snowking

I know this is obviously just posted for informational purposes SS But just to give an example of the record of this particular output, this is taken from a washington post article about the success of Cohen's SAI-based temperature projection for last winter (can be found here - well worth a read: http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/04/25/aers-judah-cohen-produces-amazingly-accurate-winter-outlook/) Here was the IRI forecast for last winter: And that was issued in December! This is why I place very little faith in any sort of NWP-derived output at such range. SK

Hi VS. Yes its going to be an interesting test of the analogue years over the next few weeks. As mentioned in the model thread up until now the general trend with the absence of tropical forcing has been for ridging to take charge after a slight lag time (usually around 3-10 days). The most recent update of my Autumn forecast (from August) was suggestive of an unsettled start, but for high pressure then to build sometime around the 5-10th October. At present, given the MJO signal, this still very much stands, but it all now depends on what sort of 'base state' we encounter with the lack of tropical activity, with both MJO and GWO signals set to tail off. So for now yes this still stands, but I would suggest this is the meteorological equivalent of squeaky bum time! SK

Hi Rob, Think you might have got a few wires crossed here. Yes the MJO orbits are weak, but you're generally looking at anything > 1SD on the RMM scale for it to have an influence (as ever with meteorology theres a bit of give and take in that figure, but thats the gist of it) In terms of the composites, the phase 6 for September suggests an upper ridge just to the West of the UK, and for October moves that upper ridge even further Westwards, with the trough to the NE responding in kind - again these are never gospel, but it gives the general idea of where MJO phase 6 leaves us around the turn of the month, especially with regards to the discussion from earlier this morning about troughing to the East and West of our incoming high Hope that helps SK

Well an interesting experiment coming up over the next few weeks, but more on that shortly. First of all lets take a look at the current MJO forecasts from NWP: We have a gathering consensus for a phase 5-6 progression over the next 5-10 days time, and so after our drier interlude, I would expect a rapidly deteriorating scenario towards something far less settled as we enter the final days of September. In fact, if we take a look at the composites for phase 6 as we progress from September to October, it depicts the likely scenario: I know BA was discussing this morning whether we would see more influence from the Western or Eastern trough, well I am with him on this one, I think most likely the Eastern one. The experiment comes thereafter. OLR plots out to days 15-20 generally suggest a rapidly deteriorating MJO signal as tropical convection tails off at around 130E, and so we are unlikely to reach much beyond phase 6. So we are then left in whatever pattern turns out to be the 'base' state without tropical forcing for much of the first half of October. Thus far that base pattern has been a tendency for the Azores HP to ridge (Tamara last night discussed the idea of Settled - Unsettled - Settled, and this is the reason I would agree with such an assessment), and I have seen very little so far to suggest that any sort of seasonal wavelength change has come in to play to alter this....for now at least. It may well be that in the coming 10 days we start to see some huge changes hemispherically, but that is simply conjecture for now. So the theory, at least, is that whatever we see beyond the unsettled spell following our upcoming settled spell could prove to be the default pattern for Autumn when there is little tropical forcing....and looking at OLR plots further out towards days 25-40, whilst of course at such range partially reconstructed data is always going to be open to a certain level of doubt, the signal generally is for a continued rather subdued MJO outlook, with a weak signal perhaps for a short phase 1/2 period through the second half of October, and so for those looking for some more high pressure, lets just hope that period in 15 days time or so turns out to be settled! SK

I am beginning to keep my own records of 10.7cm Flux and the SESC solar count Very limited data obviously at present, but it has been really rather quiet in the last 10 days - though a sudden increase yesterday with 5 new regions observed SK EDIT: Apologies for some reason the key is missing - blue is the SESC count, green in flux.

As ever Tamara a fantastic summary and one I wholly concur with. It is a very unclear picture at present heading in to the medium term but at the moment the best punt is based around the idea that as we lose the tropical forcing once again (both MJO and GWO look likely to flatline) we could well end up heading back towards the same scenario we have had for several months now without any tropical forcing, and that is of a tendency for the Azores HP to ridge - so the assertion of a Settled-Unsettled-Settled outlook out to 15 days is one I would very much back. SK

Despite its utter uselessness, if we are to take a face value conclusion from that particular run of the CFS - February would likely be a very snowy month with that sort of profile. Nothing spectacular temperature wise, but plenty of precipitation being thrown in to a shallow continental feed would usually = snowy fireworks, especially in the North there, with the average 850mb profiles sub zero. Of course being the CFS, by 12z this will either have flipped to The Day After Tomorrow levels of cold, or an early February BBQ SK

Yep activity remaining really rather low. It will be many weeks yet before we are able to determine the trend, but with activity so low at the moment (the lowest since the start of the current cycle) it is beginning to look as though cycle 24 may have already double-peaked...which means we could be in for a longer slumber (similar to the end of cycle 23) than expected. Here's the latest graph tracking the activity: SK

As has already been commented upon this evening we really do have a very complex situation coming up with Humberto causing some headaches, not only on its track and intensity, but also with the fusion of energy as it interacts with the Jet. Therefore, it really is wise to give things another 48-72 hours before making any judgement. What I would say is that for some time now (since March, in fact) my own composites have pointed towards October being a rather HP dominated month - and so as we edge closer to October my expectation is for high pressure to start taking charge of the outlook. At present we are still, other than the likelihood of a temporary ridge next weekend, chasing charts out at days 9 and 10 for anything extensively settled, and indeed that has been the case now for some days, but I feel that within the next week or so we should begin to reel this signal back in once again. We have spoken previously about seasonal wavelength changes, but as we start to lose the tropical forcing once again it will be interesting to see whether we maintain the same background signal - I.E ridging - as we have seen in recent months. SK

Thought I would drop some of my own preliminary thoughts in here for now (bearing in mind these are preliminary). First of all lets get straight to the meat of things...SSW? Well...I know Ed's early thoughts on this are leaning towards a potential February MMW, and he is without a doubt the expert in this field. My own thoughts differ slightly from this, and this difference will likely be explained by a difference in composite years chosen. For a very preliminary idea of things from my current chosen composite years, here's a breakdown of the 30mb temperature anomaly across the three vital months: As we see there the biggest chance according to my composite years of an SSW/MMW would appear to be in January - which actually fits in quite nicely with my thoughts in general for the winter at this early stage, with the two main thrusts of cold coming in mid January (initial SSW response?) and then through much of February. Interestingly though, despite my thoughts that the Westerly QBO is likely to lead to a strong vortex through December until we see some form of warming, if we roll back that 30mb anomaly to November: If we see that sort of pattern reflected towards the surface in November, with the main thrust of the early season vortex displaced towards the US sector, it could well lead to the holy grail for early season wave activity - with a potential Siberian/Scandi high to drive wave 2 activity, and the potential Aleutian low to drive wave 1 activity. Are there any early caveats to the idea of some sort of stratospheric warming this winter? Well there is one that I am a little concerned about, based around the 2006 Labitzke et al. paper on the relationship between the 11-year solar cycle and the QBO. It is largely from this paper that the idea of solar maximum conditions and a Westerly QBO leading to a higher likelihood of SSW events originates. However as we can see from this graph, taken from the paper: The criteria set out for solar maximum conditions is a solar flux greater than 150 units. Given the unusually quiet solar cycle 24 so far, current flux levels are around 92 units, having peaked at around 132 units last month. In the data analysed here (1942-2006, some of which was reconstructed), there has not been an MMW event with a solar flux value of any less than 125 units under Westerly QBO conditions. However, and this is a big however....65 or so years of data is, in the grand scheme of things, a very small sample size - something for which the study has come in to criticism for already, although unfortunately given the relatively small range of accurately recorded data for both QBO and Solar Flux (only stretching back in to the 1950's), it was not really an avoidable criticism. Now from that we can ascertain a potential flaw... Thus far, we do not have an example of a Westerly QBO under solar maximum conditions during a much quieter 11 year cycle, with the last quieter cycle having been back in the early 1900's. Therefore, it could be surmised that the conditions that require a 'solar maximum' definition might not actually be reliant upon solar flux, but perhaps instead on the sun's magnetic field lines reaching maximum distortion, owing to the magnetic differences between the poles and the equator on the sun - in other words, it doesn't matter what level of solar flux is observed, its actually defined by the magnetic changes on the surface of the sun that occur every 11 years. Therefore, this year could prove to be really rather useful to test such a hypothesis. So then in summary, my expectation is for an MMW in January based upon my preliminary composite years (taken from the Autumn forecast) - these years are still very much open to change, and a good test of these composite years will be October, not only for the SAI, but also because my composite years point towards a rather settled month and so if we do indeed see extensive periods of high pressure this would suggest to me that the composite years are well on track. SK

Indeed I've just caught a glimpse of the Exactaweather forecast and it reads...well pretty much the same as every single other forecast Madden has ever produced for winter - basically snowmageddon right the way through December, January and February. Still if he keeps saying it for enough years then one year he has to be correct... SK

Yep remember this one well. I was still at university at the time and I had to drive back in my good old P reg ford fiesta from Cheltenham to Essex via Oxford (Headington funnily enough) to drop somebody off who couldn't get home because the buses had stopped running. Approximately 2ft of snow on the A40 over the cotswolds (that was once I had got on to it - they had actually shut the entrance to the A40 in Cheltenham because it was uphill and 4x4's we're struggling to get up, so I had to re-route and join it about a mile further up navigating some completely un-gritted residential back streets). Fortunately the A40 had been ploughed that morning, but there were just solid lumps of compacted snow all the way along the road, with the grit having not touched it as the temperature was still around -10c. Got in to Headington and the level depth was easily around 15 inches. Really pretty surreal. All told that journey took me about 10 hours. One of my favourite events, just purely for drama, was the thundersnow of 2004: You can see the clearly defined frontal system within that archive chart. I remember tracking the radar all day at school with friends asking me (by this stage I was known universally as the weather man) whether it was going to be a snow day the next day. Looking at the radar returns I boldly proclaimed yes, almost certainly. It got to 4pm and the front still hadn't arrived. I was waiting for the bus home when....it started to drizzle. I thought uh-oh, don't tell me its a warm sector. 10 minutes in to the bus journey I looked out the window and suddenly you couldn't see out, the snow was coming down so heavily it actually looked like thick fog. My dad was sat on a bridge over the M11 at the time and I remember him saying he could see it coming south down the M11 and it really looked like sea fog slowly moving inland. We must have had about an inch fall within the first 12 minutes, and all told I would say we ended up with around 6 inches, along with some really loud claps of thunder through the evening. Not the biggest total we have seen here (indeed almost exactly a year before this we had another big snow event in 2003 which caused chaos on the M11 as a band of snow formed in the North Sea completely unexpectedly. By the time the gritters got out everyone was panic-leaving work as the Met Office issued warnings, and the gritters got stuck in the traffic as the snow set in - we had about 9 inches from that in the end), but for pure drama certainly a memorable one! SK

Absolutely - hence the warning of the imperfect relationship. It's all part of the puzzle

Yep - part of the basis of the theory as to why global warming appears to have 'slowed down' in the last 10 years or so. Its not a perfect relationship and there are, as with any area of meteorology and climatology, a lot of variables to take in to account. But indeed both the Maunder and Dalton minimums co-incided with well below average temperatures globally - as indeed did the spotless period through 09/10 with our very cold winters: You'll also notice, on a more localised scale, that the milder winter in our current run of cold winters (11/12) co-incided with a peak in solar activity SK

Indeed I think JB is going a little OTT, as per usual. I am keeping a track on the solar activity (I will have a permanent link with a daily update soon enough) but it has certainly plummeted in the last week, though there has been a slight recovery today with a new region visible too: It is still really rather low though, and we will have to just monitor and see whether this is a permanent change, with the double-peak already being reached, or whether this just proves to be a blip. If it is something a little more permanent, then yet again all estimates of the solar maximum have been well off the mark, and heading towards the last 5 years of this decade we could have an unprecedented period of spotless days. You also then have to wonder what cycle 25 has in store for us... (hint: probably more of the same...or should that be less of the same) SK

Something to keep an eye on - solar activity has absolutely plummeted in the last few days. Of course it will likely rebound once again in the next week or so, but as of yesterday only 13 spots were observed. I have started keeping a track of this and here is the data from the last 35 days or so:

^^ Fully agree with this prognosis February 2014 has, since about last March, been showing up via composites, and continues to show the potential to be a really rather below average month SK

Not so sure about the final prognosis, to me FI looks rather unsettled: Brief ridge of high pressure: Before becoming more unsettled once again: As ever though it's only one FI run for now....I still suspect the second half of September will likely be rather more unsettled. SK

It showed a slight uptick in activity through August...but then in the last 4 days or so activity has really plummeted, with the count now down at 24 observed spots as of yesterday. It is likely to rise again from those values but it does suggest to me we are perhaps in an overall downward trend once again, having reached the projected double maxima SK

And if it's written in the express it must be true. I would be able to take this sort of 'forecast' seriously if any due care or attention had been taken to actually provide methodology, rather than repeatedly mentioning 'cycles' and supposedly unusually above average Atlantic SST's....something which, once again, simply isn't true: Yes the Atlantic is slightly above average overall, but not unusually so and not to the sort of extent where it would actively encourage the sort of tropical storm activity he refers to. There's a difference between keen interest (the likes of which we see from many on here) and simply creating a needlessly over-the-top publicity-seeking prediction with little or no explanation of how the prediction has been derived and with little evidence to back it up other than referring to a hollywood blockbuster and how we have already supposedly been seeing the events that took place within it coming to fruition this year. To to those intents and purposes I strongly disagree with your last sentence. We should absolutely be encouraging young people interested in the field of meteorology to come to places like this, learn about meteorology and use scientifically sound principles, techniques and evidence-based fact gathering to help derive and justify forecasts, just as the majority on here manage to achieve. I have absolutely no time for somebody actively seeking to publicise themselves through the medium of weather forecasting in the manor in which he has displayed here. We have all been here and seen this too many times with the likes of James Madden. SK

Equally though SS, the summers of (picking two at random) 1984 and 1990 were well above the summer CET average too....and below average CET winters followed those too SK

There are so very many things which have already been picked out that would rubbish this madden-esque forecast, and present it rightly as merely a publicity type exercise for whatever reason. But if we want to talk purely in facts, I would like to know where this warmest and driest summer in 247 years figure has come from. First of all we only have reconstructions that go back that far, and crucially....its just not true. http://www.metoffice.gov.uk/news/releases/archive/2013/early-summer-stats I am growing increasingly tired and frustrated at morons using extreme weather forecasts for nothing other than publicity, taking a medium I (and many of us on here) have a huge passion for and destroying its credibility. Rant over! SK EDIT: Just to confirm that this guy is indeed a genuine crackpot, other fascinating examples of his work on youtube includes: "aliens coming to earth 2014 to take people fact"Wonderful. Just wonderful.

Of course the best example potentially of cherry-picking charts, it could be argued, is this: We could, instead, look at paleo-climatological reconstruction of temperature trends through history, rather than an almost insignificant period of 150 years or so (insignificant in the grand scheme of climatology, of course). SK

And to further add to Tamara's point, anyone who thinks the days 5-15 day pattern is in any way certain just needs to take a look at this: 4 models....4 completely different MJO outcomes at days 10-15. I'm not sure in the shorter term the prognosis of the trough to the East of the UK is too far away from the mark, given the continued MJO phase 1 signal for at least the next 5-7 days, but beyond that it becomes unclear. I would suggest that given any lack of tropical forcing so far this year has tended to co-incide with the Azores high ridging towards the UK then this must surely be the form horse, and this is indeed the favoured approach from the GEFS this morning: ...but this is September, and we are looking at very different seasonal wavelengths beginning to come in to play now. My personal thoughts are a predominantly unsettled second half to September, but before we get there plenty of uncertainty still to come! SK

Funny you should mention 1990 Lorenzo. I have been looking in recent weeks at the QBO and ENSO indexes with regard to compiling the initial detail for my winter forecast....1990 for me provides the strongest composite going in to this winter, along with 1978....back in spring the strongest was a combination of 1962/1978. This still leads me towards the conclusion that February 2014 could well be really rather severe. We should hopefully get an update today from ISES on the sunspot count progression too. SK