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


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Posted
  • Location: Stevenage Herts
  • Location: Stevenage Herts

    I will be just as interested next October as I was October gone! No tool is 100% right and even though this season it didn't live up to what we all hoped I don't think it's right to say oh well I won't bother with it next year! It is no different to any other tool and should not be taken as anything else otherwise we may as well not bother looking at sst, qbo, solar output, mjo etc. the OPI should be viewed like all those other factors and I for one will be watching to see how the OPI fares over the next few years!

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    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

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    Posted
  • Location: Irlam
  • Location: Irlam

     

    I wonder whether we will be looking back at this in March to be taking it with a huge pinch of salt in the future or whether we have unlocked a new long term winter forcecasting pattern...totally fascinating either way...

    A huge pinch of salt. The AO has been largely positive,

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    Posted
  • Location: Broadmayne, West Dorset
  • Weather Preferences: Snowfall in particular but most aspects of weather, hate hot and humid.
  • Location: Broadmayne, West Dorset

    Just for a bit of fun.

     

    The OPI has proved successful for my location. every sub -1.5 year has produced at least one decent covering of snow in my backyard and it has yet again this winter. So I am very happy and will be following it again with interest next year.

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    • 2 weeks later...
    Posted
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    Well, well, well looks like another predictor of a cold winter heads to the bin?

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    Posted
  • Location: Bude
  • Weather Preferences: Extreme weather...heavy snow and heat waves
  • Location: Bude

    Well, well, well looks like another predictor of a cold winter heads to the bin?

    What are the others?

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    Posted
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    What are the others?

    umm ..SSTs, El Niño, La Nina, Siberian Snow index, Pattern matching, solar activity, warm octobers etc etc im sure there are plenty more that have been touted in the past none are proven to have a firm link with a good predictor of a cold winter 

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    Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

    umm ..SSTs, El Niño, La Nina, Siberian Snow index, Pattern matching, solar activity, warm octobers etc etc im sure there are plenty more that have been touted in the past none are proven to have a firm link with a good predictor of a cold winter 

     

    In isolation, no. The issue is that we have no capacity YET to understand how the variables, (which undoubtedly have some effect upon the weather we experience), interact with each other. This is where the challenge lies IMO and we're a way off piecing it all together yet. I think solar activity is undoubtedly a very important factor (that's where our energy comes from afterall). Though if you're using a precise number of sunspots to create an accurate forecast of a season of weather then you're bound to fail!

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    Posted
  • Location: Stockport
  • Location: Stockport

    October seems like such a long time away from the start of winter for any patterns experienced in it to have an effect. There's an awful lot of water to run under the bridge between Halloween and December 1st.

    Surely an NPI (November, obviously) would make more sense, as it directly precedes winter?

    By no means am I rubbishing or dismissing the OPI as a legitimate forecasting tool/method, I'm just not sure about how effective it's capable of being, bearing in mind the mountain of variables.

    Edited by March Blizzard
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    Posted
  • Location: Bude
  • Weather Preferences: Extreme weather...heavy snow and heat waves
  • Location: Bude

    umm ..SSTs, El Niño, La Nina, Siberian Snow index, Pattern matching, solar activity, warm octobers etc etc im sure there are plenty more that have been touted in the past none are proven to have a firm link with a good predictor of a cold winter

    So you think it's pointless looking at the above during the winter to give us some clues to what our winter may hold??? Trust me we will still be looking at them next winter? There is some kind of connection between the OPI and our winter, but clearly other factors combined will determine the outcome. More research needed, not a complete dismissal!!!
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    Posted
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    So you think it's pointless looking at the above during the winter to give us some clues to what our winter may hold??? Trust me we will still be looking at them next winter? There is some kind of connection between the OPI and our winter, but clearly other factors combined will determine the outcome. More research needed, not a complete dismissal!!!

    i think it is pointless unless you look at all other signals that point to mild winters in combination which honestly 90% on here do not... which are probably much stronger and can overide the rest...no doubt it will be the same next autumn and so on and so on...
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    Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

    For comparison it would be good if someone could post NAO May forecasts and what the average NAO value was the following winter. Last year the NAO forecast was positive, and alas we have seen a very positive NAO winter. However, I'm not sure whether an actual NAO figure is predicted or if it is simply a negative, average or positive prediction.

     

    I remember 2005 very well, with forecasts for a negative NAO and alas the following winter saw quite a negative NAO or near neutral pattern dominate.

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    • 5 months later...
    Posted
  • Location: Yatton, South of Bristol
  • Location: Yatton, South of Bristol

    Will be interesting if anyone bothers with this 'tool' this year and takes it into account for their forecast.

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    Posted
  • Location: Near King's Lynn 13.68m ASL
  • Weather Preferences: Hoar Frost, Snow, Misty Autumn mornings
  • Location: Near King's Lynn 13.68m ASL

    Will be interesting if anyone bothers with this 'tool' this year and takes it into account for their forecast.

     

     

    garden-path.jpg

     

    Never mind.  :)

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    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.

    It wont Gav, they wont bother making it work until October.

     

    FWIW I think if we get a really strong negative value, it wont guarantee a cracking winter but gives us a fighting chance, however, if we get a positive value my guess is that would almost certainly be the nail in coffin so in my opinion its worth watching.

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    Posted
  • Location: Yatton, South of Bristol
  • Location: Yatton, South of Bristol

    It wont Gav, they wont bother making it work until October.

     

    FWIW I think if we get a really strong negative value, it wont guarantee a cracking winter but gives us a fighting chance, however, if we get a positive value my guess is that would almost certainly be the nail in coffin so in my opinion its worth watching.

    Yes, but last year was negative and was over-ridden by other factors. This year could be positive and other factors come into play bringing more 'seasonal' weather.

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    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.

    Yes, but last year was negative and was over-ridden by other factors. This year could be positive and other factors come into play bringing more 'seasonal' weather.

     

    Agree with the first bit but if you look at Steve's analogues last year it does seem that its very unlikely to get a cracking winter with a positive value, mind I just wonder if this is one of those things we wont really get a handle on things properly until some real time analysis over several years is done.

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    Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

    I doubt we'll see the fanfare of last winter; that's if we hear anything from the team at all. They might still do the calculations but with the difficulties of both OPI and snow cover from last year it is all rather underwhelming as any kind of predictor. If I remember correctly, the last big Nino was one of the busts in their correlation stats... would be an immediate query on any forecast for this year.

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    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

    Remember that the OPI is only correlated with the AO 83% of the time so we may have just gotten unlucky. Even then though, the AO only correlates with the CET about 70% of the time.

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    • 1 month later...
    Posted
  • Location: Huddersfield, 145m ASL
  • Weather Preferences: Lots of snow, lots of hot sun
  • Location: Huddersfield, 145m ASL

    Well, they haven't got long now to get the OPI website back up and running..................

     

    https://app.til.it/opi/

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    Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

    Remember that the OPI is only correlated with the AO 83% of the time so we may have just gotten unlucky. Even then though, the AO only correlates with the CET about 70% of the time.

     

    That was my thought too, it was never touted as a guarantee....though a positive figure is almost always the death knell on the coming winter (as has been shown by the research). Maybe we should wait for another significantly negative value year to enable us to better make a judgement?

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    Posted
  • Location: Huddersfield, 145m ASL
  • Weather Preferences: Lots of snow, lots of hot sun
  • Location: Huddersfield, 145m ASL

    Remember that the OPI is only correlated with the AO 83% of the time so we may have just gotten unlucky. Even then though, the AO only correlates with the CET about 70% of the time.

     

    So, 70% of 83%, if my maths is right the OPI percent correlation with the CET average is 58.1% ? So in fact not much higher than 50/50, and that's to correlate with the CET, not necessarily to give a significantly below average month...........

     

    When you actually break down the correlations, the question starts to loom 'what was all the fuss about last year' ??? Perhaps less of a fault with the OPI, and more a fault of peoples tendency to over-excitement when any kind of predictor seems to be suggesting it'll be a cold winter ???

     

    T'was ever thus.........................

    Edited by Pennine Ten Foot Drifts
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