Jump to content
Cold?
Local
Radar
Snow?

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


Recommended Posts

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

    At first, a cold stratosphere basically meant winters over, now it'll be a positive OPI means winters over :rofl:

    A cold strat and organised PV certainly puts us righ on the back foot, so what's the point?

    BFTP

    • Like 5
    Link to post
    Share on other sites
    Spotted a post you think may be an issue? Please help the team by reporting it.
    • Replies 1.5k
    • Created
    • Last Reply

    Top Posters In This Topic

    Top Posters In This Topic

    Popular Posts

    As ever, a great summary of how things stand from Ed and I think for the last 19, or pretty much 20 days now we have all been waiting for this point in the month and beyond. It's been rather 'fun' wat

    The discussion of the OPI index trend is understandably causing a lot of interest and (cautious) excitement amongst members after Riccardo's very interesting opening post that started this thread. The

    The monitoring page of the “October pattern index†(OPI) is presented. The OPI index  represents a analytic synthesis of the October hemispheric pattern at 500 hPa, and shows from  previous studi

    Posted Images

    Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

    I respect them all, but my point was nothing is a certainty.

     

    I think that's the usual cravat with-in a forecast. 

    Link to post
    Share on other sites
    Posted
  • Location: Batley, West Yorkshire
  • Weather Preferences: Heat and Snow
  • Location: Batley, West Yorkshire

    A cold strat and organised PV certainly puts us righ on the back foot, so what's the point?

    BFTP

     

    My point was it still doesn't mean winters over. An SSW could occur for example.

     

    p.s The comment wasn't meant to wind anyone up, it was just a joke :angry:

    Edited by Barry95
    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

    My point was it still doesn't mean winters over. An SSW could occur for example.

    Yep saw your reply which you posted as I typed. However, we are learning when such episodes are going to really struggle materialising

    BFTP

    Link to post
    Share on other sites
    Posted
  • Location: Manchester
  • Location: Manchester

    It doesnt matter how many runs they ignore, the final value is based on actual results only. They use the gfs to estimate what it might be and they probably ignore runs to refine their methods. Whatever their reasons, they dont affect the final result. At this range it will make very little difference anyway. We are now guaranteed the second lowest OPI value in 38 years⛄

    Well said!

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Wakefield, West Yorkshire
  • Weather Preferences: Anything except blazing hot summers!
  • Location: Wakefield, West Yorkshire

    1990/91 gets me - positive OPI but a stonking winter (well Feb 1991 anyway).

    Conversley 1997/98 - negative OPI but an above average CET? Read the same for 2002/03 and 2003/04.

    On the whole though the correlation is very very interesting.

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Penrith Cumbria
  • Weather Preferences: Cold, snowy winters and warm sunny summers
  • Location: Penrith Cumbria

    1990/91 gets me - positive OPI but a stonking winter (well Feb 1991 anyway).

    Conversley 1997/98 - negative OPI but an above average CET? Read the same for 2002/03 and 2003/04.

    On the whole though the correlation is very very interesting.

    Yes, but 1990 was only slightly positive and the other years only slightly negative.

    The correlation only really kicks in with anomalies exceeding plus or minus one each way.

    I would say anything between plus and minus one should be regarded as neutral and the OPI signal likely to be overwhelmed by other factors, this was certainly the case in 1997/98 with its mega El Niño. Winters 2002/03 and 203/04 were not without interest either being two of the better winters of the 2000's.

    Andy

    • Like 5
    Link to post
    Share on other sites
    Posted
  • Location: Wakefield, West Yorkshire
  • Weather Preferences: Anything except blazing hot summers!
  • Location: Wakefield, West Yorkshire

    Yes, but 1990 was only slightly positive and the other years only slightly negative.

    The correlation only really kicks in with anomalies exceeding plus or minus one each way.

    I would say anything between plus and minus one should be regarded as neutral and the OPI signal likely to be overwhelmed by other factors, this was certainly the case in 1997/98 with its mega El Niño. Winters 2002/03 and 203/04 were not without interest either being two of the better winters of the 2000's.

    Andy

    Great points, cheers Andy for responding.
    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Crouch End, North London
  • Weather Preferences: Snow
  • Location: Crouch End, North London

    with only 4 days left it's looking almost certain for an overall OPI of -2.25-ish. Think we all would have taken that at the start of the month!

    Link to post
    Share on other sites
    Posted
  • Location: Woodham Walter Essex,between Danbury and Maldon 42 m asl
  • Location: Woodham Walter Essex,between Danbury and Maldon 42 m asl

    with only 4 days left it's looking almost certain for an overall OPI of -2.25-ish. Think we all would have taken that at the start of the month!

    Very true,but it has made for an excellent start to the winter season.

    We've had a really active topic,excellent engagement from senior coldies,not too much bickering,and we are all primed for model watching,lamp post watching,and the highs and lows of a british winter!!

    Best of luck everyone!

    • Like 6
    Link to post
    Share on other sites
    Posted
  • Location: Penrith Cumbria
  • Weather Preferences: Cold, snowy winters and warm sunny summers
  • Location: Penrith Cumbria

    It's been a great thread with some really good informative posts.

    We should finish I reckon with an OPI of about -2.3 which would be the second lowest recorded even 1978 was only -1.8!

    Now, what could possibly go wrong........lol

    Andy

    • Like 6
    Link to post
    Share on other sites
    Posted
  • Location: leicester
  • Location: leicester

    with only 4 days left it's looking almost certain for an overall OPI of -2.25-ish. Think we all would have taken that at the start of the month!

    I would take that all day long!!I can't believe its crept even further down!!!its got to the point where am starting to think what is the point in coming into this thread!!lol!!!we know for definite that its gone be really negative now!!!
    Link to post
    Share on other sites
    Posted
  • Location: Ashtead, nr Epsom Surrey
  • Weather Preferences: Hot Summer, Cold/Snowy Winter! Just SEASONAL!!
  • Location: Ashtead, nr Epsom Surrey

    Omg what on earth are we going to read/do thru the whole of November :-o !!! Lol!!

    Here's hoping it's just a mere 4wk interruption of fun before we see the results of the OPI starting to show in December :) x

    • Like 8
    Link to post
    Share on other sites
    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

    1990/91 gets me - positive OPI but a stonking winter (well Feb 1991 anyway).

    Conversley 1997/98 - negative OPI but an above average CET? Read the same for 2002/03 and 2003/04.

    On the whole though the correlation is very very interesting.

    Paul

    I believe the correlation kicks in at high level when exceeding -1.5 and +1.5. I think in between -1 and 1 it isn't as decisive.

    BFTP

    Edited by BLAST FROM THE PAST
    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Sunderland
  • Weather Preferences: cold
  • Location: Sunderland

    -2.45 with 120 hours of input to go

    Considering that means it's had 624 hours of real data and 120 of forecasted data; so I think it's very much settled between -2.2 and -2.7; think everyone here would have took that on the 1st.

    • Like 6
    Link to post
    Share on other sites
    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

    -2.45 with 120 hours of input to go

    Considering that means it's had 624 hours of real data and 120 of forecasted data; so I think it's very much settled between -2.2 and -2.7; think everyone here would have took that on the 1st.

    I think most would have taken the magic -1.5 figure at the start, sub -2 is very interesting and particularly so as it will put the correlation under scrutiny.

    BFTP

    • Like 3
    Link to post
    Share on other sites
    Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

    1990/91 gets me - positive OPI but a stonking winter (well Feb 1991 anyway).

    Conversley 1997/98 - negative OPI but an above average CET? Read the same for 2002/03 and 2003/04.

    On the whole though the correlation is very very interesting.

     

    I posted this in response to a similar comment in the forecast thread.

     

     

    rjbw, on 23 Oct 2014 - 22:24, said:snapback.png

    I was thinking along the same lines as Roger until I started reading the OPI thread - now I don't know what to think. However, on reflection, I'm wondering if this finally will be the year to revisit 1991 and a proper severe cold pool from the east. My thinking is that the Scandi High, quite unexpectedly, emerged as the main player of the summer, and IIRC nearly so nearly tipped the scales on the Atlantic during January 2014 - i wonder if this is now a long term trend and if there is the absence of such a strong Canadian/Greenland vortex, perhaps any Scandi/Russian High will be able to assert itself westwards.

     

    This is a good example of how an uninspiring OPI figure is not the death knell on winter hopes - MMW rides to the rescue in Late January.

     

    http://curriculum.pm.../1991_01_28.gif

     

    Animation courtesy of Patrick Martineau.

     

    Meteociel 15 day archive for corresponding period.

     

    http://www.meteociel...91&map=7&mode=2

    • Like 3
    Link to post
    Share on other sites
    Posted
  • Location: Hindolveston North Norfolk 68m asl
  • Weather Preferences: Sunny Warm summers Cold Frosty winters
  • Location: Hindolveston North Norfolk 68m asl

    I like everyone else is following this very exciting thread with some very informative posts so thanks to everyone who has made this the thread it is.

     

    It is now looking very likely the opi is going to end up somewhere sub -2 really great great news as this does seem to have a good correlation with regard to us having a cold winter especially so when it is sub 1.5, having said all this I think some of us maybe need to take a deep breath and step back a bit, as we know there are a lot of other drivers in the mix, the opi alone I feel cannot guarantee a snowfest winter for us in the UK I wish it was that simple and straightforward, I am not saying anyone has quite that far but with that in mind I do think some folk on here do get a little carried away, I am as much a coldie as the next person but I think we need to see what happens with all the other background teleconnections such as the strat,wave breaking solar flux,and so forth to see the full picture.

     

    Having said all this to my very untrained eye it is looking promising thus far, certainly a far cry from this point last year so fingers crossed all the pieces of the jigsaw fall into place for us this year to have a really memorable cold winter, whatever transpires its looking like very exciting model watching times ahead I think for everyone!!!. 

    • Like 5
    Link to post
    Share on other sites
    Posted
  • Location: North Bristol
  • Weather Preferences: Thunderstorms / Sunshine / Snow
  • Location: North Bristol

    Omg what on earth are we going to read/do thru the whole of November :-o !!! Lol!!

    Here's hoping it's just a mere 4wk interruption of fun before we see the results of the OPI starting to show in December :) x

     

    Stratosphere Temperature Watch thread is another great one to keep an eye on :D

     

    https://forum.netweather.tv/topic/81567-stratosphere-temperature-watch-20142015/

    • Like 3
    Link to post
    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
    ×
    ×
    • Create New...