Model Output Discussion 1200 hrs 15/11/14

[Cloud 10]

Ridiculous differences between the day 7 ECM 12z and the 18z GFS P,may as well be day 77!

 

ecm..ECM1-168.gif  gfsp..gfs-0-168.png

 

Just going back to this from yesterday and its clear to see the GFS new direction of travel when comparing yesterday's 7 day to this evening's 6 day.

 

yesterday..  today..

 

The new parallel run seems to have similar "symptoms" to the old GFS.

[Daniel*]

Day 6:

GFSP 18z has some quite cold uppers -5 widely over the UK - although moderated by Atlantic

Possible snow risk for those further south with those inland with elevation something to keep a tab on. These cold uppers which are supportive for snowfall is gaining in momentum.

*Fixed grammar, cleaned up*

Edited November 29, 2014 by Daniel*

[nick sussex]

We're saved the NAVGEM 18hrs run has  trended towards the UKMO solution ! lol On the other hand the GFS and GFS P are flatter upstream, although in terms of temperatures it could still turn colder for the UK under a slack flow and surface inversion.

 

In terms of the UKMO fax charts they seem to go with the UKMO raw output so no modifications but these can change as quickly as the outputs.

 

We should know in the morning whats happening over the  USA given the divergence really starts as early as T96hrs over there, and this dominoes into  some big changes in the Atlantic.

Edited November 29, 2014 by nick sussex

[Midlands Ice Age]

 

GFSP 18z has some quite cold uppers -5 widely over the UK - although moderated by Atlantic

image.jpgimage.jpg

image.jpgimage.jpg

Possible snow risk for those further south with those inland with elevation something to keep tab on.

Looks to me as if ths side of the Atlantic the GFSP has become more amplified. Is this the start of the move to the ECM solution?

It still does not like the idea of a linkup with the raised heights over Greenland, maybe it is too much for it all in one go!! It has been a consistent trend that when the GFS backs down it does so in baby steps (A lesson from Steve Murr!)

Interesting times for model watchers

MIA.

[blizzard81]

We're saved the NAVGEM 18hrs run has trended towards the UKMO solution ! lol On the other hand the GFS and GFS P are flatter upstream, although in terms of temperatures it could still turn colder for the UK under a slack flow and surface inversion.

I know this sounds a little cynical but don't you find it just a tad suspicious how the ops ( more so ECM these days) throw out very cold runs. One could argue it is a marketing ploy to increase interest so to speak! I know it sounds cynical but we all know how the world works these days - unfortunately! Just a thought.

Edited November 29, 2014 by blizzard81

[nick sussex]

I know this sounds a little synical but don't you find it just a tad suspicious how the ops ( more so ECM these days) throw out very cold runs. One could argue it is a marketing ploy to increase interest so to speak! I know it sounds synical but we all know how the world works these days - unfortunately! Just a thought.

The ECM is fast becoming a big disappointment and is even more attention seeking than the GFS, the latter used to be the NWP that used to deliver colder solutions that never verified.

 

It still gets to keep its Crown however because it normally ditches its outlandish output before this gets into the T144hrs timeframe so then can still look good on the verification stats, it hopes that people will forget the drivel its come out with past that point over recent months.

 

Until the ECM stops delivering over amplified scenarios past T144hrs I'd view its output with suspicion past that point, if the other models back it then fair enough we can have a bit more confidence.

 

I used to be its biggest fan but I think we need to view it now as good  and normally the best NWP upto T144hrs but falling over a cliff and not to be trusted after that point. I'd use the analogy of athletics, its great over 200 metres but is about to pass out at 400 metres!

[bluearmy]

I think the issue is more that we don't remember the runs which aren't cold in fi. I promise you there are far more of those!

[damianslaw]

144 hours is always the point at which the reliable timeframe ends.. with this in mind always treat any model output beyond such a timeframe with great caution.. There is a reason why the BBC/Met until recentlynever went beyond the 5 day timeframe, and why there recent 10 day outlooks often chop and change and remain exceptionally vague.

[knocker]

Just a passing comment regarding the the T1534. One concern is that the track of any of these depressions relocates a tad further south. The end of the run is quite chilly.

Charts courtesy weatherbell

 

[nick sussex]

I think the issue is more that we don't remember the runs which aren't cold in fi. I promise you there are far more of those!

Yes I think you make a good point BA. It's unavoidable though that we'll view it through a microscopic lense in winter .

[bobbydog]

not sure why a commercial numerical weather prediction model, or its creators, would have a "marketing ploy" or "seek attention" by being inaccurate...

[knocker]

 

 Ryan Maue â€@RyanMaue

ECMWF pushes HRES global to T2047 or 10-km in 2015 as the new Cray supercomputer is firing on all cylinders.

[Charlton Adam snow]

this must be in the running for least sensible comment today?

blizzard81, on 29 Nov 2014 - 22:55, said:

 

How on earth do you imagine the model, any model, actually computes the weather. Science or skulduggery?

  

i find your lack of faith disturbing....

I only watch this thread from a far, due to some of the tone of the posters in here, but the comments suggesting that ECMWF somehow makes it up as it goes along is unbelievable. EC has the most powerful supercomputer, (-and will do for some time until the Met Offices new HPC is installed), best-performing medium-range model by far and it provides this for 34 European contributing Member States, who pay £millions to receive the outputs.

Sorry, had to say this -appreciate that some are feeling frustrated with the search for cold, but the sentiments expressed needed a response.........I feel better now!

[A.J]

Hey.....I've got a great idea!

 

Why don't we create a thread where we can actually discuss the current model output?.......what a novel concept! 

 

....yes, you've guessed it, several posts are about to be binned for being off topic and rather personal

[Barry12]

Don't understand the negativity on here tonight, ECM looks very good too me. Polar Vortex moving East away from Greenland, ridging towards Greenland from the Atlantic. If day 10 verified we would be in a brilliant position.

[kumquat]

GFS 0Z is full of eastern promise at 168

 

Even better down the line

 

If the poor playing models are doing this to us, I'm even more thrilled by the continued numerical output.

 

Not even looked at the parallel yet.

 

Edit: the parallel is awful lol!

Edited November 30, 2014 by kumquat

[knocker]

GFS 0Z is full of eastern promise at 168

 

Even better down the line

 

If the poor playing models are doing this to us, I'm even more thrilled by the continued numerical output.

 

Not even looked at the parallel yet.

 

Edit: the parallel is awful lol!

 

I'm sorry but I'm at a bit of a loss to where you get that. It does briefly produce an easterly way down the line with the passage of a deep depression SE.

[IDO]

At last GEM has ditched its outlier op runs and is more in line with last night's UKMO at D6: 

 

And flattens out afterwards:  UKMO this morning: 

 

That northerly is very brief and rather underwhelming and that assumes it will not continue to be downgraded.

 

This morning GFS op plays with the LP system at around D8 that develops as it interacts with the jet. I have been watching this for a few days in case it does cause mid-latitude disruption, however it has been rather anonymous till the GFS 0z op. Today it sends WAA on its back end and we develop a temporary Greenland ridge. Again it is too early to sustain due to the PV profile to its North:

 

 

 

All well and good but the GEM at D10 still has that LP system in the W.Atlantic! The P has it innocuously roaming to the west of the UK and the pattern as in previous days remains flatter:

 

 

The control pushes that low into the jet and simply reinvigorates it over the high, pumping up the UK MLH:

 

 

The London ENS keep the 850s between -5 and +5, a sure sign of no cold spell developing, just alternating between TM and a PM flow. The op looks on its own synoptically:

 

 

ECM at D6: 

 

As usually the case, ECM and GFS meet in the middle ground, not as flat as GFS but a lot less amplified than GEM and ECM. D7 onwards and the flow flattens as expected due to the PV energy flow to our north.

 

 

 

At D9 ECM continues with the consistent modelling of the PV energy moving east and draining the Greenland lobe and with the Atlantic storm entering stage left this could help exploit the Atlantic ridge's propensity to build towards Greenland:

 

 Miss on this run: 

 

The ECM op height rises are nearly always the best case scenarios, feasible as the GFS op shows, but very reliant on all the pieces of the puzzle fitting together, so mainly unlikely. Early days to dismiss a D10 chart but the op, IMO would appear to be more in line with its mean when that arrives later.

 

However very fine margins with that theory as timing issues will greatly effect the result as we have seen from the GFS different solutions. 

 

The trend at D10 for the PV movement is fluid but the mean suggests that there is a strong indication low heights are moving east and then back towards Greenland and it is this morning a more even flow:

 

 

At D16 the PV is still mobile and mainly disorganised with no clear signal a lobe will set up in Greenland/NE Canada:

 

So uncertainty as to the Atlantic storms introduction into the mix, but the GEFS after D10 although seasonal, don't suggest any blocking leading to a cold setup (apart from the unsupported op).

 

 

 

 

[Iceaxecrampon]

Bringeth it Oneth

 

00z

 

Tuesday potential albeit altitude at 1800ft.

 

 

Then 5th to the 7th at the far end of reliable (+144?) but this has been trending on

quite a few runs - we will as ever see.

 

(Back home visiting relatives in Cumbria on 7th so the sledge will be in the boot.)

 

 

 

Happy Advent Sunday everyone.

 

Ian

Edited November 30, 2014 by Iceaxecrampon

[Captain Shortwave]

So, again posts have been removed. Can we please stay on topic and not have to go down the route of insulting and sarcastic remarks. Thank you

[winterof79]

Having flicked through the output and read a couple of posts I have come to the conclusion that the week ahead is getting steadily colder.UKMO at 144 says cold that's as far as it goes.ECM cold run.Gfs also cold.Welcome winter.Most of the charts have been posted above and how some find fault at this early juncture is open to debate.

Edited November 30, 2014 by winterof79

[Banbury]

GFS 0Z is full of eastern promise at 168

 

Even better down the line

 

If the poor playing models are doing this to us, I'm even more thrilled by the continued numerical output.

 

Not even looked at the parallel yet.

 

Edit: the parallel is awful lol!

http://modeles.meteociel.fr/modeles/gfs/runs/2014113000/gfsnh-0-168.png?0

 

No one wants a frozen landscape more than me but I don't see Eastern promise on the above

[Polar Maritime]

http://modeles.meteociel.fr/modeles/gfs/runs/2014113000/gfsnh-0-168.png?0

 

No one wants a frozen landscape more than me but I don't see Eastern promise on the above

 

You can if you move it on a few frames..

 

[BlueHedgehog074]

Following on from what the Captain said, let's keep this thread friendly please. We don't want to have to put some of you in the naughty chair...

Just a quick summary of some of the models, but it looks as though some kind of cold Polar Maritime blast looks possible very late next week and into the weekend, maybe with a chance of something wintry for some. Whether it will be a cool/cold blast from the North-West, or from the North, would still depend how much amplification that can be achieved to the West of the UK. Some models like the ECMWF, though, generally keeps the UK locked into a flattish Westerly flow, but with another Polar Maritime shot right at the end. The operational GFS, for example, has a Low dropping to our South-East in fairly deep FI pulling in a chilly flow from the East/North-East with heights building to the North and North-West. The blocking High slowly gets knocked down to become a Mid Latitude Blocking high to our West. But still with the Atlantic quite blocked and Lows getting steered well to our North.

The GFS Parallel bears similar ideas to the ECMWF beyond next weekend with a general Westerly or South-Westerly flow for the UK with spells of rain or showers at times, especially for the North - perhaps wintry at times over the Northern hills during the moor cooler Westerly interludes. Does briefly go for a High Pressure system taking a seat over the UK in quite deep FI, but gets knocked off its seat rather quickly.

The GEM looks as though it is gearing up to provide is with a Northerly at 240 hours with High Pressure significantly amplifying behind a trough of Low Pressure trying to swing down towards the UK.

Before then, the models continue to show High Pressure building through the UK from the West next week, with varying brighter and cloudier periods. Could feel quite chilly, especially at night-time with some quite sharp frosts possible. A cold front will also slip through the country tomorrow bringing some rain to places.

[winterof79]

Just to clarify now that i am able to post charts.

 

UKMO  nice early winter chart

http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=144&carte=1021

vortex shifting west to east.

 

GFS  Has the vortex correcting eastward too and i feel the ukmo will follow something similar.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2014113000/gfsnh-0-192.png?0

 

ECM  Polar Vortex as of today

http://www.meteociel.fr/modeles/ecmwf/runs/2014113000/ECH1-0.GIF?30-12

 

And by the end of the run

http://www.meteociel.fr/modeles/ecmwf/runs/2014113000/ECH1-240.GIF?30-12

 

GEM 

http://modeles.meteociel.fr/modeles/gem/runs/2014113000/gemnh-0-240.png?00

 

All variations of a theme that will reap rewards later.One thing is for sure,there will be no repeat of the vortex machine that set up way to our N/W and bombarded us with maritime misery.This year could well be the polar opposite.