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Recretos

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  1. Recretos
    Something like that. This current wave2 is welcome by all means. Any disruption no matter how small, is welcome. You cannot really expect an SSW split from the upcoming wave 2, it just doesn't work that way. But it has its role in whole picture. Now what I expect in a relatively mid range: As the W2 wanes, the W1 will remain present. I dont really expect it ever to completely back off this season (that would be a surprise). The vortex will reform some if not almost all of its composure, but the wave1 will hold it in a "not full strength" position, slightly dispositioned. With the natural flow of events i expect the vortex to eventually get back to disposition more over Scandi area or perhaps Siberia, which would be in time for "wave's" 2 to to re-emerge as we head into December. So much for now.
  2. Recretos
    Well, to reveal some of the mystery, I expect the vortex to fall at a certain time, dont get me wrong. I was staring at certain graphics and forecasts and some other stuff, literally starring, and I kinda lost myself in it, brainstorming like usually, and then it kinda hit me what might happen.
  3. Recretos
    As far as 2009 is concerned, we really are in a slightly different situation this year, as far as this forecasted split goes. I have to say that I am really not too happy about this current split, or at least what is forecasted to follow after it. But on the other hand, I can almost see where it is going after that (after FI), and I think I am kinda starting to understand how this whole story of the 14/15 season might look like stratospherically. But enough speculation for now. All in its time. Regards.
  4. Recretos
    And about the QBO topic from the other day, this is how you can easily spot the QBO phase, without the number crunching. Green is the current negative phase, dominating the mid strat (the main area of influence), which is quite strong, an it is obviously way too big to be defined to one level, and especially to 50mb. In the yellow is the "probable" next positive phase in development. That is why graphics are sometimes way more practical than raw numbers, since you get the feel of perspective, unless you are going for hardcore details, which in this case would be at 30mb, not 50mb.
  5. Recretos
    Matt has beaten me to it again. Nonetheless, ECM ramping it up even further. Sweet stuff. GFS Para following nicely, while the normal GFS isnt really THAT close to the ECM as the Para run is. I automatically plotted the 240h instead of 228h, but hey, its just 12h difference. The difference is that the 10mb split is not as strongly defined on Para GFS as it is on ECM. But normal GFS is even worse, by keeping the core at 10mb intact, or not splitted and something similar on 30/50mb. Just plotted the 10/30mb height for the correct time, 228h from 00z Para GFS, and it really is quite on the par with ECM, and much closer than the normal GFS. It has the dominant cores on the same side as the ECM. This situation nicely shows how the new GFS really actually does look to be superior to its older brother, the old GFS, as far as the stratosphere is concerned. It is really close with ECM, and you could say we now have a model that could be at least a decent competition to ECM or at least something to search for model consensus. I gave more strength to the contour lines in these two plots, so the split can be seen a bit better. My graphics have a slightly different angle than the ECM, but not much. Some differences in the output with ECM are generally expected, because it is a different model, and a more fresh run (00z, while ECM is 12z from yesterday). All these PGFS graphics are from the 0.5° grid output. It appears to be weaker in the upper strat, as far as zonal wind goes. Well, even GEFS is closer to ECM than the old GFS. I'm really happy for the GEFS. This time I will not post any FI graphics of the PGFS, for certain reasons. :) But on a side note, it is important to add that it looks like this first real offensive on the vortex will not last that long, or at least not long enough by current projections. Regards.
  6. Recretos
    Not much to add. ,
  7. Recretos
    I dont know for others, but I have made a few posts so far regarding the shear "theory" part. Gonna post links to posts if anyone else is interested about the waves. https://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/?p=2862051 https://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/?p=2872515 https://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/?p=2906328 Now I was toying around with wave plots too, and lets just say that even tho I cannot go into specific functions and coding, I did manage to plot simple wave amps, tho it is not the same function as we look at FU Berlin. I wont go in to methods, but lets just say that the first graphic present wave amp focused on 10mb wave 1. And the second plot shows the 10mb wave 1 relative to the zonal mean geopotential height, which is kinda more realistic and closer to the real deal. And some wave 2 experiments. Just some experimenting basically. I will try to experiment with this a bit more in the future. Regards
  8. Recretos
    Matt and SK have beaten me too it, but oh well. A quite charming forecast from ECM this morning, that deserves to have the charts saved and uploaded, because the links will not work when we look back in a year or so. ECM really is keeping up the tempo and pushing it forward. Waves are increasing nicely, with wave 2 being the most obvious one and the most expected one. The wave2 combination on its own is excellent, Atl-Pac combination. And the EP-Flux is starting to become of importance. As for the wave charts, you have to keep in mind, that 400m at 300hpa or even 30hpa is in reality much more defined than 800m at 1mb. As far as the para GFS goes, it actually pulled out a wave 2 aswell. Tropospherically speaking, they do both have the tropospheric vortex in a pretty messed up state, but with some important differences. Tho it gets obvious where the strat wave 2 came from. Cant have a model post without FI, where judging by the Para GFS, the vortex is slowly but steadily losing the battle. If the double MT event would also come into fruition, we could be looking at a very beat up strat vortex around the first half of December, without speculating any further. Regards
  9. Recretos
    QBO is an oscillation that covers quite a vertical depth. It is a complex thing that cannot be bound to just one level, regardless what a study from 1980 said, because it is phasing through more than 35km of vertical depth. As far as the winter stratosphere, SSWs and polar vortex are concerned, I personally, for practical reasons look at 30mb level, +/- 20mb. 50mb is not practical because that is pretty much the treshold below which the "dispersion" starts. QBO is easy to spot actually (much easier than on raw numbers), if you look at mean zonal wind plots like the ones I make or the nice ones from FU Berlin. So yes, we are without a doubt in a negative QBO phase right now.
  10. Recretos
    Pretty much yes. It has one hell of a wave 1 in the upper strat, with secondary and terciary "quasi" waves. If I could translate it to the FU Berlin wave charts, wave 1 would peak at 1600-1800 and wave 2 around 600-800. NOAA analysis would also detect wave 3 in there, but temperature wise it is pretty much a temp. wave 1 in the dominance, tho not that strong. It is very similar to ECM in the mid range, and in the FI its something I would expect from ECM if it would go beyond 240h. Normal GFS on the other hand is quite biased as resolution drops. Most evident is mid and upper colder vortex and too warm upper strat temp waves.
  11. Recretos
    Cant help not to post it. GEFS and ECM to some extent, have a double MT event past 300h.
  12. Recretos
    A quick comparison between ECM and GFS Parallel for the same time: I used the 1° grid output for the GFS parallel. Not much of a diference, expect in the temperature/zonal winds, due to model biases, which tend to affect temperature more than heights. In the FI: Upper strat has a wave 3ih feel to it. Regards-
  13. Recretos
    These charts from Lorenzo remind me of SAI at work in practice, as was noted when I was doing the plots for correlations. Ok, back to now. I am going to post some parallels again. Keeps the spirit alive and the upper strat vortex in a pretty bad shape, I have to say. And a reminder on the beast of last year: And finishing off with the full zonal wind mean, for comparison with ECMWF. I really wish I would have more time for the stratosphere, but I just cant seem to find it at the moment. Regards.
  14. Recretos
    For now it is, yes.
  15. Recretos
    I agree. Any model with better vertical resolution and higher model top, is preferred. Tho GEFS is not really that bad, or it was not that bad last season, it has a bit of a problem since it is topped at 2mb. But we will see how it will handle this situation with more dynamics. So far it follows the main trends and also that of the ECMWF. I look at it nonetheless, since it is the best ensemble for strat, that is freely and easy available. If everything goes as planned, and it gets a resolution upgrade, it will be topped at 0.1mb and will have 64 vertical layers, which will be quite an upgrade strat-wise and it will be a totally viable stratospheric ensemble model.
  16. Recretos
    That ECM ENS anomaly chart is superb, because it really gives a lot of credit and support for the developing situation, regardless of it being in FI. As long as there is some model consensus, there is hope at least. Not as advanced as ECM, but still the GEFS ensemble support agrees with its European rival. Regards
  17. Recretos
    Instead of posting only model outputs, I decided to do something else. I have plotted linear correlation between November N. Hemisphere snowcover area and geopotential height in mid and lower strat. This isnt really any new info, but just it is interesting and it kinda supports the SAI theory. I am not going to go into the theory of linear correlations, unless a lot of people wouldn't know what its about. The correlation at 100mb is pretty straightforward, with the wave2-ish look to it, with the difference that instead of the usual Atl-Pac waves, we have more of a Eur/As-Pac combination. In the mid strat, the correlation is there for decent wave activity, with more of a wave2 feel to it, but at least a strong wave 1. And the 500mb correlation, which is not that far from the reality this month. Ending off with a GFS Para output. Yours truly, Andrew.
  18. Recretos
    GFS is ramping it up beyond belief in the upper strat. I am really sorry I dont have the time to make a longer post with analysis of the current GFS calamities, but on a quick look, there does seem to be a EAMT event partially behind all of it, or actually two or more sequential. And the probable reason why this scenario is so fixed in the GFS is because the EAMT starts in a fairly good range, day 6-8, which is not too bad skill-wise. I would need more time to verify all of it. SInce the normal GFS is available to all, I will add parallel GFS strat output, which is kinda in agreement, and looking fairly good. Model consistency is always nice to see when strat dynamics are in question. We will see how long it lasts and how much it evolves, but it is obvious by now, that strat-wise we are most certainly looking at potentially something totally different than last year. So much for now. Regards.
  19. Recretos
    In the outer reaches of the parallel GFS, the image is kinda different than from its older brother. It looks more wave2-ish on the end. And as far as wave2 goes, its is also starting to smell it in the mid strat aswell, with the upper strat banging that wave 1 like there is no tomorrow. I know I am dealing with FI here, and an untested model, but that is exactly the fun of it, since everybody else is covering the mid terms and other charts. Regards
  20. Recretos
    Yes, 18z kinda continues in the same spirit. Just now, a thought has hit me, that that new GFS is already running in parallel. Cant wait to get home and get my hands on it, to see what it offers us regarding the strat. It will be really fun playing around with it. EDIT: As promised... Let me be the first to have the honour to present you stratospheric output from the new GFS (first at least for some ). Nothing really special, just keeps the same idea, but with some interesting differences. Since it is a fairly new thing, with new physics and so on, it probably has a bias or two, yet to be discovered. But its fun anyway, to have such a thing to play with. Changes are also noticed in the upper strat, especially with temperature profiles. Will add GEFS Control since I had some time left.
  21. Recretos
    Since everybody is at ECMWF, I will go ahead with GEFS and GFS, which are kinda starting to be on the same page regarding that FI calamity in the upper strat. It picks up nicely on the vigorous height/temperature wave1. Keep in mind this is not the regular GEFS, but the the one with the corrected bias, which I have noticed last year is a bit better for strat. than the regular one (which makes sense). And from a different perspective to show the real wave. But the ensemble mean is of course a bit washed out, since it is a mean of many different calculations. So looking at the control run, it keeps the same spirit, but a bit amplified. As far as GFS goes,... It looks really cute in the last few runs to say the least. I don't have a lot of time these days for any bigger posts, so just a few graphics from a different perspective than you are usually used to. As far as energetics go, the upper strat vortex is pretty much being "eaten" alive. Not looking too good for the poor guy, I must say. Cant have a post about strat modelling without CMC and FNMOC. Both biased in its own way obviously, but keep the idea in place. All in all, what to say... Lower wave 2, with a decent upper wave 1 later on... No wonder the vortex seems out of sync. Nothing bad about it tho. Its all just forecasts, and FI,... But nonetheless, fun times ahead. Regards.
  22. Recretos
    I remember too well how those runs were playing around. But I also remember that those runs were with bad input data, with one actually being "red", while this year the runs are fairly good on input data, with no anomalies. Nevertheless, the GEFS suite, bias corrected, has the vortex a bit displaced from the pole, but otherwise no real surprise. Oh, p.s.: And the vortex does not really look that powerful, tho its still in the early stages of intensifying. Regards
  23. Recretos
    Well if you thought 6z was good, along came 12z, slightly furthering the shift in the balance of power. We will see how long it will keep up with it. I checked the input data, and both 6z and 12z are clean.
  24. Recretos
    Or if you know how, you can get the data from datasets like ECMWF or MERRA and plot it manually like I do usually. Bluearmy if you need any specific years, tell me and I can make the vertical zonal mean plots similar to FU Berlin.
  25. Recretos
    I couldn't have said it better myself. And as far as seasonal models go, this was one of the points I was trying to say, about telleconnections, and also their effects/correlations with the stratospheric development. When you have a "normal" or a more stable stratosphere, with less activity or no SSW the models might be right, but when it is unstable, many things can happen, that are beyond the low resolutions of seasonal models (low resolutions relative to the complexity of the events). Seasonal models can simulate SSWs, but on a questionable basis and with questionable feedbacks. Seasonal models normally have stratosphere included. But, as far as modelling of it goes, they are inferior to the general models like GFS and ECMWF, and even those have a bit of a accuracy problem if we go into deeper FI. Stratosphere is a complex thing, tightly connected to the troposphere dynamics. It is not an entity on its own. So when it comes to seasonal forecasts, well, you see, if you get the tropospheric picture wrong, you gonna have the stratosphere wrong, and you might get the winter wrong. So that is one part why seasonal models tend to get the patterns at least a bit wrong. Modelling the troposphere for 2 weeks ahead is challenging, but modelling it months in advance gives you a wide room for error and you can easily undershoot or overshoot important activity for the stratosphere. So seasonal models can easily miss possible MT events that can lead to wave breaking, and since that is a complex thing on its own, it depends on the model physics how it handles any of these possible events that it does create, and even if it handles that, how will it then handle the possible development in the strat. and if it does and makes an SSW, how will it handle the possible feedbacks down into the troposphere, if it has the tropospheric patterns wrong to begin with, if we are looking 2-3 months ahead, where the tropospheric skills are low. As far as seasonal models go, yes they have vertical layers in the stratosphere. The most advanced by far, is the S4 from ECMWF, with 91 layers and a model top at 0.01mb. The rest are much weaker than that. I would dare to say that if we could look at skill scores of seasonal models, we might get a bit lower scores in years with SSWs. Just an assumption. We will see, as always, but I also have a feeling that the models might not be giving as much importance to the stratospheric "imbalance" that is kinda shaping up in the current projections. Of course if it stays as projected, and as far as teleconnections go. Regards. Edit: In case someone wonders about the ECM32, it has 62 vertical levels, with the model top at 5mb. The ECMWF ensembles have 91 vertical levels with a model top at 0.01mb (S4 uses the same vertical schematics). Now GEFS has a model top at 2mb, but around December, it is said to get an upgrade of resolution, both horizontal and vertical. So after the upgrade it would have 64 vertical layers with the model top at 0.1mb. Looking forward to that if it happens.
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