MattH

The north-eastward extension of the Azores high with more of a troughed pattern over the N Atlantic has clearly been flagged as an expected/possible evolution deeper into May, for some time, despite little evidence for this within the NWP. As usual, especially in certain circumstances, this is where the usefulness of the GSDM comes into play, especially seeing it is often a far more stable variable to look at. We know the MJO is on the move, with a significant WWB on the way, one can surmise (despite still no GSDM website) that both +FT and +MT events are taking place and AAM will rise. That process, at the moment, is likely now underway, given where the analysis of the AAM was up to the 6th of May and clearly where it is set to go. The MJO is rapidly moving through the phases and those trying to use it as a guide will struggle. There has been some in-depth analysis on the composite anoms in recent posts, but, again the problem is that the MJO is quickly progressing through the phases of 3-4-5-6 and trying to match each one to a likely evolution, under this situation, will likely lead to confused and uncertain end results. Definitely need to keep a watchful eye on NWP moving forward to hopefully see this broader signal gain consistency with an Atlantic trough and downstream ridge pattern. Cheers, Matt. Original post: https://community.netweather.tv/topic/98519-model-output-discussion-15th-march-onwards/?do=findComment&comment=4850274

NB: As a side note, the PNA is set to go positive as well.... Again, all no surprise given the WWB and the atmospheric push towards a Nino regime (High GWO orbit) and we can see that pattern well just looking at the 00Z GEFS anom plot. The key thing for the N Atlantic and W Europe is where the primary trough, after the W USA ridge, ends up. The GEFS mean has it somewhat further west than we would like, but clearly this can all be refined eastwards somewhat, it is the broader pattern that is now, finally, gaining momentum (no pun intended!) for an improving, anticyclonic scenario as we progress deeper into May, linked to upstream, Pacific developments etc. Cheers.

The north-eastward extension of the Azores high with more of a troughed pattern over the N Atlantic has clearly been flagged as an expected/possible evolution deeper into May, for some time, despite little evidence for this within the NWP. As usual, especially in certain circumstances, this is where the usefulness of the GSDM comes into play, especially seeing it is often a far more stable variable to look at. We know the MJO is on the move, with a significant WWB on the way, one can surmise (despite still no GSDM website) that both +FT and +MT events are taking place and AAM will rise. That process, at the moment, is likely now underway, given where the analysis of the AAM was up to the 6th of May and clearly where it is set to go. The MJO is rapidly moving through the phases and those trying to use it as a guide will struggle. There has been some in-depth analysis on the composite anoms in recent posts, but, again the problem is that the MJO is quickly progressing through the phases of 3-4-5-6 and trying to match each one to a likely evolution, under this situation, will likely lead to confused and uncertain end results. Definitely need to keep a watchful eye on NWP moving forward to hopefully see this broader signal gain consistency with an Atlantic trough and downstream ridge pattern. Cheers, Matt.

The constant with the outlook deeper into May is still linked to the expected and noteworthy eastward progression of the MJO and associated -ve VP200 anoms and the associated WWB. As usual, all this brings about a long-predicted rise in AAM, as, atmospherically, we get another Nino push, which will no doubt aid (oceanically) the trend towards El Nino as well. The last few runs of the EC46 for the AAM anoms have, literally, been off the scale and it has been an upward trend in AAM for the last 2 weeks as this signal has grown and developed... Unfortunately, for those with interest in the GSDM, we continue to be walking 'blind' by the fact that the primary GSDM website remains well out of date and despite several attempts to gain information from the owner of the site, it doesn't look good at all for this to come back, which is a very bad thing indeed. One can only hope that someone over in the US picks this up separately moving forward and it returns, but, for now, it's gone. Moving on from that and, overall, despite the cyclonic outlook to the first half of May one would still expect, with reasonable confidence for there to be a Rossby wave pattern and evolution that supports a more troughed Atlantic and ridged pattern over W Europe, including NW Europe towards and beyond mid-May. This is still a long-term prediction of mine for May, and, tentatively, there is some evidence of this now in NWP which I would hope will gain some traction in the coming days. Personally, this has been a dreadful spring and is a perfect example of why (again personally) spring is my least favourite season in the British Isles, but that is for another thread. One can only hope that with the assistance of the upstream Pacific developments a more pronounced warmer, anticyclonic spell will (finally!) arrive this month, but that isn't likely until mid-May at the earliest I would suggest. The summer itself, as some have already said may not follow what spring has brought, it doesn't necessarily work that. However, the positive for those hoping for warm, anticyclonic summer days is that we are progressing into early summer clearly within a more Nino regime, some of the worst summers usually come with a -ve AAM pattern at this time of year, plus other factors, that isn't the case this year, but the eQBO summer can, sometimes, aid northern blocking. With ENSO neutral conditions set to rumble one for a while yet I still think, overall, most of the summer will be relatively volatile, potentially flipping from very warm, anticyclonic NW European ridge patterns (as MJO passages come to pass and we get +GLAAM), to then an approaching trough pattern from off the Atlantic, as AAM then falls. It is, however, as usual, very difficult to call and with the usual uncertainties these days that AGW brings, then confidence is obviously low. Personally, though I don't expect a repeat of 2018, nor do I expect a horror show like 2012, but a more changeable, volatile period. As ever, time will tell. Cheers. Original post: https://community.netweather.tv/topic/98519-model-output-discussion-15th-march-onwards/?do=findComment&comment=4848968

As ever visible regional variations and personal opinions on the weather dictate comments and outcomes, but, personally, this has been up there with the worst spring in years... Here in E Lancs, especially at altitude, it has been dreadful and has been a perfect example of why, especially in the British Isles and away from the south, spring is, IMO, the worst season of the year. Despite the welcomed lighter days, as this year has shown, we move out of winter into another 2 months of painstaking weather. The lack of any early warmth or even more prolonged settled conditions has been the most noteworthy feature and the maximum temperature here so far this year is just +15.3C and here we are in the 5th month of the year, with just 6-7 weeks until the longest day. To an extent, in recent years, we have been 'spoilt' by early warmth and good springs, first covid long-down for example, but we've also seen early summer weather arrive to then disappear as the main summer period progresses. Again, all personal and viewed from a local and regional perspective but I have been very glad, as usual, to see the back of the worst 2 months of the year, in March and April. Still, the outlook, until mid-May, at least remains not significantly different, with a cyclonic bias and, overall, not a particularly warm outlook either. After the long winter months, despite being my favourite part of the year, even I welcome some early warmth and better weather. Still, in the British Isles and especially for certain areas of it, March and April can be two of the 'longest' months of the year, as they have been this year...Most certainly good riddance to spring this year and bring on summer, whatever it may bring. Cheers.

The constant with the outlook deeper into May is still linked to the expected and noteworthy eastward progression of the MJO and associated -ve VP200 anoms and the associated WWB. As usual, all this brings about a long-predicted rise in AAM, as, atmospherically, we get another Nino push, which will no doubt aid (oceanically) the trend towards El Nino as well. The last few runs of the EC46 for the AAM anoms have, literally, been off the scale and it has been an upward trend in AAM for the last 2 weeks as this signal has grown and developed... Unfortunately, for those with interest in the GSDM, we continue to be walking 'blind' by the fact that the primary GSDM website remains well out of date and despite several attempts to gain information from the owner of the site, it doesn't look good at all for this to come back, which is a very bad thing indeed. One can only hope that someone over in the US picks this up separately moving forward and it returns, but, for now, it's gone. Moving on from that and, overall, despite the cyclonic outlook to the first half of May one would still expect, with reasonable confidence for there to be a Rossby wave pattern and evolution that supports a more troughed Atlantic and ridged pattern over W Europe, including NW Europe towards and beyond mid-May. This is still a long-term prediction of mine for May, and, tentatively, there is some evidence of this now in NWP which I would hope will gain some traction in the coming days. Personally, this has been a dreadful spring and is a perfect example of why (again personally) spring is my least favourite season in the British Isles, but that is for another thread. One can only hope that with the assistance of the upstream Pacific developments a more pronounced warmer, anticyclonic spell will (finally!) arrive this month, but that isn't likely until mid-May at the earliest I would suggest. The summer itself, as some have already said may not follow what spring has brought, it doesn't necessarily work that. However, the positive for those hoping for warm, anticyclonic summer days is that we are progressing into early summer clearly within a more Nino regime, some of the worst summers usually come with a -ve AAM pattern at this time of year, plus other factors, that isn't the case this year, but the eQBO summer can, sometimes, aid northern blocking. With ENSO neutral conditions set to rumble one for a while yet I still think, overall, most of the summer will be relatively volatile, potentially flipping from very warm, anticyclonic NW European ridge patterns (as MJO passages come to pass and we get +GLAAM), to then an approaching trough pattern from off the Atlantic, as AAM then falls. It is, however, as usual, very difficult to call and with the usual uncertainties these days that AGW brings, then confidence is obviously low. Personally, though I don't expect a repeat of 2018, nor do I expect a horror show like 2012, but a more changeable, volatile period. As ever, time will tell. Cheers.

The cold (poor) spring this year is, overall, not something of a surprise, especially given the late winter SSW and particularly so given the evidence of how the influences from the late winter SSW have continued to influence the tropospheric pattern for weeks down the line. I certainly think the up-coming blocking pattern and retrogression towards Greenland has some links still, even though it is a time of year, as we all know, that this kind of amplification of the pattern can occur. How many times over the years, whether there has been a late winter SSW or not, do the 'winter fans' often bemoan the synoptics that arrive in March and April, that they all wanted about 8 weeks prior... Personally, this is why spring, IMO, is the worst season of the year, if we could jump from Feb to May each year, given the UK's climate, then that would be superb. I, for one, am always glad to turn the calender over and see the 1st of May each year and leave behind the likes of what we have seen this year that can arrive through March and April, sometimes two of the "longest" months of the year... Looking further ahead though and this high latitude blocking signal will, eventually wane as seasonal wavelength changes continue to influence the overall outlook. Northern blocking patterns at this time of year can become locked in under the right broader setups, as they did in 2012 and 2017, but that is usually linked to a fundamental fall in AAM (La Nina regime) and an eQBO combination. Clearly, we are not going into late spring and early summer in a falling AAM setup, in fact it is the opposite as the below EPS data shows... Another active MJO passage seems likely during May with an associated signiifcant WWB. Equally, what stands out on the latest EPS VP200 plot is the development of the low frequency El Nino standing wave signature as well, near and just to the west of the dateline, this a sure-fire piece of evidence that El Nino is on the way. Clearly, note the continued rise and trend in the AAM signal as well throughout May and, again, no doubt linked to the expected next up-coming MJO and WWB signature. So, while this spring has been a long-ol slog and we are not yet out of the woods, given what is on the way next week, there may well come a time when with a reduction in northern blocking patterns, that a more typical late spring/early summer pattern will emerge and, IMO, that will be focused around NE extensions of the Azores high, rooted within a broader El Nino background state, especially atmospherically, but also increasingly oceanically as well. The MJO may well still have some big influences on the first half of the summer, especially with ENSO neutral conditions dominating, with a 'waxing and waning' +ve AAM and -ve AAM patterns possible as the MJO passes through the Pacific, with associated WWB, while then clearing to see something of a return to the trades (falling AAM etc), which could see the rossby wave train alter to bring both ridges and troughs to the British Isles at times. However, if you're looking for a half decent summer, then, overall, you want to be going into the summer period within a broader rising (El Nino) AAM regime, not the other way around and that could be one key piece of the puzzle for summer this year... Regards, Matt. Original post: https://community.netweather.tv/topic/98519-model-output-discussion-15th-march-onwards/?do=findComment&comment=4843542

The cold (poor) spring this year is, overall, not something of a surprise, especially given the late winter SSW and particularly so given the evidence of how the influences from the late winter SSW have continued to influence the tropospheric pattern for weeks down the line. I certainly think the up-coming blocking pattern and retrogression towards Greenland has some links still, even though it is a time of year, as we all know, that this kind of amplification of the pattern can occur. How many times over the years, whether there has been a late winter SSW or not, do the 'winter fans' often bemoan the synoptics that arrive in March and April, that they all wanted about 8 weeks prior... Personally, this is why spring, IMO, is the worst season of the year, if we could jump from Feb to May each year, given the UK's climate, then that would be superb. I, for one, am always glad to turn the calender over and see the 1st of May each year and leave behind the likes of what we have seen this year that can arrive through March and April, sometimes two of the "longest" months of the year... Looking further ahead though and this high latitude blocking signal will, eventually wane as seasonal wavelength changes continue to influence the overall outlook. Northern blocking patterns at this time of year can become locked in under the right broader setups, as they did in 2012 and 2017, but that is usually linked to a fundamental fall in AAM (La Nina regime) and an eQBO combination. Clearly, we are not going into late spring and early summer in a falling AAM setup, in fact it is the opposite as the below EPS data shows... Another active MJO passage seems likely during May with an associated signiifcant WWB. Equally, what stands out on the latest EPS VP200 plot is the development of the low frequency El Nino standing wave signature as well, near and just to the west of the dateline, this a sure-fire piece of evidence that El Nino is on the way. Clearly, note the continued rise and trend in the AAM signal as well throughout May and, again, no doubt linked to the expected next up-coming MJO and WWB signature. So, while this spring has been a long-ol slog and we are not yet out of the woods, given what is on the way next week, there may well come a time when with a reduction in northern blocking patterns, that a more typical late spring/early summer pattern will emerge and, IMO, that will be focused around NE extensions of the Azores high, rooted within a broader El Nino background state, especially atmospherically, but also increasingly oceanically as well. The MJO may well still have some big influences on the first half of the summer, especially with ENSO neutral conditions dominating, with a 'waxing and waning' +ve AAM and -ve AAM patterns possible as the MJO passes through the Pacific, with associated WWB, while then clearing to see something of a return to the trades (falling AAM etc), which could see the rossby wave train alter to bring both ridges and troughs to the British Isles at times. However, if you're looking for a half decent summer, then, overall, you want to be going into the summer period within a broader rising (El Nino) AAM regime, not the other way around and that could be one key piece of the puzzle for summer this year... Regards, Matt.

Quick reply... Many have got to remember that this event was never meant to be 'over' by the end of Thursday afternoon. The amount of abuse and bad commentary forecasters have got so far today because of a no-show is really poor. Judge a forecast when the whole event is over. However, to counterbalance that...there has definitely been an underestimation in the models of the influence of this time of year, I'm guilty of not remembering it as a forecaster even though seen it a handful of times over the years. Despite the thicker cloud layers, the increasingly 'strong' March sun still has an influence on surface temperatures, this is why, for many, it has snowed today but not settled and especially why on tarmac and road surfaces, which are black, absorb even the smallest amount of insolution, so surface temperatures have been +2C and +3C. This kind of fine detail models will just not sort out. Time will tell, by tomorrow morning, whether this is a complete forecast bust across the scale, from all organisations and forecasts or not. It is, however, from now onwards that with the sun issue being removed from the equation snow should start to settle and, again, this event isn't over for another half a day and a bit!... Cheers, Matt.

Hi to all across the NW!... Worth a post here given the setup just to add some extra thoughts and comments on the situation for tomorrow. The primary thing to mention at the moment is not to get too hung up on HRES models from different sources. The forcing associated with the fronts, plus the combination of regional variations will mean there will also be some differences in which areas see the largest snowfall totals. Getting that out of the way and the main thing to remember is that this is the best synoptic situation the NW has seen for widespread snowfall, strong winds and disruptive conditions in a good number of years. As we all know you don't need to travel far across the NW to change altitude and also see a change in micro-climate. All that will definitely play a role in which areas see the most snowfall. Let's get real first - If you're in Manchester, Bury, Liverpool, Blackpool et al then don't expect >10cm or more. That being said even those areas are likely to see more snow than seen for some time. If you're at higher altitudes (>150-200m) then clearly you're likely to see higher totals. The primary reason for the Amber warning from the MO is related to the pivot point on the fronts as the low pressure comes east, plus orographic enhancement, clearly there will be some areas, to the immediate west of the Pennines that may end up in a 'shadow' but knowing exactly where and when is near impossible to tell. From what I've seen and forecast in recent days, it is definitely more eastern areas of Lancashire and W Yorkshire, along with parts of the Peak District that are likely to see the largest totals from this, especially above 200m. Clearly, the Amber warning region from the MO is a key focus for some very large totals and these may well be realised more locally, again, that border between W Yorkshire, E Lancashire and N Yorkshire is likely to be a focal point IMO. There will no doubt be some banding features that become present on radar that model data hasn't captured that well that can make a big difference over short distances. That being said, this is a frontal snowfall event and when coupled with the E'ly flow, with mean speeds of 20KT and much higher gusts, then on the grand scheme of things whether you're at low lying areas of Manchester or in E Lancashire/W Yorkshire, it is now a simple case of watching the radar and enjoying the synoptic event. I have a feeling it could be a good few years again until the region falls under this kind of setup with a low that tracks perfectly for this kind of snowfall event! Forget the intricacies of it all now, accept the local and regional variations that are likely to appear and simply enjoy what this synoptic event will bring. Cheers. Matt.

A quick post on this as the second part of this is very misleading to people trying to learn or look at the outlook... There IS evidence for the strat to imprint on the trop looking ahead, the 00Z EC Det once again shows that. Using the GEFS mean as a foundation to highlight that there is no evidence for a strat to trop imprint just isn't realistic at all. You're also leaving out that if you do want to use ENS that the EC ENS from the last 24 hours doesn't return the main tPV to Canada either. Use ENS plots and means days out at your peril in times like the present. Cheers, Matt. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4811705

A quick post on this as the second part of this is very misleading to people trying to learn or look at the outlook... There IS evidence for the strat to imprint on the trop looking ahead, the 00Z EC Det once again shows that. Using the GEFS mean as a foundation to highlight that there is no evidence for a strat to trop imprint just isn't realistic at all. You're also leaving out that if you do want to use ENS that the EC ENS from the last 24 hours doesn't return the main tPV to Canada either. Use ENS plots and means days out at your peril in times like the present. Cheers, Matt.

An interesting shift in the 00Z MOGREPS this morning, which are just getting analysed. A good number of these show the colder flow from the N and NE by the 5th and the 6th, certainly worth taking note if MOGREPS is showing this, but clearly, there is a lack of consistency, but one to keep tabs on. Lastly, the associated loop from top of the strat to the bottom clearly shows evidence of how this morning's 00Z Det EC imprints from the SSW onto the trop, very easy to match up the key +ve and -ve MSLP and 500mb height anomalies when you look from top down now... Steady away. Latest.mp4 Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4811058

An interesting shift in the 00Z MOGREPS this morning, which are just getting analysed. A good number of these show the colder flow from the N and NE by the 5th and the 6th, certainly worth taking note if MOGREPS is showing this, but clearly, there is a lack of consistency, but one to keep tabs on. Lastly, the associated loop from top of the strat to the bottom clearly shows evidence of how this morning's 00Z Det EC imprints from the SSW onto the trop, very easy to match up the key +ve and -ve MSLP and 500mb height anomalies when you look from top down now... Steady away. Latest.mp4

Take a look at the N Hem view of the 00Z ECMWF - https://www.wetterzentrale.de/en/topkarten.php?map=2&model=ecm&var=1&time=216&run=0&lid=OP&h=0&mv=0&tr=24 To me, that is one of the first runs that shows a more obvious and large change in trop pattern linked to the SSW. Note how earlier in the forecast period the low heights and low pressure systems dominate over the Canadian arctic and Alaska. Run through the sequence and get towards the end of the first week of March and - boom - the whole pattern over that region of the N Hem has rapidly changed, along with a clear and obvious displacement of the main tPV to where you would expect it given the strat developments as well. Time will tell whether it's a one-off run, but that has stood out significantly this morning and needs watching closely but continues to tie in with the broader expectations and risks looking ahead in terms of northern blocking and colder air eventually arriving from the N or NE, etc. Cheers. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4811028

Take a look at the N Hem view of the 00Z ECMWF - https://www.wetterzentrale.de/en/topkarten.php?map=2&model=ecm&var=1&time=216&run=0&lid=OP&h=0&mv=0&tr=24 To me, that is one of the first runs that shows a more obvious and large change in trop pattern linked to the SSW. Note how earlier in the forecast period the low heights and low pressure systems dominate over the Canadian arctic and Alaska. Run through the sequence and get towards the end of the first week of March and - boom - the whole pattern over that region of the N Hem has rapidly changed, along with a clear and obvious displacement of the main tPV to where you would expect it given the strat developments as well. Time will tell whether it's a one-off run, but that has stood out significantly this morning and needs watching closely but continues to tie in with the broader expectations and risks looking ahead in terms of northern blocking and colder air eventually arriving from the N or NE, etc. Cheers.

Morning. If your winter patience is wearing thin then the next week or two weeks will put that to the test even further! - While the debate does go on as to how and where the recent signal for blocking patterns to the NW has originated from, what does carry high confidence is that model (NWP) volatility will continue in the coming days and no doubt weeks, it is a logical outcome given the MJO and SSW influences, etc. Overall, the recent craziness from some of the NWP, in terms of retrogressing the high towards the NW and bringing in a very cold N'ly airflow by the opening weekend of March is, IMO, related to the MJO and not any SSW influences, there is too much evidence to support this. Also, it is worth highlighting that this upcoming secondary and significant warming has not yet even happened and isn't expected to take place until the final few days of February, as highlighted well by the recent ECMWF plot. What we could be seeing within NWP is an initial amplification of the pattern and retrogression, linked to the MJO, but as the upcoming additional strat warmings take place, there may well still yet be a period of 'flushing out of the W'lies' within the system and, in a way, it is not a surprise to perhaps see the huge Greenland blocks being watered down now, with something of a more displaced high to the W and SW by the opening weekend of March - Does this mean that is it for cold synoptics? - Most certainly not, it's just back to the old situation of having to wait yet again. There are so many variables in place that support blocking patterns and a heightened risk of cold weather patterns looking ahead, I just have a feeling some of the crazy charts in recent days have been a false dawn and come too soon, linked to the MJO and not the SSW, but there is still plenty of time for all the key drivers of the medium and long term to come together to bring some wild and crazy late winter synoptics to the British Isles as the first half of March progresses. Also as a side note, if/when the time comes for cold weather to make an appearance, then at this time of year, for anything noteworthy the British Isles really does need to be looking at getting the -10C 850mb isotherm over it, if not below. Cheers, Matt. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4810396

Morning. If your winter patience is wearing thin then the next week or two weeks will put that to the test even further! - While the debate does go on as to how and where the recent signal for blocking patterns to the NW has originated from, what does carry high confidence is that model (NWP) volatility will continue in the coming days and no doubt weeks, it is a logical outcome given the MJO and SSW influences, etc. Overall, the recent craziness from some of the NWP, in terms of retrogressing the high towards the NW and bringing in a very cold N'ly airflow by the opening weekend of March is, IMO, related to the MJO and not any SSW influences, there is too much evidence to support this. Also, it is worth highlighting that this upcoming secondary and significant warming has not yet even happened and isn't expected to take place until the final few days of February, as highlighted well by the recent ECMWF plot. What we could be seeing within NWP is an initial amplification of the pattern and retrogression, linked to the MJO, but as the upcoming additional strat warmings take place, there may well still yet be a period of 'flushing out of the W'lies' within the system and, in a way, it is not a surprise to perhaps see the huge Greenland blocks being watered down now, with something of a more displaced high to the W and SW by the opening weekend of March - Does this mean that is it for cold synoptics? - Most certainly not, it's just back to the old situation of having to wait yet again. There are so many variables in place that support blocking patterns and a heightened risk of cold weather patterns looking ahead, I just have a feeling some of the crazy charts in recent days have been a false dawn and come too soon, linked to the MJO and not the SSW, but there is still plenty of time for all the key drivers of the medium and long term to come together to bring some wild and crazy late winter synoptics to the British Isles as the first half of March progresses. Also as a side note, if/when the time comes for cold weather to make an appearance, then at this time of year, for anything noteworthy the British Isles really does need to be looking at getting the -10C 850mb isotherm over it, if not below. Cheers, Matt.

Morning. This is a key post so far today, and the last couple of days too. The winter has evolved in something of an unusual way, especially since the week of colder weather in mid-January, with sub-tropical blocking patterns often in evidence, this definitely seems to becoming more of a frequent occurrence of the UK and European winters. Obviously, European blocking patterns have always been present, but usually across Spain, France, Italy, Central Europe, etc, in the winter period, leaving the UK at the mercy of the usual Atlantic storms. Despite more of a +ve NAO pattern of late, we continue to see below or well below average rainfall totals and that trend is clearly not likely to change. We've seen this setup a handful of times in recent years through Jan and Feb with high pressure near or just to the south of the British Isles, etc - Will this become a problem towards summer or, as is often seemingly possible, the weather balances itself out? - Time will tell on that one as the month's tick by, but ENSO Neutral conditions usually, for the UK mean a potentially volatile summer setup, often driven by the MJO which is usually more pronounced in ENSO neutral conditions too. Back to the hear and now and regarding the above, I think some are being too quick to expect quick trop changes. We are already seeing interesting synoptics appear in medium and long-term data and particularly from the overnight EC46 which is really noteworthy, IMO. This second warming event though which has only really been properly modelled over the last week or so, is still potentially the 'deal breaker' for significant trop changes, but not until further into March - Patience is, as ever, required even though I can see why that is now running out, mine too to an extent. However, with the MJO passage of 4-5-6-7 and now likely 8 all part of the tropospheric processes, then coupled with the strat, from a UK perspective we can't ask much more in terms of a solid foundation for blocking patterns. Obviously, the finer details will determine whether the outcome is a watered-down mess, or something more significant, we have to take into account that this will be March too, not January and that aspect needs to adding to the equation when looking at potential air masses and intensity of any cold. Still, from everything I've seen then the overall outlook which continues to be highlighted already is the one that is most likely to play out - High builds in this weekend, lingers, but with then all eyes on the main tPV leaving NE Canada and Greenland being 'sucked' eastwards towards the Russian side of the pole and with blocking patterns and retrogression taking place as the first half of March progresses with more of a N or NE'ly more likely, than a very cold E or SE'ly as things stand. It is, however, that time of year when the lovers of cold and warm can increasingly disagree - March for the UK can be a long drawn out month, one of my least favourite months/periods of the year, some hoping for late cold, others longing for some mild days and sunshine and daffodils. As things stand, it is the former that is far more likely than the latter, overall, for March this year IMO. Cheers, Matt. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808792

Morning. This is a key post so far today, and the last couple of days too. The winter has evolved in something of an unusual way, especially since the week of colder weather in mid-January, with sub-tropical blocking patterns often in evidence, this definitely seems to becoming more of a frequent occurrence of the UK and European winters. Obviously, European blocking patterns have always been present, but usually across Spain, France, Italy, Central Europe, etc, in the winter period, leaving the UK at the mercy of the usual Atlantic storms. Despite more of a +ve NAO pattern of late, we continue to see below or well below average rainfall totals and that trend is clearly not likely to change. We've seen this setup a handful of times in recent years through Jan and Feb with high pressure near or just to the south of the British Isles, etc - Will this become a problem towards summer or, as is often seemingly possible, the weather balances itself out? - Time will tell on that one as the month's tick by, but ENSO Neutral conditions usually, for the UK mean a potentially volatile summer setup, often driven by the MJO which is usually more pronounced in ENSO neutral conditions too. Back to the hear and now and regarding the above, I think some are being too quick to expect quick trop changes. We are already seeing interesting synoptics appear in medium and long-term data and particularly from the overnight EC46 which is really noteworthy, IMO. This second warming event though which has only really been properly modelled over the last week or so, is still potentially the 'deal breaker' for significant trop changes, but not until further into March - Patience is, as ever, required even though I can see why that is now running out, mine too to an extent. However, with the MJO passage of 4-5-6-7 and now likely 8 all part of the tropospheric processes, then coupled with the strat, from a UK perspective we can't ask much more in terms of a solid foundation for blocking patterns. Obviously, the finer details will determine whether the outcome is a watered-down mess, or something more significant, we have to take into account that this will be March too, not January and that aspect needs to adding to the equation when looking at potential air masses and intensity of any cold. Still, from everything I've seen then the overall outlook which continues to be highlighted already is the one that is most likely to play out - High builds in this weekend, lingers, but with then all eyes on the main tPV leaving NE Canada and Greenland being 'sucked' eastwards towards the Russian side of the pole and with blocking patterns and retrogression taking place as the first half of March progresses with more of a N or NE'ly more likely, than a very cold E or SE'ly as things stand. It is, however, that time of year when the lovers of cold and warm can increasingly disagree - March for the UK can be a long drawn out month, one of my least favourite months/periods of the year, some hoping for late cold, others longing for some mild days and sunshine and daffodils. As things stand, it is the former that is far more likely than the latter, overall, for March this year IMO. Cheers, Matt.

This may well 'leave a mark' looking ahead! - As a few have mentioned of late the tropospheric and stratospheric connection which could be made as a result of the SSW and the MJO really does signal the possibility of signficant interest for winter synoptics in late Feb and Mar. As ever some would argue it's all too late and delays spring etc, but putting mild and cold biases aside after what has been a heck of a benign (boring, depending on your viewpoint) winter, overall, the atmosphere is about to get quite the 'shake up' and that can only bring interest from all angles and also provides another learning curve given how these variables will play out and interact with each other. As ever this doesn't guarantee cold or another BFTE but it sure does spike interest for significantly increasing the risk of producing some wild synoptics down the line. Cheers. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4804256

This may well 'leave a mark' looking ahead! - As a few have mentioned of late the tropospheric and stratospheric connection which could be made as a result of the SSW and the MJO really does signal the possibility of signficant interest for winter synoptics in late Feb and Mar. As ever some would argue it's all too late and delays spring etc, but putting mild and cold biases aside after what has been a heck of a benign (boring, depending on your viewpoint) winter, overall, the atmosphere is about to get quite the 'shake up' and that can only bring interest from all angles and also provides another learning curve given how these variables will play out and interact with each other. As ever this doesn't guarantee cold or another BFTE but it sure does spike interest for significantly increasing the risk of producing some wild synoptics down the line. Cheers.

Morning. Quick post but, overall, still nothing has changed looking ahead, both short-term and long-term and those hoping for late winter weather may still have to pin their hopes on the final third of February or, most probably, March. We have fallen into the late winter trap of dominant -ve AAM anomalies through the sub-tropics, being propped up by constant WAA over the North Atlantic as the dominant trop PV remains a force to the NW, where it often sits through the late winter, as mentioned a while back any sort of Scandinavian block was never going to happen and, for now, the dominant outlook, as clearly shown by many on here already, is for a sub-tropical/mid-latitude high pressure system to remain influential over W-NW Europe and this won't move very far. The overall AAM profile highlights this pattern quite well, with plenty of -ve AAM anomalies flooding the sub-tropics, note as well the ECM dynamic trop plots, constantly showing a series of anticyclonic wave breaks which will do nothing but simply reinforce the block that many want nearer 60-70N. The MJO is now on the move and is likely, at a minimum to progress through phases 4 and 5, most probably 6 as well. If your looking for a potential forcing or something to at least mix things up a bit then this may help the cause, but not for at least another 7 to 14 days, which clearly takes us past mid-February. Some of the composite anomalies of the MJO through phases 4-5-6 do bring northern blocking but, as ever, it is never A+B=C and other factors, especially the current dominant tPV may well have some say in this. The increasingly strong signal for a potential early final warming or a very late winter SSW is gaining traction but, once again this is most certainly not going to immediately deliver synoptics to bring late winter weather any time soon, if at all, especially if it is another displacement event. There is, however, some science behind the risk of synoptics appearing in March that many would have wanted in January and February, how many times have we seen that happen before, especially as seasonal wavelength changes start to come into play as well. Obviously one could argue the seasonal models have called the late winter pattern correct. There is clearly a connection between a more dominant +ve NAO regime through later winter within a La Nina state and, overall, that has come to fruition, not to the extent it could have, given the blocking pattern over 30-40N currently and lookig ahead, but the winter is likely to fizzle out, overall, IMO. Clearly, winter weather and synoptics can extend beyond February and that clearly does remain a possibility, especially through March, but by then you need some 'proper' synoptics for any significant cold weather and those kind of synoptics can simply delay the onset of spring for many. Cheers, Matt. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4802440

Morning. Quick post but, overall, still nothing has changed looking ahead, both short-term and long-term and those hoping for late winter weather may still have to pin their hopes on the final third of February or, most probably, March. We have fallen into the late winter trap of dominant -ve AAM anomalies through the sub-tropics, being propped up by constant WAA over the North Atlantic as the dominant trop PV remains a force to the NW, where it often sits through the late winter, as mentioned a while back any sort of Scandinavian block was never going to happen and, for now, the dominant outlook, as clearly shown by many on here already, is for a sub-tropical/mid-latitude high pressure system to remain influential over W-NW Europe and this won't move very far. The overall AAM profile highlights this pattern quite well, with plenty of -ve AAM anomalies flooding the sub-tropics, note as well the ECM dynamic trop plots, constantly showing a series of anticyclonic wave breaks which will do nothing but simply reinforce the block that many want nearer 60-70N. The MJO is now on the move and is likely, at a minimum to progress through phases 4 and 5, most probably 6 as well. If your looking for a potential forcing or something to at least mix things up a bit then this may help the cause, but not for at least another 7 to 14 days, which clearly takes us past mid-February. Some of the composite anomalies of the MJO through phases 4-5-6 do bring northern blocking but, as ever, it is never A+B=C and other factors, especially the current dominant tPV may well have some say in this. The increasingly strong signal for a potential early final warming or a very late winter SSW is gaining traction but, once again this is most certainly not going to immediately deliver synoptics to bring late winter weather any time soon, if at all, especially if it is another displacement event. There is, however, some science behind the risk of synoptics appearing in March that many would have wanted in January and February, how many times have we seen that happen before, especially as seasonal wavelength changes start to come into play as well. Obviously one could argue the seasonal models have called the late winter pattern correct. There is clearly a connection between a more dominant +ve NAO regime through later winter within a La Nina state and, overall, that has come to fruition, not to the extent it could have, given the blocking pattern over 30-40N currently and lookig ahead, but the winter is likely to fizzle out, overall, IMO. Clearly, winter weather and synoptics can extend beyond February and that clearly does remain a possibility, especially through March, but by then you need some 'proper' synoptics for any significant cold weather and those kind of synoptics can simply delay the onset of spring for many. Cheers, Matt.

Morning. On full review of model data, the GFS still remains the 'least likely' option despite the consistency within itself. Comparing and contrasting previous model 'wins' against up-coming events just won't lead to much success, GFS may well have correctly picked up the summer synoptics and heat, but that doesn't automatically mean it'll be correct with this setup either. The overall teleconnections still don't support a block to that extent, in that local. Think of a fishing swimming against the tide, that is what the GFS is currently doing. Clearly, the tide being the more dominant zonal, W'ly flow which the UKMO and ECMWF are bringing across the North Atlantic in time. It is always a very difficult task to push back against that flow, especially when there is such a deep, entrenched tPV now over NE Canada and Greenland, but it is the individual cyclonic wave breaks and short-wave details that will likely 'make or break' this outcome. Overall, from last detailed post earlier in Jan, not much has changed - We all had to see what any strat developments would do, clearly not much. The outlook there does look interesting for late Feb/early Mar, one to keep tabs on, while the AAM remains firmly negative, but upstream changes with the MJO may well be on the way. It is certainly a fascinating watch to say the least and, as has happened before here, one or more models will suddenly change and switch and, again, after complete analysis of the situation this morning then the GFS still remains firmly within the 'least likely' corner, while the UKMO and the ECMWF are more probable outcomes. Clearly, in meteorology just because it is 'least likely' doesn't mean it isn't impossible and those hoping for a more significant early to mid February cold spell, really from out of nowhere, have got to hope that the GFS has got this one correct. Long-term and the key feature will be this potential warming in late Feb. The Scandinavian block coupled with the Aleutian low setup, as per GFS would likely 'do it', but how many times have we been here before, then having to trawl through synoptics in March and potentially April that nobody wants and of which would have been superb 8 weeks prior. The joys of the British and NW European climate within an ever changing background due to AGW. Cheers, Matt. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4800067