MattH

No fancy graphics and no significant changes in this update, and @s4lancia sums up the situation well a few posts back... While, as will always be the case, an interest in each model run it is about keeping focus on the trends and overall developments as the days progress. The overall evolution remains unchanged and as highlighted a few days ago, the AAM profile is/has changing and clearly there are reasons for that but, finally, after numerous weeks of the Atlantic trough that will degrade and amplification to the pattern will arrive. Clearly there has been amplification in recent weeks, but that's a different period of weather to what is coming up. The key things to remember right now are; 1) We are within the RI (Rapid Intensification) period for the strat vortex and this can often quickly connect to the trop vortex, there's no clear signs for that 2) Model data both seasonal and sub-seasonal and consistantly indicated early winter-time blocking patterns, that is now falling into 'short-term' NWP time frames 3) The "standard" UK pattern at this time of year is for a +ve NAO pattern and an Atlantic dominated regime with wind storms, that clearly isn't the outlook 4) Models and evolutions are often more tricky to gauge when amplification occurs, especially at this time of year, so caution over individual model runs We could, in theory, look beyond the next 2 weeks or so and there remains some clear evidence for the MJO to return through mid-to-late December. There has always been evidence too for the MJO to often be a frequent visitor to phases 5-6-7 this winter, with the main VP200 anoms firmly over the W Pacific/Maritimes and, at times, getting into the central PAcific too, especially as the La Nina weakens. A quick example of that is below from the EC46 Control overnight and the CFS. This kind of MJO evolution through mid-December would, without question, spike interest in bringing further potential amplification of the pattern and also perhaps have some stratospheric implications as well before the end of the year. All that aside and we are rapidly saying goodbye to autumn and saying hello to winter in a regime that wouldn't really be expected across NW Europe. It remains pleasing to see that many long range forecasts (mine included!) have constantly signaled early winter-time blocking and is especially of significance this year to have both teleconnections and seasonal models generally signing from the same hymn sheet. Often there is a disconnect and that provides further uncertainties. As usual there are many wild cards; global warming influences that are, without question, unknown, the impact of the massive volcano earlier in the year and the huge amount of gases and moisture it sent up into the stratosphere, so we never know the full story, but coming back to the here and now, follow the trends, keep tabs on the broader amplifications and see where we go. Yes, we may not get a 'screaming' NE'ly of epic proporations, we may end up with high pressure that brings dry, settled cold, seasonal and crisp early winter weather and, for me, that'll do for now. Cheers, Matt.

We seem to be finally seeing something of a turning point and while NWP may well flip and flop around the overall trend, to me, now will be one that is more anticyclonic in nature than cyclonic. Don't forget NWP often struggle with these kinds of evolutions and 'turning points' and the most recent AAM analysis highlight a pattern that is reversing with more E'ly AAM anoms at higher lats as the momentum transports continue to increase as well. The earlier mentioned graphic from NOAA highlights the way the atmosphere is going as well through much of the trop and isn't one that supports raging zonality and all that kind of 'unpleasantness' that can develop this time of year. Been long overdue, but I would imagine it'll be all about more anticyclonic solutions and developments now than compared with cyclonic ones like we've had moving forwards. Cheers, Matt.

Hi, yeah, sorry about that. The CDAS is from NOAA over in the US and stands for Climate Data Assimilation System, while the GPH is Geopotential Height, but the plot is showing anomalies within the atmosphere (scale on the left is hPa/mb, 1000 essentially being the surface, 10 being the stratosphere), but your explanation is generally right, yes. As I used the plots as an example, where there is more red colours and +ve anomalies within the atmosphere, through the vertical, then this is essentially highlighting more blocking patterns (high pressure) between 65N and 90N latitude, the opposite for the blue colours. The AO (Arctic Oscillation) index essentially just highlights whether high pressure or low pressure is more dominant over the arctic region, a +ve AO often means our weather is cyclonic and from the west, a -ve AO usually means the opposite, higher pressure and more wavy jet stream and amplification to the pattern. Cheers, Matt.

Just a side note but one of the best updated charts I've seen this year is the CDAS GPH Anom plot from NOAA. This was always a more 'rough around the edges' plot, but the update has provided clarity and really does help to visualise where we are, atmospherically, and where we may well be progressing, especially at this important time of year. I've just used two examples to highlight how it highlights very well the blocked, amplification pattern of the 15th Sept to 1st Oct, for example and, in contrast the 1st to 15th Oct switch to a more -ve GPH anom through the troposphere and a clear spike in the NAO. Keep a close eye on this plot moving forward and clearly note the current situation too, far right! - https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.ao.cdas.png Cheers.

Smokes and mirrors or tealeaves aside, the science being the GSDM and the AAM is sound, so whether you're a 'believer' or not is another topic of discussion. What isn't up for debate is how poor both seasonal and sub-seasonal models have struggled with Nov. The EC Seasonal Nov updated flipped the -ve NAO signature around with ease, exact reasoning for this, this month remains uncertain and up for debate, but a few suggestions are more obvious than others. All that aside we are set to see changes and are seeing changes now that will likely have impacts down the line, the EPO flip for one after being extremely -ve. The AAM was discussed, I think, on the previous page or two but can't find it now, but it's not just a reduction in the W'ly anomalies at the mid-lats that's important, it's the AAM transports and we can now visually see a propogation of -ve E'ly AAM anoms to higher latitudes and this links in with the other post that some steam will be taken out of the W'ly flow looking ahead. As mentioned days back, November often comes and goes anyway with little interest and I would far sooner keep any winter synoptics for December and January, then in November, even though the forecast has changed as the month has progressed, but that's meteorology of course. I still fully believe and expect a change in pattern as we move into December, this isn't a situation whereby the strat and trop are now connected at the hip within what is the RI (Rapid Intensification) period either, if anything it is the opposite. Equally, we need to keep a very close eye on the strat as there is some model data, combined with recent and up-coming teleconnections (Scandy block, Dec MJO developments) that do point towards a more significant weakening of the sPV later in Dec and early Jan. A frustrating wait and watch keep seeing low after low in the Atlantic, but think back to mid-summer and the requirment for rain, winter synoptics can arrive when it is finally winter, not in late autumn IMO. Cheers, Matt.

Just a word to the wise to some thinking the E or SE'ly undercut is likely, then disappointment may well follow. There's very little evidence for this to take place. The general theme is cyclonic with the Atlantic flow winning through. For those that like cold weather then the key point to acknowledge right now is the seasonal temperatures that have now arrived and will dominate looking ahead - it'll feel like it should for the time of year after the recent 'warmth'. Despite evidence for blocking patterns to arrive, eventually, as I posted earlier on today the primary caution here is that the likes of the EC Monthly and the Weekly GloSea have failed in terms of capturing the blocked Nov that was predicted weeks back, that includes my (work) outlook on Nov too. The reasons why it never materialised are difficult to figure out but the alarm bells here could be that the early winter blocking linked to La Nina could be being overridden by other drivers - Fine margins with a dominant block to the E but it was never signaled to be there anyway this month. We always have to remember that the domant flow is from the west this time of year onwards and to stop that dominant pattern especially early in the winter takes some signficant variables to come into play. For the winter lovers out there then the tease already this season (and winter has yet to start) has been the long-standing prediction for early winter blocking. Yes, there still remains a lot of evidence for that to finally arrive but their was also evidence for it through November too, which didn't, so keep an open mind as the next few weeks progress. Cheers. Matt.

These plots may have been dropped in somewhere else but as, yet I've not seen these, but worth sharing the Nov C3S seasonal output for Dec and then Feb. What these plots highlight perfectly is how the 3-month mean plots can really mask monthly variations and clearly, we can get even more variation within a monthly period as well. Caution is always recommended with taking 3-month seasonal plots 'as is' and one must always try and view monthly plots or at least analyse other variables as welll. The standout feature here for Dec is the continued signal for blocking patterns, a consistent signal for months. Will the key +ve MSLP anom end up exactly there?...clearly nobody knows, but it is the -ve NAO signature that remains very interesting indeed. In contrast and as has been expected for a similar length of time is the +ve NAO pattern for later in the winter. The primary caveat here, however, is the SSW risk which I do honestly think is higher than some may suggest within a wQBO/Nina regime, but as ever time will tell on that. All in all it provides significant interest for the early winter period when, usually, more significant cold weather is often more realistic than compared with later in the winter, without some sort of significant stratospheric assistance/disruption. Regards, Matt. NB: These plots were grabbed from the Copernicus front page, not the main area where the plots are as they are still 3-monthly means. Future updates from Copernicus are set to incorporate monthly plots as well as the 3-month means which will be a great addition to the site.

This loop makes for interesting viewing. Obviously with the lack of ECM data in particular from Berlin site it's hard to cross examine to be honest but I often find the GEOS data to be reliable. If we look at another pressure level we can see how continued Scandinavian block is a key feature in aiding this degeneration of the vortex, while there is also evidence for a reduction in Uwinds as well through much of thr trop and into the lower strat but these plots can vary from run to run so it's more about a tend with the Paul Newman plot. As mentioned earlier today, steady away but the building blocks and jigsaw pieces are certainly there for an interesting outlook in the coming weeks, but can it all come together, time will tell as usual. FullSizeRender.MOV

It's still a case of steady away for now, but there are definitely some 'unusual' conflicating evolutions taking place that, without question, have lowered the confidence for a rise in pressure before months end. I think there has been a lot of attention on this rise in pressure because it has been well signaled from the EC46 for a number of weeks and the seasonal models all indicating early blocking patterns. Clearly, for the majority of times, November is rarely looked at as being a month that provides the UK with any winter synoptics, the few exceptions of course along the way, but generally speaking November comes and go with little signficance. As per usual trying to piece all the 'jigsaw pieces' together to get the end picture is often easier to do if you can physically see how the pieces will go together, at the moment that isn't the case. The MJO activity, for example, over the last few weeks really didn't come to any assistance, but the continued downstream block to the E and NE is, as I mentioned a number of days ago, a very interesting late autumn feature that may well have influences down the line, with regards to the strat. The problem with November as well is the continued on-going seasonal wavelength changes that can muddy the water as well, obviously that becomes less of a problem by the time we get into December and beyond, as is the case in the summer. The continued signal for the MJO to return to phases 5-6-7 remains very interesting and, should maintain an atmospheric response that is more Nino, rather than Nina. As a general rule of thumb, Nino is better for colder synoptics, than compared with Nina so to get that currently is definitely an interesting piece of the puzzle. The implications of a Nina-esque AAM regime through winter (obviously we are still in autumn, so bear that in mind re; seasonal wavemength changes etc) supports a pattern which props up sub tropical ridges to mid latitudes (e.g Azores high and associated +NAO) and also usually reduces the risk of wave activity and poleward EP flux that can help disrupt the strat, etc. Overall, the opposite is true when we see more of an atmospheric Nino response. Again it's all rather messy at the moment to be honest, but the overall building blocks towards a switch to more high pressure dominated regimes remains, albeit with lower confidence than was originally the case a few weeks back, for some of the reasons discussed above. The other key feature that we all have to continue to take on board these days is climate change influences as well. After being involved within meteorology for over 20 years now, professionally for 15 years long range forecasting is most certainly being made more difficult and uncertain because of the changes that are occuring because of climate change. Analog comparisons, for example, seem to be far less useful than they used to be and there are just far more unknowns. All that aside, those hoping for any sig cold before months end is likely to be dissapointed, but at least temperatures return to near average values this week and looking ahead, which is seasonal and where we should be. I would still place a wager though that towards months end and into early December we will see a pattern change. Cheers.

The atmospheric disconnect to the La Nina base state has been somewhat underestimated but has happened before, can't remember the year, a few years back I think at this time of year within a La Nina and wQBO combination. Seasonal wavelength changes muddy the water still at this time of year, but the text-book mirrored hemispheric AAM pattern stands out like a sore thumb with AAM and the GWO both in their highest states/phases in nearly a year, again atmospherically we are within a Nino regime, oceancially (if thats a word!), it is still, obviously La Nina. At the moment this +ve AAM spike is helping to reinforce the Atlantic trough (W'ly momentum being added to the mid-latitudes, albeit within a relatively amplified N Hem pattern), due to how the configuration is playing out upstream, but as time ticks by, as you rightly suggest another MJO passage through the Maritimes and W Hem late Nov, which does look like it will be a feature of the tropical forcing, at times, throughout this winter, may well 'come good'. Equally, the Atlantic trough and downstream ridge pattern is clearly almost semi-permenant, we have had multiple reoccuring spells of SW'lies with the trough to the W and a downstream ridge to the E. The constant blocking signal over Scandinavia at this time of year is most certainly not a bad thing with regards to wave breaking within the strat down the line either. So, while we continue to bask in unusual 'warmth' in the coming days, in time this spell may well be long forgotten about. Obviously models are toying with the idea of the Scandinavian block becoming dominant with an undercut, as per the 00Z UKMO, as we see a fall in AAM, in the short-term, there is a window of opportunity for this to actually happen as the Atlantic looses some 'steam' but, equally, the counterbalance is the cold pool and increasing thermal gradient over the N Atlantic, the cyclonic pattern won't be push aside easily just yet and we all know the 'fine margins' that are required for this kind of setup to occur anyway. All that aside, things are ticking along very nicely indeed at the moment with regards to how November is playing out and the long-standing seasonal model predictions for early winter blocking patterns to rule the roost will/hopefully make an appearance. Steady away...

It's unfortunately been pulled, the information won't be put online this year for a number of reasons, I got in touch with FU Berlin last week. I did stress, mind how important the data is, but it's not likely to return this winter which is a big loss.

Hi. Worth a post on this one as it is definitely that time of the year when some general guidance on the summer pattern can be gathered. As per usual, whether it is based on short-term NWP or long-term seasonal models and teleconnections, there are no certainties, look at this past winter and teleconnections for example. That (disclaimer) aside, I don't think we need to look too far back, in terms of years, to gather some indications as to how this summer may pan out. Clearly, we are now entering a third spring and summer period where La Nina is in play. While an up-coming passage of a more coherent -ve VP200 (WWB) is expected across the Pacific, short-term, this isn't set to be enough to wipe out the current SST anoms present, so, IMO, La Nina will remain present this summer. Depending on where you look and who you ask, there are still some conflicting comments, some saying neutral, some even still saying a progression to El Nino, especially by late summer, but not for me. As a bit of background, focused on La Nina, increased easterly trade winds across the Pacific create a -ve frictional torque signal around 30N and this allows amplification of sub tropical anticyclones across the Pacific which results in extra westerly momentum around 50N above these anticyclones. The downstream pattern then develops a trough/ridge pattern so that the sub tropical ridge response in the Atlantic also pulls westwards to fill the vacuum created across the US by the Pacific anticyclone and decelerated Pacific jet. Simply put, as a general guide, particularly through the summer, La Nina is often associated with a Pacific ridge and a N Atlantic ridge, with a downstream trough pattern over NW Europe, clearly not a good thing for broader summer patterns. Obviously this is broadly speaking and short-term evolutions can and will alter this pattern. Another feature looked at this time of year is the QBO and angular momentum link with solar activity. Some of the poorest summers have seen angular momentum fall or generally be within a -ve AAM state, in late May at the same time as the QBO phasing has chnaged from westerly to easterly. Low solar forcing in tandem with low momentum tendencies and trending easterly QBO has some links to increasing the risk of northern blocking patterns through summer, no better example than the likes of the summer of 2012 which was riddled with northern blocking and S'ly tracking jet pattern with a dominant trough over NW Europe, the 'year without a summer'... If we look through the above information, we are clearly checking some boxes there. We remain within an eQBO pattern and are likely to do so as we push into summer, couple that with La Nina and that isn't a great start. One counterbalance is solar mind, low solar activity isn't expected this year as we continue to progress out of the solar min from a few years back and, as ever, who knows how that may or many not influence things is anyones guess. We have seen AAM rise over the last 5 to 7 days and that will get a further push into a more Nino atmospheric base state, short-term, so it is no surprises that NWP is modelling the significant N Atlantic trough extension and downstream ridge over the next 7 to 10 days. How quickly that is cleared away remains very uncertain, IMO, some NWP are breaking down the ridge too quickly, but even if the initial high does wane after this weekend the pattern is still conducive to early summer-type (generally wider higher temperatures, higher dew points etc) conditions than most have seen so far this year. But...There is clear evidence for the AAM to fall once again through late May and into early June (see overnight EC46 plot, for example) which could be linked into the above paragraph once more about falling angular momentum at the wrong time. Overall, while there is a lack of northern blocking from the seasonal models, which is a good thing and half the battle, to me this summer while potentially not likely to be a 2012 et al washout, is likely to be far from a 2018 classic either. There is simply too much stacked against this being a long-hot UK summer with high pressure often dominant. Whether, as per other La Nina years, the best of the weather arrives early and then the wheels come off as the summer progresses is difficult to tell, but I have a feeling this summer will be highly modulated by the MJO. If we remain within a dominant trade wind pattern (Nina) and I can see persistent spells of unsettled weather, but get a more active MJO or kelvin wave on the move and we could easily flip that pattern, so we could end up with a summer that is 'down the middle', a couple of good weeks and a couple of bad which, overall, I think most would take. It could also be a highly convective summer as well, potentially 'warm and wet'. Couple that with remnant tropical features through July and August onwards in particular and it may well be far from a benign summer too. Anyway, just two pennies worth at an important point in the annual calendar... Cheers, Matt.

The seasonal models, especially the 3 month mean plots are often useless. The individual monthly breakdown while still likely to bring errors, at least does provide some further insights which support the broader background teleconnections, with the signal there for blocking patterns through the early part of the winter. While one could call this cherry picking, we only need to look back to this time last year and the 500mb EC Seasonal Nov update for the Dec, Jan and Feb period and what actually occured, it wasn't even close... Again, cherry picking perhaps and what's not to say it won't be right this year, etc, etc. The point here mind is that just like we can pre-empt NWP in the short-term, with teleconnections and the likes the GSDM, we can also provide a counterbalance to the raw seasonal model output which we all know is fraught with difficulties, despite the impressive computer power at hand. Given the broader background signals in play then I don't think we have a better chance of blocking patterns this winter and also it will bring in to play scientific analysis as well. There are clearly many studies/journals/analysis on the early winter blocking signals within an La Nina regime (especially depending on the type of Nina), while there is also a known link between the relatively rare La Nina and eQBO combo combining to increase the risk of a winter SSW, as well. The 'modern unknown' mind which I don't think anyone can factor in properly is global warming, the state of the arctic and global wildfires, etc. As ever mind we can never cover it all to the nth degree when it comes to seasonal predictions and analysis, it's just not possible as you know too. While we always need to be cautious for any connection between the strat and the trop within the next 4 to 6 weeks, there remains room for optimism, that this won't be a period where the connection is strong and robust like would be seen within a strong Nino/wQBO winter, for example. We all know it is the default pattern, so are constantly fighting against it, but clearly that fight can be won, as perfectly exampled in 2009, 2010, etc. Therefore the SSW risk may not necessarily be the 'holy grail' this winter, as is often the case IMO. Granted, the broader evolution through Jan and Feb within a La Nina winter is towards a +ve NAO regime, which the seasonal models do show, etc. This is also another setup whereby if a significant SSW event occured in Jan (particularly if a split/wave 2 event, as compared with a wave 1 displacement), then the seasonal models could be way off for the second half of the winter, but that whole potential will take care of itself as the weeks progress by. The 'holy grail' for all winter fans this winter would be a trop-led blocking pattern through the early winter, and this then being followed by a mid-Jan SSW of significance which then potentially brings late winter blocking synoptics as a resultant of the SSW. First and foremost, between now and late Dec, the key features to keep tabs on are a continued lack of any organised strat and trop connection, and an overall 'unusual' setup whereby blocking patterns are often in evidence within NWP, again similarly to 2009/2010. I'm not saying, by any means this will be a repeat early season, but it's that unusual repetative blocking signal that needs to be watched for, as apposed to the typical PV of doom that setups up shop over Greenland within the next 2 weeks and then writes off the first third of winter. Again, this the often 'usual' evolution for our 'corner of the N Hem' but I have a distinct feeling that won't be the case this year... Cheers, Matt.

Just sharing some pics from yesteday here in E Lancashire. Quite the rate event driven by a well established convergence zone on Sat evening and the slow-moving nature of the precip helping totals. Interestingly there were some very localised differences in accumulations. More western areas of the Rossendale area of E Lancs, including here saw lower totals than across more eastern areas nearer to the border of W Yorkshire, that highlighted by one poster day ago from Bacup where totals where much higher there than say 4-5 milea to the West. No doubt related to local variations in intensity and longevity of the snow on Sat evening. Regards.

Hi. Just briefly dipping into this thread, as a one off, to perhaps provide some further insight here... The spike in AAM in Oct was, of course, directly related to the eastward movement of the MJO and that created a surge in AAM, clearly at a time when seasonal wavelengths would still have supported the Atlantic ridge and downstream trough, which clearly dominated all of summer. That is definitely the annoyance, on a more short-term, as we had to put up with relentless -ve AAM trends all summer that repeatedly brought about the Atlantic ridge - downstream trough. However, the key aspect here, which can be mis-understood or forgotten is that what happens with AAM through the summer doesn't mean it is the same for winter, and we are now at a point where seasonal wavelengths actually mean something of the opposite. Looking forward we do actually want and need +ve AAM to develop through the tropics to counterbalance the broader La Nina background. We are moving out of the period now when getting -ve AAM and getting an all round La Nina profile won't actually help in bringing blocking patterns. The reason, is as follows... In winter extra +AAM momentum at around 50N (under La Nina setup we have this year) is inhibitive to the creation of stable higher latitude blocking under a +AO regime and it is +AAM transport from the tropics poleward that creates the mechanisms to slow the polar jet and bifurcate the tropopause/stratosphere layers. But once this has happened, its quite often a low angular momentum regime that can lock in the pattern as the usual polar jet flow that prevents blocking cannot penetrate the blocked tropopause layers once it has been set up and is forced to loop around the pole instead. The looping of the polar jet into the pole, rather than straight across on a flat jet at mid latitudes, propagates even further warm air advection into the pole and this in turn prolongs the duration of the blocking. While this is subject to some 'give and take' as a general guide Nino phases are better for cold spells in winter and warm spells in summer. There had been examples of this recently, especially through late Oct, in association with the +ve AAM spike, but this coming at the wrong time, again destructively interferring with the broader Nina background. As the recent AAM plot below highlights, there has been some attempted northward movement of -AAM anomalies (which we need) but that has, unfortunately, recently stopped as the trades have returned. Within the last few days there is a clear evidence for a robost +AAM anomaly at, surprise, surprise, around 50N, as circled. So no wonder no GFS blocking has come off and only minor amplification between systems from the W will dominate the next 7 to 10 days... Also, using earlier in the year as another example, look at the AAM profile from between late Dec and through the whole of last winter. It was locked within a profile that had +AAM around 40-60N, driven by the extremely strong polar vortex as well, with any -ve AAM anomalies around 30-40N. If you look at reanalysis plots of this same time frame, you'll actually see a 'ring' of high pressure circulating the globe at around 30-40N, this propping up a robust W'ly and strong polar jet stream. It wasn't until April and May when those -ve AAM anomalies finally move to a more N'ly latitude and, surprise, surprise, look at the weather we had in April and May!... There were some tweets on this a few days back, the link to those are below. Looking forward, what is needed is additional eastward movement of the MJO, to increase +AAM through the tropics which in turn will help to propagate -ve AAM anomalies further north, out of the sub-tropics. Total AAM, relative AAM etc etc sort of all fall second-string to the most important variable now for the coming 3 months and that is AAM transports, which links back in to what was discussed above. So don't hope for a La Nina reset now, that time has been and gone, seasonal wavelengths have altered the 'goal posts' on that. However, we are very finely balanced once again this year because the strat vortex is so strong, there's some residence from an E'ly QBO regime acting as a lid, but AAM isn't playing ball either. We could very easily end up where we were 12 months ago within the next 4 weeks, which does seem likely and hence why the mid-winter period is likely to be +NAO and why, most of Dec still provides the potential for amplification. Also, as a hint, keep an eye out for an EAMT within 10 days too, that could tip the balance for blocking, for a time, into the first half of December... Hope, this is of some interest...

Low pressure continues to dominate as we look further into October, but with possible changeable and varied conditions developing. View the full article

A cyclonic period of weather is set to develop as we move into early October but with potential changes to more anticyclonic conditions as October progresses. View the full article

A transition towards a more unsettled and cyclonic period is weather is forecast as SEptember ends and we move into OCtober, but with then potential long-term changes further into October. View the full article

A transition towards a more unsettled and cyclonic period is weather is forecast as SEptember ends and we move into OCtober, but with then potential long-term changes further into October. View the full article

A changeable and more varied period of weather on the way, but with low confidence in the medium and longer term as an amplified pattern develops View the full article

A changeable and more varied period of weather on the way, but with low confidence in the medium and longer term as an amplified pattern develops View the full article

A changeable and more varied period of weather on the way, but with low confidence in the medium and longer term as an amplified pattern develops View the full article

The stratospheric polar vortex is now in its early stages of development, find out more on how it can influence winter weather patterns. View the full article

The stratospheric polar vortex is now in its early stages of development, find out more on how it can influence winter weather patterns. View the full article

The stratospheric polar vortex is now in its early stages of development, find out more on how it can influence winter weather patterns. View the full article