polarwind
25 September 2013 07:13:29

Originally Posted by: Stormchaser 


Originally Posted by: Gooner 


Been loking at he CFS runs as they come out and it really is struggling ot produce anything wintry for a decent period through the months of DJF


JFF JFF JFF JFF



Well it is a model that has a case of over-progressiveness that makes GFS FI look sensible and restrained


I have long wondered how it ever manages to produce multi-run averages indicating high latitude blocking, and from what I've seen over the past year, it appears that even when it sends the jet well to the south south, it keeps it very active, producing vicious storms which in turn support monstrous blocking highs that span huge stretches of the northern hemisphere.


That's why when it does show a bit of high-lat. blocking, it tends to be sensational, leading to those charts that leave people dreaming of raging blizzards and all the rest.


What's more, CFS loves to project a very flat jet profile (fits with the tendency to ramp up the intensity), so on those occasions where that jet is fired due east, CFS can end up showing an entire month of blizzard after blizzard . Conversely, if the jet is fired NE, the blocking lasts no more than a few days.


Thanks to the habit of developing huge storm systems, CFS favours the NE jet, which IMO makes those occasions when it shows more than a transient period of blocking a more significant occurance; it's working against even greater odds than reality to project that.


I have given this a lot of thought over the past 12 months. The tendency to develop extensive blocking only occasionally, but to then take that to the extreme, explains a lot of what I've observed, but what about others on this forum? I'm very interested in your opinions on this


IMO, this is a significant cause of the different climate regimes of multi decadal warming and cooling. The Azores high, affected by the ozone changes caused by the different output by the sun at certain UV levels, either generally, deflects the jet NEwards - or it doesn't.


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Dave,Derby
Gooner
25 September 2013 07:19:21

Originally Posted by: JoeShmoe99 


Originally Posted by: Gooner 


Been loking at he CFS runs as they come out and it really is struggling ot produce anything wintry for a decent period through the months of DJF


JFF JFF JFF JFF



David Icke is more likely to be right than any of these CFS charts. I look at as a bit of fun but you cant take anything it produces (trends or otherwise) seriously, same as any long range view



Hence the repeated JFF


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Stormchaser
25 September 2013 08:51:21

Originally Posted by: polarwind 


Originally Posted by: Stormchaser 


What's more, CFS loves to project a very flat jet profile (fits with the tendency to ramp up the intensity), so on those occasions where that jet is fired due east, CFS can end up showing an entire month of blizzard after blizzard . Conversely, if the jet is fired NE, the blocking lasts no more than a few days.


IMO, this is a significant cause of the different climate regimes of multi decadal warming and cooling. The Azores high, affected by the ozone changes caused by the different output by the sun at certain UV levels, either generally, deflects the jet NEwards - or it doesn't.



Makes a lot of sense - perhaps the people behind CFS should focus on very accurate modelling of the Azores High. Trouble is, the overcooking of storm systems and resultant steering of the jet energy NE often leads to more ridging of the Azores High northeastward than is realistic.


When CFS was persistently predicting an extreme March in terms of blocking at the high latitudes, it could be that there was a very strong signal for the Azores High to be supressed or absent, something that no amount of northward bias can overcome.




To be fair on CFS, GFS can be just as bad in the 192-384h range, and ECM is sometimes not much better for 168-240h.


I believe the problem the computer models have is that they transfer energy too efficiently, this being a result of assumptions made in the programming, which were required partly to prevent the modelling becoming so complex that a single run takes more than a day, and partly because some of those smaller details remain poorly understood.


As an example, the models often see all of the energy from a strong thermal gradient (clash of airmasses) being bundled neatly into a large and powerful storm system which then retains a lot of it's energy and makes a lot of progress in whatever direction the steering pattern allows for. Yet the reality is often far less tidy, with energy either forming a more unstable system that breaks apart (disrupting trough) or forming numerous seperate disturbances which interact in a complex manner, making for tricky forecasting. In both cases, progression is usually far more limited as energy is dispersed - it has a lot less 'shove'.




My entire theory is now here for all to see... make of it what you will


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Gooner
25 September 2013 10:48:06

What model is good after 168??


 


In mobile conditions I should add


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Scandy 1050 MB
25 September 2013 10:53:28

Not bad snow cover for late September across Eastern Siberia - more than this time last year (scroll down for Eurasia):


 


http://www.climate4you.com/SnowCover.htm


 


And latest:


 


http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_asiaeurope.gif


 


Will be interesting to see if that builds up further.


 


 

Ally Pally Snowman
25 September 2013 12:04:34

Originally Posted by: Scandy 1050 MB 


Not bad snow cover for late September across Eastern Siberia - more than this time last year (scroll down for Eurasia):


 


http://www.climate4you.com/SnowCover.htm


 


And latest:


 


http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_asiaeurope.gif


 


Will be interesting to see if that builds up further.


 


 



Looks like a lot more ice as well around the North pole. I wonder what effect if any that will have on the NH winter.


 


 


 


Bishop's Stortford 85m ASL.
JoeShmoe99
25 September 2013 12:28:22

Originally Posted by: Stormchaser 


Originally Posted by: polarwind 


Originally Posted by: Stormchaser 


What's more, CFS loves to project a very flat jet profile (fits with the tendency to ramp up the intensity), so on those occasions where that jet is fired due east, CFS can end up showing an entire month of blizzard after blizzard . Conversely, if the jet is fired NE, the blocking lasts no more than a few days.


IMO, this is a significant cause of the different climate regimes of multi decadal warming and cooling. The Azores high, affected by the ozone changes caused by the different output by the sun at certain UV levels, either generally, deflects the jet NEwards - or it doesn't.



Makes a lot of sense - perhaps the people behind CFS should focus on very accurate modelling of the Azores High. Trouble is, the overcooking of storm systems and resultant steering of the jet energy NE often leads to more ridging of the Azores High northeastward than is realistic.


When CFS was persistently predicting an extreme March in terms of blocking at the high latitudes, it could be that there was a very strong signal for the Azores High to be supressed or absent, something that no amount of northward bias can overcome.




To be fair on CFS, GFS can be just as bad in the 192-384h range, and ECM is sometimes not much better for 168-240h.


I believe the problem the computer models have is that they transfer energy too efficiently, this being a result of assumptions made in the programming, which were required partly to prevent the modelling becoming so complex that a single run takes more than a day, and partly because some of those smaller details remain poorly understood.


As an example, the models often see all of the energy from a strong thermal gradient (clash of airmasses) being bundled neatly into a large and powerful storm system which then retains a lot of it's energy and makes a lot of progress in whatever direction the steering pattern allows for. Yet the reality is often far less tidy, with energy either forming a more unstable system that breaks apart (disrupting trough) or forming numerous seperate disturbances which interact in a complex manner, making for tricky forecasting. In both cases, progression is usually far more limited as energy is dispersed - it has a lot less 'shove'.




My entire theory is now here for all to see... make of it what you will



im by no means a techy but are the models programmed to 'learn' or are they purely predictive based on some set of complex algorithms


I agree with what you say but as we see the same thing year on year, across most models, do they not incorporate some level of predcictive analysis based on whats actually transpired and factor that into future modelling?

Gooner
25 September 2013 14:38:33

http://modeles.meteociel.fr/modeles/cfs/run3/cfsnh-0-2382.png?12


JFF JFF JFF JFF


A New Years Day easterly


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


some faraway beach
25 September 2013 14:41:20

I suppose it's a question of scale. The surface area of a sphere the size of the Earth is vast, making computer-calculations of the small-scale events which disrupt troughs impractical, unless you're prepared to wait 168+ hours for the model run to finish.


If an attempt were made to cause the model to learn not to allow huge, organized storm systems to develop so readily, I guess you would have to programme it to generate some sort of random disruption, which would render the rest of the run equally random, and God doesn't play dice with the Model Output thread.


2 miles west of Taunton, 32 m asl, where "milder air moving in from the west" becomes SNOWMAGEDDON.
Well, two or three times a decade it does, anyway.
Stormchaser
25 September 2013 18:42:58

Good points there I've not seen any evidence of the models learning from what's transpired and I can't really see that sort of thing being possible without requiring unjustifiable computor resources.


The learning has to be done by humans through research, which can then be used to upgrade the model workings. A very useful area of research in the past few decades has been one that involves taking a complex relationship between variables and developing a way of achieving very good approximations for the outcome using fewer variables. Unfortunately, that leads to assumptions which then cause the problems seen in the current models.


With that in mind, it's going to be hard to produce more accurate forecasts in the future through any other means than faster computers. Thankfully, there are promising developments in computing technology at the moment, including atomic-level manufacturing (early days on that though) and quantum-computing which could prove very useful indeed for weather forecasting.


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T-Max: 30.4°C 21st Jul | T-Min: -6.8°C New Years Day! | Wettest Day: 34.1mm 2nd Oct | Ice Days: 2 (27th Jan & 8th Feb)
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Essan
25 September 2013 18:55:15

I hope computer models aren't able to 'learn' just yet.  I'd like a few more years before Skynet takes over


Andy
Evesham, Worcs, Albion - 35m asl
Weather & Earth Science News 

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JoeShmoe99
26 September 2013 07:22:23

Originally Posted by: Stormchaser 


Good points there I've not seen any evidence of the models learning from what's transpired and I can't really see that sort of thing being possible without requiring unjustifiable computor resources.


The learning has to be done by humans through research, which can then be used to upgrade the model workings. A very useful area of research in the past few decades has been one that involves taking a complex relationship between variables and developing a way of achieving very good approximations for the outcome using fewer variables. Unfortunately, that leads to assumptions which then cause the problems seen in the current models.


With that in mind, it's going to be hard to produce more accurate forecasts in the future through any other means than faster computers. Thankfully, there are promising developments in computing technology at the moment, including atomic-level manufacturing (early days on that though) and quantum-computing which could prove very useful indeed for weather forecasting.



The 'big data' approach and the ability to store and process huge data sets in new ways (Hadoop etc) might be the answer. After all weather data must be a great source for this type of approach and then layer predictive analysis tools on top of it


Indeed you wonder if the more predictive analysis approach might overtake the tradiotional algorithm led 'super computer' approach at some point?


 


http://www.wired.com/insights/2013/02/how-big-data-can-boost-weather-forecasting/


http://arstechnica.com/business/2012/03/how-ibms-deep-thunder-delivers-hyper-local-forecasts-3-12-days-out/


http://www.forbes.com/sites/alexknapp/2013/06/13/forecasting-the-weather-with-big-data-and-the-fourth-dimension/


 

Gooner
26 September 2013 12:10:18

http://modeles.meteociel.fr/modeles/cfs/run2/cfsnh-0-2958.png?06


JFF JFF JFF JFF


An Easterly late on in January from CFS , but that is about all.


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Medlock Vale Weather
26 September 2013 13:56:30

Moscow will be 10 degrees below average by Tuesday with a max of only 2C  not sure how this bodes for our weather down the line >>> http://www.wunderground.com/cgi-bin/findweather/getForecast?query=Moscow,%20Russia&wuSelect=WEATHER


And look at those uppers too  http://www.wetterzentrale.de/pics/MT8_Moskau_ens.png


Alan in Medlock Valley - Oldham's frost hollow. 103 metres above sea level.
What is a frost hollow? http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm 
LeedsLad123
26 September 2013 14:03:29

Stockholm, Helsinki and Vilnius are the first European capitals to fall below freezing this autumn. Let the descent into winter begin.


Whitkirk, Leeds - 85m ASL.
Medlock Vale Weather
26 September 2013 14:14:46

Originally Posted by: LeedsLad123 


Stockholm, Helsinki and Vilnius are the first European capitals to fall below freezing this autumn. Let the descent into winter begin.



Looks like you missed one, Oslo was another http://classic.wunderground.com/history/airport/ENGM/2013/9/26/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA


Alan in Medlock Valley - Oldham's frost hollow. 103 metres above sea level.
What is a frost hollow? http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm 
Gooner
26 September 2013 14:49:05

Originally Posted by: Medlock Vale Weather 


Moscow will be 10 degrees below average by Tuesday with a max of only 2C  not sure how this bodes for our weather down the line >>> http://www.wunderground.com/cgi-bin/findweather/getForecast?query=Moscow,%20Russia&wuSelect=WEATHER


And look at those uppers too  http://www.wetterzentrale.de/pics/MT8_Moskau_ens.png



Gavin highlights this well in his reccent video, some decent cold coming down to Eastern Europe early


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Stormchaser
26 September 2013 19:01:24

Originally Posted by: JoeShmoe99 


The 'big data' approach and the ability to store and process huge data sets in new ways (Hadoop etc) might be the answer. After all weather data must be a great source for this type of approach and then layer predictive analysis tools on top of it


Indeed you wonder if the more predictive analysis approach might overtake the tradiotional algorithm led 'super computer' approach at some point?


 http://www.wired.com/insights/2013/02/how-big-data-can-boost-weather-forecasting/


http://arstechnica.com/business/2012/03/how-ibms-deep-thunder-delivers-hyper-local-forecasts-3-12-days-out/


http://www.forbes.com/sites/alexknapp/2013/06/13/forecasting-the-weather-with-big-data-and-the-fourth-dimension/


 


Thanks for those informative linsk Seems to be a lot of promise in that, although we don't want the models becoming so accurate that we can't enjoy discussing the probability of various charts verifying unless there at 240h+


On a serious note, there's still good progress to be made for locallised forecasts even at just a day's range or two - that's where efforts should be focused for now IMO




Before long we'll have another winter unfolding, with various models gaining and losing credence as it progresses


If you have any problems or queries relating to TWO you can Email [email protected] 🙂
https://twitter.com/peacockreports 
2021's Homeland Extremes:
T-Max: 30.4°C 21st Jul | T-Min: -6.8°C New Years Day! | Wettest Day: 34.1mm 2nd Oct | Ice Days: 2 (27th Jan & 8th Feb)
Keep Calm and Forecast On
Solar Cycles
26 September 2013 19:29:57

Originally Posted by: Stormchaser 


Originally Posted by: JoeShmoe99 


The 'big data' approach and the ability to store and process huge data sets in new ways (Hadoop etc) might be the answer. After all weather data must be a great source for this type of approach and then layer predictive analysis tools on top of it


Indeed you wonder if the more predictive analysis approach might overtake the tradiotional algorithm led 'super computer' approach at some point?


 http://www.wired.com/insights/2013/02/how-big-data-can-boost-weather-forecasting/


http://arstechnica.com/business/2012/03/how-ibms-deep-thunder-delivers-hyper-local-forecasts-3-12-days-out/


http://www.forbes.com/sites/alexknapp/2013/06/13/forecasting-the-weather-with-big-data-and-the-fourth-dimension/


 


Thanks for those informative linsk Seems to be a lot of promise in that, although we don't want the models becoming so accurate that we can't enjoy discussing the probability of various charts verifying unless there at 240h+


On a serious note, there's still good progress to be made for locallised forecasts even at just a day's range or two - that's where efforts should be focused for now IMO




Before long we'll have another winter unfolding, with various models gaining and losing credence as it progresses


Any model which shows a mild outlook will be consigned to the bin and told to disregard, as it's data is incomplete  due to not enough fairies on the wing over Greenland on any given date. 

Gooner
26 September 2013 21:14:01

http://modeles.meteociel.fr/modeles/cfs/run4/cfsnh-0-1554.png?18


CFS gives us a chilly end to November


http://modeles.meteociel.fr/modeles/cfs/run4/cfsnh-0-2184.png?18


Santa brings a bitter blast with him


http://modeles.meteociel.fr/modeles/cfs/run4/cfsnh-0-2694.png?18


Middle of January sees a Easterly blow


 


All JFF JFF JFF of course


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


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