MattH

Just finished the winter outlook and analysis for work and absolutely no reason to deviate from many long-standing predictions and signals that have been in place for a good few months. Granted, as is seemingly more frequently the case due to global warming and the extremes taking place, there is always an unknown and uncertainty in play. However, I've not been at this point in November, for a good few years with a clear picture and prediction in my mind of how the winter is likely/expected/predicted to pan out. The summary is below, again no surprises here and could be a very interesting one indeed for those who like and love winter for what it can bring... Cheers, Matt.

No changes to the forecasts and no surprises the Amber for NW Eng has appeared. These kinds of wind speeds into NW in the middle of the day on a Mon are going to cause some problems... RPReplay_Final1699859308.mov RPReplay_Final1699859308.mov RPReplay_Final1699859906.mov RPReplay_Final1699859574.mov

Text book stuff... RPReplay_Final1699823689.mov

Looking at earlier satellite imagery it looks like the wave is already more developed than what earlier models had so the 12Z UKMO isn't a surprise with a deeper low and a stronger core or strong winds. Can see the cloud ahead on the below and that's an hour or two back. Really not looking good this system at all now for specific areas...

Hi. Just want to post link to the Storm Debi thread. This system looks very nasty indeed with evidence now for a Shapiro-Keyser system to develop.

There is a good shout for this to be a Shapiro-Keyser (K-P) system. The UKMO certainly on board with this and highlighted on the 00Z plot tomorrow with a fractured cold front... This is likely to be a very nasty system indeed for parts of Ireland the Irish Sea and into NW and N Eng on Mon. The wind gusts over the Pennines could be extremely disruptive especially main road networks that run north to south/south to north with extreme cross winds. This system isn't getting a great deal of attention due to the last minute development of it but this is serious for the aforementioned areas tomorrow. Matt RPReplay_Final1699800609.mov

Hi Paul. Yeah great little addition is the model viewer. Really tidy and easy to use and UKV data is great. Like the ability to flick back to previous run as well so see if there is any consistency, etc. Just need a precip type plot for winter now... Cheers. Matt.

This is becoming even more noteworthy for parts of Ireland but particularly the Irish Sea and into NW Eng on Monday. The very late development of this low is seemingly keeping discussion on it to a minimum and there does remain model spread over it's develoment. However, there is equally enough evidence to suggest that "last minute" warnings will be issued for the aforementioned areas today, covering Mon for wind. UKV in particular producing some nasty wind gusts for NW Eng and N Eng through the middle of Mon while there is now quite widespread MOGREPS agreement along with a clear and strong signal from the EPS. Whether it's named or not is another matter it probably won't be because of the last minute nature of its develoment which is another reason the naming system is a farce, but that's another topic of discussion. Certainly one to watch rest of Sunday in HRES data... Regards. Matt.

A quick screenshot of the latest thoughts (work-related) is below, but, overall the evolution through the rest of November continues to 'sit well' with the overall expected patterns given El Nino and +IOD event. Atmospherically there is still a lag to the oceans in terms of a 'true' El Nino link, but we've seen AAM rise over the last week or two and the upcoming WWB through the central Pacific will help to do that further. While it is often the EAMT (East Asian Mountain Torque) event that can increase AAM, linked to a more mobile MJO moving through phases 2-3-4-5, etc, I would still expect some rise and recovery once again in the AAM, with a resultant rise in the GWO as well which continues to flap around through neutral if not slightly Nina-like phases. The significant development within the strat needs watching as well as the vortex is definitely 'on one' right now and there is evidence for downwelling of the stronger W'lies to take place too. If we do see those make more of an impact on to the trop later in Nov, then, IMO, this combined with El Nino and the +IOD all points towards a cyclonic and mild start to winter, but this in-keeping with many long-range thoughts anyway. Regards, Matt.

The outlook period, through much of November, carries higher than usual confidence, especially for the week 3 and 4 period. We can link that prediction back to the ongoing developments within the tropics. The key uncertainty over the last week or so has been where the MJO would emerge, or become more dominant this month. Through October it has been a feature within phases 8 and 1. As we continue to see the combination of +ENSO and +IOD in the tropics, in terms of +ve and -ve VP200 anoms the pattern remains very slow-moving indeed, with the continued subsidence over the Maritimes (phases 4-5-6), while the key areas of rising motion (-ve VP200 anoms) have been over the W Hem and also near the dateline. It now looks as though the predictions for a more pronounced WWB will come to fruition this month and perhaps with some eastward movement as well. Not only will this aid in another rise in AAM, but will reinforce the oceanic and atmospheric Nino link. What it means is that for much of November, the MJO will often continue to reside in phases 7/8 and 1. Despite little or no connection between the strat and trop vortices, it is the trop that is currently dominating with clear influence on the N Hem from the tropics. With the above in mind, then it is highly unlikely that the N Atlantic will see anything other than a more troughed pattern with a general dominance of further Atlantic lows for the foreseeable. Any sort of rising pressure will be short-lived, with temporary ridges and the chances of a 'full-blown' anticyclone over the British Isles or in a location that could bring early significant cold is highly unlikely as well. Whether we are seeing the pattern now settling into the late autumn/early winter regime that is associated with a +NINO/+IOD combination, only time will tell. If, eventually, there is some connection as well between the strat and the trop vortices later in Nov then that really would reinforce the overall early winter expected pattern of something often 'mild, wet and windy' with any colder synoptics following deeper into winter, but that's more long-term than short-term. The +IOD event, by the way, has now peaked, but its influences are likely to be felt for another 4 to 8 weeks, before a likely breakdown of the subsidence that dominates the E I/O and the Maritimes later in Dec onwards, I would imagine. In essence, very much standard November patterns looking ahead, but do we really want cold, blocked November synoptics? - IMO the answer is, no...so steady away with typical late autumn weather for now. Regards, Matt. Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4947991

The outlook period, through much of November, carries higher than usual confidence, especially for the week 3 and 4 period. We can link that prediction back to the ongoing developments within the tropics. The key uncertainty over the last week or so has been where the MJO would emerge, or become more dominant this month. Through October it has been a feature within phases 8 and 1. As we continue to see the combination of +ENSO and +IOD in the tropics, in terms of +ve and -ve VP200 anoms the pattern remains very slow-moving indeed, with the continued subsidence over the Maritimes (phases 4-5-6), while the key areas of rising motion (-ve VP200 anoms) have been over the W Hem and also near the dateline. It now looks as though the predictions for a more pronounced WWB will come to fruition this month and perhaps with some eastward movement as well. Not only will this aid in another rise in AAM, but will reinforce the oceanic and atmospheric Nino link. What it means is that for much of November, the MJO will often continue to reside in phases 7/8 and 1. Despite little or no connection between the strat and trop vortices, it is the trop that is currently dominating with clear influence on the N Hem from the tropics. With the above in mind, then it is highly unlikely that the N Atlantic will see anything other than a more troughed pattern with a general dominance of further Atlantic lows for the foreseeable. Any sort of rising pressure will be short-lived, with temporary ridges and the chances of a 'full-blown' anticyclone over the British Isles or in a location that could bring early significant cold is highly unlikely as well. Whether we are seeing the pattern now settling into the late autumn/early winter regime that is associated with a +NINO/+IOD combination, only time will tell. If, eventually, there is some connection as well between the strat and the trop vortices later in Nov then that really would reinforce the overall early winter expected pattern of something often 'mild, wet and windy' with any colder synoptics following deeper into winter, but that's more long-term than short-term. The +IOD event, by the way, has now peaked, but its influences are likely to be felt for another 4 to 8 weeks, before a likely breakdown of the subsidence that dominates the E I/O and the Maritimes later in Dec onwards, I would imagine. In essence, very much standard November patterns looking ahead, but do we really want cold, blocked November synoptics? - IMO the answer is, no...so steady away with typical late autumn weather for now. Regards, Matt.

Bringing this back on topic, but keep tabs on the daily updates from the EC Ext looking ahead. The anomalies continue to favour blocking over W Russia and the Urals, to what extent any wave breaking and activity takes place in disrupting the strat or creating some sort of warming event is, clearly, uncertain, but as we can see since the middle of last week the signal is increasing through late Nov and early Dec period. Any sort of early winter warming event is often rare, but such a strong +ve temp anom at 10hPa simply can't be ignored, despite the long lead time, especially when you investigate further and acknowledge there are some tropospheric links as well, given expected broader blocking patterns. 27th Nov to 4th Dec 4th to 11th Dec With the MJO set to remain in phase 8/1, more like phase 8 IMO, then if reanalysis of this phase, in Nov, in a Nino year is anywhere near correct then the two broader anomalies stand out like a sore thumb and those being the Ural/W Russian blocking and the likely progression towards an Aluetian trough. Just one piece of the jigsaw of course, but as we all know Nov and into Dec (forget the rest of the winter for now) is the key period, annually, for the RI of the sPV, if that suddenly organises and strengthens and down wells with an increased W'ly connection between the strat and trop then, usually, the first half or 2/3 of Dec is a right off for any winter synoptics. (Out of interest, I don't expect that to happen this year anyway, but you know what I mean...) Regards, Matt.

Bring on the change to GMT, the correct time (IMO!)...oh and the usual hour earlier for all model data, ALL meteorologists look forward to that I can tell you, it seems like it has been BST this year for a very long time. The arrival of 12Z model data at 4-5 pm in the afternoon and by early morning is a true sign it's time for the winter season... M.

Here to be proven wrong, but a full-blown 'true' +NAO +AO is unlikely through Nov, IMO. The key ingredient for that will be a rapid sPV and tPV connection and I can't see that anytime soon. The wildcard of a reinforced +IOD may well help, but as we are seeing now, we can still get, what some would call a zonal pattern, but of which, as you've stated isn't true in the sense of a dominant tPV behind it. It'll be an interesting watch through Nov this year, in particular... Matt.

The low next week is definitely one that needs watching, frontal wave leaves NE USA or far E Canada and looks set to be picked up by the jet as it drops on to the cold side of it and then rapidly deepens. This aspect of the forecast carries high confidence, what does mind and won't do for a few days is where the main development and RACY event takes place. It'll be that which determines just how severe (or not) the impacts of the system will be as it approaches the UK. Keep tabs on MOGREPS for this as well as the EPS, but a decent shout for a named storm by next Wed/Thu with yet more rain! Cheers, Matt. (NB: Is it just me or does this period of Oct into Nov have a 'feel' of 2009 about it...)

The highly useful addition this season, for us all, is the ability to see previous runs of the EC46 in terms of the various plots, but, importantly the 10hPa temperature plots, etc. Some would argue being run every day isn't useful, but as long as the data is analysed correctly, then more data the better IMO and that applies to the 10hPa data from the EC46, etc. It is definitely worth looking at the plots in a 'Base Time' instance, as you can get a much better feel for how the model is evolving every 24 hours for a given week period... https://charts.ecmwf.int/products/extended-anomaly-10t/overview/base_time?base_time=202310260000&projection=opencharts_arctic&valid_time=202312040000 The initial warming is around the late Nov and early Dec period, between the 27th Nov and 4th Dec and it is the last few days that the anomaly has increased in terms of temperatures and this snowballs forward into the following week or two. Caution is required as experience tells these signals can often become far more watered down much nearer to the present day and if this were a La Nina/wQBO season I would be wondering what the model is doing really. However, that isn't the case, of course. The eQBO is now well bedded in, especially above 30hPa and quite significantly so with the zonal wind now just passed -25m/s at 20hPa and isn't going anywhere in the coming months. This kind of warming will more than not be linked to wave-breaking events from within the trop and if one looks at the anomalies predicted, while the Aleutian low is somewhat lacking, for now, the Ural blocking is almost semi-permanent. Potentially, too, one would expect the N Pacific low to make more and more of an appearance moving forward as oceanically and atmospherically El Nino takes hold too. https://charts.ecmwf.int/products/extended-anomaly-z500/overview/base_time?base_time=202310260000&projection=opencharts_north_pole&valid_time=202311200000 Two of the best plots in this instance are the D+11 ALZ ENSM plot along with the ever-highly useful CDAS GPH plot... https://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/alens500_maps.d11.2.gif https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.ao.cdas.png So, Dec SSW is certainly rare, we've been here before with such long lead time anomalies, to then come to nothing but if you strip all that back, as a bare minimum what it does do is provide evidence to the long-standing predictions that the sPV and most likely tPV will not 'rule the winter roost' this season and, overall, be more disrupted than normal and also with the eQBO/Nino mix increases the chances, with a scientific basis, of an SSW at some point. The interest in this winter continues to grow... Regards, Matt.

Bringing this back onto topic quickly one of the key things that has now been set up, linked to the +ve IOD and the El Nino is the key areas of rising and subsiding air. One of the reasons why the MJO has been particularly 'on holiday' in recent weeks is because of this ongoing development, but oceanically and atmospherically we are now starting to see a connection, this was highlighted in a post yesterday with regards to a gradual rise and recovery in AAM moving forward. The +IOD is set to dominate through to Dec at the moment, not the whole winter and unlike in 2019/2020 isn't expected to 'rule the winter roost' as it did back then. Equally, both short-term and long-term data both show the same velocity potential anomalies setting up, both sub-seasonally and seasonally as I've highlighted below just using the CANSIPS data. What is crucial here is that the persistence of the +ve IOD means that subsidence (upper-level convergence, low-level divergence) will often dominate the Maritimes, eastern areas of the I/O and Australia, meaning the MJO is highly unlikely to be a resident here in the coming weeks and months. Instead, we should be expecting the MJO to be often a feature of phases 6-7-8 and then into 1 and 2, obviously, we don't know exactly which. However, with clear evidence for rising motions through the central and western Pacific looking ahead, then a sound prediction would be that the MJO will often reside through phases 6-7-8 through Nov and into Dec, perhaps some changes thereafter. These are all very interesting phases in terms of Rossby wave activity and influences on the strat and northern blocking patterns. While this is just one piece of the jigsaw, we do need to factor in sea ice coverage, northern hem snow cover developments, and how the strat and trop vortices develop as well during November, but it's a mouthwatering outlook for cold winter fans with regards to Pacific pattern and how we would expect the MJO to often evolve and behave. Regards, Matt.

The developments are becoming very interesting in terms of the evolution of the N Hem pattern as we push deeper into autumn. Obviously, we are weeks away yet from the onset of winter and, as is always the case, the primary watch through November is on the development of the stratospheric polar vortex and how this interacts (or doesn't) with the tropospheric polar vortex. It should come as no surprise at all that if there is an organised sPV which then links and connects to the tPV into December there is usually only one outcome and that is an enhanced westerly, zonal flow, this is the "standard" evolution of the N Hem pattern in early winter. The likes of the MJO etc can help to alter this, a good example being the first half of December last year, but that is always the first port of call to keep analysing as November progresses. The +IOD event remains a troublesome feature mind, amongst favourable patterns and evolutions but we will just have to wait and see on that. Despite AAM having been persistently -ve for numerous weeks, the recent and consistent WWB near and just west of the dateline now seems to be having some impacts. We've seen a pronounced uptick in global MT and the recent tendency plot is 'off the scale', but does usually get watered down as each update progresses, but the broader development here is noteworthy. This links to what Tamara was mentioning with regards to finally a more gradual, linear increase in AAM and, importantly, this may progress and arrive at a time that has implications on the early winter patterns and the sPV too. The two dominant features are the -ve 850mb wind values near 60E, linked to the +IOD and now the more semi-permanent +ve 850mb winds (WWB) near and just west of the dateline, of which according to the Carl Shreck data is a noteworthy equatorial Rossby wave event. As we all know the MJO has been 'dead' for some considerable time now, the last noteworthy event way back in spring, clearly this links back into the evolution of the summer as well. It will be interesting to see how the MJO develops through the rest of the year as, eventually, a more pronounced development and event should make an appearance and that will also be key to some influence on the early winter pattern too. Generally speaking, the MJO is often more active during the winter months, than it is during the summer. As highlighted numerous times by Tamara over the years, a more Nina-like (-ve AAM) regime in winter is one that often supports more amplified mid-Atlantic ridges, which can build towards mid-latitudes. Amplification of this type, in winter, is often associated with inflated Azores high and with the usual tPV in play, which usually means a general +ve NAO pattern. There are also some links here to this stopping or inhibiting wave activity and flux that is required to help disrupt the sPV as well. The key thing towards winter is that a more atmospheric progression towards a Nino pattern (decline of easterly trade winds) means that the AAM pattern will lead to a greater risk of easterly anomalies at higher latitudes, bringing about a more amplified jet stream pattern. It is interesting to note that such a pattern has been in play of late, with a more dominant W'ly regime at lower latitudes, blocking, E'ly signal at higher latitudes. This is also why, over the next 7 to 14 days we see a dominant cyclonic pattern but one which is often set to see a more southerly tracking jet with high pressure trying to dominate at higher latitudes. Clearly, November blocking especially Russian and Ural blocking can have significant impacts down the line as well. The importance of the E'ly AAM anomalies at higher latitudes, compared with W'lies is exampled well if we look back a year ago on the below plot through Nov and into Dec - Note how through late Nov and into Dec, last year, the 50-60N region saw -ve E'ly anomalies dominant, being propped up by W'lies through the sub-tropics, overall it is this kind of AAM pattern that signals amplification and higher latitude blocking. If you then follow through last winter you can see how that pattern reversed with increased W'ly momentum being added to the mid-latitudes into the New Year as AAM fell to more negative territory - the key thing here, is that this year we could/should see the opposite occur with AAM rising. All in all, with the Nino/eQBO combination in play, some interesting signals already for a weaker vortex and, importantly, a likely progression towards a more +ve AAM pattern then the foundations remain firmly 'set' for a potentially interesting few months ahead, etc. Cheers, Matt Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4941765

The developments are becoming very interesting in terms of the evolution of the N Hem pattern as we push deeper into autumn. Obviously, we are weeks away yet from the onset of winter and, as is always the case, the primary watch through November is on the development of the stratospheric polar vortex and how this interacts (or doesn't) with the tropospheric polar vortex. It should come as no surprise at all that if there is an organised sPV which then links and connects to the tPV into December there is usually only one outcome and that is an enhanced westerly, zonal flow, this is the "standard" evolution of the N Hem pattern in early winter. The likes of the MJO etc can help to alter this, a good example being the first half of December last year, but that is always the first port of call to keep analysing as November progresses. The +IOD event remains a troublesome feature mind, amongst favourable patterns and evolutions but we will just have to wait and see on that. Despite AAM having been persistently -ve for numerous weeks, the recent and consistent WWB near and just west of the dateline now seems to be having some impacts. We've seen a pronounced uptick in global MT and the recent tendency plot is 'off the scale', but does usually get watered down as each update progresses, but the broader development here is noteworthy. This links to what Tamara was mentioning with regards to finally a more gradual, linear increase in AAM and, importantly, this may progress and arrive at a time that has implications on the early winter patterns and the sPV too. The two dominant features are the -ve 850mb wind values near 60E, linked to the +IOD and now the more semi-permanent +ve 850mb winds (WWB) near and just west of the dateline, of which according to the Carl Shreck data is a noteworthy equatorial Rossby wave event. As we all know the MJO has been 'dead' for some considerable time now, the last noteworthy event way back in spring, clearly this links back into the evolution of the summer as well. It will be interesting to see how the MJO develops through the rest of the year as, eventually, a more pronounced development and event should make an appearance and that will also be key to some influence on the early winter pattern too. Generally speaking, the MJO is often more active during the winter months, than it is during the summer. As highlighted numerous times by Tamara over the years, a more Nina-like (-ve AAM) regime in winter is one that often supports more amplified mid-Atlantic ridges, which can build towards mid-latitudes. Amplification of this type, in winter, is often associated with inflated Azores high and with the usual tPV in play, which usually means a general +ve NAO pattern. There are also some links here to this stopping or inhibiting wave activity and flux that is required to help disrupt the sPV as well. The key thing towards winter is that a more atmospheric progression towards a Nino pattern (decline of easterly trade winds) means that the AAM pattern will lead to a greater risk of easterly anomalies at higher latitudes, bringing about a more amplified jet stream pattern. It is interesting to note that such a pattern has been in play of late, with a more dominant W'ly regime at lower latitudes, blocking, E'ly signal at higher latitudes. This is also why, over the next 7 to 14 days we see a dominant cyclonic pattern but one which is often set to see a more southerly tracking jet with high pressure trying to dominate at higher latitudes. Clearly, November blocking especially Russian and Ural blocking can have significant impacts down the line as well. The importance of the E'ly AAM anomalies at higher latitudes, compared with W'lies is exampled well if we look back a year ago on the below plot through Nov and into Dec - Note how through late Nov and into Dec, last year, the 50-60N region saw -ve E'ly anomalies dominant, being propped up by W'lies through the sub-tropics, overall it is this kind of AAM pattern that signals amplification and higher latitude blocking. If you then follow through last winter you can see how that pattern reversed with increased W'ly momentum being added to the mid-latitudes into the New Year as AAM fell to more negative territory - the key thing here, is that this year we could/should see the opposite occur with AAM rising. All in all, with the Nino/eQBO combination in play, some interesting signals already for a weaker vortex and, importantly, a likely progression towards a more +ve AAM pattern then the foundations remain firmly 'set' for a potentially interesting few months ahead, etc. Cheers, Matt

As usual, it isn't just about the vortex strength at 10hPa it is about how its behaviour and influence progress down through the strat and into the trop as the next few months progress which are always important. If you get that late Nov/early Dec connection between the strat and the trop, whereby zonal, W'ly winds have downwelled into the trop then as is often the case the first half of December, if not more can soon be written off in terms of anything wintry. That is often the standard progression across the N Hem through late Nov and into Dec and it takes some other 'external factor' like a pronounced MJO event, for example, to create a different outcome, at least for a time. The key thing this season to look for though is a clearly disorganised sPV and one that has little or no significant impacts on the trop given the eQBO and Nino combination. The caveat here is potentially other variables within the troposphere that could be an overriding factor, like the +ve IOD event, while some are talking about the high amounts of H20 within the strat after the Hunga-Tonga volcano from well over a year ago potentially aiding to cool the strat and intensify the vortex. There is some science behind this as this is how the vortex develops in the first place, but no one really knows how much (or not) of an influence this will be. As ever each season is slightly different from the last, but we go into this winter season with the long-awaited, entrenched eQBO and Nino combination and while a November SSW is extremely unlikely, one would be expected at some point this winter. However, the key point here is that it's not just what the vortex is doing up at 10hPa, etc, it's how it's influencing conditions in the trop that is equally, if not more important. At the moment there is a clear disconnect expected looking ahead, but not surprising for now given the time of year... Cheers, Matt.

Some people like marmite, others don't, some people put HP sauce on a bacon sarnie, others put ketchup on, some people like heat, some people like cold... Same setup when it comes to the annual discussion around dark nights. Personally, I'm in the camp of 'love dark nights', it has never bothered me and still doesn't. I actually welcome the arrival of cosy evenings after many months of light well into the evening. As ever, the British Isles gets more 'longer days' than it does the other way around, with BST clearly lasting for pretty much 7 months, GMT just 5 months. As with the choice over a bacon sarnie, it is a case of 'each to their own' - it's HP sauce for me and dark nights with it. #likesummerlovewinter Cheers, Matt.

Very difficult synoptics through the week ahead, especially regarding the position for frontal features and resultant large rainfall totals and which areas at greatest risk. The block to the NE certainly a key feature in determining the position and orientation of frontal systems as they move up into the UK from the SW. Primary areas seem to be well highlighted at the moment, with E and SE Scotland for real concern for a significant weather event later in the week from rainfall totals. With regard to the colder ingress through the forthcoming weekend it does seem more likely than not, clearly this is October of course and not January, but it should still lower temperatures and create quite a cold/raw feel with the E'ly wind into the weekend. The 00Z EC seems to be messing about too much with the low over England and Wales, not clearing it quickly enough and the deterministic frontal position highlights this well, over E England on Sat. It isn't without support, mind, but as things stand especially for more central and northern areas, at least, temperatures should fall away again this coming weekend. Cheers, Matt. Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4937781

Very difficult synoptics through the week ahead, especially regarding the position for frontal features and resultant large rainfall totals and which areas at greatest risk. The block to the NE certainly a key feature in determining the position and orientation of frontal systems as they move up into the UK from the SW. Primary areas seem to be well highlighted at the moment, with E and SE Scotland for real concern for a significant weather event later in the week from rainfall totals. With regard to the colder ingress through the forthcoming weekend it does seem more likely than not, clearly this is October of course and not January, but it should still lower temperatures and create quite a cold/raw feel with the E'ly wind into the weekend. The 00Z EC seems to be messing about too much with the low over England and Wales, not clearing it quickly enough and the deterministic frontal position highlights this well, over E England on Sat. It isn't without support, mind, but as things stand especially for more central and northern areas, at least, temperatures should fall away again this coming weekend. Cheers, Matt.

The key differences between the likes of the GFS bringing a chilly E or NE flow and a milder flow from the UKMO and the EC, is how the main development of the ridge takes place. Some of the last few runs of the GFS are absolutely text-book in terms of what you need to look for to get a Scandinavian high. The reason the UKMO and the EC don't really get there is because they make more of the cyclonic pattern to the NW, over Greenland and Iceland, with more than one main low pressure, the one that stops the amplification is east of Greenland at 126hr - https://www.wetterzentrale.de/maps/UKMHDOPEU00_126_1.png However, the GFS has one large area of low pressure, one low over Scandinavian and then another low over Iberia that is waiting for trough disruption to connect to the trough of Scandinavia, which then essentially 'pulls' the low over Iberia eastwards which props up the main developing high pressure. On the Wetterzentral plots, in particular, you then get the text-book 'finger' of yellow colours at 500mb tha arch northwards and then north-eastwards into Scandinavia as the large dominant low near Greenland pumps warm air up on the western side of the ridge, which, as ever, builds GPH and hence the high develops. It is quite fascinating to watch these kinds of synoptics whether they come off or not, obviously this kind of pattern would be what many cold fans would die for come the winter months, but forgetting all that, it is more of a learning experience for those wanting to keep tabs on the key features that can help develop a Scandinavia high in the future. I wouldn't rule out the GFS just yet, despite the lack of agreement from other models, as the evolution is very difficult to model, if the GFS has got a better handle of the synoptics near Greenland then it will come off, but equally if it hasn't and there is more than one cyclonic development there then a flatter pattern is more likely. Recording #279.mp4 Regards, Matt. Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4936014

The key differences between the likes of the GFS bringing a chilly E or NE flow and a milder flow from the UKMO and the EC, is how the main development of the ridge takes place. Some of the last few runs of the GFS are absolutely text-book in terms of what you need to look for to get a Scandinavian high. The reason the UKMO and the EC don't really get there is because they make more of the cyclonic pattern to the NW, over Greenland and Iceland, with more than one main low pressure, the one that stops the amplification is east of Greenland at 126hr - https://www.wetterzentrale.de/maps/UKMHDOPEU00_126_1.png However, the GFS has one large area of low pressure, one low over Scandinavian and then another low over Iberia that is waiting for trough disruption to connect to the trough of Scandinavia, which then essentially 'pulls' the low over Iberia eastwards which props up the main developing high pressure. On the Wetterzentral plots, in particular, you then get the text-book 'finger' of yellow colours at 500mb tha arch northwards and then north-eastwards into Scandinavia as the large dominant low near Greenland pumps warm air up on the western side of the ridge, which, as ever, builds GPH and hence the high develops. It is quite fascinating to watch these kinds of synoptics whether they come off or not, obviously this kind of pattern would be what many cold fans would die for come the winter months, but forgetting all that, it is more of a learning experience for those wanting to keep tabs on the key features that can help develop a Scandinavia high in the future. I wouldn't rule out the GFS just yet, despite the lack of agreement from other models, as the evolution is very difficult to model, if the GFS has got a better handle of the synoptics near Greenland then it will come off, but equally if it hasn't and there is more than one cyclonic development there then a flatter pattern is more likely. Recording #279.mp4 Regards, Matt.