Jump to content
Thunder?
Local
Radar
Pollen
IGNORED

OCTOBER PATTERN INDEX (OPI) MONITORING WINTER SEASON 2014-2015


Riccardo
 Share

Recommended Posts

Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    Thank you for posting this Riccardo, and welcome to Netweather.

     

    I have been following your work with the October Pattern Index since last year. There does seem an extremely high correlation between October's pressure pattern and the following winter's AO index - but it appears that last year may not have been as accurate as previous years. Is there a reason for this?

     

    I am looking forward to seeing this year's index values tested and thank you for linking to your work.

     

    c

    • Like 1
    Link to comment
    Share on other sites

    Thank you for posting this Riccardo, and welcome to Netweather.

     

    I have been following your work with the October Pattern Index since last year. There does seem an extremely high correlation between October's pressure pattern and the following winter's AO index - but it appears that last year may not have been as accurate as previous years. Is there a reason for this?

     

    I am looking forward to seeing this year's index values tested and thank you for linking to your work.

     

    c

     

     

    it is mainly the period mid December / mid January is concerned. Last winter, the OPI was 1.7, the AO index was 0.3 (1.5 in December, -1 in January). In the end it had been quite right since the polar vortex was often very compact

    • Like 1
    Link to comment
    Share on other sites

    Posted
  • Location: Reigate, Surrey
  • Location: Reigate, Surrey

    Thank you Riccardo - I've been looking every where for this as I followed it last year, but forgot to bookmark the url.

    Link to comment
    Share on other sites

    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    A good start! (negative)

    • Like 3
    Link to comment
    Share on other sites

    Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

    Is there a graph from last year? It would be interesting to see if it indicated positive through the whole month.

    Link to comment
    Share on other sites

    Posted
  • Location: Dulwich Hill, Sydney, Australia
  • Weather Preferences: Hot and dry or cold and snowy, but please not mild and rainy!
  • Location: Dulwich Hill, Sydney, Australia

    Thank you for posting this Riccardo, and welcome to Netweather.

     

    I have been following your work with the October Pattern Index since last year. There does seem an extremely high correlation between October's pressure pattern and the following winter's AO index - but it appears that last year may not have been as accurate as previous years. Is there a reason for this?

     

    I am looking forward to seeing this year's index values tested and thank you for linking to your work.

     

    c

     

    With a 0.9 correlation, I think it was very likely that future estimates won't score as highly. That is not to say that there is nothing in it, just that 0.9 seems infeasibly high given what we know about chaotic systems. Data mining often turns out high correlations in past data that don't have the claimed predictive power in the future.

     

    Again to be clear I am not trying to say it has no value, just that it was always very unlikely to have the extremely high predictive power claimed.

    Link to comment
    Share on other sites

    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    This was highlighted last year as a means to predicting the future AO-

     

    Can we have some more details around the figures for the analysis years, with the NH pattern available on archive for every October I would expect data used all the way back to 1900??

     

    Once you've done that you can reanalyse DJF's with a negative value & DJF's with a positive value-

     

    look forward to the information-

     

    s

    • Like 1
    Link to comment
    Share on other sites

    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    This was highlighted last year as a means to predicting the future AO-

     

    Can we have some more details around the figures for the analysis years, with the NH pattern available on archive for every October I would expect data used all the way back to 1900??

     

    Once you've done that you can reanalyse DJF's with a negative value & DJF's with a positive value-

     

    look forward to the information-

     

    s

    How good is your Italian Steve.

     

    Links to last years Italian forum threads

     

    http://www.centrometeotoscana.it/forum/index.php?topic=7364.msg

     

    http://www.centrometeotoscana.it/forum/index.php?topic=7364.msg

     

    I guess google translate comes in handy but not perfect if I remember from last year.

    • Like 1
    Link to comment
    Share on other sites

    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
    Link to comment
    Share on other sites

    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    The 36 year OPI Graph V Winter AO looks VERY VERY well correlated, with only extreme ends of NINO being years where the correlation is weaker.

     

    I will monitor the index for the next month- Without going into detail the Vortex alignment doesn't look very 'traditional' at the moment which seems to fit well with a negative OPI, so hopefully a negative Month....

     

    Also the AO index is set to go VERY negative in the means- although the measure of the OPI isn't the same as the AO-

    http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

     

    S

    Edited by Steve Murr
    • Like 4
    Link to comment
    Share on other sites

    Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

    Late Breaking News people.

     

    as long as the reanalysis charts are Available on Nov 30th I will be releasing a forecast for Winter.

     

    In terms of the OPI it will be covered.

     

    These legends are KEY to remember.

    Junior AO months are winter months with an average index -1.0

    Super AO months are Winter months with an average index -2.0

     

    This Winter is going to be a STRONG Negative QBO Winter & relating to that based on the OPI graph we find the following.

     

    with an OPI index or -0.4 or Above there is nearly a 100% chance you will not see a Winter with a Junior or Super AO.

    with an OPI Index from -0.5 to -1.5 you have nearly a 100% chance of seeing a Junior AO month ( possibly 2), & around a 40% chance of seeing a Super AO month

    With an OPI index below -1.5 there is nearly 100% chance you will see a Super AO & at least X2 junior AOs.

     

     

    In a nutshell, an OPI over -0.4 & you can forget a good blocked Winter, below that -pref below -1 & your odds on at least 1 very blocked Month..

     

    S

    Steve that's really interesting , and while it all seems to good to be true in a forecasting sense , if the correlation is that strong , surely LRF's will be much more accurate than they are ? I understand it's only one tool in a big tool box used but we all know how much a blocked pattern can help us ?!

    Link to comment
    Share on other sites

    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    Yes however there is 1 more variable I use for November - which will help the forecast which isnt part of the OPI-

     

    I expect the OPI to level out around -0.1/-0.2 over the next few days before the index drops out again after that... real big fingers crossed for a sub -1 index for Oct

    S

    Link to comment
    Share on other sites

    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

    Yes however there is 1 more variable I use for November - which will help the forecast which isnt part of the OPI-

     

    I expect the OPI to level out around -0.1/-0.2 over the next few days before the index drops out again after that... real big fingers crossed for a sub -1 index for Oct

    S

    In my view Steve I think we'll get your wishes...for at least one month anyway.  Nothing has changed from my early view of early and snowy periodic cold in Dec and very blocked and cold late winter/early Spring.  I think you've chucked some added spice in here, it would be popular anyway...but even moreso now as I detect some early 'interest' from you. 

     

    BFTP

    • Like 4
    Link to comment
    Share on other sites

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

    I understand it's only one tool in a big tool box used but we all know how much a blocked pattern can help us ?! 

     

    so very very true

    If it was so good at predicting the winter months why is it not used by the major computer centres, or maybe they do?

    What did October last year show, did it predict the mobile westerly which is what the UK and parts of western Europe suffered while parts of NE America had deep cold. It would be interesting to see just what it showed 12 months ago or rather what it showed 31 october with all the October data in.

    • Like 3
    Link to comment
    Share on other sites

    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    Last year was +1.64 in a westerly QBO. THe Second worst possible year.

     

    the worst year for OPI index was 1992 which was +1.7 & a westerly QBO...

     

    Look at the AO index for 1993 & the NAO index for 1993.

    S

    • Like 2
    Link to comment
    Share on other sites

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

    Last year was +1.64 in a westerly QBO. THe Second worst possible year.

     

    the worst year for OPI index was 1992 which was +1.7 & a westerly QBO...

     

    Look at the AO index for 1993 & the NAO index for 1993.

    S

     

    thanks Steve, quite interesting

    Link to comment
    Share on other sites

    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers
  • Location: Hadleigh, Suffolk

    Wow! The OPI index has plummeted to -2.12 today! 

     

    Karyo

     

    Very interesting situation at the moment karyo. The OPI modelling has taken the first 5 days of October (actual readings) and added on the forecast for the next 10 days. With the index dropping as it has today, my take is that it suggests the GFS model doesn't see the PV getting its act together in any significant way in the next 10 days. Can't wait for Steve Murr's winter forecast if this keeps up!

    But a word of caution... we mustn't forget there's 26 days of Oct left!!

    Edited by Blessed Weather
    • Like 2
    Link to comment
    Share on other sites

    Posted
  • Location: Ripon , North Yorkshire 34m/112ft ASL
  • Weather Preferences: heat and cold, storms and blizzards...zonal a no no
  • Location: Ripon , North Yorkshire 34m/112ft ASL

    Steve, your just too bad  :yahoo:

    Have you any idea how inspiring you are ? Its really good to see you playing out early in the season too. we all missed your sausage last winter, hope your going to make amends this coming winter lol... and bare all bwahhhhh . .

     

    just being sarcastic of course, but its definately a different pattern compared to this time last year.

    Edited by bryan629
    Link to comment
    Share on other sites

    Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

     

    But a word of caution... we mustn't forget there's 26 days of Oct left!!

    Indeed BW, we have to take it a day as a time. 

    Link to comment
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
     Share

    ×
    ×
    • Create New...