Model Output Discussion - 10th Jan Onwards

[damianslaw]

What is the actual point of posting replies like this.

 

Its unlikely to happen exactly like that, but this is why you remove the surface features & look at the heights.

 

 

I think people are treating this development like a bulk standard Northerly toppler.

 

Look at this chart- its near identical to the ECM chart with the arctic high

http://modeles.meteociel.fr/modeles/reana/1984/archivesnh-1984-12-29-0-0.png

 

& 2 days later

http://modeles.meteociel.fr/modeles/reana/1984/archivesnh-1984-12-31-0-0.png

 

& 2 more days

http://modeles.meteociel.fr/modeles/reana/1985/archivesnh-1985-1-2-0-0.png

 

+ 2

http://modeles.meteociel.fr/modeles/reana/1985/archivesnh-1985-1-4-12-0.png

 

 

As long as the Arctic high gets SOME link up with the atlantic it WILL get cold.

 

S

 

 

Thanks for posting these charts from tail end of December 1984 - an almost uncanny similiarity to some of this evenings outputs for later next week notably ECM and shows a perfect example of how a strong arctic high can turn a mild atlantic fest into a continental cold feast should it link with heights building over mid atlantic.

 

ECM continues to suggest the arctic high will become an influential player thanks to an amplified flow developing over NE Canadian and E USA seaboard allowing mid atlantic heights to build quickly and link up with the arctic heights.

 

Still such evolutions remains well beyond the reliable timeframe - and everything hinges on the flow coming out of NE USA/E Canada and how this interacts with projected heights rises over the pole. The AO forecast certainly suggests a strong build of heights over the Pole and if this verifies then there will be significant force placed on the PV shifting its core further west - which is key if we are to develop the amplified flow. So all eyes on developments over the Pole.... the azores high is an important factor as well, but the key player is the interaction of the PV and any height rises over the Pole.

[Summer Sun]

ECM ensemble has -4 850's covering all the UK at t192 some -5s around as well, certainly cold enough for snow just about anywhere

 

 

850's start to ease back slightly at t240 but still low enough for some snow the further north you go possibly to lower levels at times too

 

Edited January 18, 2014 by Summer Sun

[bryan629]

ECM ensemble has -4 850's covering all the UK at t192 some -5s around as well, certainly cold enough for snow just about anywhere

 

 

850's start to ease back slightly at t240 but still low enough for some snow the further north you go possibly to lower levels at times too

 

right , you will not be asked again...where is summer sun and where did you steal his password from

[Cheshire Freeze]

ECM ensemble has -4 850's covering all the UK at t192 some -5s around as well, certainly cold enough for snow just about anywhere

 

 

850's start to ease back slightly at t240 but still low enough for some snow the further north you go possibly to lower levels at times too

 

 

The majority of the ens aren't backing the op at day 10...that's clear I think from the ensemble mean chart. I'm sure Bluearmy will fill us in shortly!

[Frosty.]

I've been waiting for a long time..far too long to post charts as magnificent as these from the Ecm 12z op run tonight, especially the T+216 & 240 charts with the 522 dam thicknesses. I pray the ecm is on the ball tonight because this is the stonking pattern change all us long suffering snow and cold starved peeps have been dreaming of, these charts are a thing of beauty.

 

come on...verify dammit, I want to see a snow flake, I will definately ramp this up if it gets closer

[cooling climate]

 

Also some people are confusing the H5 anomalies with the surface feature. The person that posted the 5 day ECM for today & from 5 days ago shows the ECM has nailed the whole pattern, the issue being if your living in the UK then the models error at day 5 can mean a swing of 10 maybe even 15 degrees for us. However it nailed the height anomalies in the right place. If you look at 168/192 if its modelling those height anomalies correctly again then the odds are FAVOURING a cold NW Europe as opposed to an atlantic driven pattern due to the teleconnections that support the anomalies. Our best chance of cold this season & certainly better than the beat up coke can scandi high from this past few days. S Just to show whos boss look at the low disappear in 48 hourshttp://www.meteociel.fr/modeles/ecmwf/runs/2014011812/ECM1-192.GIF?18-0 955 LOWhttp://www.meteociel.fr/modeles/ecmwf/runs/2014011812/ECM1-216.GIF?18-0 990 LOWhttp://www.meteociel.fr/modeles/ecmwf/runs/2014011812/ECM1-240.GIF?18-0 1010 LOW over the continent.

With the amplifing pattern the low has no choice but to disrupt and undercut. Plusyou will not have to worry about shortwaves running northeast or east into theblock but would in fact move south or southeast.I think your quite right in that some stella runs are not far off in the model runsand that the chances of real winter weather in the extended range is gainingmomentum. The ECM and GFS has started to become quite persistent with a tanking AOand possibilities of a link up with a Scandi high.If this does happen then ourchances of seeing some proper cold will greatly increase because the energy and lowsthat will continue to want to push east will have nowhere to go but southeast andundercut.Some posters this evening are either blinkered or have no idea what they are lookingat. We have not seen anything like these sort of blocked charts showing in the modeloutput this winter until now so things are definitely not the same.In a couple of days time it may well be a case of not will it get cold but how coldwill it get.I saved that insane cold op run from the ECM ens last night just to seehow near the mark it may be in 10 days time.If things go our way it may not be that insane a run after all. Edited January 18, 2014 by cooling climate

[karlos1983]

I know people are going to be holding back in shouting the cold is coming etc, after all the ECM has lead us up the garden path more than once this winter, and we have endured a pretty dismal winter thus far, as far as cold goes   . I am one of those who want to remain open minded. BUT this is by far our best opportunity this winter, we have the right ingredients for cold, The Vortex is weakening and a split is expected, Europe is finally cooling down, Heights are rising over the Pole, possible ridging in the Atlantic and even linking with the polar Heights, even signs of the Strat warming. Now I know none of this guarantees our little island Cold, but we have a damn good shot at getting it now, I'm fully expecting some real eye candy runs in the near future, we need to take them a run at a time, I'm optimistic our patience will be rewarded and soon! 

[bryan629]

I've been waiting for a long time..far too long to post charts as magnificent as these from the Ecm 12z op run tonight, especially the T+216 & 240 charts with the 522 dam thicknesses. I pray the ecm is on the ball tonight because this is the stonking pattern change all us long suffering snow and cold starved peeps have been dreaming of, these charts are a thing of beauty.

 

come on...verify dammit, I want to see a snow flake, I will definately ramp this up if it gets closer

Very nice to see you back on the ball Frosty...keep em comming , you are an asset to this forum

[bluearmy]

the ecm mean doesnt see sufficient amplification in the atlantic at day 9 which means the mean ridge at day 10 is quite shallow and we see the warm front approaching clearly on the uppers at day 10. the spread has a much sharper ridge at day 9 and the spread on uppers at day 10 is supportive of the op around sw greenland.  the ens are probably coming slowly to the op theme but not following like lemmings quite yet.  take the hint - exeter will not either.

 

some mileage to go yet. gfs ops in the medium term are all wrong by pushing the jet through into the us west coast and withdrawing the alaskan ridge. despite this, they still manage a decent mid atlantic ridge but the arctic high will likely not be modelled well due to the alaskan ridge being withdrawn too quickly. ecm could be too bullish on the arctic high aswell.  we need to look closely at the london ens later around the 27th onwards to see how many of the less cold runs are dropping out.  this is a solution that has decent x model support rather than just ecm on its own.  

[R.P. McMurphy]

Cold & Snowy for Midlands Northwards on this run. Pennine Areas, Northern/North Western England Especially in that convective flow. The trend is there...

 

 

 

Lots of scatter towards the end, but firming up on agreement, the cold is on it's way.

 

[Zenarcher]

My view on the models this evening,

 

First the reliable timeframe

 

24 Hours 19th Sunday - High pressure sits to the North East and low pressure sits over the UK. For Scotland and most of Ireland it will be a cloudy day with showers around but Southern Ireland, Wales and England looks to get plenty of sunshine for much of the day. Severe gales over the Northern Scottish Isles but for the rest of the UK it will be a light breeze. Max temps 9c & min temps -1c.

 

 

48 Hours 20th Monday - Similar picture to Sunday on where high and low pressure sits. For all of the UK it will be partly cloudy with sunny intervals but most places will see a few hours of clear sunny conditions. Some showers will be in the West at the start of the day but they will ease out by lunchtime. The severe gales over the Northern Scottish Isles drops to a gale force strength, the wind across the UK will remain a light breeze. Max temps 9c & min temps -2c, its worth noting inland parts will see those low minimum temperatures.

 

 

 

72 Hours 21st Tuesday - High pressure still sits to the North East as a low sits to the North West. Mostly a cloudy day with rain pushing in from the West and moving East through out the day. Eastern England will see the best of the sunshine during the early morning before the rain arrives. Snow showers are possible over the Scottish Highlands as well. Gale force winds will affect the West all day and a strong breeze elsewhere. Max temps 10c & min temps -2c. Inland parts again looking very cold in the morning.

 

 

 

Now onto comparing seven weather models up to Friday the 24th. Using the GFS, ECM, UKMO, JMA, GEM, NAVGEM and CMA.

 

96 Hours 22nd Wednesday - Most seem similar side by side at this point with no real major differences. The Azores High starts to move into the Atlantic as the jet stream starts to get a little more power into it sending at this time some weak low pressure across Southern Greenland and Iceland. The UK generally sits under weak low pressure.

 

 

120 Hours 23rd Thursday - The differences start to show now between them they all send in a low pressure system into the Atlantic but they all disagree on its track and deepness. The Azores High starts to head North West slightly and edges into the South West of the UK. The Jet Stream is still over the far North of the Atlantic to the South of Greenland taking energy up there but the Jet Stream also comes back down through the UK sending some weak low pressure over.

 

 

144 Hours 24th Friday - All of the models send in a deep low around the South of Greenland and Iceland as the Jet Stream continues to send low pressure systems up there. The Azores High has been pushed down further South.

 

 

Overall - The week ahead starts off with sunny spells and showers but all parts of the UK are likely to see a good few hours of sunshine at some point. Monday and Tuesday mornings are looking very cold for inland parts of the UK as well with 0c to -2c temperatures being wide spread. As we head into the later part of the week the models paint up a more unsettled theme especially for those in the North.

 

The end of the month trends - All of the seven models tonight show in the final few days an Artic High forming I've put this image together below showing each of them side by side. The exact details for it varies amongst them but it's great to see them all showing it and this could influence our weather at some point towards the end of the month in a cold way.

 

[Summer Sun]

right , you will not be asked again...where is summer sun and where did you steal his password from

 

I've said before I try to post what the charts are showing, sometimes I haven't done so for one reason or another and I'm happy to admit it I'm still learning many parts and can't go into the detail of some folk on here but thats why there here.

 

If the charts are showing cold then it can be discussed but I'll never "ramp" anything until it comes into a reliable time frame ie t120 and lower (again I admit I used to with hot charts in the spring / summer but I've learned now)

[damianslaw]

A word on the meto 4 week update which as ever remains conservative and non-committal, however, if you read between the lines it speaks volumes i.e. heights to the NE are going to develop which in itself is a pattern change - forcing troughs/low pressure on a more NW-SE path opening us up to colder shots from a northerly quarter.

[UV-RAY]

I've been waiting for a long time..far too long to post charts as magnificent as these from the Ecm 12z op run tonight, especially the T+216 & 240 charts with the 522 dam thicknesses. I pray the ecm is on the ball tonight because this is the stonking pattern change all us long suffering snow and cold starved peeps have been dreaming of, these charts are a thing of beauty.

 

come on...verify dammit, I want to see a snow flake, I will definately ramp this up if it gets closer

Lol Frosty, please give me  plenty more of your enthusiasm  as these last few weeks have taken their toll on mine and my energy reserves of cold ramping are in need of some much needed replenishing.

[IDO]

The extended ECM Dutch Ens highlight the recent modus operandi of the op and control to overdo the cold compared to its members:

 

 

However with a pattern change on the horizon then I am more interested in the higher res members (op & control) so the above is more useful for trends. At the moment there is no clear signal that the ens are jumping towards the colder cluster, however it is still ten days out so in the next few days members need to start to head in that direction.

 

I am just happy that a change is coming by the end of the month. A bit of luck now needed.

 

 

[mulzy]

The extended ECM Dutch Ens highlight the recent modus operandi of the op and control to overdo the cold compared to its members:

eps_pluim_tt_06235.png

However with a pattern change on the horizon then I am more interested in the higher res members (op & control) so the above is more useful for trends. At the moment there is no clear signal that the ens are jumping towards the colder cluster, however it is still ten days out so in the next few days members need to start to head in that direction.

I am just happy that a change is coming by the end of the month. A bit of luck now needed.

If truth be told, theses ensembles are rather disappointing - it's quite possible that the ensembles aren't as reliable when a pattern change is imminent.

If and when the NH pattern change occurs, I'm worried about the position and strength of the Polar Vortex - the ECM ensemble mean at 240 illustrates this perfectly.

Lots of water to flow under the bridge but just want to warn members that a NH pattern change may not significantly change the weather for our small part of the world.

Edited January 18, 2014 by mulzy

[bluearmy]

If truth be told, theses ensembles are rather disappointing - it's quite possible that the ensembles aren't as reliable when a pattern change is imminent.If and when the NH pattern change occurs, I'm worried about the position and strength of the Polar Vortex - the ECM ensemble mean at 240 illustrates this perfectly.Lots of water to flow under the bridge but just want to warn members that a NH pattern change may not significantly change the weather for our small part of the world.

 

they werent last january but i put that down to the fact that, at the time, they couldnt see the top  of the strat and therefore the strong warmings coming down. perhaps they just arent any good post day 10 at seeing what coming. (or perhaps they are very good and we'll still be looking two weeks away this time next week!)

[Earth Wind and Snow]

We need to be cautious with regard to the artic high - when it lands in our favour ala 1985 (as Steve M posted) and 1987 we hit the bulls eye

 

There are other times when it has failed to land:

 

For example 2001 (The Kettley v Met Office Saga pre Net Weather days)

and 2007 which lead to a lot of tears on these forums as for several runs the models expected another 1987 (only for Nicks dreaded shortwaves to scupper us)

 

Hopefully we can hit the bulls eye in 2014 - I think we deserve it after this stormy / washout of a winter so far

 

Going to be very interesting watching all this pan out over the next number of days

 

EWS

 

Edited January 18, 2014 by Earth Wind and Snow

[Gibby]

Good evening. Here is tonight's look at the 12 noon outputs from the NWP for today Saturday January 18th 2014 taken from http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

 

All models show a Low pressure area out to the NW of Britain. A frontal trough will swing East across Britain tonight carrying outbreaks of rain as it goes. This will be followed with very slack conditions for all areas by tomorrow and with clear skies later frost and fog is likely with sunny spells by day and coastal showers in the West and SW. After more slack pressure on Monday freshening winds on Tuesday will develop from the SW as a new frontal systems approaches from the West with rain spreading East through the day. The front stalls and weakens over the East on Wednesday as pressure rises across it reducing the rain to drizzle through the day. On Thursday the weather looks bright and chilly as a ridge of High pressure moves slowly down over the UK from the NW.

 

GFS tonight shows changeable conditions for the rest of it's run tonight as further Low pressure moves East to the North of the UK then South towards NW Europe pulling winds into the North for a time with wintry showers before Atlantic Westerlies return at the end with some more rain at times but some reasonable dry periods in the South.

 

The GFS Ensembles tonight have drifted back into a chillier mode in the South for the second half of the run. The weather will remain very changeable with rain at times but most members show some drier spells too with breezy conditions as well at times. 

 

UKMO next Thursday shows a ridge moving away East and allowing another trough of Low pressure to spill back in off the Atlantic later next week with rain spreading East late in the day along with freshening SW winds.

 

GEM tonight shows less wet weather but still very changeable conditions later next week and into next weekend and beyond. The Azores High plays a more direct effect on the weather at least in the South with rain at times, heaviest in the NW while SE Britain sees longer drier periods between shorter rainier spells. Temperatures are shown to present no real problems over the period.

 

NAVGEM also shows another trough bringing rain late next week along with a blustery West then NW wind as the rain turns to showers ahead of drier weather under a ridge by next Sunday.

 

ECM tonight shows rainfall in the South becoming a much less troublesome feature late next week as the proximity of High pressure to the SW becomes more influential. However, troughs continue to flow down from the NW with at least some rainfall for all areas but with some drier spells too with temperatures a little below average overall and rather more than just a little below average with the chance of some wintry showers of sleet or snow in places by the end of the run.

 

The ECM 9 and 10 day Mean Charts continue to show the most likely pattern in 10 days time of Low pressure to the NW and a very strong Azores High. Signs of pressure rises to the North remain quite limited from these charts and I would suggest the operational chart will be an exaggerated version of a potential cold outcome with plenty of members still showing an unstable Atlantic flow from the West or NW over Britain.

 

http://www.wetterzentrale.de/pics/Reem2161.gif

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The Jet Stream shows the flow following a similar course to that of recently with the main difference being an increase in it's strength later pushing it across Britain and then onto Europe.

 

In Summary tonight there is some sign of something perhaps less wet for Southern areas from later next week as the Azores High becomes more of a feature to the SW of the UK. With NW winds at times the chances of anything overly mild or cold remains quite small but the worst of the rain from the troughs continuing to afflict all areas at times will be more towards the NW or North with some decent drier spells in the South. While there is still a slim chance of a slightly colder slot of weather there is still no evidence within the time frame of anything major expected to affect the UK.

[I remember Atlantic 252]

We need to be cautious with regard to the artic high - when it lands in our favour ala 1985 (as Steve M posted) and 1987 we hit the bulls eye

 

There are other times when it has failed to land:

 

For example 2001 (The Kettley v Met Office Saga pre Net Weather days)

and 2007 which lead to a lot of tears on these forums as for several runs the models expected another 1987 (only for Nicks dreaded shortwaves to scupper us)

 

Hopefully we can hit the bulls eye in 2013 - I think we deserve it after this stormy / washout of a winter so far

 

Going to be very interesting watching all this pan out over the next number of days

 

EWS

 

 

was good 2013, Arctic high may have failed but '07 was very snowy for me 8th and 9th

[Earth Wind and Snow]

was good 2013, Arctic high may have failed but '07 was very snowy for me 8th and 9th

Sorry 2014 - still trying to get my head around the change of year - amended now

 

Yes some places managed some snow in 2007 but the earlier predicted freeze by the models leading up to that event failed to materialize

I think Scotland also managed some snow from he 2001 event but again the widespread severe spell failed to land

 

EWS

[Purga]

Yes, it's been correctly stated that the ECM does not support the Op run and looks pretty poor in the longer term

A lot of hurdles to overcome before any chance of proper cold is likely.

[draztik]

The ext ecm ens, post day 10, continue with the theme of troughing to our NW with a negative anomaly in Europe. With this synoptic pattern, temps should be below average, but no meaningful cold is highlighted on the temp anomaly charts this evening.

 

day 10-15 heights ecm mean

 

The control run also offers little support.

day 10-15 heights ecm control

[johnholmes]

A lot of chat on here about a 'pattern change'? Why, who has predicted it and how reliable is this?

 

What we have is the POTENTIAL no more for a pattern change.

Be a shame to hype it up out of all proportion for it to go ---s up and loads of toys out of prams from the usual suspects.

 

yes the MJO prediction of phase 6 or 7 for both January and February does hold out the promise of promising 500mb anomalies, but it ain't happened yet.

The 500mb anomaly charts, see link below, for 6-10 and 8-14 NOAA outputs, again holds out POTENTIAL nothing more at the moment. They have shown this for almost a week now, clue 6-7 days ago, and they still show similar charts 6-7 days down the line. So care and sensible ideas are best for the moment. If deep cold and snow rattle down on the synoptic outputs to 72h then okay ramp it up but now???

 

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

Edited January 18, 2014 by johnholmes

[Buzz]

A lot of chat on here about a 'pattern change'? Why, who has predicted it and how reliable is this?

 

What we have is the POTENTIAL no more for a pattern change.

Be a shame to hype it up out of all proportion for it to go ---s up and loads of toys out of prams from the usual suspects.

 

yes the MJO prediction of phase 6 or 7 for both January and February does hold out the promise of promising 500mb anomalies, but it ain't happened yet.

The 500mb anomaly charts, see link below, for 6-10 and 8-14 NOAA outputs, again holds out POTENTIAL nothing more at the moment. They have shown this for almost a week now, clue 6-7 days ago, and they still show similar charts 6-7 days down the line. So care and sensible ideas are best for the moment. If deep cold and snow rattle down on the synoptic outputs to 72h then okay ramp it up but now???

 

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

 

Well said John, it's always a pleasure to read your balanced, analytical and non-hysterical posts.