 departure for work, and I think there is now a very good chance i will not be doing so this month.

No change on GFS this morning. Huge low/deep upper trough over UK deep in FI, though not much support for that on the ensembles.

I much prefer mild in winter so that I can watch the mighty AFC Bournemouth without freezing my bits off, but I also I agree that the thumbs up adds nothing and will only wind up other users. Anyone know what time the De Bilt ensembles update?

The operational brings in a northerly blast but not until well after 300 hours, and out of the ensembles maybe a couple support it. The other colder runs are as a result of a NW'ly, but there are more members than that showing HP over/near the UK or the continent. Yes, from those charts there is the possibility of cold weather but it could just as equaIly be mild. I fully expect that northerly to be gone from the 18z operational. ECM shows a continuation of the status quo (or slight variations of) through to the end of its run.

bobbydog... absolutely normal, which is why some of us only look for trends and consistency between runs and models when looking beyond a few days. GFS almost always flip-flops between scenarios at the 15 day range or so, as the model output isn't much better than white noise by that range. As an example of what I mean... If you go to http://www.netweathe...ewer;type=panel; and select 384h together with H850 Temps, you can see how almost every possible outcome can be seen among the 20 ensemble members.

It would certainly be a start... even though it's 15 days away so pretty much equivilant to guesswork. If that pattern starts to show itself consistently from run to run, and across the models and 8-10 days away then I would take the view that a pattern change is more than a possibility. It would then be down to where the upper trough/ridge pattern settles. As we have seen over the past few weeks, if it settles in the wrong position for coldies, then it's back to mild. The particular setup shown above would favour quiet, probably rather chilly conditions, colder in the east, but very probably dry everywhere.

Seconded. OK it's a bit boring from a weather interest point of view, but I'd rather my wife didnt have to contend with ice and snow driving to and from work! Or me for that matter as I have an 80 mile round trip to do. Plus I hate sports fixtures being screwed by the weather. Keeps the fuel bills down as well. Yep.. it can stay like this till April so far as I am concerned!!

Thanks John, that was the exact quote I tried (and failed!) to find.

Agreed - I have seen HP progged over Greenland on the models on a few occasions lately but never supported by strong 500mb heights. And it's a scenario often seen during milder winters that some coldies latch onto in hope!

Have a look at http://forum.netweat...ated-with-snow/ Compare the "Bartlett" scenario with the much more meridional "persistent southerly winds" one. It is the latter we have had lately, not the former. A Bartlett pattern is much flatter. I understand a Bartlett to be an omni-present 'belt' of HP across the Atlantic, centred Iberia/ North Africa and extending eastwards as in the examples I posted above.

I am guessing mid-December before a pattern change driven by seasonal wavelength changes? What we have had of late is not a Bartlett set-up. Not with a weak upper trough towards Iberia and strong ridging into Scandinavia and towards GIN sea. This is a classic Bartlett set-up:-

Another day, another similar picture. ECM brings back the Euro block by the end of its run. Looks like a drop in temps to normal for a time before it possibly turns milder again, albeit near la-la land. Some of the GFS members on nthe 06Z flirts with an upper ridge towards Greenland, bu by day 10 the jet wakes up and blows hard along the 50 degree line right back across the Atlantic, hinting at a more disturbed spell of weather, but thnat is a long way out. Either way, it looks average to mild, leaving coldies rather clutching at straws and hopecasting for the time being at least. (and as Chiono hints above, 24 hour topplers being the best hope) We are still a long way away from 88/89-style deep PV over Greenland/Bartlett high scenario however..

OldMetMan is speaking from experience, in that limpet Euro blocks that have stuck around for weeks don't generally retrogress. Looking at the GEFS ensembles this morning, no members have the pressure dropping below 1010hpa here until at least the 18th, and taking a reasonably central location in Europe (I can see why a certain former member chose it!) Berne remains above 1020 for all members until almost the same point, a good indicator that the Euro high is going nowhere very quicky. Around a quarter of the members showing heights building over Greenland via a ridge from the south at T+168 however, so that idea is not entirely without support.

It could just as easily change into zonality. I remember a situation in early winter a few years ago not dissimilar to this one with everyone calling for a "pattern change" or "reset" with the Euro high being killed off. We got that - and what followed was several weeks of raging zonality.

Another day, another set of model output showing no change to the current pattern. Well.. maybe some changes but not till very deep in la-la land. Any charts to back that up? or is that a hopecast? Genuine question.

Not sure I really agree with that assessment - the T850s for ECM 240 show a fairly 'zonal' kind of pattern with the cold air well north.. the exception being some less cold air over Greenland. The high pressure over Greenland is not strongly 'supported' with heights either.. I cannot see much sign of colder than average weather from the current model output... as before, the only crumb of comfort for cold weather fans is that the upper air pattern is not flat zonal at the moment, so shifting wavelengths could bring a change from this average to mild rut we are in. That is a reasonable assessment. No model has 'trumped' any other untill it has actually verified.....

Indeed! I know he is away for a couple of weeks now, but when he returns, Gibby's twice daily summaries of the 00h and 12h model output are well worth a read as he tells things as they are without any "cold bias", or otherwise, for that matter! It's Eff Eye (FI ) F1 is 24 powerful cars with big tyres going round a circuit at speeds of up to 200mph. Even faster than the jet stream! Back to this morning's output. Still 'as you were' - mild for the foreseeable. If there is one crumb of comfort for cold lovers, it's that the pattern remains meridional rather than flat zonal, and that a decent shift in the wavelength pattern could markedly cool things down for us, but not much sign of that in the models right now.

Indeed - there is nothing approaching a consistent sign that a pattern change is likely in the near future. To be honest, IMO talk of a major change in the 2nd half of this month to cold is nothing more than hopecasting as there is nothing in the teleconnections I've looked at to suggest it. Not saying it's not going to happen, of course, (it would be hopecasting on my part to say that December will be mild as it seems locked in), but until there is a consistent sign of a change in the upper air patterns across the models and from run to run, then it's as you were I'm afraid.

It's "Eff Eye" (FI) F1 goes round and round on tarmac at 200mph. I see absolutely nothing in the model output that suggests anything other than average to mild, sometimes very mild, and more unsettled the further N and W you go. Even in deep FI the HP shown over Greenland is not "supported" by strong heights, therefore no signs of northern blocking. So.. a continuation of the overall very benign weather this autumn. Not too exciting for weather watchers, but at least it makes being out and about more pleasant for the time of year and keeps the heating bills down

Sign of the times when folks are commenting on the possibility of frost in 12 days time!! Unfortunately for coldies, there seems to be no sign whatsoever of much of a shift in the overall upper air pattern, and - as in the summer just gone - until we get that, it's going to be 'as you were' in Gibby's daily summaries to a large extent. Personally, I hope this pattern sticks around till March.. keeps the heating bills down and awkward decisions about driving 40 miles to work each day to a minimum! One sign though of a slight upward trend in stratospheric temps - while I am not an expert in these, I believe it might be a sign of a change 3 weeks or so down the line if this is sustained...