Model Output Discussion; into 2015

[Mucka]

These charts look quite impressive in their own right from GFS 00z.

 

 

But there doesn't seem to be any fast way out of the upcoming zonal spell - anything but in fact.

 

Edited December 31, 2014 by reef
Quoted post removed (off topic)

[Sky Full]

There doesn't seem much of interest in the models to talk about so to keep on topic I have a question to which I hope someone can provide an answer.

Why was it felt necessary to introduce the GFSp when they already had the GFS? If they had discovered a better algorithm or written some improved code for their model, why not simply upgrade the existing one?

In my admittedly very inexperienced view, there appears to be little similarity between the two GFS models as their forecasts diverge very quickly after a couple of days. Does this indicate a significant difference in their programming or is this because the weather has such an infinite number of variables that even the same computer program can show many different solutions from exactly the same starting point?

[mezzacyclone]

Why was it felt necessary to introduce the GFSp when they already had the GFS? If they had discovered a better algorithm or written some improved code for their model, why not simply upgrade the existing one?

Natural evolution to try establishing further probability of higher accuracy outcomes?

But ive no idea if NCEP will make a switch & drop the former when the testing phase is done, maybe after gauging said accuracy?

The increased res is obvious over the operational but the new "grib filters" are bandwidth intensive due to increased file size

But here are the major changes fwiw?

*T1534 Semi-Lagrangian.

*More accurate spectral-grid transforms.

*Reduced grid consistency when creating orographic fields.

*Use of high resolution daily SST analysis.

*Use of high resolution sea ice.

*Physics:

**Cloud estimate modifications.

**EDMF parameterization.

**Dissipation heating paramterization.

**Convective gravity wave drag.

**McICA.

**Modify how GFS diagnoses snow accumulation to be consistent with post.

**Land Surface - Removal of soil moisture nudging.

*Unification of analysis ensemble with GEFS ensemble.

*Ensemble resolution increase to T574L64.

*Analysis upgrades - See global GSI implementation roadmap.

*Post Processor:

**Faster/less memory version.

**Updated version to use new crtm 2.1.3.

**Add user requested fields:

***H/T/U/V at FL410.

***Ozone at 150, 200, 250, 300, 350, and 400 mb.

***2m dew point.

***Wind chill and heat index.

***Instantaneous precipitation type.

***Membrane SLP in GDAS pgb files.

**Improved in flight icing algorithm in post.

**Consolidation of GFS master file creation with GFS DNG, similation of GOES radiances and WAFS.

All a bit jargonistic but if anything then i favor the last line of your post (cut short sorry) in that of the many variables?

We are all spoilt in this digital age so I also hazard a guess that like "MP"s in Westminster then simply "the more the merrier"? (More being this new venture/tryout)

[johnholmes]

Thanks for that - What data collection period do they use for the averages (I assume they are moving averages) and are they available anywhere?  Thanks

not sure but would imagine currently up to 2000 or it might be 2010, that perhaps more likely, try their web site for the truth though please?

[MPG]

Models look ok if your up a Scottish mountain. Apart from that, mobile Atlantic based weather. The phantom warming currently having no effect on the Troposphere so nothing regarding a hint of a SSW. I would forget about this and hope other factors like the MJO will come into play. But the METO have been spot on so far this winter and they still go for a +NAO for the foreseeable due to the MJO. Winter is not over, but best to check the models in 10 days if your really looking for a pattern change.

[IDO]

As expected no quick flip to anything away from zonal. D10 charts for our sector:

 

GEM is flat:   GFS Op is SW to NE: 

 

ECM's much like the others with the UK in full westerly flow with the PV lobe to the NW: 

 

GEFS at D16 still showing any blocking across the other side of the NH: 

 

So even by 16 Jan the Atlantic sector promises very little other than PM shots, mean: 

 

I am not sure if the promise over the last 2-3 days over the other side of the NH is going to develop into anything in our region, it may just be a result of the main PV lobe  circling the N. Atlantic sector to and fro from the Greenland region, allowing the wedge(s) of heights to disrupt the Asian/Pacific mid/upper lats? I would have thought a response to the current warming would be more effective? We need some changes to start to show up otherwise Jan is looking a write off for any blocking longevity.

 

Temps for London now settling around average fo the next 2 weeks with snow chances now at best 5%, so a real downgrade for the south for any PM snow (20% at times on the 12z). Looking at the mean 850's we can see that the PV lobes are on the wrong axis for cold for the UK. If there was some blocking it could divert some of the flow but with a flat pattern we are relying on cold uppers crossing the Atlantic, that are diluted time they reach the south and east:

 

 

 

With the Major SSW looking far from certain in the next two weeks disregarding if it happens and if it favours the UK, then we maybe in for a long haul to reset this pattern.

Edited December 31, 2014 by i'm dreaming of...

[Duane S.]

Models look ok if your up a Scottish mountain. Apart from that, mobile Atlantic based weather. The phantom warming currently having no effect on the Troposphere so nothing regarding a hint of a SSW. I would forget about this and hope other factors like the MJO will come into play. But the METO have been spot on so far this winter and they still go for a +NAO for the foreseeable due to the MJO. Winter is not over, but best to check the models in 10 days if your really looking for a pattern change.

 

It's not a "phantom warming", it's underway now, as forecast. It is affecting (and will continue to for a while) the troposphere just not currently in a favourable fashion for us to get a cold spell as it stands. +NAO whilst likely to remain for the forseeable is not "due to the MJO", moreover the MJO is not helping reducing the +NAO signal.

 

Correct though, winter is not over!

[Severe Siberian icy blast]

As expected no quick flip to anything away from zonal. D10 charts for our sector:

 

GEM is flat: gem-0-240 (4).png  GFS Op is SW to NE: gfs-0-240 (7).png

 

ECM's much like the others with the UK in full westerly flow with the PV lobe to the NW: Recm2401.gif

 

GEFS at D16 still showing any blocking across the other side of the NH: Meteociel_-_Panel_GEFS 9.png

 

So even by 16 Jan the Atlantic sector promises very little other than PM shots, mean: gensnh-21-1-384 (6).png

 

I am not sure if the promise over the last 2-3 days over the other side of the NH is going to develop into anything in our region, it may just be a result of the main PV lobe  circling the N. Atlantic sector to and fro from the Greenland region, allowing the wedge(s) of heights to disrupt the Asian/Pacific mid/upper lats? I would have thought a response to the current warming would be more effective? We need some changes to start to show up otherwise Jan is looking a write off for any blocking longevity.

 

Temps for London now settling around average fo the next 2 weeks with snow chances now at best 5%, so a real downgrade for the south for any PM snow (20% at times on the 12z). Looking at the mean 850's we can see that the PV lobes are on the wrong axis for cold for the UK. If there was some blocking it could divert some of the flow but with a flat pattern we are relying on cold uppers crossing the Atlantic, that are diluted time they reach the south and east:

 

graphe6_1000_306_141___Londres (7).gif  gensnh-21-0-384 (1).png

 

With the Major SSW looking far from certain in the next two weeks disregarding if it happens and if it favours the UK, then we maybe in for a long haul to reset this pattern.

I agree in the sense at the minute it all looks very zonal and a complete opposite to what the signals were going for .

The only thing about the models I will say is considering we'r not in the zonal pattern yet , it seems today maybe the day of transition ? My point being is very often we can see the models banging the zonal drum , but once the change has actually occured it then picks up the next pattern , so at the minute the only strong signal coming through is indeed this zonal spell , but once it's actually hear the models will then look for the next pattern change , if indeed there is one ?

Il be amazed if there's no troposphere response from the warmings , especially the one over Greenland area , but maybe another week or 10 days before the mods actually pick upon it , although there seems to be a quick strat/trop response at the min , it's still likely to be a good 7 days at least for the propegation to filter through ? All speculation at the minute but I'd be very surprised if we go through January without having at least one big cold spell and snow . Even with an average uk winter we would squeeze out 2 or 3 cold spells with at least one widespread snow event . So no need to panic just yet , just more damn patience !

[cyclonic happiness]

I'm a little bit happier this morning.

 

We've been seeing a full on onslaught by the Atlantic for a few days now, but this morning high pressure is nudging a bit further north, so it's not going to be as much of a wind/rain fest as the earlier models.

 

Maybe a switch back towards settled weather is on the cards, especially the later part of the ECM.

[MPG]

It's not a "phantom warming", it's underway now, as forecast. It is affecting (and will continue to for a while) the troposphere just not currently in a favourable fashion for us to get a cold spell as it stands. +NAO whilst likely to remain for the forseeable is not "due to the MJO", moreover the MJO is not helping reducing the +NAO signal.

 

Correct though, winter is not over!

 

Ok warming is happening, but nothing that resembles a SSW until day 10! Then you have to wait 2 to 3 weeks for that to show its hand regarding our or somebody else is the world's weather. The METO are basing the +NAO on factors mainly including the MJO, as per thier corrospondance by email.

[karlos1983]

ECM is stuck on the 12z from yesterday on meteociel?

[johnholmes]

No signs of any marked change on any of e anomaly charts, including NOAA 8-14 so little probability of any much change in surface weather for uk, and no sign as yet of any cold outbreak from any direction, other than colder behind any surface ridge following Atlantic weather systems as they move, mainly somewhere between Iceland and NW Scotland, sometimes over NW of Scotland, much as the New Year day depression.

[TEITS]

You know the output is poor when I can't even find a GEFS member below -6C.

 

http://max.nwstatic.co.uk/ensimages/ens.20141231/00/t850Cambridgeshire.png

 

The SLP mean for Iceland says it all.

 

http://max.nwstatic.co.uk/ensimages/ens.20141231/00/prmslReyjavic.png

 

Apart from the SSW the other straw im clutching is I do recall numerous times how the models can dramatically change. Never forget the awful output during late Jan 2005 and how this changed significantly towards blocking in Feb.

[nick sussex]

How many exclamations of horror can I fit into one post regarding todays output!

 

Ghastly, hideous, dismal,depressing,...... I could go on and on and on!

 

The faint glimmer of hope from last nights ECM has sadly vanished from todays outputs and it joins the others in a flat zonal pattern with PV limpeted to the north and strong Azores high.

 

There was some brief interest at day 6 when that ridge gets thrown towards Svalbard, in any other circumstances that could have developed further but unfortunately the ejection of those low heights eastwards upstream means this has no chance of surviving the onslaught.

 

All the outputs are in agreement on the way forward which isn't a good one if you're looking for some cold and snow, as for the Greenland strat warming well ordinarily that might deliver something but as you can see the PV is in no mood to play second fiddle.

 

Overall little sign of any change for the timebeing, hopefully the patience shown by members in here will be rewarded at some point.

[Frosty.]

Dare I say the models look very like they did last winter, I.e. technically mild, wet and windy at times with colder showery incursions..this just happens to be exactly as the met office are predicting for the next month..gets tin hat on just in case of angry responses.

[Penrith Snow]

I'm a little bit happier this morning.

 

We've been seeing a full on onslaught by the Atlantic for a few days now, but this morning high pressure is nudging a bit further north, so it's not going to be as much of a wind/rain fest as the earlier models.

 

Maybe a switch back towards settled weather is on the cards, especially the later part of the ECM.

More high pressure to the south is bad news as it prevents any PM shots!!

One if the most stable synoptic types is what Brian Gaze on TWO christened the Zonal Bartlett with high pressure over Iberia, low pressure over Iceland and a strong zonal flow. This is modelled across the piste today and is very bad news IMO.

The only way out of this is for high pressure to the south to decline and the persistent low pressure to transfer towards Scandinavia, the movement northwards of the AH will not save us this time, in fact if is our nemesis.

Model watching does not get any worse than this that's for sure.

Andy

[MPG]

How many exclamations of horror can I fit into one post regarding todays output!

 

Ghastly, hideous, dismal,depressing,...... I could go on and on and on!

 

The faint glimmer of hope from last nights ECM has sadly vanished from todays outputs and it joins the others in a flat zonal pattern with PV limpeted to the north and strong Azores high.

 

There was some brief interest at day 6 when that ridge gets thrown towards Svalbard, in any other circumstances that could have developed further but unfortunately the ejection of those low heights eastwards upstream means this has no chance of surviving the onslaught.

 

All the outputs are in agreement on the way forward which isn't a good one if you're looking for some cold and snow, as for the Greenland strat warming well ordinarily that might deliver something but as you can see the PV is in no mood to play second fiddle.

 

Overall little sign of any change for the timebeing, hopefully the patience shown by members in here will be rewarded at some point.

Great posts as always Nick, but there is nothing showing that is remotely 'cold' so patience isn't required. The output is what it is and the way things are set up no change is in sight. I suppose we could patiently wait for spring!

[Penrith Snow]

Dare I say the models look very like they did last winter, I.e. technically mild, wet and windy at times with colder showery incursions..this just happens to be exactly as the met office are predicting for the next month..gets tin hat on just in case of angry responses.

No angry response from me because your post is 100% accurate! the projected charts for the first week in January are a mirror image of last year and no waffle about SSW's and background signals will change that.

Andy

[Frosty.]

Unless we lose those heights to the south, coldies are in for a world of pain.

Edited December 31, 2014 by Frosty.

[nick sussex]

If anyones looking for a miracle GEFS member 4 tries at least!

 

 

 

[Captain Shortwave]

More high pressure to the south is bad news as it prevents any PM shots!!

One if the most stable synoptic types is what Brian Gaze on TWO christened the Zonal Bartlett with high pressure over Iberia, low pressure over Iceland and a strong zonal flow. This is modelled across the piste today and is very bad news IMO.

The only way out of this is for high pressure to the south to decline and the persistent low pressure to transfer towards Scandinavia, the movement northwards of the AH will not save us this time, in fact if is our nemesis.

Model watching does not get any worse than this that's for sure.

Andy

Actually shifting that Iberian slug northwards can bring rewards, for a start as soon as we develop a slacker flow then temperatures will fall at the surface and if the winds are off the continent then frost and fog will start to form. Of course if we end up with a Euro or even Scandi/Euro high then we have a better chance of swinging the winds easterly over time. 

The output for those who like cold is poor, no point dressing it up and at this present time the events in the stratosphere don't seem to be working in our favour as the warmings are just not strong enough at this present time/modelling.

@Frosty, I think that Greenland lobe of the polar vortex has stolen your hat 

Edited December 31, 2014 by Captain shortwave

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY WEDNESDAY DECEMBER 31ST 2014.

NEXT UPDATE WEDNESDAY DECEMBER 31ST 08:00

THE CURRENT GENERAL SITUATION Fronts will move SE across the UK in a freshening SW flow today and again tomorrow with a colder interlude of Westerly winds across the NW tonight..

MODELS-2 WEEK HEADLINE Becoming unsettled and windy later this week and onward with rain or showers at times and snow on Northern hills. Some drier periods likely in the South.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows little change from that of recent output, remaining flowing in a relatively flat pattern West to East across the UK or close to the South between Low pressure to the North and NW and High pressure in a belt from Southern Europe and the Azores.

GFS OPERATIONAL The GFS operational this morning shows a prolonged zonal spell of weather coming up with just brief chillier and drier spells in a NW flow alternating with much longer periods of relatively mild but very windy weather with spells of rain and showers with snow restricted to Northernmost high ground where the heaviest rain is also expected.

THE GFS PARALLEL RUN The Parallel run is very similar to the operational this morning with the emphasis on the heaviest and most unsettled conditions lying across the North of the UK as High pressure comes very close to Southern Britain at times pumping mild and rather cloudy and drizzly conditions here rather than the heavy rains of the NW. Some short cooler periods with showers, wintry on Northernmost hills is shown but this covers the minority of time within the period with ni imminent change indicated by Day 15.

THE GFS CONTROL The GFS control run is very akin to the parallel run with days of mild SW winds and occasional rain while short colder interludes with showers occurs more likely at first in the period. As with the other runs the wettest conditions will be in the North with the highest of the rather mild temperatures in the South.

THE GEFS ENSEMBLES The GFS Ensembles show strong support for a Westerly flow to dominate the UK through the period. With Low pressure biased to lie to the North and High near the Azores and Southern Europe Westerly winds, strong at times will follow their normal characteristics of spells of wind and rain for all with slightly colder and more showery interludes in between, these most prolific across the North while the heaviest rain occurs across the North and West.

UKMO UKMO shows a mobile Westerly flow developing across the UK from today onwards. With Low pressure to the North and High to the South there will be fronts moving East in the flow bringing rain at times and short brighter, slightly colder conditions with showers perhaps wintry over the Northern hills.

THE FAX CHARTS The Fax Charts follow the raw data quite well today with a milder SW flow replacing the cold High across Southern Britain over the New Year. A cold front in the stronger SW flow will clear SE by the weekend with another set of fronts approaching the UK from the SW later in the weekend following a brief chillier ridge on Saturday.

GEM GEM today shows a sustained period of strong Westerly winds with gales possible in all areas. It will be generally mild with just short colder and more showery phases, chiefly across the North whereas most of the time outside of this will be cloudy and dull with spells of rain, especially across the West and North.

NAVGEM NAVGEM also shows the well worn track between the models recently of replacing High pressure with a milder Westerly flow between High pressure to the South and Low to the North with rain at times with some brief drier and chillier days in between, these mostly restricted to the North.

ECM ECM this morning shows High pressure to the South or SE and SW of the UK driving mild and strong West or SW winds across the UK with rain at times especially towards the North and West. Later in the period as the pressure gradient strengthens across the UK gales and heavy rain can be expected for all areas with some colder and blustery westerly winds with showers wintry in the North becoming more dominant.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart shows Low pressure to the North and High to the South the most likely scenario at Day 10. This would indicate a strong Westerly flow with spells of rain mixed in with slightly colder and more showery conditions in between, the latter most likely over the North.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning remains unchanged with all models supporting a sustained and little removed period of Westerly winds across the UK, quite mild at times especially across the South with spells of rain and a few brighter and colder interludes especially at first and again later over the North.

MY THOUGHTS To illustrate how set the models are in their output currently I could of cut and pasted a lot of the models text from yesterday into today's and it would not of looked out of place. The theme remains for a strong Westerly component to the weather in a persistently zonal period driven by a strong belt of High pressure from Southern Europe to the Azores and Low pressure to the North and NW of the UK. Differences day to day will depend on whether we are under warm sector conditions of cloudy and drizzly weather with temperatures near or above average and this looks more likely for longer periods across the South where not too much rain is likely. Alternatively there will be some chillier and clearer weather on occasion, these most likely at first almost anywhere and later more likely over the North where a little snow will continue to be a risk at times over the mountains. The long term pattern of the next two weeks depressingly looks unlikely to change at the end of the period either reading from today's output as GFS and other long term models support little if any significant change in synoptics at Day 14-15 with the only trend that I can see in being a deepening of the unsettledness across the UK with all areas coming under Westerly gales and colder showery periods in between, a point at which all areas could share in some wintry showers over the hills but this is a grain of sand in a desert of damp and mild Westerly winds when few of any of us living in lowland Britain will see any snowfall this side of mid January at least. Frosts will also be relatively scarce and slight with no chance of any as sharp as those of recently being repeated within the period and conversely night's could be unusually mild at times in the warm sector conditions across the South expected.

[bluearmy]

The stratospherical silver bullet receding fast for a quick solution to this zonal outlook. ECM has backed off any SSW prediction with the n pacific ridge no longer pushing into the pole through week 2 and the strat vortex happily setting up shop over n Greenland.

How it all manifests in the trop remains questionable. I doubt we will see no consequences of the strong warming currently

underway which continues into the distance but no longer causing a polar vortex split . I could make some semi informed guesses but there really isn't any point in guessing whilst the outlook seems quite assured to be zonal alternating TM/PM.

Perhaps a small polar block establishing svaalbard area could see the zonality continue further to our east rather than swinging ne. Colder opportunities appear in this instance. Always a silver lining for coldies though nothing very concrete.

[Long haul to mild]

Yes, models still poor for cold this morning, but was anyone really expecting any different? We've known for a few days now that a zonal spell will be taking place for the next couple of weeks but having just checked my calendar, I note that it is still December and even taking into account the output, assuming it is correct, that takes us to mid Jan. That means that we still have a whole two months opportunity to get something better (yes, I include the first half of March as historically I have seen far more snow then than I ever have in December).

 

An SSW may well happen over the next 10 days and if so we will need to see if that can produce something for us; but the models will not be picking up on that as yet. Even if it does not occur, it doesn't mean winter is a bust; there are other ways to get pattern change.

 

All coldies know the output is poor at the moment, but we also know things can and do change, and the weather has made fools out of very clever people in the past. It would certainly be nice to see the schadenfreude cut from some posts I have seen here in recent days.

[Frosty.]

Well the Ecm 00z looks very wintry at times in Scotland during FI..blizzards for upland areas.

Edited December 31, 2014 by Frosty.