Model Output Discussion 12z 07/11/2012

[johnholmes]

I have to say that a lot of folk are probably not going to like my Friday look at the signals that would take us into the last week of November judging by some of the posts in the two main weather threads this morning!

Come on folks let us have a touch of reality. yes the expected basic chart update due from Met today MAY keep the normal to below temperature theme going; it has been consistent so far, but it is only one of the various model outputs. ECMWF is losing its flavour of the month for winter simply, in my view, because, although we are not able to see it, those that can are suggesting its a mild theme.

Forecasting is about looking at ALL the available data and giving an honest, scientific summation of the most likley subsequent weather NOT using the data to massage it to show what YOU want.

Its going to be a long hard winter on here for admin and mods the way its shaping up this autumn!

Edited November 9, 2012 by johnholmes

[Frosty.]

Its going to be a long hard winter on here for admin and mods the way its shaping up this autumn!

Agreed, but in terms of what the models are showing, there are plenty of colder options on the table as well as mild, would you agree with me john that after next weeks mild blip, it will be turning more cold zonal? I currently think it could be a stormy and rather cold last 7-10 days to november rather than mild sw'lies.

[bluearmy]

even the GFS 06z run is 'getting it' !! autumnal till the back end november. that should be ok with everyone. what else does one expect from autumn!!

[Frosty.]

even the GFS 06z run is 'getting it' !! autumnal till the back end november. that should be ok with everyone. what else does one expect from autumn!!

The 6z shows a cold zonal further outlook with a threat of a cold and stormy spell with late nov snow, very nice.

[Tim Bland]

I have to say that a lot of folk are probably not going to like my Friday look at the signals that would take us into the last week of November judging by some of the posts in the two main weather threads this morning!

Come on folks let us have a touch of reality. yes the expected basic chart update due from Met today MAY keep the normal to below temperature theme going; it has been consistent so far, but it is only one of the various model outputs. ECMWF is losing its flavour of the month for winter simply, in my view, because, although we are not able to see it, those that can are suggesting its a mild theme.

Forecasting is about looking at ALL the available data and giving an honest, scientific summation of the most likley subsequent weather NOT using the data to massage it to show what YOU want.

Its going to be a long hard winter on here for admin and mods the way its shaping up this autumn!

John, do you disagree with GP re all the signs pointing to a negative NAO / AO. Do you disagree with the ECM 32 day model which has just been updated and signals higher pressure to our north and lower to our south? Do you disagree with latest CFS which shows the same. And Do you bet against the Meto long term forecast? These are the things that most people are alluding to regarding the signal for a cold end to Nov.

[Guest]

The 6z shows a cold zonal further outlook with a threat of a cold and stormy spell with late nov snow, very nice.

Aye, some lovely potential on the 06z, some of the frames deep into FI are absolutely beautiful if you like typical autumnal weather. How long until the ensembles are out, I haven't done much proper weather watching for a long time!

[johnholmes]

Agreed, but in terms of what the models are showing, there are plenty of colder options on the table as well as mild, would you agree with me john that after next weeks mild blip, it will be turning more cold zonal? I currently think it could be a stormy and rather cold last 7-10 days to november rather than mild sw'lies.

cold zonal looks the form horse from most sectors to me, not just the synoptic models

[Frosty.]

cold zonal looks the form horse from most sectors to me, not just the synoptic models

Cheers john, I thought I might have been alone in thinking a cold zonal further outlook is the most likely outcome, even though the gfs 00z ens mean is trending that way. I reckon hill snow in the north should become more frequent after next week, maybe to lower elevations with time, if the controlling trough can keep edging northeast. I have been reading a lot about how there is little of interest for coldies in the next few weeks, but I think there is beyond the next 10 days which look either mild or near average generally.

Edited November 9, 2012 by Frosty039

[johnholmes]

John, do you disagree with GP re all the signs pointing to a negative NAO / AO. Do you disagree with the ECM 32 day model which has just been updated and signals higher pressure to our north and lower to our south? Do you disagree with latest CFS which shows the same. And Do you bet against the Meto long term forecast? These are the things that most people are alluding to regarding the signal for a cold end to Nov.

morning Tim

a brief answer and not a helpful one would be yes and no!

However in more depth. GP set out the situation he will be looking at, all the players he needs to look at to consider what the meteorological winter may have in store.

My forecasts NEVER go beyond 25 days or so, so there is no argument or difference there. Similar with the Met O video which is for the end of November and early December. I would love to have routine access to the ECMWF 32 day outlook as, with ANY model, it is NOT what one output shows but how it behaves over a period of time.

Likewise with the CFS, my views on that are well aired, see my final summing up from last Christmas having followed it, basic and CFS 2 when it started, from September! Since then I have not looked at it enough to be able to pass comment on its reliability.

No doubt everyone, the coldies anyway, are awaiting the latest Met O 2-5 month prediction charts, probably due sometime today. They have been consistent for the Dec-Feb period in predicting below average temperatures.

I hope that answers constructively your question, but please ask again if you feel not. Perhaps better via pm rather than the open forum.

My own version of what the links are showing and my assessment of what that means out to about 25 November will I hope be ready sometime this evening.

John

Edited November 9, 2012 by johnholmes

[phil nw.]

Regardless of other forecasts from whatever outside source we can only gauge the outlook from the daily runs available to us.Often we can gain a realistic idea of trends to the second week of mean outputs.

At the moment these are signalling a westerly type pattern with the uk affected by a persistent upper trough.

stuck between mean blocks in the nw Atlantic and Russia.

so the changeable and rather unsettled spell continues- somewhat milder next week then a cooling trend again in week 2 of the run.

I guess this is what John is alluding too and what he sees in the current outputs

Now beyond that period then we can all speculate and hope and those views are very welcome in the Winter threads

For the sake of clarity and information lets keep this thread on topic-the clue is in it`s title.

Thanks everyone.

[bobbydog]

morning Tim

a brief answer and not a helpful one would be yes and no!

However in more depth. GP set out the situation he will be looking at, all the players he needs to look at to consider what the meteorological winter may have in store.

My forecasts NEVER go beyond 25 days or so, so there is no argument or difference there. Similar with the Met O video which is for the end of November and early December. I would love to have routine access to the ECMWF 32 day outlook as, with ANY model, it is NOT what one output shows but how it behaves over a period of time.

Likewise with the CFS, my views on that are well aired, see my final summing up from last Christmas having followed it, basic and CFS 2 when it started, from September! Since then I have not looked at it enough to be able to pass comment on its reliability.

No doubt everyone, the coldies anyway, are awaiting the latest Met O 2-5 month prediction charts, probably due sometime today. They have been consistent for the Dec-Feb period in predicting below average temperatures.

I hope that answers constructively your question, but please ask again if you feel not. Perhaps better via pm rather than the open forum.

My own version of what the links are showing and my assessment of what that means out to about 25 November will I hope be ready sometime this evening.

John

interestingly john, i have just had a look back at the Meto long range charts. they did not pick up on the 09/10 cold spells at all. for 10/11, they were predicting above average up to octobers update, then novembers update completely flipped the opposite way. last winter was consistent with average to above (which was fairly accurate). up to now they have been showing colder than average, so i'm eagerly awaiting the latest update....

[phil nw.]

interestingly john, i have just had a look back at the Meto long range charts. they did not pick up on the 09/10 cold spells at all. for 10/11, they were predicting above average up to octobers update, then novembers update completely flipped the opposite way. last winter was consistent with average to above (which was fairly accurate). up to now they have been showing colder than average, so i'm eagerly awaiting the latest update....

John has answered BD-let`s not continue this as it`s not model discussion.

Edited November 9, 2012 by phil n.warks.

[johnholmes]

John has answered you BD-let`s not continue this as it`s not model discussion.

happy to chat via pm BD or anyone else but as phil and Paul before have said let's keep the thread on track please?

[latitude]

happy to chat via pm BD or anyone else but as phil and Paul before have said let's keep the thread on track please?

John, why dont you become a MOD? You seem to always be the voice or reason and telling the children off when its not your place to do so.

[Guest]

Some hints of pressure rises towards Iceland later in the period from the 06z GFS ensembles:

Some interesting weather ahead I think, although the GFS seems to be cooking the lows a little more than the ECM:

http://www.netweather.tv/index.cgi?action=modelcomp;sess=

[legritter]

Morning all ,this post is aimed at new posters and posters with less knowledge in meteorology . When looking at modell output always remember on the GFS for example you can look for trends in the later stages of the run ,but you certainly cant Bank it .Take note of the regular posters who have been around for severall years .Most days at some stage a regular Poster will give their take on the modells ,sometimes twice a day . [sometimes twice a day] . This is the complexity of modell output ,it goes to show how much Data is being fed into weather computers ,trillions of bits of information . AT the moment modells are pointing to a fairly typical autumnal spell ,but later in their output things could get very interesting ,but at this stage still far from certain . If there is a major change around the corner im sure it will be picked up , weather forecasters have the technology now , but the biggest problem is ,the next stage in the set up , im sure there are plenty of interesting times to come .

[Frosty.]

The latest Ecm 00z ens mean shows the milder and drier spell evolving through next week but nw britain looks unsettled throughout and windy at times, the south and east becoming more settled and mild briefly with high pressure over the near continent, eventually the high is pushed away and low pressure to the northwest becomes the dominant feature with progressively cooler air feeding down across the uk by week 2, an unsettled and chilly further outlook from the gfs and ecm with the uk on the cold side of the polar front jet after the mild spell next week, northern britain probably having near average temps next week apart from tuesday which looks mild everywhere.

[Backtrack]

Regarding the end of the month I think recent trends have been hinting strongly towards lower pressure to the south with higher than average pressure to our north/north east, giving an easterly themed end to November.

It's also likely to be drier and much more settled with some wintryness around especially in the east.

Obviously there are other options being explored but at the minute the above scenario is the most likely outcome.

[IDO]

The 6z shows a cold zonal further outlook with a threat of a cold and stormy spell with late nov snow, very nice.

Yes some of these colder Op runs may start showing up in FI. However the ensembles (06Z) suggest the zonal (cool) flow is more likely to continue:

http://cdn.nwstatic....prmslLondon.png

The Control (06z) run for GEFS, backs this up:

gensnh-0-1-384.png

However, I like the blocking high on the GEFS (above) at three o'clock. All way out in the unreliable, so guesswork for the next 5-7 days, to see if this potential cold spell is yet another false dawn. No clear signs either way at the moment.

Edited November 9, 2012 by i'm dreaming of...

[Gibby]

Regarding the end of the month I think recent trends have been hinting strongly towards lower pressure to the south with higher than average pressure to our north/north east, giving an easterly themed end to November.

It's also likely to be drier and much more settled with some wintryness around especially in the east.

Obviously there are other options being explored but at the minute the above scenario is the most likely outcome.

I really wish I shared your optimism. I have seen very little in recent output other than to say it looks like more of the same in the output today and I'm sure the Meto's watered down update today is testament to that. Yes there are some colder and showery spells for the North at times but until I see a 'trend' as you put it come into the pre 180hr time frame and have cross model agreement from the ensembles I refuse to be drawn into the trap of yet another false dawn. Any chance of any change shown via GFS Ensembles has yet to reach far FI yet when looking at the 00z and 06z runs let alone T180hrs. I am well aware that things can change at relatively short notice in the models and when and if they do I will be one of the first to report it. However, for those learning on this and other forums the desire for cold from some people distort the true reflection of the output shown and might best be discussed in another thread.

Edited November 9, 2012 by Gibby

[Frosty.]

Yes some of these colder Op runs may start showing up in FI. However the ensembles (06Z) suggest the zonal (cool) flow is more likely to continue:

http://cdn.nwstatic....prmslLondon.png

The Control (06z) run for GEFS, backs this up:

gensnh-0-1-384.png

However, I like the blocking high on the GEFS (above) at three o'clock. All way out in the unreliable, so guesswork for the next 5-7 days, to see if this potential cold spell is yet another false dawn. No clear signs either way at the moment.

At least zonal cool to rather cold is better than endless mild sw'ly mush like we had last autumn, we are at least seeing charts that offer hope of something colder in FI which is the opposite of last year at this time.

[Nick F]

Regarding the end of the month I think recent trends have been hinting strongly towards lower pressure to the south with higher than average pressure to our north/north east, giving an easterly themed end to November.

It's also likely to be drier and much more settled with some wintryness around especially in the east.

Obviously there are other options being explored but at the minute the above scenario is the most likely outcome.

I wouldn't be so confident in saying your above scenario is the most likely outcome. Particularly as there are no concrete signs, in fact little signs, of such a scenario coming about for now.

Laws of averages would probably give a reasonable likelihood of a cold spell at the end of the month - after a run Atlantic westerlies eventually blowing itself - but what's not to say the cold may come from the north rather than the east. Ok the teleconnections MJO phase, etc may also point to to a cold spell at the month's end too - but it may lead to broken promises!

Edited November 9, 2012 by Nick F

[pyrotech]

I think there are some valid points made from both corners on this.

There are no valid signs of signifigant cold spell in the models yet, but the factors that usually cause a cold spell for Northern and often Western Europe are in place.

This atleast makes model watching interesting for a signs of a change in trend deep in Fi and to see if it happens which model picks it up first.

There is alot for cold lovers to be optermistic about the coming winter, but each part of the puzzle although seems to be there, still needs to be put in the right place.

Subtle changes will be slow to be picked up by models, i expect the GFS to start playing with some cold scenarios in fi over next week or two, but as often it might be like some of us and over eager and too proactive in trying to bring cold to our shores.

Atleast the models now give us something to watch, as signs of cold are not evident currently from the models, but background symptoms are lurking.

I just hope we can watch what evolves without too many heated arguements, after all what someone thinks will not change the eventual outcome.

[Snowy Easterlies]

Whats with all this zonal talk?, charts look dry, mild and settled for next week, for most areas. yet again synoptics we would like in summer albeit not the perfect summer synoptics, come at the wrong time of year and vice versa happens in summer, yes FI looks autumnal but who wants to bet these systems will end up further north again keeping us with high pressure over us or near us

Edited November 9, 2012 by Snowy Easterlies

[Glacier Point]

...another GFS run doing some rapid transitions in mid tropospheric / lower strat profiles over the high latitudes from day 10 onwards. Normally I regard the GFS op with some scepticism at this range, but it's run after run bang down the middle of the ensemble mean anomalies suggesting a developing 4-wave pattern across the NH days 11-15. Note the continual building of the trough off the east coast of the US which will assist in ridge development towards Newfoundland and Greenland.