frederiksen90

Big, big run again from EC46 MJO phase 7 is very clear, and possibly next 8. It statistically gives this development : And it happens around the time the strato weakens strongly (mid-February). Then a response to the rise of strong Atlantic/Greenland blocking from below which weakens it all the way up and then the process may then intensify down into the troposphere again in the following weeks. As I see it, it looks like a coupling from below, where the MJO drives strong blocking and the cold propagation with an upward wave of high pressure that moves from the troposphere up into the stratosphere, weakens it above, and then prolongs this process in the troposphere . Then we don't have to wait for an impact after a SSW, as it occurs from below. So it also makes sense that the models have been so consistent about the development. In the case of warming, where high pressure starts in the stratosphere and moves down, you see the effect approx. 10-14 days after, but now you see the potential long before it weakens the stratosphere. This means that the MJO moving into the western Pacific will probably have the greatest influence on the flow change from around 10-15. February onwards. In addition, EC46 is strongly supported by CMC ENS and GFS35 with strong blocking and cold spread from mid-February onwards, and potentially colder over Northern and Western Europe before. It is certainly not certain that we have seen the best winter weather yet.

Wind reversal at 10hpa in EC OP and EC ensemble mean in both 12Z and 00Z 16.-17. january

Doesn't it look more like a split than a shift? https://charts.ecmwf.int/streaming/20231216-2000/6f/webp-worker-commands-64f9dd744-p2f2h-6fe5cac1a363ec1525f54343b6cc9fd8-oflmUL.webp And with strong wave 2 activity now, which is more of a precursor to a split than a dislocation: https://www.stratobserve.com/plots/20231216/tseries/anoms/gfs_nh-hgt-w2-60n_20231216.png

Is there SUDDEN stratospheric warming brewing? Or what happens? It is therefore an extremely interesting change that has occurred in a short time. Therefore perhaps suddenly? EC46 has shown a stable strengthening vortex with a slow weakening at the end for a long time. But now the strong intensifying warming in 10 hPa from the North Pole on its way to Canada/Greenland over the last two days shows. EC 46 on Sunday: https://charts.ecmwf.int/streaming/20231121-2000/47/render-worker-commands-76898cbbf-zdbjw-6fe5cac1a363ec1525f54343b6cc9fd8-rHarLF.png?fbclid=IwAR0cP_ymedoQZbRZKavBj2J2Mf24WvN8uQXUItKx4fHPZBx09ia-na7jVbM EC46 today: https://charts.ecmwf.int/streaming/20231121-2000/8a/render-worker-commands-76898cbbf-z7r8s-6fe5cac1a363ec1525f54343b6cc9fd8-PQSOm2.png?fbclid=IwAR3Fkhjtjlkb2dn2rDGas4NDCrLRBGX6p3xdkIHyVW2pEj8p0pJFWkAQ85w And just look at the change in the zonal wind from Sunday to today: https://charts.ecmwf.int/streaming/20231121-1240/5d/ps2png-worker-commands-76898cbbf-5kktb-6fe5cac1a363ec1525f54343b6cc9fd8-eOe5nM.png?fbclid=IwAR3twESXABbKnetwZf0WI3gVd2qfyF7wXuG_bzpiG_SvMcJaX64rXE1pGBk https://charts.ecmwf.int/streaming/20231121-2000/da/ps2png-worker-commands-76898cbbf-f5rht-6fe5cac1a363ec1525f54343b6cc9fd8-rdu4pd.png?fbclid=IwAR3Fkhjtjlkb2dn2rDGas4NDCrLRBGX6p3xdkIHyVW2pEj8p0pJFWkAQ85w There is something to keep an eye on. It has appeared like a troll from a box with the change from one day to the next, But now suddenly some interesting development happens. And it is perhaps connected with the Atlantic ridge connecting Scandinavia and increasing wave 2 activity? Something is being written here: The tripole in the Atlantic has also developed. The jet stream is much further south than expected. Perhaps as a result of the combination of ice growth and solid cold over Scandinavia, the contrast between cold in the Nordics and warm in Southern Europe has increased. So the flow is further south than normal even in a strong stratosphere. And now with good trends also in the stratosphere. I think it matches very well with 2009/10. I think Europe will get plenty of winter this year.

Is there an early sudden stratospheric warming coming? EC46 continues the strong signal of warming in 10 hPa and it gets stronger and stronger also into December. Note that it is the entire hemisphere that gets warmer than normal, so the heat spreads from the North Pole across Europe. This could indicate much more of a stretched vortex that heralds a split rather than a displacement with resulting heating. And there is a strong signal of Ural blocking into November, which could form a backbone for Northern Scandinavia-Greenland. It is very favorable for wave 2 which are precursor patterns to a split. https://charts.ecmwf.int/products/extended-anomaly-10t/overview/valid_time?base_time=202310260000&projection=opencharts_north_pole&valid_time=202311060000

Warming underway in the stratosphere in late November and early December. It becomes clearer every day in EC46. Really exciting trends. Note that it is the entire hemisphere that gets warmer at 10 hPa. So not just a shift. It looks like 2009 I think. Dynamic November with low pressure in the UK and intensifying Ural block for the next 3-4 weeks: https://charts.ecmwf.int/streaming/20231025-2000/62/render-worker-commands-74964888f5-5qg8g-6fe5cac1a363ec1525f54343b6cc9fd8-cVwWNR.png With eastern QBO and EL Niño. And the same pressure anomalies and trends in the stratosphere already now

Vortex is splitting in GFS 30 hPa: https://max.nwstatic.co.uk/gfsimages/gfs.20221113/00/216/npst30.png

Now it is starting to look like a real Greenland blockade. It seems more like it gets associated with arctic blockade EC12Z-ENS https://wxcharts.com/charts/ecmwf_ens/polar/charts/gph500_anom_20211115_12_240.jpg? https://wxcharts.com/charts/ecmwf_ens/polar/charts/850temp_anom_20211115_12_240.jpg?

Den NAO -indekset i efteråret 2021 til sammenligning med NAO i 2012 2021 https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif 2012 https://1.bp.blogspot.com/-OwO-iO59NXw/UKOoMxTVZKI/AAAAAAAAFHU/YgMrEyqVQ8Q/s1600/NAO_late2012.JPG?fbclid=IwAR3g4aR-Wv9o2UcdqTMrdDPaMufDyU7MYxHqRPa37Gq2XFg9Xh7mawvu7F8 Bemærk den identiske tendens med først en negativ NAO i august begge år, derefter en stigning til kortsigtet positiv i september. Dernæst kraftig negativ NAO i oktober, før en kort stigning igen fra start til midten af november. En generel negativ NAOmed korte afbrydelser. De minder ret meget om tidspunktet for de korte positive perioder i september og november med den mest negative periode i oktober. Går den så i negativ igen i december? 2012 var året, hvor vi var på vej ud af det sidste solminimum (begyndelsen af solcyklus 24) med stigning i solpletter, men med lav geomagnetisk aktivitet. 2021 er med andre ord samme sted som 2012, hvor vi nu igen er bevæget os ind i en ny solcyklus på vej ud af minimumet med en stigning i solpletter, men stadig med lav geomagnetisk aktivitet. Begge år med Eastern QBO og et dødt Atlanterhav. Optimismen er fortsat høj. For det første passer korrelationen mellem AP-indekset og oktober NAO perfekt. Nu stemmer sammenhængen også mellem efterårets NAO- tendens i år med 2012 (begge år samme sted i solcyklussen). Og i forhold til sidste år er den negative NAO blevet endnu stærkere dette efterår. AP/ NAO- forskning antydede, at blokade i troposfæren og en negativ NAO skulle forbedres, når et lavt AP-indeks faldt sammen med østlig QBO . Det kan nu bekræftes, at efter skiftet til østlig QBO kombineret med lav geomagnetisk aktivitet, har vi nu den mest negative NAO- periode siden vi forlod vinteren 2012/13

And when you then see such a 500 hpa anomaly from GFS-ENS for the last third of November, then it really starts to look interesting. Blockage is perfectly located across the Atlantic with troughs over Northern and Central Europe: https://wxcharts.com/charts/gefs/polar/charts/gph500_anom_20211108_12_336.jpg?fbclid=IwAR2-Z7jQvl3LUhOYn9O8JzNZQjE7Vm3maaOb54H7PpI1I1Eupe9FfRsKoVU

It does not resemble the stronger vortex coupling with the troposphere. There is plenty of blockage in the next 6 weeks in EC46. And this may contribute to a further weakening of the vortex and perhaps SSW during December or January. Maybe eastern QBO along with the sun helps to maintain high pressure block and periodic cold into December?

As I interpret it, we see the effect of the Canadian warming in the stratosphere by shifting the vortex to Europe, which provides increasing low-pressure activity over Scandinavia and the opportunity for short-term cool elements from the northwest in the next 2-3 weeks. Then it is clear that the low pressure trend disappears again - all the while the zonal winds of 10 hPa try to normalize. The effect of the Canadian warming disappears at the surface and the signal to go back towards more high pressure over Europe / Scandinavia as well as the Urals in the 3rd and 4th week is quite clear. This may be a precursor to a new and perhaps even more powerful weakening of the vortex. It is also seen that the heat rises in 10 hPa over Siberia in the same period. And once the vortex has weakened sharply once, is there more often a tendency for a warm-up or possibly a split on another attempt? It looks very interesting, because we do not go into a totally dynamic westerly current, but back to strong positive height anomalies, which contribute to planetary wave motion from the troposphere

Men en svækkelse i forhold til mandagens ensemble-kørsel. Ret stor ændring: https://stream.ecmwf.int/data/gorax-green-001/data/scratch/20201112-0600/d7/ps2png-gorax-green-001-6fe5cac1a363ec1525f54343b6cc9fd8-7oWzWZ.png Fra noget, der udviklede sig til en stabil stærk PV, er det nu en større ændring. Måske en tendens mod en stor svækkelse, som bliver endnu tydeligere i næste kørsel på mandag?

What an interesting change u vortex according to EC-ensemble. A weakening on the way: https://stream.ecmwf.int/data/gorax-green-001/data/scratch/20201112-2040/57/ps2png-gorax-green-001-6fe5cac1a363ec1525f54343b6cc9fd8-T8V3Hu.png

Hvis der er et år, der i øjeblikket minder meget om 2020, er det 2012. Havisen er tæt på minimum 2012. Læg mærke til det usædvanligt varme Barentshav og havet jeg det nordlige Atlanterhav vest for Grønland til Newfoundland sammenlignet med september 2012. Det kolde område, der var i Atlanterhavet i tidligere år, er helt væk. Så havet er varmt i hele området. Sidste gang dette skete var i 2012. Samtidig har vi et mindre og koldere område nord for Island. Derudover er PUD gået negativt med koldere farvande ud for USAs vestkyst, omend i mindre grad ultimo 2012 hidtil. Dette sammen med udviklingen af en moderat La Niña i det sene efterår / vinter, hvor vi havde en neutral ENSO i 2012 efter en La Niña. 2012 er sandsynligvis meget lig 2020 ved SSTog havniveau. Spændende om det så fører til højtryksblokeringer denne vinter mere dominerende over Nordeuropa med en svækket solcelle på grund af den lave have ved Barentshavet, hvilken øre sandsynligheden for en SSW / split?

Really strong blocking signal at Greenland and Iceland at 300+ hours in GFS ensemble http://modeles7.meteociel.fr/modeles/gens/runs/2019121712/gensnh-21-5-300.png http://modeles7.meteociel.fr/modeles/gens/runs/2019121712/gensnh-21-5-360.png And at the same time, the east wind is now hitting 30 hPa: https://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_UGRD_ANOM_ALL_EQ_2019.png Maybe this can help amplify the blockages at solar minimum, which can expand the cold potential? Maybe the trends between Christmas and New Year can really be the start of something?

Recent studies have shown that more than half of SSWs occur when MJO enters phases 6-7. Interesting if the trends of a weakened PV towards the end coincide with the evolution of MJO in phases 6 and 7? https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/foregfs.shtml

Compare to 2009: https://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_2009.gif Here, PV is markedly strengthened in October with downward movement. At the same time, increasing tropospheric blocking prevents a coupling, which then significantly reduces PV. Today we seem to have seen the peak of PV in October? Now, is increasing tropospheric blocking by forcing PV into a displacement / weakening in November? https://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_2019.png After all, does it seem clear that the downward negative anomalies will stop and perhaps disappear completely in November and be replaced by positive anomalies? : D I really think the dynamic seasonal models are having problems this year and they don't understand why the troposphere is blocked and what creates a constant -NAO. Solar minimum? It continues in the opposite direction for the first 7-10 days.

Yes, Matt Hugo mentions the same thing as Judah Cohen yesterday about whether the combination of aluetically low and scandi-high in mid-November can disrupt PV and possibly lead to an SSW subsequently, as it lies on each side of the Arctic. This is exactly what led to an early SSW in 2009/10. It is good that PV is stronger than normal, which can collect very cold in the upper stratosphere. If it is quickly attacked afterwards, an SSW allows to push very cold air away from the Arctic. Interesting things are already appearing in the PV forecasts despite the strengthening. In 2009, PV also strengthened first, while November transitioned from -NAO to neutral NAO. It provided high pressure over Scandinavia-Eurasian and the North Pacific, which weakened PV via energy transfer. We had a blockage in the troposphere and fast wave 1 and 2 activity. It reminds me this year? Solar minimum? And so I think everything continues to go against the season models until day 7-10. It is only afterwards that you constantly see the peak of PV in the forecasts, while it changes continuously for the first 10 days.

Bemærk, at den stigende opadgående blokering i troposfæren fortsætter nu: https://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_2019.png Selvom vi forventer en styrket PV , forbliver denne tendens ud over dag 10, hvor vi konstant ser toppen af den zonale vindstyrke. Samtidig opretholder vi en negativ NAO og stigende blokering i troposfæren i de første 5-7 dage. Jeg er opmærksom på, at blokeringen nu ser ud til at kunne stige lodret, så vil opadgående bølgeflux fra troposfæren svække stratosfæren og sende en SSW i 30 og 10 hPa? Dette modsætter sig, hvad prognoserne har vist med en stabil negativ NAO siden maj måned. Og er dette som et resultat af, at solvinden er svækket? Jeg synes virkelig, det begynder at se interessant ud, at troposfæren arbejder for at forhindre, at dette stratagem bryder sammen? : D EDIT: TRANSLATION ADDED: Note that the increasing upward blocking in the troposphere now continues: (use original link) Although we expect a strengthened PV, this trend remains beyond day 10, where we constantly see the peak of zonal wind power. At the same time, we maintain a negative NAO and increasing blockage in the troposphere for the first 5-7 days. I am aware that the blockage now appears to be rising vertically, so will the upward wave flux from the troposphere weaken the stratosphere and send an SSW at 30 and 10 hPa? This contradicts what the forecasts have shown with a stable negative NAO since the month of May. And is this as a result of the solar wind weakening? I really think it's starting to look interesting that the troposphere is working to prevent this stratagem from breaking down?

Are we heading into -PDO? Now note the sea at Alaska and the west coast of America. It gets colder and colder as the hot water moves west: https://www.ospo.noaa.gov/data/sst/anomaly/2019/anomnight.10.17.2019.gif This is how it looked a month ago: https://www.ospo.noaa.gov/data/sst/anomaly/2019/anomnight.9.16.2019.gif

Because seasonal forecasts do not predict an SSW, this does not mean that a significant SSW cannot occur. Keep in mind that last winter was a unique case, with forecasts predictably an early SSW, which Europe did not see the effect of. Going back to 2018, a historic SSW emerged within 2-3 weeks in February, which subsequently resulted in a much better impact for Europe at the surface. SSWs may come suddenly, as models can never foresee several weeks ahead. For example, 2009 and 2012 are also. I would just like to point out that the forecasts did not foresee the stable negative NAO over the year since May, nor was the triple in the Atlantic projected. The two things seem to have had a clear connection with each other this year. If driven by the much weakened solar wind via the stratosphere-troposphere coupling after last winter / spring, then forecasts are not good at understanding how the surface responds to the influence of solar activity. All year, the trend has been the opposite of the forecasts, so why shouldn't it do this winter as well.

A strengthened PV with + AO is well up to winter, as it is understood that the air around the Arctic will be colder than normal. At a weak PV there is higher pressure and the air mass will be warmer over the Arctic. Then it will be difficult to get cold. So that's why it's good that PV is amplified to begin with. The most important thing is that NAO does not follow. The worst thing is, if it changes phase, then it becomes difficult. But keeping it neutral to negative while AO goes in + can a subsequent weakening of PV give us even colder air in Europe than if PV had not been strengthened? And where one can hope that the forecasts go wrong, could just be the link between strato and tropo, which signals a strong jet across the Atlantic. If SST anomalies maintain an attenuated gradient and -NAO continues after PV is strengthened, then you must probably see it as good signs It will be exciting to follow.

Is the solar minimum driving the interaction between NAO and SST? Recent studies have shown that SST anomalies change with some delay between solar maximum and solar minimum. At the same time, the NAO suggests following the sun's AP index (geomagnetic activity). Looking back over the last 10 years, we have a clear tendency for changes in SST to follow changes in NAO. The most positive NAO values were around the solar maximum. Since then, NAO has been downhill slightly with a cold-warm-cold Atlantic tripole that has maintained colder waters around Greenland and warmer waters at Newfoundland. This year, the NAO has then passed the point where, on average, it is negative over several consecutive months, and it has apparently resulted in the SST anomalies following this trend. Now these have been changed to a hot-cold-hot tripol with warm sea in Greenland and cold in Newfoundland. The changes of the SST followed the changes of the NAO via the stratosphere-troposphere coupling coinciding with the solar wind previously downward. And the NAO should be correlated with the solar wind. If it is the solar wind that modulates NAO, then we have reached the point where the pressure gradient has been weakened, thus the ocean currents in the North Atlantic turned via sustained blocking over the Greenland and Arctic regions. And what makes it difficult to see a correlation globally is that the correlation appears to be greatest regionally and across Europe and the Atlantic as well as North America with little delay effect relative to maximum and minimum. If all this year is related to the solar minimum, then we really have an interesting winter ahead, I think. I'm excited. Here is the NAO index for autumn 2010-2019. 2010 https: //blogs.agu.org /.../ Screen-shot-2010-12-11-at-02:56:14 .... NAO Average: -0.71 2011 https: //dcstorms.files.wordpress.com /.../.../ naoindex_ensem.jpg ... NAO average: +0.63 2012 http://www.cbc.ca/nl/blogs/ryansnoddon/naoOct2412.PNG NAO Average: -0.57 2013 https://www.weather2020.com/.../u.../2013/12/NAO-December-15.jpg NAO average: +0.12 2014 https://www.boston.com/wp-conte.../uploads/2014/.../nao12314.png NAO Average: -0.13 2015 http://www.meteorologistjoecioffi.com/.../up.../2015/11/nao8.gif NAO average: -0.00 2016 https: //cristcacewx.files.wordpress.com /.../ screenshot-2016-1 ... NAO Average: -0.13 2017 https: //encrypted-tbn0.gstatic.com/images ... NAO Average: -0.16 2018 https: //weatherloverblog.files.wordpress.com /.../.../ nao467.gif ... NAO Average: +0.59 2019 https://www.cpc.ncep.noaa.gov/.../pr.../CWlink/pna/nao.sprd2.gif NAO Average: -0.52 Looking at the last 10 fall, this year we have an average of several consecutive months representing the lowest NAO average along with 2010 and 2012. And how did they get winters?

Perfect SST anomalies in the North Atlantic. The sea is designed to be warm all the way around Greenland and Iceland, while the cold water at Newfoundland has developed and grown. https://www1.ncdc.noaa.gov/pub/data/oisst/navy-anom-bb.gif We now have a very good tripole, which contributes to a weakened pressure gradient and very favorable for an -NAO and blockages from the beginning of winter. It gives hope for an interesting winter coinciding with low geomagnetic activity on the sun.