Model Output Discussion - 17th Oct Onwards

[Bobby]

You'd expect due to the law of averages that a cold run deep into the mists of FI will pop up now and then on the GFS. Not even worth bothering about unless it becomes a theme and other models start toying with the idea when we get into +240.

[Catacol]

Why would they? The 06z is the 1st run to show it. They will quickly change their tune though if this is shown on future runs! something to watch!

 

As Gavin P's videos have shown that is not the case. There have been signals pointing to colder second half of November for a few days now... but the met office model is not in agreement. I dont know how many of the medium to longer range guys down there are "forecasters" and how many are maths men. I have a contact at work here whose wife works down at the Met in Exeter and he tells me that many of the people he has encountered there seem to be model/maths/computer experts and not so much forecasters and interpreters of data. Apparently recently they ran the latest computer model simulation of future ice loss and it took the most powerful computer they had a whole month to finish the projections. All the talk was of the model and the algorithms etc etc... They trust their computer models implicitly and will not change until the computer says "yes."

 

The question I suppose is - how good a grasp of things of background teleconnections do the models have? Do they read SSTs and project possible SSW? If the input data changes then presumably the output does too. So... the sun has gone a bit quieter now. Does this alter the modelling at supercomputer level?

 

The answer to these sorts of questions would be fascinating.

 

Any chance we have a Met model/maths expert lurking on this forum??

Edited October 31, 2013 by Catacol_Highlander

[johnholmes]

an interesting post c

Do remember that whatever the requirements are for type of staff to run whatever model, in the case of predicting from its output the ONLY folk that do that are forecasters. And very well experienced and qualified forecasters, those who have a degree in meteorology, then have passed various courses run by Exeter for junior, middle range and senior forecasters before they are given tasks that involve predicting for the public. Yes researchers are there in the climatology side with a particular special interest in some particular aspect. But I would be surprised if any pure mathematician or modeller is anywhere near the data when it comes to working out which output is more believable in meteorological terms.

 

ps

maybe if you pm Jo she will have a much more recent picture of what happens in Exeter that she can pass on to you?

Edited October 31, 2013 by johnholmes

[UV-RAY]

an interesting post c

Do remember that whatever the requirements are for type of staff to run whatever model, in the case of predicting from its output the ONLY folk that do that are forecasters. And very well experienced and qualified forecasters, those who have a degree in meteorology, then have passed various courses run by Exeter for junior, middle range and senior forecasters before they are given tasks that involve predicting for the public. Yes researchers are there in the climatology side with a particular special interest in some particular aspect. But I would be surprised if any pure mathematician or modeller is anywhere near the data when it comes to working out which output is more believable in meteorological terms.

 

ps

maybe if you pm Jo she will have a much more recent picture of what happens in Exeter that she can pass on to you?

But the forecaster is presented with algorithms  from these John and just how good are they at picking up teleconnections and so on?

[johnholmes]

like I suggested Jo may be able to give you an up to date idea but pm her not on the open forum

 

In my day no one made any attempt to predict beyond a month ahead and more routinely beyond T+120/144 and all the data was in either chart or numerical data format

 

no disrespect but whatever format with their large experience it has to be very much greater than any of us on this forum I would suggest?

Edited October 31, 2013 by johnholmes

[Catacol]

an interesting post c

Do remember that whatever the requirements are for type of staff to run whatever model, in the case of predicting from its output the ONLY folk that do that are forecasters. And very well experienced and qualified forecasters, those who have a degree in meteorology, then have passed various courses run by Exeter for junior, middle range and senior forecasters before they are given tasks that involve predicting for the public. Yes researchers are there in the climatology side with a particular special interest in some particular aspect. But I would be surprised if any pure mathematician or modeller is anywhere near the data when it comes to working out which output is more believable in meteorological terms.

 

ps

maybe if you pm Jo she will have a much more recent picture of what happens in Exeter that she can pass on to you?

 

Thanks John - you are right of course: the Met must employ the best qualified forecasters out there. Of that I have no doubt.

 

But I wonder how many of those are employed at the range of 16 day plus. Presumably - and quite rightly - the majority of effort is put into the 5 day range and into informing the many agencies they work for of up to date info round the clock. But it seems likely to me that, in austere times, the one area that is easy to cut back on is long range stuff. After all - long range forecasting is problematic at best.

 

If that is the case then much rests on the modelling provided by computers and not on the type of interpretative stuff that GP was so good at in the past (though not foolproof!!) and RJS too. I hope to goodness that RJS's forecast for the winter is wrong... but he is rarely a long way off - unfortunately. Not wishing to leave out any names - there are other good long range people on here to. Chio's gentle prediction of a SSW late winter for example... I'd rate that as pretty damn likely purely because of his expertise.

 

Maybe that is expertise the Met could usefully look at extending themselves? Is there much effort in interpretative long range forecasting, rather than just reading the computer models, going on? That is the crux of my question I guess.

 

Speaking of GP - do we know which company threw money at him and employed him? Someone somewhere rates this type of forecasting anyway!

[Frosty.]

 

no disrespect but whatever format with their large experience it has to be very much greater than any of us on this forum I would suggest?

Totally agree but 4 weeks ahead and just to say it's going to be mild? it's hard to believe the weather won't have a few tricks up it's sleeve

Edited October 31, 2013 by Frosty.

[johnholmes]

Thanks John - you are right of course: the Met must employ the best qualified forecasters out there. Of that I have no doubt.

 

But I wonder how many of those are employed at the range of 16 day plus. Presumably - and quite rightly - the majority of effort is put into the 5 day range and into informing the many agencies they work for of up to date info round the clock. But it seems likely to me that, in austere times, the one area that is easy to cut back on is long range stuff. After all - long range forecasting is problematic at best.

 

If that is the case then much rests on the modelling provided by computers and not on the type of interpretative stuff that GP was so good at in the past (though not foolproof!!) and RJS too. I hope to goodness that RJS's forecast for the winter is wrong... but he is rarely a long way off - unfortunately. Not wishing to leave out any names - there are other good long range people on here to. Chio's gentle prediction of a SSW late winter for example... I'd rate that as pretty damn likely purely because of his expertise.

 

Maybe that is expertise the Met could usefully look at extending themselves? Is there much effort in interpretative long range forecasting, rather than just reading the computer models, going on? That is the crux of my question I guess.

 

Speaking of GP - do we know which company threw money at him and employed him? Someone somewhere rates this type of forecasting anyway!

 

to my knowledge latterly it has to be said and in my view not before time they do use pretty much what is available and no doubt stuff we may not see.

So SST's, etc etc out to the sun and the anomalies involved with each paramter are all studied and analysed as far as I know. So the knowledge they build up as professional forecasters and on how to interpret metoeorological data is going to be used to assess this along with data charts that we see some of, ie their own outputs and the oft quoted EC 32 day. ECMWF also no doubt do similar stuff to UK Met with regard to longer term forecasts and obviously will exchange that data within the WMO, something which we would never see.

I honestly think if you e mail them, explain what you are interested in that you will get a constructive answer-it may take some time!

Edited October 31, 2013 by johnholmes

[johnholmes]

Totally agree but 4 weeks ahead and just to say it's going to be mild? it's hard to believe the weather won't have a few tricks up it's sleeve

 

If they feel that it has and the data is sufficiently strong enough in probability then they will post it in their forecasts be it 6-15 or 16-30 days. We have seen that often enough. Just because at the moment they do not suggest this, other than brief incursions of polar air does not mean they are not correct frosty. For what its worth, out to day 16 I suspect that any cold incursions will be just that, brief and probably more likely in the south due to high pressure type cold nights rather than deep cold.

[Captain Shortwave]

Totally agree but 4 weeks ahead and just to say it's going to be mild? it's hard to believe the weather won't have a few tricks up it's sleeve

Very mild?

 

Couldn't help myself. Well at least it would be dry 

Edited October 31, 2013 by Captain shortwave

[Summer Sun]

UKMO showing a slight improvement for the south at t144 (Wednesday) with the high to our south just starting to edge up shifting the low further north

 

Edited October 31, 2013 by Summer Sun

[Frosty.]

Very mild?

 

Couldn't help myself. Well at least it would be dry 

This is my only response to that captain

[Gaz1985]

Still the chance of mouthwatering Bartlett pressure building in FI. Should be noted that once these patterns set up they can take weeks or even months to shift 

 

[Chris K]

Still the chance of mouthwatering Bartlett pressure building in FI. Should be noted that once these patterns set up they can take weeks or even months to shift 

 

You can say that but I feel it would be highly unlikely that surface weather would be the same for weeks on end. Even if we had a winter dominated by a what you call 'mouthwatering' Bartlett high, you'll find patterns often get interruptions even if they come back after a 'blip'.

[weatherguy]

Still the chance of mouthwatering Bartlett pressure building in FI. Should be noted that once these patterns set up they can take weeks or even months to shift 

 

 

I certainly wouldn't describe that as mouthwatering 

Don't mention the B word, lest we coax it into fruition! B**tlett be gone! 

[Cheshire Freeze]

I certainly wouldn't describe that as mouthwatering 

Don't mention the B word, lest we coax it into fruition! B**tlett be gone

 

I don't even know what he's talking about, that chart isn't even that bad hemispherically. That high to the S certainly wouldn't be assured of staying in situ for very long given the migration of the vortex away from E Canada/Greenland area.

[UV-RAY]

I don't even know what he's talking about, that chart isn't even that bad hemispherically. That high to the S certainly wouldn't be assured of staying in situ for very long given the migration of the vortex away from E Canada/Greenland area.

IMO it looks nothing like the makings of a Bartlett high, in fact I would say the upstream pattern looks more likely to deliver a cold snap at least down the line.

[Frosty.]

IMO it looks nothing like the makings of a Bartlett high, in fact I would say the upstream pattern looks more likely to deliver a cold snap at least down the line.

Totally agree SI, I refuse to believe that the next 4 weeks will be mild all the time, I'm sure a cold snap or two will pop up as we go through november.

[cooling climate]

I think we should keep a close eye on what is happening on the Pacific side

as this will have a big impact on our weather mid November onwards.

[East_England_Stormchaser91]

I'd rather see a Bartlett form now, and not Mid winter! 

Stacks of time for patterns to change. Any conditions that form can be hard to break out of sometimes, whether it be raging zonal, or Easterlies that took the whole of Spring to get rid of! 

I do think if we see any blowtorch Southerlies, they could well be rapidly replaced by Raging Northerlies before your eyes. Its at this time of the year when conditions like this happen most, as well as Spring. One extreme to the other.

[bluearmy]

I think we should keep a close eye on what is happening on the Pacific side

as this will have a big impact on our weather mid November onwards.

 

twas ever thus CC thought you'll find few on here able to take it on board.

 

my take on the ridging t'other side is that it will be progressive and flattened fairly quickly, probably leaving a residual piece of higher heights drifting around the pole but mixing out as the vortex becomes more intense.

Edited October 31, 2013 by bluearmy

[Summer Sun]

Latest from Gibby mild or very mild for the next 5 to 7 days then becoming even milder with High pressure building over Europe sending winds back SW

 

All models show the unstable and often strong Westerly flow with Low pressure areas and troughs spilling East across or near to the UK between now and next Tuesday. All areas will see periodic spells of rain and showers with squally winds. Temperatures will never be far from average but it will feel and possibly become a little colder for time on Sunday and Monday. On Tuesday an active warm front is shown to cross the UK with rain for many before a mild but windy Westerly flow sets up as we move towards midweek.

 

GFS then takes us through a very changeable and wet period for a time before drier weather and very mild weather too in the South spreads further North and East late in the run on a backing wind towards the SW and South.

 

UKMO closes it's run with a broad and strong West to South-west flow with mild weather and rain at times especially towards the North and West.

 

GEM too shows strong and unstable Westerly winds with lower pressure overall meaning all areas will see further rain and showers in mild weather. Late in the run the weather may become milder still as the Westerly flow backs off to a long fetch SW flow with rain most likely then in the North and West.

 

NAVGEM tonight expands High pressure up towards the South of Britain late next week with any rain then restricted to the far North with most of the UK enjoying mild temperatures if rather cloudy and misty conditions especially near Southern and Western coasts.

 

ECM is yuk tonight if it's cold weather your after as next week looks like being mild and windy with rain at times across the UK. The last frame of the run indicates High pressure over France with a warm West or SW flow over the UK with rain at times in the North and West with the South and East seeing drier if rather cloudy but very mild weather.

 

The GFS Ensembles show a very mild prospect tonight under incessant Westerly winds, strong at times with occasional rain. Later in the run if anything even milder weather is more likely rather than colder as High pressure to the South pushes winds more towards the SW rather than West.

 

The Jet Stream is set to continue blowing West to east across the atlantic and the UK for the next week or so before the flow turns further North over Europe to make a SW to NE orientation North of the UK towards the end of the run.

 

In Summary tonight there is little to say that hasn't been said already. A mild and eventually very mild period seems likely with a lot of rain from the close proximity of Low pressure in the next 5-7 days before High pressure building over Europe sends things even milder as winds back SW at the same time as sending rain bearing fronts further North to affect just the North and West later.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

Edited October 31, 2013 by Summer Sun

[Ian Brown]

Still the chance of mouthwatering Bartlett pressure building in FI. Should be noted that once these patterns set up they can take weeks or even months to shift 

 

 

That isn't a Bartlett, and the core of HP there could easily be transferred West or North. For a Bartlett look at the late 80s or late 90s winter archive charts and you will soon find a proper Barty.

[Summer Sun]

This is more like good old uncle Barty

 

Edited October 31, 2013 by Summer Sun

[Yarmy]

This is more like good old uncle Barty

 

And look at the PV. Ouch.