Model Output Discussion 1200 hrs 15/11/14

[knocker]

The GEFs T240 anomaly has the Atlantic trough further east with a NW/SE orientation. This basically fits in with the NOAA 8-14 interpretation. Essentially this leaves us  in a Mexican standoff position with lows driven by a very strong jet that curves SE in mid Atlantic before turning NE around the HP.

 

[mushymanrob]

Only on Saturday, mild air has moved away by Sunday according to the ECM

 

.... But not according to the gfs and youre assuming the current ecm will become reality. The facts are that its well to early to make any definitive statement. Its looking likely that a mild spell is on the cards, how long it lasts assuming we get one, is far from certain. The current gfs suggests that most of the run will be average-mild.

On tablet, cant post complimentary charts but everyone knows where the gfs can be viewed.

[Paul]

stratospheric warming. have a look here- http://www.netweather.tv/index.cgi?action=nwdc;sess=  choose chart type and away you go.

 

have a look in the strat thread. it will help you understand what these charts mean (not that i'm an expert by any means!)

 

Ed wrote an excellent tutorial on the stratosphere for those who may be interested:

 

http://www.netweather.tv/index.cgi?action=stratosphere-tutorial;sess=

[knocker]

Sunday with the upgrade.

 

[nick sussex]

Confusing, frustrating are just some of the words that might describe the output if you're looking for cold.

 

Small irritations pop up like the shortwave which phases with the troughing to the nw this gives the trough a nice pull eastwards just as it was reaching for the white flag!

 

This shortwave is now the subject of much contention, effectively what we have is the jet heading out of the ne USA wanting to dive south it then encounters the shortwave and gets pulled further east/ne, its not till this shortwave has finally separated from the Alien Queen that Ripley can go about repairing the damage.

 

If you look at the ECM postage stamps you'll see how many different solutions there are for this, for cold lovers you do not want any of the solutions like 31, 42, 46 etc these are likely to deliver the GEM solutions because the upstream trough will phase with this over the UK:

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014111712!!/

 

This is the point of no return I alluded to in my previous post,  remember here when looking at the ECM mean this will dilute out the proper signal because of the uncertainty over the phase point.

 

Essentially and not to be too theatrical any chance of cold with T240hrs rests on a shallower shortwave further to the nw allied with enough dig in the jet upstream to send some WAA to develop a stronger ridge to the north/ne, or a huge turnaround which ejects the shortwave se'wards before the Alien Queen arrives on the scene.

 

Tonights ECM was very close to unravelling in terms of cold with the shortwave too close for comfort.

 

On a more positive note the CPC charts certainly don't scream mild, if anything those anomalies look okay for cold but we need some luck with the shortwave:

 

 

 

 

 

 

 

[IDO]

The GEFs T240 anomaly has the Atlantic trough further east with a NW/SE orientation. This basically fits in with the NOAA 8-14 interpretation. Essentially this leaves us  in a Mexican standoff position with lows driven by a very strong jet that curves SE in mid Atlantic before turning NE around the HP.

 

Hi

 

That NOAA consists of 60% of yesterdays GEFS/GFS 18z and 40% of the 0z ECM mean at D11. The game has moved on since then. I think NOAA are behind the ball with this output, and they used the 18z!!!

 

Quote: "THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 40% OF YESTERDAY'S 18Z GFS

ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF YESTERDAY'S OPERATIONAL 18Z GFS

CENTERED ON DAY 10, AND 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON

DAY 11" 

Edited November 17, 2014 by i'm dreaming of...

[frosty ground]

Sunday with the upgrade.

what is that showing?

[Summer Sun]

what is that showing?

 

The 2m temperatures which are shown to be above average, surface temperatures could also be above average maybe mid teens for parts of the south given the southerly winds

[Midlands Ice Age]

 

The last chart finishes with a very disorganised PV, Heights pushed well up into the Poles and the Jet way South..

 

[img=http://modeles.meteociel.fr/modeles/gfsp/runs/2014111712/gfsnh-1-384.png?12

 

Did anyone notice the new low temp of -36C on the above chart in Siberia.

Can't recall it getting this low for quite a time.

MIA

[Timmytour]

A very complexed and confusing  outlook from gfs and ecm from the 12zs and probably the 06zs. The ebbing and flowing from the models is quite amazing. I think we will have to wait to tomorrow to see a more clearer outlook but even that seems unikely. Tonights output seems that the ecm has the colder run

I think I've seen variations of the "have to wait till tomorrow to see a more clearer outlook" every day for the past fortnight!

I think you're right though....we probably won't see it clear up tomorrow. The only consistent factor at the moment seems to be dear old Shannon

Edited November 17, 2014 by Timmytour

[fergieweather]

Only on Saturday, mild air has moved away by Sunday according to the ECM

 

Cautionary note: the partial thicknesses may look decidely impressive, but aren't a good guide to likely surface temperatures in this set-up (due to the noticeably cooler undercut for many, and equally, the low inversion amply shown in f'cast profiles). So yes, low teens are possible in places perhaps (W London for example), but generally panning-out at seasonal average through the weekend or just a nudge above.

[Gael_Force]

The 2m temperatures which are shown to be above average, surface temperatures could also be above average maybe mid teens for parts of the south given the southerly winds

 

There's a freebie ensemble in the ECM link that Nick posted - looks to be about 13-14c on the ground for Saturday. Much higher temps showing now - it was barely into double digits on recent runs.

[snowice]

Confusing, frustrating are just some of the words that might describe the output if you're looking for cold.

 

Small irritations pop up like the shortwave which phases with the troughing to the nw this gives the trough a nice pull eastwards just as it was reaching for the white flag!

 

This shortwave is now the subject of much contention, effectively what we have is the jet heading out of the ne USA wanting to dive south it then encounters the shortwave and gets pulled further east/ne, its not till this shortwave has finally separated from the Alien Queen that Ripley can go about repairing the damage.

 

If you look at the ECM postage stamps you'll see how many different solutions there are for this, for cold lovers you do not want any of the solutions like 31, 42, 46 etc these are likely to deliver the GEM solutions because the upstream trough will phase with this over the UK:

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014111712!!/

 

This is the point of no return I alluded to in my previous post,  remember here when looking at the ECM mean this will dilute out the proper signal because of the uncertainty over the phase point.

 

Essentially and not to be too theatrical any chance of cold with T240hrs rests on a shallower shortwave further to the nw allied with enough dig in the jet upstream to send some WAA to develop a stronger ridge to the north/ne, or a huge turnaround which ejects the shortwave se'wards before the Alien Queen arrives on the scene.

 

Tonights ECM was very close to unravelling in terms of cold with the shortwave too close for comfort.

 

On a more positive note the CPC charts certainly don't scream mild, if anything those anomalies look okay for cold but we need some luck with the shortwave:

 

814day_03.gif

Hi Nick,so is tomorrow's runs the last throw of the dice in relation to the position of the shortwave, that will decide if we will see any Cold.

[Snowman.]

Hi Nick,so is tomorrow's runs the last throw of the dice in relation to the position of the shortwave, that will decide if we will see any Cold.

 

Cold in the near future*

 

Always plenty of chances 

Edited November 17, 2014 by SN0WM4N

[nick sussex]

Hi Nick,so is tomorrow's runs the last throw of the dice in relation to the position of the shortwave, that will decide if we will see any Cold.

The two key things to look at is where the shortwave is and how far south that troughing behind it has dug into the Atlantic, between the two theres a nose of high pressure.

 

You want to see the shortwave as weak as possible and as far north as possible, as the Atlantic troughing digs south it pushes that nose of high pressure ne, as the shortwave finally becomes detached from lower heights associated with the trough you have a window of opportunity to develop some WAA basically this helps build high pressure, if you're looking for an easterly then the shortwave will run east to the north and then sw as the jet cuts back towards the UK, however the models have been reluctant to do that bar the odd run.

 

The main thing is just to get the pattern as far west as possible before any phasing.

[Yarmy]

3 hour intervals on the 18z P?

[knocker]

Hi

 

That NOAA consists of 60% of yesterdays GEFS/GFS 18z and 40% of the 0z ECM mean at D11. The game has moved on since then. I think NOAA are behind the ball with this output, and they used the 18z!!!

 

Quote: "THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 40% OF YESTERDAY'S 18Z GFS

ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF YESTERDAY'S OPERATIONAL 18Z GFS

CENTERED ON DAY 10, AND 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON

DAY 11" 

 

Even so the 12z GEFS is similar although of course the ECM shows the trough much further east with surface low pressure effecting the UK with a split jet, the northern arm of which curves SE west of the UK with the southern arm running into the MED. Cold seems very unlikely to me.

Edited November 17, 2014 by knocker

[Dean E]

Out in relative FI yes, but look at the difference at +150hr

 

GFS P 18z                                               GFS P 12z

 

 

 

 

Small difference yes, but just goes to show how unreliable we are right now.

 

SM

Edited November 17, 2014 by SnowMania

[Captain Shortwave]

The GFS never pulls up that Euro ridge and is very progressive with the oncoming Atlantic systems. The resut is a weak UK high which would bring some sunnier and chilly weather from Sunday onwards

 

GFS parallel

Still gives a southerly on Saturday

Rather mild too. 

 

A lot of uncertainty to say the least

The parallel then pushes the Atlantic through eventually producing a north/south split

 

Can't really buy any run from this weekend onwards to be honest. Lets see what the morning runs give.

Edited November 17, 2014 by Captain shortwave

[bluearmy]

are we going to assume that the 10 day ens charts are going to be right in respect of how far east the mean trough gets against the sceuro block? no one is seriously arguing that the block is going anywhere and yet some are happy to accept the models assertion that brings the mean trough close to the west of the uk by day 10. or does it??  meteociel anomoly charts show the area of no mans land between high and low anomolys to be the east of the uk. i don't accept that the charts are even showing the trough close enough to the uk and thats before you take into account that they are probably too far east anyway.  

[nick sussex]

No joy from either the GFS or GFS P, the former made a halfhearted attempt to cut the shortwave back into the UK but just not enough upstream amplification and the pattern is too far east.

 

Still a chance of some surface cold and the ECM desperately wants to keep some interest with the jet running se in towards the UK but its a close run thing. 

 

More changes are likely, hopefully after the recent slump the output improves tomorrow for those looking for some colder weather.

[Altohumorous]

There has never been any consistent modelling for real cold at all. Most output has pointed to exactly what we have, stalemate and continuing average weather overall. So the models have not been, nor are confused, nor have slumped or anything like that.

Far too much emphasis on the inevitable few outputs that have shown potential cold synoptics developing. There is no real sign of change so that is what the output mostly is and that is the most likely outcome.

Edited November 17, 2014 by Altohumorous

[Geordiesnow]

There has never been any consistent modelling for real cold at all. Most output has pointed to exactly what we have, stalemate and continuing average weather overall. So the models have not been, nor are confused, nor have slumped or anything like that.

Far too much emphasis on the inevitable few outputs that have shown potential cold synoptics developing. There is no real sign of change so that is what the output mostly is and that is the most likely outcome.

 

Have too agree with that when you look at the models on face value but it seems a pattern change is edging in and we may see a more westerly influence, ether that is via a low pressure system or a high pressure cell ridging in from the Azores remains to be seen. At least if its the latter then we may see some cooler air toppling in which could lead to clear skies at night and some frost. 

 

As I mentioned yesterday, certainly no significant cold on the way for the foreseeable but if there is one crumb of comfort, its not Bartletts and a raging PV over Greenland either. 

[Cloud 10]

are we going to assume that the 10 day ens charts are going to be right in respect of how far east the mean trough gets against the sceuro block? no one is seriously arguing that the block is going anywhere and yet some are happy to accept the models assertion that brings the mean trough close to the west of the uk by day 10. or does it??  meteociel anomoly charts show the area of no mans land between high and low anomolys to be the east of the uk. i don't accept that the charts are even showing the trough close enough to the uk and thats before you take into account that they are probably too far east anyway.  

 

The ensemble mean's are as fickle as the op runs at the moment,with the ECM day 10 being most guilty.

 

yesterday..  today..

[Nick F]

My latest 14 day outlook, taking in this evening's NWP output into account. Pretty much see a stalemate between Atlantic upper trough trying to advance east against stubborn block over eastern Europe and W Russia - which could continue right until the end of the month:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6297;sess=

 

Might look different by the time all of tomorrow evenings output's out, but can't really see any big changes given the current/recent way the upper pattern's been portrayed by NWP right until the end of the month.