Recretos

Going away again for a few days (staying at girlfriends place), but I will try to setup the software on her computer. Sorry for offtopic.

Not much to add, the before mentioned GEFS Control which had an interesting trop. output, was nothing special strat wise. GFS zonal wind profile is what you would expect. Now, JMA on the other hand, has at 264h 7m/s 60N zonal mean wind at 10mb with a strong wave 2. Strong wave 2 is also evident on the vertical velocity profiles with the stronger wave breaking over the Canada/Atlantic sector. JMA seems over-optimistic, tho configuration-wise for the strat, it is the second best model, following ECM and leading before GFS. So much for now. Cheers Edit: Adding FNMOC Control:

What to say, finally my dear expected wave2 has emerged in its full glory, tho it is still just in the forecast. Very close now.

WSI has good graphics, but they sometimes have a hard time interpreting whats on them. That is by no means an intact vortex. It has a cross polar flow, with the vortex zonal momentum nicely reduced and the core split on two individual units under wave 2 pressure. Just a side note on NAEFS: Its low res, and its a combination of CMC ENS and GEFS, basically it has a reduced top to 10mb.

I am completely "timeless" during these holidays, but nonetheless here is the 10mb gph, since I made it because I was wondering too about the height profile.

That would be the temperature waves. What we usually refer to as a split, is based on geopotential heights. In this case it is not really a split on that graphic, but since it is an ensemble mean, it can be interpreted as an indication of it somewhere down the line, or around that time once it gets closer and if it keeps the same idea and once the ensemble spread reduces and the picture crystallizes. This particular Atlantic secondary height wave is not resulting because of the Eurasian temperature wave as WSI is saying, but it is tropospherically driven. As I said in my mysterious posts quite a while back, I was expecting the Atlantic wave 2 to emerge eventually, tho I have to admit I was expecting it a little bit sooner. But oh well, as long as its at least in the forecast for now.

When that ridge starts crawling towards Greenland, dont forget which models were the first and most direct about it. The FTP is offline atm. so I will plot the R2 a bit later. In the mean time, yesterdays ECM really began to spice up the Atl. ridge. (image removed on request)

Dont forget that CFSv3 is already in the workshop, getting ready to see its dawn, somewhere down the line

Before I go into more details, I wonder how many of you are familiar with NCEPs GEFS Reforecast 2 project/model? To quote ESRL: "The ESRL/PSD 2nd-generation Reforecast Project has produced a dataset of historical weather forecasts generated with a fixed numerical model, using the 2012 version of NCEP's Global Ensemble Forecasting System (GEFS). This Reforecast V2 dataset consists of an 11-member ensemble of forecasts, produced every day from 00 UTC initial conditions from Dec 1984 to present. The horizontal resolution of GEFS is T254 (about 50 km) out to 8 days, and T190 (about 70 km) from 8-16 days. Real-time forecasts are ongoing. Among the advantages associated with this long reforecast dataset is that model forecast errors can be diagnosed from the past forecasts and corrected, thereby dramatically increasing the forecast skill. Past results have shown that the improvements may be particularly large for medium-range forecasts and for forecasts of relatively uncommon events such as heavy precipitation."

Perhaps JMA is onto something.

Close (relatively) to the ECM mean yesterday was JMA 12z. Since it goes only to 192h on Meteociel, here is 264h:

Nope, the scale is from 25 to 54 Well, Its all about the love for your hobby. If you like doing what you do, there is almost no limit to what you can learn in this day and age of the internet era. Tho I also emphasise as much practice as possible, not just theory. GEFS zonal wind mean indicating we might perhaps need a new wave phase to end it.

Thanks for the support guys, I am totally happy to write for you and to debate about this phenomenal topic. Here is a new type of graphic I was working on: ENS members by time:

Thanks, but I wouldnt worry about that if I were you, because I am just an amateur/enthusiast like most people here. I have no meteo education whatsoever, and I had physics only 2 years in elementary school. So dont worry, nobody will hire me.

Nah, I I will spent it at my GF's place. Am starting to teach her how to plot graphics actually. And I am not sure what my "analysis skills" have anything to do with my social life?

I am totally with Chiono on this one. First: We are looking at the mean of 51 members, ok? For the strat, less members is perhaps sometimes better, because of the "wavelengths" and depth of the layers. 51 members better all have a similar forecast if you want to see something meaningful in the average. But yes, we are seeing a wave1 displacement like Chiono said. Second: This is 50mb level, which goes under lower strat, which is not where the dynamics start, but actually where they "end up" on their "descent" downward, shall or would there be one. Third: For the 7433259432th time, if someone from WSI is reading this, please, please can you show the normal temperature on these charts, and not anomalies? Anomalies are good as a side product, but in general, seeing the actual temperature is way better and more meaningful. Fourth: GEFS. Enough said. A model with the model top at 2mb, unlike the ECM ENS at 0.01mb, but still sees pretty much similar dynamics. And it still has the warming in it. And judging how it looks compared to this ECM chart, I would say that the ECM looks better and quite probably has an even stronger height/temp wave than GEFS (which due to model top at 2mb, doesn't even have the whole upper strat in it ), which would be logical given its model top and strat coupling and better vertical/horizontal resolution. Fifth: We cant see anything above 10mb from ECM ENS, despite their model top at 0.01mb, because the post-processing only includes layers 10,20,30,50,70 and 100 I think for strat. Sixth: Remember folks: This ECM chart speaks volumes! And remember, its not all about what is in the chart, but also what it represents and how you will interpret it. You have to look at many layers, interaction, various models, ensembles, operationals, controls,... etc... Then you can start to put together the full picture. And let me tell you, based on my amateur observation/knowledge and the facts I pointed out above, this ECM chart looks really good actually. Doesnt mean much on its own, but speaks volumes in the "model collective". Meteorology is sometimes like forensics, you need to know certain details to put together the full picture. And in this post I am giving you an example how I usually solve "mysteries" like this one (like is this a good chart or not ). Regards

A test upload to youtube. It is the todays 12z GFS from. In color is the downward propagating warming, with the isosurface set at -45°C, and the color indicating the height. In Cyan color is the polar vortex core, set at -82°C.You can see how the core of the vortex re-strengthens before being surrounded by the warming, when it starts shrinking. I call it the heart of the vortex. Enjoy. http://youtu.be/BPkJRJdkZ90 Added is the 09 SSW uploaded to youtube, so you can have a feeling how it looks. Notice how the warming cuts into the troposphere (bottom layer @150mb), creating the "fat" ridge towards Greenland. http://youtu.be/Mknim3Luuo8 I will upload to youtube from now on. Regards Edit: Adding 12z JMA, which is onto "it". Lets hope ECM follows.

I wouldnt worry over it too much for now. Since this thread is the best around for the stratosphere, I cant help myself not to post 3D animations of 4 SSWs that I have made. This layout includes: 3D is the isosurface of a certain temperature (written on the bottom, usually -45C), the bottom level is 150mb geopotential height, and the middle layer is 30mb geopotential height. This is layout version 1. In the version 1.2 I will include the heart of the vortex. But lets leave that for another time. It is nicely seen how over the Atlantic, downward warmings really "ignite" tropospheric ridging with some delay, and how it cuts into the troposphere. I made the layout as a preset, so once I tweak it, I can just put in any data, and simulate any SSW since 1950s, or as far as the datasets go. https://db.tt/lZ0gAOWD https://db.tt/co8AorvK https://db.tt/t5PZ9bO2 https://db.tt/y3BvBQSL And some other graphics I made today. Usually everything can be found on twitter where I stared posting a bit more recently. Regards

JMA which is on a similar level as ECM, configuration wise, is already grabbing onto it. And yes, GFS has a positive temperature bias for top strat in deeper FI.

More 3D stuff from the latest GFS. It basically shows the propagation of the warming, set at -46°C. Same thing, from different angles. Color means the height of the -46 isobar. And two videos, animation, first showing the downward propagation of the warming, and the second is the heart of the vortex, which shows shrinkage at the later stages. Top is at 10mb. db.tt/M0FSuyKH db.tt/CnKoFchI

Now I am working quite a bit with GEFS for the strat., but I work with the bias corrected version of the GEFS, while meteociel and wetterzentrale I think use the normal one. So,.. if anyone is interested what kind of a difference that makes, here is a comparison of the 6z GEFS, the bias corrected vs the normal one. I usually always prefer the BC one, because it removes some of the known bias or a false tendency of the GEFS, compared to the normal one. Differences are not that big, but are meaningful. This basically shows where the BC version of the GEFS is higer/lower in heights, and where the BC version is warmer/colder than the normal one. Cheers

I hear you. I was targeting more on the "down the line" part, into the last quarter of the model.

As far as ECM32 is concerned, it has a model top at 5mb, so that could perhaps have an effect regarding the upcoming strat dynamics and coupling down the line. And it is run at 00z on Mondays and Thursdays, so before any 12z of the day.

GEFS looking good. And the warming in 3D. Or more like the warming "core", set at -45°C. From 100mb to 1mb, from the 384h GFS 00z.

There is no technical SSW yet forecasted by any global deterministic model. What is forecasted tho, is "preconditioning" of an SSW, or an onset of one. I can plot many things now, and rest asured I will be among the first to graphically present you the very detailed hour when a status of a technical SSW will be first forecasted. You can sometimes interpret it from the GFS height maps when its obvious, but plots/calculations are still the most accurate.