Redbull165

Good point.

This is an absolute disaster, look at the zonal winds at the top of the stratosfere from 60-90N. The strong zonal-winds are progressing quickly into the lower parts of the troposfere. Which means an increase chance of the Atlantic (zonal-flow) for Europe dominating. I think we are about to lose the whole december, only a strong warming of the stratosfere with an increased wave1, and then wave 2 activity could change that. Otherwise the polar vortex will again regained its strenght and return to his roots at around Greenland. All we can do is hope, but for now it looks worse as in the start of 2018/19 winter. Maybe the second part of winter will bring something different. And we can already see a crucial QBO (-EAST) flow around the equator from 1 hPa to 30 hPa. But usually the lag-time response from the QBO (west) to QBO (east) transitioning is at least about a month. So we might have to wait until january for the proper effect.

On ECMWF model we can see the downward propagation is still lagging in the area below the 100 hPa in the troposfere. This SSW event is really slow with its effect. But I hope it will be worth the wait.

New update, for how are the things looking with SSW effect later in the january. Great read. http://www.severe-weather.eu/long-range-2/latest-model-guidance-for-the-mid-late-january-winter-weather-across-europe/?fbclid=IwAR1o3oYT7AQejN6HpRGC2lcdeodlHy074x7GKYM6kP15hI3OXFmWDvzBCBk

Very impressive GFS06Z chart also for us on the SE side of the Alps with a Balkan/Genoa low pressure system in the middle of next week. On the N-NE side of the Alps they have heavy snowfall in last few days, and here on the other side we get nothing, its sunny with strong NW wind and zero snow.

http://www.severe-weather.eu/long-range-2/update-on-the-splitting-polar-vortex-and-winter-trends-across-the-european-continent-through-mid-january/?fbclid=IwAR3WdioMzXDSJ8Rl3Bmur2gh9IY0UEBFKgEMokYNb4fEnfXmIYi5_-qlSFk Great read.

Some weak-moderate wave 2 (Azores high-pressure) activity is also seen. It could push the robust AC ridge more towards the north and into the area around Iceland or Greenland. Its still a "waiting game". I hope of course for the best.

What I find great to watch are the zonal wind anomalies at the equator. We know that the QBO (-) and (QBO (+) cycle usually last for about 12 months. And we now have a strange looking situation, if we look at the top of the stratosfere (1hPa-10hPa) we already see the QBO (east) filtering slowly down. The real QBO (+) is currently based from the 10hPa-50hPa stratosfere area. But if everything was normal there should be the strong QBO (+) now reaching the troposfere. But in my opinion something is "lagging" the westerly (QBO) response, which is usually a very good thing for us, if we want a colder than average winter. If we look at the zonal wind index for november at 50 hPa, there was still a QBO (east) present.

Statistically in terms of accuracy I would always prefer the morning ECMWF 00z run with ensembles over 12z. But thats just me.

If we look at the conditions this winter. We have a transitional QBO (east) around equator to (QBO) west index. The first time the QBO was positive on 30 hPa was this november if we look at the numbers. But that doesnt tell us the whole story. There is usually a 1-2 month lag between this two phases. So tehnically below the 30 hPa towards troposfere area we still have a negative or east QBO index. We are in neutral to weak el nino ENSO state if we look at the 3.4 area around Pacific. The el nino is central based (modoki). Which is for Europe much better than the east based one, if we look at the average anomalies at 500 hPa, comparing the years back. Comparing winters with traditional (east-based) el nino with hybrid and to the one we have this year (central based modoki). Solar activity is very low, we are about just one year away from a solar minimum. Low solar activity usually means a weaker polar vortex in general, which might be happening this year. But we have to combine other factors as well. It is usually true, that the combination of QBO(east) and low-sunspot activity promotes the chance for a colder than average winter in Europe, which is also true for the QBO(west) and high-sunspot activity. I was analysing this things back a couple of years back on the other forum. So in my opinon the current ENSO conditions are very good for us, we dont have a moderate-strong el nino or la nina events, which are in most of the winters the worst for cold winter in Europe if we look in general. I find neutral to weak el nino ENSO conditions to be the best for this winter. But its just my opinion. And with the SSW event happening right now, I think anything is possible. We have to hope for a MJO index (phase 7,8) and some help with the propagation of weaker zonal winds into the troposfere. The morning ECMWF (00Z) run was very impressive for the most of the Europe, and the GFS 06Z (P) followed him. The GFS (P) is actually a new FV3 weather model. Whats happening with the NAM, is it already predicted to go into the negative state in the lower parts of troposfere?

If we look at the GFS (ensemble) scenarios it doesnt look that bad. 12/20 of them on GFS06Z are seeing the rise of height with the Azores high pressure system that pushes towards the north in the area around Greenland. With this SSW event already in progress we really dont know what will happen, the PNA index looks to stay positive, thats good news. AO index is currently slightly positive, but will probably go to neutral to negative state in the next few days. NAO index is now negative, but is predicted to go to into positive state in 7-10 days time. But that isnt done and dusted yet. I think interesting days, weeks are ahead of us. This forum is quite amazing, I already learnt a lot of new things from you guys here. And I respect that. Cheers.

Is that the first sign of downward propagation that I see on this GFS zonal wind chart. What I mean with downward propagation is when the effect of weaker zonal winds is seen below the 200 hPa area in the troposfere. And some of that might now be seen, starting around the second dekade of january 2019. What do you think, am I missing something here? It might be also the case that its just one run, and the new one will change that, but it doesnt look that bad at all. Situation now. And the zonal winds (with EP flux) on 13.1.

There actually is, the webpage is called weatheriscool. You can find many interesting things there, in terms of stratosfere, troposfere that page is based on GFS weather model. You can also find some CFS zonal charts there on the graph. http://weatheriscool.com/index.php/stratosfaren-zonal-mean-u-wind-60n-vcs/

There is quite a difference if we compare the yesteday ECMWF 12z (main) run to the one we have today at 96h. The high pressure is moved a little bit more to the NW near Iceland.

Amazing morning ECMWF 00z run for parts of central,SE,and also NW Europe. The ensembles are pretty solid as well. But we need to push that ridge more towards Greenland, this is the most important thing.

Thank you buddy for this information. We can only hope for the best. In the evening runs I find the UKMO model quite interesting at 144 h. Statistical comparision has shown us that if we compare the GFS, ECMWF, UKMO models together, that UKMO model was even the second on the list right behind the ECMWF model. The GFS came just third on the list. It also depends on the situation.

Singularity very impressive post. I agree with you. What I find also amazing is that the GLOSEA based ECMWF seasonal model has hinted a dominant high-pressure system over Atlantic, starting in January. It doesnt mean that this will come true, but what I am saying that the ECMWF seasonal model has done a very good job for now. Much better than seasonal CFS which has a warm-bias. I usually prefer ECMWF model over GFS if we look at the stratosfere. But in some cases GFS does win over ECMWF when we analyse the situation in the troposfere. Below is a pioneer model (taken from Weatherbell). It was updated on the 1.12.2018, and it shows us the predicted 500 hPa anomalies for J,F,M 2019.

The Italian IL meteo weather site is seeing something similar to winter of 1984-1985 with stratosfere warming. Dont know if they are right, but at least they are very positive about this current event. https://www.ilmeteo.it/notizie/meteo-atmosfera-impazzita-ci-si-prepara-ad-un-nuovo-1985-conseguenze-dirette-sullitalia-a-gennaio If we look at the current heat flux on the top of the stratosfere its very amazing to see that its record breaking. If we compare years from 1978-2018. Warming in february 2018 was also very strong. But didnt see that coming. The weather models are having a major problem to see that propagation into the parts of troposfere, but each event is of course very unique. . Cheers.

That morning ECMWF (00Z) made my day. I have to say its quite brutal for parts of eastern, central Europe with below -15 on 850 hPa. I am coming from the parts of central Europe, on the SE side of the Alps. Also the ensembles are good. Now all we need is to push that AC ridge more towards Iceland. The more that high pressure system is pushed towards that part, the more potential there is for extraction of cold Sibirian air. Or so called beast from the east. I know its more difficult for UK in general, but there is high potential in this morning runs. The GFS still doesnt want to see that change.

In my humble opinion the weather models are still very good, and most of them are showing us split vortex in the beginning of january. One center of vortex goes on the Canadian side and one on European. If we combine that with the favourite MJO phase 7,8 we are getting a very positive results. The big question is with the downvelling or propagation from high-parts of stratosfere to the troposfere. But after comparing other years with the SSW events, I found out that it might be the case that when the zonal winds in troposfere are weak before this event it might be easier. And I am seeing pretty much weak to normal zonal winds from 100 hPa to 1000 hPa which lasted for entire december. The problem was with the strong zonal winds in the upper parts of stratosfere. Because of strong strat. warming (wave1,2,3) near the pole this zonal winds have weakened a lot in last few day. So we are now seeing weaker zonal winds in the troposfere and in the stratosfere. This is why I am still confident that even if the the "main" part of propagation doesnt reach the lower parts of troposfere that we can still see good effect of it for Europe. The weakening of zonal flow is always welcomed, and this early in the winter we can still see some extra warming in the stratosfere in january, so the vortex can get that final "blow". It will be also very important how strong the Sibirian high will be with the very cold continental flow from the east. Its gonna be intriguing to watch how the entire situation will develop in the next few weeks.

Greetings. This is my first post. GFS06Z ensemble mean is seeing split vortex in the beginning of january, which is very important. The control one still doesnt see it, but in this kind of events ensembles are probably the one we need to look at for an accurate forecast. There are 20 ensembles available for us if we look at GFS model, and 50 if we look at EMCWF. I trust the ECMWF much more, that the GFS weather model. it also has a better resolution if we analyse this two models. I am also very pleased, that there are so many people on this forum, that are monitoring the situation in the stratosfere. Keep on the good work.