Stratosphere Temperature Watch 2014/2015

[MattH]

Not much to add today that hasn't already been mentioned really, but a few thoughts and suggestions. It's a waiting game really and as a few have highlighted this morning even if we don't get anything of worth in the short term having the vortex in the state it is in, at this time of year, can only be a good thing down the line. I mentioned this the other day in terms of us potentially not ending up on the right 'side' of a possible upper trough over Greenland in the next 7 to 14 days but at least the vortex will be in a weakened state for future developments. It seems highly unlikely that the vortex will get anywhere near "full strength" in the coming weeks no matter how hard it tries.

A week to two weeks is a long time in meteorology so who knows what position we will be in as we progress towards mid-Dec in a months time. I still having a feeling, not particularly scientific I know, but from what I've seen of things in terms of the SAI, QBO et al and my own 'feeling', is that we'll have to wait another month before anything of 'worth'. Clearly a 2 day N'ly doesn't come under this scenario and those kinds of brief incursions of colder weather, even on a NW'ly, obviously become more of possibility at this time of year anyway due to climatology etc. For me though I think Xmas and New Year could be when things get 'interesting' with regards to the stratosphere and the tropospheric connection and the potential for more significant HLB and some 'proper' winter synoptics. A white Xmas or at least seasonal conditions could be a good bet this year for the back end of Dec...

Cheers. Matt

Edited November 15, 2014 by MattHugo

[Northern Sky]

Thanks Matt, I'm sure that for most people the back end of December would be the perfect time for some wintry synoptics!

 

Apologies if this has been covered elsewhere but I'm puzzled by the disparity we see between all the promising signs and signals and the forcasts of the seasonal models. Surely the current state of the vortex and on going wave 1, 2 (and possibly 3) activity must be factored in? Is it just that the models don't see a tropospheric response from this activity or perhaps a they show a response which just doesn't impact (in terms of cold weather) on our small part of the world?

[blizzard81]

Thanks Matt, I'm sure that for most people the back end of December would be the perfect time for some wintry synoptics!

 

Apologies if this has been covered elsewhere but I'm puzzled by the disparity we see between all the promising signs and signals and the forcasts of the seasonal models. Surely the current state of the vortex and on going wave 1, 2 (and possibly 3) activity must be factored in? Is it just that the models don't see a tropospheric response from this activity or perhaps a they show a response which just doesn't impact (in terms of cold weather) on our small part of the world?

I wonder the same thing. What do the seasonal models base their long term forecasts on ? All I see are anomaly maps for pressure and temps but no explanation as to how they reach their conclusions. Does anyone know ?

[johnholmes]

I wonder the same thing. What do the seasonal models base their long term forecasts on ? All I see are anomaly maps for pressure and temps but no explanation as to how they reach their conclusions. Does anyone know ?

 

You could try the Met O site they have quite a lot on how the different models work?

[Crocodile23]

I wonder the same thing. What do the seasonal models base their long term forecasts on ? All I see are anomaly maps for pressure and temps but no explanation as to how they reach their conclusions. Does anyone know ?

 

They are numerical prediction models. I.e they are just solvers of equations of motion of the atmosphere.

 

I want to ask if there is any archive of GFS or ECMWF about the stratosphere(multiple layers, 5,10,20,30 etc hPa)? Like the ones here but for the past years:

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?var=HGT&lev=10mb

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

Edited November 15, 2014 by Crocodile23

[bluearmy]

They are numerical prediction models. I.e they are just solvers of equations of motion of the atmosphere.

 

I want to ask if there is any archive of GFS or ECMWF about the stratosphere(multiple layers, 5,10,20,30 etc hPa)? Like the ones here but for the past years:

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?var=HGT&lev=10mb

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

I don't believe there are croc but for a running commentary of the past few years (with attached charts to illustrate) look at the archived net weather strat thread!

[Recretos]

They are numerical prediction models. I.e they are just solvers of equations of motion of the atmosphere.

 

I want to ask if there is any archive of GFS or ECMWF about the stratosphere(multiple layers, 5,10,20,30 etc hPa)? Like the ones here but for the past years:

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?var=HGT&lev=10mb

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

 

Past years no, GFS has a one month archive for the full vertical profile up to 1mb as far as I see. But I am not sure for ECMWF. But there is reanalysis data for the full profile up to 1mb and some in the mesosphere from ECMWF. You also have the great MERRA dataset or many others. I dont really see the point of looking at past forecasts, because each season is a bit different and "tricks" the models in their own way, so there isnt much you cant get out of it, as far as skill is concerned. 

Edited November 15, 2014 by Recretos

[Crocodile23]

But there is reanalysis data for the full profile up to 1mb and some in the mesosphere from ECMWF.

Link please?

 

You also have the great MERRA dataset or many others.

Links please?

 

I dont really see the point of looking at past forecasts, because each season is a bit different and "tricks" the models in their own way, so there isnt much you cant get out of it, as far as skill is concerned. 

No i guess you misunderstood me. I'm not seeking for the forecasts archive, but for the actual(observed) archive of the atmosphere for a historical time e.g 03 February 1912 (12Z).

And this is for learning/comparing/statistics etc purposes so there is a point.

Edited November 15, 2014 by Crocodile23

[lorenzo]

The MERRA Dataset is located here, they must be getting a good hit rate from this thread !

 

http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

 

Another quick way of looking at things is via the CPC page

 

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/

[Crocodile23]

The MERRA Dataset is located here, they must be getting a good hit rate from this thread !

 

http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

 

Another quick way of looking at things is via the CPC page

 

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/

 

Thanks but what about this:

 

But there is reanalysis data for the full profile up to 1mb and some in the mesosphere from ECMWF.

 

 

[lorenzo]

Thanks but what about this:

 Sorry can't help you there, hopefully Andrew can, the link I had to a SPARC dataset is now demised.

 

I found this page but login rights are required.

 

http://apps.ecmwf.int/datasets/data/era20c_daily/

[MattH]

Sorry can't help you there, hopefully Andrew can, the link I had to a SPARC dataset is now demised.

 

I found this page but login rights are required.

 

http://apps.ecmwf.int/datasets/data/era20c_daily/

I can access that website through login from work so let me if any charts or info is required. The page is bit of a 'select box' minefield to be honest but if specific variables can be highlighted I'll see what it fires out

Cheers. Matt

[skatefan]

I think the developments arround T240 are quite interesting: both GFS and ECMWF predict ridging at 500HPA in the direction of Iceland/Greenland:

This introduces a cold spell from the North.

 

http://www.wetterzentrale.de/pics/Recmnh2401.gif

 

https://max.nwstatic.co.uk/gfsimages/gfs.20141115/18/240/npsh500.png

 

the, at that time reinforcing, stratosferic vortex also positions in that place:

 

https://max.nwstatic.co.uk/gfsimages/gfs.20141115/18/240/npst30.png

 

I don't know but it looks to me that at this stage the (shattered) troposferical vortex determines the development of the stratosferic vortex and not the other way.

 

 

.

[Recretos]

I can access that website through login from work so let me if any charts or info is required. The page is bit of a 'select box' minefield to be honest but if specific variables can be highlighted I'll see what it fires out

Cheers. Matt

Yea I forgot to mention, you have to register first, and all the data is in the gridded form only, so you have to make graphics yourself out of that data.

Its a gold mine of reanalysis for me because that is pretty much what I love the most, playing around with data and making plots.

[bluearmy]

The Berlin update provides a slightly less exuberant picture high up. The upper split is gone beyond day 8 (which ties in with gfs forecast). The wave 2 relaxes towards the end (the two are connected) and overall, the upper strat vortex looks more organised by day 10. However, further warmings are shown high up and they will have ramifications. Whilst zonal flow shows a slight uptick, I don't think it's significant at this time. we had some consistency on this current picture so would need to see the same if there is any change. without analysing each chart in detail, I think zonal flow across the NH is forecast to be higher than it has been low down in the strat. High up, it still looks very tepid for the time of year.

Incidentally, the two week gfs plots have continued strong 1hpa warming which is now close to taking positive temps to the pole. Whilst 10hpa has shown the warmings weakening, I expect we will see these increase again at the back end of the next few runs. It may be my imagination, but I think that the op looks more consistent on 10hpa temp forecasts than the parallel. I recall that previous upgrades of other models have sometimes resulted in a lowering of stats somewhere in the strat.

Edited November 16, 2014 by bluearmy

[ukpaul]

Incidentally, the two week gfs plots have continued strong 1hpa warming which is now close to taking positive temps to the pole. Whilst 10hpa has shown the warmings weakening, I expect we will see these increase again at the back end of the next few runs. It may be my imagination, but I think that the op looks more consistent on 10hpa temp forecasts than the parallel. I recall that previous upgrades of other models have sometimes resulted in a lowering of stats somewhere in the strat.

 

The GFS 10hpa parallel charts look much smoother in the supposed high resolution than the op. I presumed that they weren't yet running them at the higher resolution. 

[bluearmy]

The GFS 10hpa parallel charts look much smoother in the supposed high resolution than the op. I presumed that they weren't yet running them at the higher resolution.

I also noticed that Paul - not sure how you run a higher res model at anything other than high res??

[Recretos]

The GFS 10hpa parallel charts look much smoother in the supposed high resolution than the op. I presumed that they weren't yet running them at the higher resolution.

Well if I explain this from experience, since I use and plot the raw data from the model:

The parallel GFS does run at a higher resolution, 13km. The output grids are tho different. You have "a","b" and "full" grid outputs in GRIB2 format.

a files are available in 0.25° (original), 0.5°, 1° and 2.5° grid outputs. The point is basically in the file size, with larger the grid spacing, smaller the file size, and higher speed, etc... Depends what details you need. For strat I use normally 1° grid or 2.5 if I am in a hurry.

b files are available in the same output resolution, except there is no 2.5 grid output.

Now the difference between a and b are the vertical levels and parameters. a output has certain layers from surface to 10mb, and b output has the missing ones that are not in a, and the upper strat from 10mb to 1mb. The point is again in lower file size if you need only specific parameters (b has less parameters than a) and specific vertical layers.

Both a and b go to 384h in all degree grid outputs.

The "full" output goes from 0 to 240h, and has full vertical layering and max resolution (0.25°) and all parameters. But the file sizes are of course bigger and the loading is slower if you run it on your website, etc... Its not a big deal if you only download specific files, since one file (each forecast hour has its own file) of the full output is around 190MB.

The same a,b,full system is applied to op GFS and GEFS. Basically you can only use specific files or combinations and depending on the detail, parameters, etc required, you can use one file type that fita and you have faster loading with smaller file size, and NCEP saves sone if their bandwidth. And its practical for people like me that need specific vertical layers, specific times and specific parameters. I dont have to download full outputs and gigabytes of data.

Meteociel by the look of it uses 1° grid for the FI in old GFS and 2.5° grid for the parallel GFS. That is quite a difference, but for a large scale like the stratosphere its not too big of a big deal for the FI.

I hope I cleared a thing or two.

Kind sunday regards,

Andrew.

Edited November 16, 2014 by Recretos

[johnholmes]

gawd you are making my head hurt, decades ago I might have understood most of that.

[Crocodile23]

The parallel GFS does run at a higher resolution, 13km. The output grids are tho different. You have "a","b" and "full" grid outputs in GRIB2 format.

a files are available in 0.25° (original), 0.5°, 1° and 2.5° grid outputs. The point is basically in the file size, with larger the grid spacing, smaller the file size, and higher speed, etc... Depends what details you need. For strat I use normally 1° grid or 2.5 if I am in a hurry.

Hi again and sorry for another off topic post.

I want to ask from where do you obtain these GRIB2 files you are talking about.

I know this page: http://www.nco.ncep.noaa.gov/pmb/products/gfs/index.shtml.upgrade

And from there, there is this page for example: http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/

Where you can download what you want(seemingly). But i don't get it how exactly and where exactly to go and what means what.

 

So for example if i want the 0.25 grid files of the new GFS for a grid of 40° to 45° north, 10° to 15° east and for let's say geopotential heights of 500 hPa, where do i have to go to download them?

 

b files are available in the same output resolution, except there is no 2.5 grid output.

Now the difference between a and b are the vertical levels and parameters. a output has certain layers from surface to 10mb, and b output has the missing ones that are not in a, and the upper strat from 10mb to 1mb. The point is again in lower file size if you need only specific parameters (b has less parameters than a) and specific vertical layers.

Both a and b go to 384h in all degree grid outputs.

The "full" output goes from 0 to 240h, and has full vertical layering and max resolution (0.25°) and all parameters. But the file sizes are of course bigger and the loading is slower if you run it on your website, etc... Its not a big deal if you only download specific files, since one file (each forecast hour has its own file) of the full output is around 190MB.

Can you also explain from where i can obtain these 3 different formats (a,b full)?

 

 

Many thanks in advance!

[karyo]

The vortex is looking weaker and stretched in the 12z gfs and the warming more pronounced pretty much throughout the run.

 

Karyo

[Snowman.]

The vortex is looking weaker and stretched in the 12z gfs and the warming more pronounced pretty much throughout the run.

 

Karyo

 

To highlight this. While FI still positive signs for some colder weather and very good start to December compared to last.

Edited November 17, 2014 by SN0WM4N

[chionomaniac]

The current tropospheric pattern with the extremely strong Scandi positive anomaly is catching my eye big time. 

 

 

This is something that we expected with the high SAI and it has not failed.

 

However, look at the upcoming pattern - here are the ECM cumulative anomaly charts

 

Days 1-5

 

Days 6-10

 

Watch that westward progression of the Scandi high - this is often seen prior to a displacement event in the strat

 

Here are the slp anomalies from Cohens paper to watch out for prior to displacement SSW's

 

 

Compare to what is programmed. So any sign of a 'big' wave 1 strat warming.

 

You bet!

 

 

Game on.

[Bristawl Si]

So what's your view on timing of this bringing cold to UK, Chiono?

Are u still going for major cold outbreak in Jan?

Or maybe later in Dec? Cheers

[chionomaniac]

So what's your view on timing of this bringing cold to UK, Chiono?

Are u still going for major cold outbreak in Jan?

Or maybe later in Dec? Cheers

Originally was going for end of Dec and January. I won't change that just yet, but the cold was linked to changes in the strat. Of course any strat warming has to filter down to the trop and there is no guarantee of that. It looks like next weeks extreme warmth is the pain that we will have to go through and is part of the bigger pattern that could lead to riches later. But lets just stick to the strat output first before worrying about tropospheric impacts as we are at the very limit of forecasting timescales.