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Gfs And Different Input


johnholmes

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    hi all

    Sometime ago I posted, well a very long time ago, and since then people like Steve Muir and others have posted about the same.

    Namely the different data, over and above the basic observational data in each run, that goes into

    00z

    06z

    12z

    18z

    For the life of me I cannot find it anywhere in the reams of files I have on the weather nor can I find it on the forum, although I know it was mentioned only a few days ago.

    If anyone has access to it, I would be very grateful if someone could, either, post the information, or point me in the right direction.

    many thanks

    John

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    Posted
  • Location: SE London
  • Location: SE London

    john thought it might be this :

    00z - Weather buoy, satellite data, shipping data, country data, NOAA data

    06Z - Weather buoy, satellite data, shipping data

    12Z - Shipping data, Satellite data ONLY

    18Z - Weather buoy, satellite data, shipping data, country data, NOAA data

    argghhh sorry SR didn't realise you had posted whilst i was searching

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    thanks both of you that is it, I'll now try and put it in the Guides so its always available.

    thanks again

    John

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    • 4 weeks later...
    Posted
  • Location: Bristol, England
  • Location: Bristol, England
    john thought it might be this :

    00z - Weather buoy, satellite data, shipping data, country data, NOAA data

    06Z - Weather buoy, satellite data, shipping data

    12Z - Shipping data, Satellite data ONLY

    18Z - Weather buoy, satellite data, shipping data, country data, NOAA data

    argghhh sorry SR didn't realise you had posted whilst i was searching

    The 00z and 18z - "too many data inputs spoil the broth"?

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    Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

    Interesting that the 06z unless my memory is fading picked up the Easterly very well.

    Pity they all can't have the same data input.

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks
    Interesting that the 06z unless my memory is fading picked up the Easterly very well.

    Pity they all can't have the same data input.

    so did the 12Z

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    Posted
  • Location: South Woodham Ferrers, height 15 metres
  • Location: South Woodham Ferrers, height 15 metres
    Not at all, you can't feed too much data into a numerical model..

    You make an interesting statement but I'd have to agree to disagree with you. With more data you've potentially stronger agreement at longer range but conversely if your methodology (the way the data is collected and put into the model) is not watertight more errors creep in to the model and make that extra data a hindrance rather than a help. You can overload a shopping trolly if you see what I mean.

    This might be why the 12z is best regarded on this site - satellite data is probably the most accurate source of weather info we have, the major sources of error on thie 12z run presumably confined to shipping data which involves human readings and presumably ever changing positions of the ships. You can't data cut indefinately without losing details and long term accuracy but maybe if shipping data was removed from the 12z the trends would not be much less easier to spot.

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    Posted
  • Location: Aviemore
  • Location: Aviemore

    To be honest the list above is much simplified when compared to what actually goes into each run - I'll try and get something put together to show you..

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    Posted
  • Location: Aviemore
  • Location: Aviemore

    As promised - a more comprehensive look at what data goes into the GFS. All of these types of data from around the entire globe are input into the model on each run. There are obviously different availabilities of some types of data (like for instance flight data will be more available during daylight hours as flights occur more often at that time).

    But bear in mind that as the data is worldwide - there will be more data available from different parts of the globe at different times. The net result is probably that each model run has a similar amount of raw data fed into it.

    As you can see there is a fair bit of raw data used...

    Surface data – Land

    Synoptic - restricted (WMO Resolution 40) manual and automatic

    Synoptic - fixed manual and automatic

    Synoptic - mobile manual and automatic

    Aviation – METAR

    Vertical soundings – other than Satellite

    Rawinsonde - fixed land

    Rawinsonde - mobile land

    Rawinsonde – ship

    Dropwinsonde

    Pibal

    NEXRAD Vertical Azimuth Display (VAD) winds

    Single Level Upper-air data (other than satellite)

    Flight level reconnaissance aircraft data

    Automated MDCRS ACARS aircraft data (from ARINC)

    Automated MDCRS ACARS aircraft data (from ARINC) via AFWA

    Manual AIREP format aircraft data

    Manual PIREP format aircraft data

    Automated AMDAR format ASDAR/ACARS aircraft data

    European ASDAR/ACARS Data Aquisition System (E-ADAS) aircraft data (originally in BUFR)

    NOAA Profiler Network (NPN) winds

    Profiler winds originating from PILOT (Pibal) bulletins

    Japanese Meteorological Agency (JMA) profiler winds

    Cooperative Agency Profiler (CAP) winds

    RASS temperatures from NOAA Profiler Network (NPN) and Cooperative Agency Profilers (CAP)

    Vertical soundings – satellite

    GOES/NESDIS-processed 5x5 field-of-view soundings/brightness temperatures

    GOES/NESDIS-processed 1x1 field-of-view soundings/brightness temperatures

    Surface data – satellite

    QuikSCAT products

    DMSP/SSM-I - operational products derived at FNMOC

    DMSP/SSM-I - Neural Net-3 products derived at NCEP

    DMSP/SSM-I - processed brightness temperatures

    NASA/Tropical Rainfall Measuring Mission (TRMM)/TMI)

    Single level upper air data – satellite

    GOES/NESDIS infrared derived cloud motion (from NESDIS server, originally in BUFR)

    GOES/NESDIS water vapor imager derived cloud motion (from NESDIS server, originally in BUFR)

    GOES/NESDIS visible derived cloud motion (from NESDIS server, originally in BUFR)

    INSAT/India infrared derived cloud motion

    INSAT/India visible derived cloud motion

    INSAT/India water vapor derived cloud motion

    GMS/JMA infrared derived cloud motion - low density (originally in SATOB format)

    GMS/JMA visible derived cloud motion - low density (originally in SATOB format)

    GMS/JMA water vapor imager derived cloud motion - low density (originally in SATOB format)

    METEOSAT/EUMETSAT infrared derived cloud motion (originally in BUFR)

    AQUA/TERRA MODIS infrared derived cloud motion

    AQUA/TERRA MODIS water vapor imager derived cloud motion

    Surface data – sea

    Sea level pressure bogus

    Ship - manual and automatic

    Buoys in FM-18 format (moored or drifting)

    Buoys in FM-13 format (moored)

    Land-based CMAN station

    Tide gauge reports in CREX format

    Radiances – satellite measured

    AQUA/AIRS, AMSU-A, HSB processed brightness temperatures

    GOES NESDIS-processed 11x17 field-of-view imager (clear sky) brightness temperatures

    NOAA-14/HIRS-2 (High resolution InfraRed Sounder-2) NCEP-processed brightness temperatures

    NOAA-14/MSU (Microwave Sounding Unit) NCEP-processed brightness temperatures

    NOAA-15,-16,-17,-18/AMSU-A (Advanced Microwave Sounding Unit-A) NCEP-processed brightness temperatures

    NOAA-15,-16,-17/AMSU-B (Advanced Microwave Sounding Unit- B) NCEP-processed brightness temperatures

    NOAA-15,-16,-17/HIRS-3 (High resolution InfraRed Sounder-3) NCEP-processed brightness temperatures

    Physical/chemical constituents

    POES/NESDIS Solar backscatter ultraviolet radiances

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    Posted
  • Location: 115meters ASL, Andover,Hampshire
  • Location: 115meters ASL, Andover,Hampshire

    with all this data why is it ever wrong .

    I know some one asked this quetion a few days ago but does it teach it`s self with possible trends or is it based on what it was programed will happen?

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    Posted
  • Location: South Woodham Ferrers, height 15 metres
  • Location: South Woodham Ferrers, height 15 metres

    Thanks for that, Paul. Peak behind the green curtain always interesting.

    Do you have any more details on each run? Or can you confirm it's as sesnow1 listed above.

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    Posted
  • Location: Aviemore
  • Location: Aviemore
    with all this data why is it ever wrong .

    I know some one asked this quetion a few days ago but does it teach it`s self with possible trends or is it based on what it was programed will happen?

    I'm not sure how the model itself works - it's extremely complex!

    Thanks for that, Paul. Peak behind the green curtain always interesting.

    Do you have any more details on each run? Or can you confirm it's as sesnow1 listed above.

    As I understand it all that data goes into each run, some runs will have more from one data source than others due to the availability of the data but I'm not sure about the list above..

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    Posted
  • Location: Central London near Canary Wharf
  • Location: Central London near Canary Wharf

    Hi AFT,

    This was part of an email I had in response to my questions re the GFS. To be honest

    I suspect as Paul quite rightly states above most of the data would try to be incorporated in each run.

    The NOAA email makes it even more confusing though...sorry! <_<

    'Model runs are generally made four times a day at 00Z (7:00 pm EST),

    06Z (1:00 am EST), 12Z (7:00 am EST) and 18Z (1:00 pm EST). Since

    radiosonde observation balloons are released throughout the world at

    00Z and 12Z, the models are "initialized" at these times with real

    data for subsequent runs. When there is little or no data, for example

    for the "off hour" 06Z and 18Z runs, the models are initialized from

    previous model run results. '

    PS - It was New Years Eve when I asked the question though, so maybe he thought I was

    strange asking that question around 5pm, so he could have been waiting to go home for a drink! :lol:

    Kind regards

    CV

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    Posted
  • Location: Aviemore
  • Location: Aviemore

    As I understand, basically how it works is that all of the data sources and types I listed above go into each 'data dump' before the model is run. If for example there is no new radiosonde data available for a run then old data will be used. Within each data type though there can be a varying amount of data available - so for instance there is probably more flight data from the atlantic within the 12z and 18z runs as there are more flights across the atlantic at those times.

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    Posted
  • Location: Central London near Canary Wharf
  • Location: Central London near Canary Wharf
    As I understand, basically how it works is that all of the data sources and types I listed above go into each 'data dump' before the model is run. If for example there is no new radiosonde data available for a run then old data will be used. Within each data type though there can be a varying amount of data available - so for instance there is probably more flight data from the atlantic within the 12z and 18z runs as there are more flights across the atlantic at those times.

    Hi Paul,

    I think that has pretty much nailed it <_<

    The interesting thing to arise from this discussion is IF we find all runs are using the same data

    where possible, it would be correct to compare the 12z to the 18z, etc yes?

    Kind regards

    Rob

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    Posted
  • Location: Aviemore
  • Location: Aviemore

    To be honest, I never really thought there was an issue with comparing runs - ok there will always some differences in the data, but I don't think that it will ever be different enough to say that comparing run for run won't work. I've never seen anything from the NCEP to suggest that each run cannot be followed in turn either <_<

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    Posted
  • Location: Central London near Canary Wharf
  • Location: Central London near Canary Wharf
    To be honest, I never really thought there was an issue with comparing runs - ok there will always some differences in the data, but I don't think that it will ever be different enough to say that comparing run for run won't work. I've never seen anything from the NCEP to suggest that each run cannot be followed in turn either <_<

    Thanks Paul,

    Seemed to be a big issue when looking at the Models as most users were under the Impression you should only

    compare an 18z with its predecessor.

    I think this has answered most of the questions raging in the Model runs.

    I for one shall now start to use a run from the previous Model shown....i.e. 12z to 18z

    Kind regards

    Rob

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    Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
    with all this data why is it ever wrong .

    I know some one asked this quetion a few days ago but does it teach it`s self with possible trends or is it based on what it was programed will happen?

    It being only a MODEL, I can imagine a few inherent flaws:

    It would need infinite computing capacity, and infinite AND continuous data-input for it to be a perfect replica of the real thing...Like all models, it's a highly simplified version of reality :)

    <_< :lol:

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    Posted
  • Location: Central London near Canary Wharf
  • Location: Central London near Canary Wharf
    It being only a MODEL, I can imagine a few inherent flaws:

    It would need infinite computing capacity, and infinite AND continuous data-input for it to be a perfect replica of the real thing...Like all models, it's a highly simplified version of reality :)

    <_< :lol:

    Yes and computer Models are always likely to receive corrupt data at some point Peter. Which means

    unless they are updating in real time they are always open to interpretation and flaws.

    Cant beat the real thing :)

    Cheers

    Rob

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    Posted
  • Location: Aviemore
  • Location: Aviemore

    Totally agree Pete - even with the huge supercomputers and incredible scientists and modellers working on the software, a model can (at this point in time) never be able to match nature!

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks
    Thanks Paul,

    Seemed to be a big issue when looking at the Models as most users were under the Impression you should only

    compare an 18z with its predecessor.

    I think this has answered most of the questions raging in the Model runs.

    I for one shall now start to use a run from the previous Model shown....i.e. 12z to 18z

    Kind regards

    Rob

    I think you will get extremely frustrated doing that mate but its up to you.

    regards

    John

    To be honest, I never really thought there was an issue with comparing runs - ok there will always some differences in the data, but I don't think that it will ever be different enough to say that comparing run for run won't work. I've never seen anything from the NCEP to suggest that each run cannot be followed in turn either <_<

    hi

    I am no expert in this business but experience with GFS over 14-15 months does, for whatever reason, suggest that comparing successive runs with one another is pretty fruitless, at least beyond a' near' time scale, say 72-96 hours possibly 120 hours.

    Like I say I have no real knowledge but 12-15 months with GFS has quite often shown this up.

    regards

    John

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    Posted
  • Location: Central London near Canary Wharf
  • Location: Central London near Canary Wharf
    I think you will get extremely frustrated doing that mate but its up to you.

    regards

    John

    Hi John,

    I am frustrated with the data full stop. You know that more than most <_<

    I think I will give up and just watch events unfold :lol:

    You are right though on a more technical basis running a 5 day 12z v 12z trend must be more

    precise than just a 5 run trend.

    Great discussion though

    Kind regards

    Rob

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    hi

    It would help if NOAA had a dedicated line for amateurs like ourselves to get relatively simple answers from them. Either they ignore e mails or give such a complex answer that its almost as bad as no answer.

    I do know, in the past at the Met Office, that each run had the same basic surface synoptic data fed into it, the upper air when that was most often available, and other(satellites, aircraft, buoys etc) when available.

    regards

    John

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