snowking

Depends where you take the data from BFTP - a problem I find with solar activity tracking in generalFor example, taking the SESC daily count there has been a real spoke in activity in recent days, with 10.7cm flux up to around 125 and the sunspot count today at 148. Obviously there are different calculation methods going on because the overall averages are far higher than the ISES monthly averaged counts.However despite this, there does appear to have been a spike in recent days.SK

The other notable trend from the CFS in recent days has been the height anomaly that has developed around the Scandinavia/Siberia area: Did somebody say Snow Advance... SK

I know this blog has been referred to a number of times already: http://torontowxcenter.blogspot.co.uk Of particular interest (http://torontowxcenter.blogspot.co.uk/2013/10/late-winter-stratospheric-warming-likely.html): Tends to back up the general thoughts from many on here so far. And if we take a look at the composite years chosen there: The general idea is of a late January/Early February potential SSW, with 85/86 being the odd one out (and a little bit of a curveball generally I feel). If we take a look at two of our other discussed analog years, 08/09 and 78/79: (The data doesn't quite go back to 1978/79, but as you can see by the time we get to February 1979, an SSW has already taken place) So this is where the general idea of a potential SSW during the second half of this winter comes from, and it may well be a case of having to be rather patient until then without a few surprises. SK

Haha - with regards to the 11pm, I will do my best! I'm not expecting anything too spectacular during the first half of winter to be honest. It will be winter, so a few odd shots of cold are of course possible but at this range all we can look for is trends over a period longer than a few days - really we are talking about looking at a period of weeks, and to that extent at present nothing especially promising shows up in the composites for December. November may prove something of a wildcard and as Ed says it will depend on how the vortex develops over the next few weeks. Early signs of this are a little more promising for November, particularly with the Wave 1 activity already showing up in the ECM forecasts, though I always think we stand a better chance in NW Europe with a wave 2 led stratospheric attack, with wave 1 often displacing the vortex in to a less favourable position for the UK.But yes unfortunately at this very early stage I can't offer too much hope of anything significant for December. SK

I fully agree with Ed on the use of 1978 and 1990 as composite years....and both of those are actually relatively decent winters in comparison to the mild Atlantic dominated drivel of that now famously titled modern period - especially 78/79.Also interesting to see 2008 in there. What do the three of those have in common - cold February spells. I do feel at present we will have to be rather patient this winter. But those composite years should not be a cause for concern. If anything I would suggest the opposite is true :)SK

Beat me to it! Nice to see Wave 1 Activity present and ridges popping up throughout the day to day runs, currently the NW Pacific and Alaskan Ridge doing the business here. Brought this paper to mind which is relevant, lifted from the teleconnection paper thread, another feedback to consider and look out for. http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50289/abstract Great illustration coming up of what the NW Pacific/Alaskan ridge (generally leading to the GP-made-famous Aleutian low) does in terms of driving Wave 1 Activity through the stratosphere: Watch out for the Alaskan Ridge/Aleutian Low combination to help drive Wave 1 activity (which in turn often leads to a displacement of the core of the vortex away from the pole), and then some form of Scandinavian/Siberian high to help drive Wave 2 (which often helps to create a split vortex). Last year we were lucky enough to see alternating phases of Wave 1 and Wave 2 activity eventually leading to the decimation of the vortex. SK

With the best of will in the world to Gavin P who does does have some decent meteorological knowledge...that's a forecast I'm sure we could all make? :)SK

There's two ways of looking at thatMuch of the time I would agree with you, but a deeply negative PNA pattern would also imply some meridonality (I'm not convinced that's necessarily an actual word!) in the flow upstream with an East coast ridge - usually I look for a strongly positive or a strongly negative PNA signature, as anything more towards neutral tends to suggest something flatter entering the Western Atlantic. The biggest risk with a -PNA and the right loading conditions I find tends to be a very weak west based negative NAO.But I would agree nevertheless of the likelihood of a slow start to the winter this year.SK

Whilst I agree with the idea of the low from the atlantic is likely to be influencing our weather in around 10 days time or so, I wouldn't be making that call right now based upon NWP, which actually shows a clear split this morning. GFS is most keen on that idea: Where as the ECM isn't too interested just yet: With the low stalling and pushing Northwards though days 8-10 this morning. So NWP actually looks more split at present. GFS det. is backed up rather well by the ensemble mean: But as we saw a few days ago, the GEFS suite is really rather prone to swings, so this is far from clear cut just yet. The current MJO forecast based upon OLR plots has changed somewhat in the last day or so away from the idea of a low amplitude phase 1/2 orbit to something really too weak to read. I would stick to the previous idea this had before which was indeed something such as the GEFS is showing this morning in terms of <1 amplitude composites, but the support for the GFS idea is far from universal. SK

No problem at all sir I was going to come back to this at the end of the week to see how it had panned out based around the forecast OLR from mid-September and it looks to have panned out reasonably well if current NWP verifies as shown. There is quite a lot of work related to the MJO and GWO going on behind the scenes at the moment and both myself and Lorenzo, along with a few others, are running some experiments for October as a whole with the possibility of some new composites being created based upon the outcome of these. Anyway, back to the here and now, pretty universal agreement out to day 10 for high pressure to build and stay there across much of England and Wales from ensemble means: Though as the newly created composites suggest, with OLR forecasts suggesting a low amplitude Phase 1/2 MJO towards the middle of October, we could well end up with a more North/South split, with low pressure close to the North of the UK, and high pressure close to the South - almost a classic +NAO type signal: So a North/South split is not entirely out of the question here as we head towards the middle of this month, but before then the low amplitude phase 7 composite sums things up nicely (ignore the dates): SK

The best way to view the CFS (if thats your cup of tea), as with any long-range model, is averaged over the space of lots of days. It essentially then becomes a super-ensemble. Net-Weather I believe do this in their weekly updates. The latest 500mb Anomalies over the Arctic, averaged over: 3 Days - 7 Days - 30 Days - The overwhelming theme of the last 5 winters of increased height anomalies continues to shine through when viewed like this, and indeed in recent days the CFS has been really rather keen on much higher than usual heights across Greenland for December and February - risk with the location shown for February of a more West-Based Negative NAO signature, but of course at this stage all of that sort of talk is mere speculation. The three winter months combined, averaged over 30 days give this: So once again, the general theme emanating from the CFS is for higher than usual heights to be in place across the Arctic through the winter months once again SK

I find the below link a useful image to keep an eye on in terms of simplifying things: http://www.cpc.ncep.noaa.gov/products/CDB/Tropics/figt3.gif The bottom image shows the zonal wind anomalies at 30 and 50hPa - the key area to keep an eye on for the QBO. As you can see as far as August there are hints at 30hPa of it just starting to top out but we will need to wait for confirmation of this with the September update. But that's the simplest way of keep an eye on things. SK EDIT: Another useful link to keep an eye on multiple levels: http://www.geo.fu-berlin.de/met/ag/strat/produkte/qbo/qbo.dat?1378278888

The recent count from the SESC is shown in the graph below: (Green is Flux, Blue is Sunspot Count) Not quite dead given 10.7cm solar flux hovering around the 100 mark, but certainly not what you would call active by any means. I know I had mentioned previously over in the stratosphere thread concerns about the pre-2006 Labitzke et al. findings about the most likely conditions for an SSW/MMW occurring under either a combination of Solar Max & West QBO or Solar Min & East QBO, with the solar maximum defined as having a 10.7cm flux value of 150 or over. However, a more up to date version shows that in recent years we have seen exceptions to this: And so this is no longer so much of a concern. It also depends how the definition of a Solar Maximum event is taken, with the possibility of the link being to the maximum magnetic disruption on the sun as opposed to a set value of flux (the two would usually correspond with one another under a more active solar cycle, and all the solar cycles studied in the original Labitzke et al. paper were under stronger solar cycles). Either way, just all little signs that point towards something more favourable for those cold winter fans among us. ^^ When this updates early next month, we should see a fairly decent decrease in the averaged sunspot count, and nothing like what we experienced prior to winter 2011/12 SK

This was posted over in the seasonal thread, although there is the caveat that it is just preliminary thoughts as he goes on to say: SK

I'm not entirely sure where you have been looking at the forecasts then, because most of the preliminary forecasts I've seen on here and elsewhere online are not pointing to anything necessarily spectacular, but they are far from pointing towards mild, with a general consensus on February being likely be the coldest of the three months.In fact I would go as far as to say that I don't think I have seen such a strong consensus ever on these forums on a cold February, numerous forecasts based upon numerous techniques have so far all pointed towards this direction - with the notable exception of RJSI certainly remember seeing many more forecasts pointing to a milder winter last year than I have done this year so far.I realise this can all be rather subjective in analysis, but I wholeheartedly disagree that the current consensus points towards a mild winter.Of course though consensus offers no absolutely certainty on anything when it comes to the weather!SK

Yep that is my main interest here. Don't get me wrong, I am not a climatologist, and I have nothing but respect for those in that particular field who have one of the trickiest jobs in the world for so many reasons. But I do not feel that anything other than the potential for warming has really been addressed at any stage during the last 15 years. All of this is, ultimately, theoretical (on either side of the argument) but only one possible scenario seems to be considered and discussed. I am not a member of the IPCC so I cannot of course say this with absolute certainty, but this is the message that seems to emanate from the organisation to an outside world's point of view SK

But once again surely this can be argued as cherry picking data as you are taking the findings from one set of reports focusing on conditions the last ice age...where as using something such as the paleoclimatological shows that fluctuations have occurred naturally through time, and that temperature rise actually occurred before C02 rise. Anyway, I am going off on a whole new tangent there. And yes, you can indeed find many such period over the last 100 years, but that still doesn't change the fact that picking a period of 30 years of warming could also be argued as insignificant using the same ideology. We simply do not have a long enough time span of potential warming yet to say with certainty that things will carry on getting warmer. If we take a quote back from your original reply: Well quite clearly the fact that such conditions appear to be having an affect on things - regardless of whether or not the pause can be argued since 1998 (I do agree with you in terms of cherry picking there) or a slightly shorter period, the point is that the temperature readings we have been using during the last 20-30 years or so have shown that something has caused a pause (how temporary that is is open to debate), and I would argue that such an impact has already proven significant. Now it could be argued that this slight pause is what would be considered a 'quite small' effect, but if that were the case then surely even this small effect should have been factored in to previous reports and projections? That way organisations wouldn't have had to lower their projections for temperature rise, they may have just been correct in the first place. Anyway, we could go on and on back and forth with this. I still remain slightly on the fence with the whole idea of global warming and I just feel that those pro the idea of AGW are too often insistent that those anti AGW are 'cherry picking', when the same is true of them. Quite frankly 30 years of warming doesn't give us enough evidence, and regardless of what the current projections might show if the projections were really completely accurate then they should have taken in to account the current pause (no matter how long it is argued it is). It just shows for me that really, despite reports such as this, we actually have very little dependable idea of where the longer term temperature trend is headed, and whether any increase will prove permanent owing to C02. SK

Surely though then I could also argue that that taking this: Is also an example of cherry picking when compared to something such as this: A very extreme example I realise, but we cannot argue that on the one hand one small 'cherry picked' period of time that suggests warming has paused doesn't count, yet another slightly less small period of time that suggests warming is taking place does count. I realise that I am slightly contradictory in the thoughts I am putting across here but that is intentional - you cannot suggest one period of time isn't significant but another period is. There is no doubt the warming period was significant, but that being the case, the recent period without warming also becomes significant. Fair enough. It seems a little convenient to me though that for years we have been told to follow datasets such as UAH and HADCRUT to see the warming....and then when it takes a pause all of a sudden more emphasis is being places on deeper ocean temperatures. No doubt that can have all sorts of consequences, it's just that at present there seems to be as much cherry picking going on from those that wholly believe in AGW as there is from those who are adamantly against the theory. SK

Regardless of how long a period something has to run for before the IPCC will consider it 'significant' (after all, surely roughly 30 years of warming, followed by 15 years of no warming should mean that the 15 years should be seen as least half as significant as the ~30 years of warming - maybe I'm being too simple here), what baffled me during the press conference was upon answering questions with regards to how the 15 years of no warming might affect climate model projections they essentially dismissed it as insignificant... Now, that sort of attitude is (just about) fine IF the pause in warming stops tomorrow and we then see a resumption in the same rate of temperature change as we saw before. But lets just hypothesise here for a second that the pause in global warming has been caused by, say, solar variability, and that the projections (including NASA's own projections) for cycle 25 do indeed see it as one of the quietest for hundreds of years, then we are not necessarily talking about the warming resuming tomorrow....we are talking about the pause (or perhaps even slight decline - bearing in mind this is theoretical) lasting at least another 10-15 years. If this occurs, surely it means that, once again, their climate models will prove incorrect and will have overestimated the temperature rise over time. There is nothing to suggest that the warming will not resume once again eventually....equally I would argue given that they could not see such a pause in warming occurring, there is no absolute certainty that the warming will resume again. But in terms of their basic modelling of the situation, even if they truly believe this is a temporary pause in warming and that it will resume again, by the time it does their projections will most likely once again be way out because they refuse to input shorter-term climatological change. The very fact that most of the answers to questions about the 15 year pause were answered along the lines of 'it's an insignificant period, you need to look at the longer term trend' was in itself hugely contradictory, given that we are currently basing our projections on a warming period that is only ~50 years old overall. SK

This is the point I was trying to get across Thanks for the papers but believe me I have already read through them and then some! I didn't suggest it does. What I was trying to get across was that looking at any one single factor in isolation is unlikely to yield gold in terms of long range forecasting - part of the reason that I have just spent the last 2 days compiling a database of ENSO, QBO, GWO and MJO phases and amplitudes for every day between 1974 and 2013. There are very likely linkages there, but as you go on to say it's likely to be a combination of factors, just as I suggested too in the original post SK

The trouble is, as has been discussed previously, whilst there may be some linkage with overall sea ice extent, it is not an exact relationship. Here is an example of two Novembers which preceded colder winters. 1978: 2012: A huge different in sea ice extent - over 2 million square kilometres! However, both produced cold winters. The paper which has been flying around recently suggesting the possibility of ice extent across the Barents sea having a role - well certainly a possibility but then again when you look at the difference in the two years above, the theory begins to fall a little flatter (though admittedly the idea for this particular hypothesis was more October based). I think what we have to look at is whether ice extent is a cause or a result...and on present evidence I would argue the latter. But even as a result it could still prove part of the overall mechanism. I would suggest though that it is part of a very long chain reaction. SK

The azores doesn't always have to be an enemy of cold-lovers: And of course a few days later we saw some almost perfect retrogression: And finally if anybody wants to look for specific SLP setups prior to a cold winter (despite their absolute zero correlation to subsequent winter patterns generally speaking) well it is still looking likely that as we head in to October 2013 high pressure may dominate once again.... That was the story for much of October 1962. And if we skip forward once again to early December 1962: See folks...even a near Bartlett scenario can morph into something pretty spectacular. Surface patterns are by their very nature chaotic, and unfortunately bear very little resemblance to the following seasons (otherwise long range weather forecasting would be a lot easier than it is!) However, it may just be that there are other signs that can lead us towards long range conclusions a little higher up in the atmosphere - I have been banging on since the spring about the signals for a high-pressure dominated month in October. We shall see! SK

Timings are a little liquid but I fully agree with that as an outlook. You might remember from my post about the MJO phase 6 a few days back about how the general trend in the transition from September to October is for a slight Westwards shift in the atlantic trough, well increasingly over the last few days the ECM 0z has started to move towards this idea: It may be just a little premature in how quickly this is taking place, but the overall idea at the moment looks to be a Westward shift in the Atlantic trough over the next 10-15 days, which means that much of the UK should remain on the warmer side of the trough, and then after that there has been a very noticeable tendency over the last few GEFS runs for a pressure rise towards days 14-15: Still a lot of scatter as one would expect at that range, but the general idea for SLP has been a rising trend towards the very end of the run. Where will any potential HP become placed? Well my own October analogues had it slap bang over the UK, though there is a tendency at the moment for the placement to be just to the North-East of the UK. SK

MJO Phase 6 signature (increasingly unsettled) beginning to be reflected in the days 5-10 NWP output. Expect some further swings for a couple of days yet as I imagine NWP is probably still having a little difficulty in resolving the energy fusing in to the jet stream from Humberto. Hopefully in to Monday/Tuesday a more consistent signal should begin to appear...and unfortunately that consistent signal looks as though it will be an unsettled one. The next shot at something more settled currently around days 15-25, with little coherent MJO or GWO signal as both tropical convection and global angular momentum fall to average levels...this is not a guarantee of settled conditions, merely the best chance of such conditions. Beyond that there is a growing trend from OLR plots to introduce something around phases 1/2/3 through the second half of October - all three of which suggest something rather unsettled. So as a rough timetable based upon current projections: 27th Sept - 5th October - Unsettled 6th-16th October - Something more settled? 17th October Onwards - Unsettled once again Timings are of course approximate SK

I certainly agree with regards to Landscheidt and I think should these projections prove indeed to be correct this will likely become known as the Landscheidt minimum.I think what we do have to do to a certain extent is temper our expectations a little. Whilst I don't necessarily buy in to the idea of AGW per se, for whatever reason be it CO2, Solar, CFC's (I saw a very good paper a while back based around the idea of reduced CFC's leading to warming) or even because God left the thermostat up a little bit too high, we are entering (or have already entered) this period with temperatures higher than, as far as we know, they were before either the Maunder or Dalton minimums.Now of course we could well see a really rapid decline over the next 30 or so years which delves us back in to something like the state of affairs experienced back then, but at the moment to this extent I think that whilst spells like December 2010 will come around again more frequently than some climatologists might have us believe, it might not get quite as extreme as the Dalton minimum.I have, however, been wrong before...at least once anyway :)Either way though I should imagine quite a few questions will be asked in the coming years about economic policy etc when it comes to weather. For all the money we continue to spend on supposedly cutting our CO2 emissions to save the world, I am sure we could have invested in, for example, better flood defences and adequate snow clearing equipment to keep us all moving.There's always a plus side to things though....I get a lot more MPG out of a car than I would have done 10 years agoSK