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Riccardo

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

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While working on my own research output for the winter forecast, I noticed some strong indications of a "front loaded" winter season ahead, meaning anomalous cold would dominate early in the season.

 

 

It looks to me as though there is some value to this OPI research, and I can also report that the QBO index value that I use shows a significant negative anomaly in NOV-DEC followed by above normal in JAN-FEB. My own final winter forecast should be available in about a week or two.

Hi Roger

Oddly enough I'm not in disagreement :D although I think quite late season will deliver too.  I'm quite pleased too the way the OPI is going, let it continue!  That is an impressive correlation.

 

BFTP

Edited by BLAST FROM THE PAST

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Indeed....

 

if its -3.54 to the 19th with 11 days to go then the last 11 days would need to be +6.1 for the month to end neutral, or +3.38 to get to -1.

 

much excitement as we head towards November!!

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Guys what a fantastic early outlook to early winter we have hear , I personally never bother with long range models , I would sooner do the research myself and look at all the parameters as we head in to winter , and at the minute , every signal is pointing toward a very interesting winter , indeed we are so so different to this time last year , having not had a winter for 2 years now , I'm really relishing the possibility of a cold blocked winter , not just for the snow , but the model watching is so much fun , all the excitement in the model thread , it's the first thing I look at when I wake up in the morning , and now with the OPI to look at aswell gives a really good build up to winter .

Really feel we are all in the best internet weather channel in the world here on netweather , it wipes the floor with anything else out there , with the most fantastic learning tools available .

Happy days guys feeling really optimistic about the winter now . Here's hoping for a 09/10 style winter :)

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Have to say I hadn't heard about the OPI but the evidence presented does look quite compelling.

Edited by Gavin P

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Interesting times ahead!

 

I generally only frequent for the winter time on the forum and do thoroughly enjoy threads like these where it is relatively easy to work what is a good indicator.

 

Excited for the months ahead!

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If the trend is correct and is -3.57 after 18 days and it is done on the calendar month 31 days it would have to push up to a stonking 4.95 for the remaining 13 days to bring the average out to zero.

Looking forward to seeing if this theory delivers a 2 month, (as a minimum!) colder than average winter.

Just a quick thanks to the usual suspects for their input, nice to see Steve back on form!

Clem

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So this OPI is helping us predict if the polar vortex will be weak or strong, is that the general gist? If it's a weak PV, does that increase chances of northern blocking? Or is it just a case of a higher chance of cold?

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I wonder if the OPI can be further researched in terms of those months which saw negative readings but were marked by for example a positive start which was taken to negative by a better second half and a deeply negative start which although stayed negative was characterized by a change of conditions in the second half.

 

This might sound simplistic but I would have thought the direction of travel was more important in the second half as this incorporates more of the natural cooling of the NH and a time when the PV starts to wind up.

 

Am I off on a tangent here? or does this make any sense?

Edited by nick sussex

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Just think a few years ago we only had the May tripole signature in the Atlantic to indicate what the NAO might be.

 

Then we had the warm, dry October theory, then the Snow Advance Index (SAI) and now we have the OPI to look at as well!

 

Then onto November we start to get an idea of the Strat and now this other indicator for November which Steve has alluded to.

 

It makes Autumn for me a lot less boring waiting for Winter!

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Have to say I hadn't heard about the OPI but the evidence presented does look quite compelling.

 

 

Have to say I hadn't heard about the OPI but the evidence presented does look quite compelling.

 

 

Will you be incorporating it into your winter forecast Gavin, or will you wait to evaluate it in real time for a couple of years first?

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This might sound simplistic but I would have thought the direction of travel was more important in the second half as this incorporates more of the natural cooling of the NH and a time when the PV starts to wind up.

Am I off on a tangent here? or does this make any sense?

A question to those who understand this:

Firstly, I second what Nick asked.

Secondly, does the OPI take into account that the PV would naturally strengthen by the end of the month? For example, say we were on -2 to the 20th and the PV did organise more greatly and move placement a little but crucially less than what is normally expected. Would our value of (this is completely hypothetical btw) -2 decrease even though the PV is still not strengthening at the 'average' rate or would the number move towards neutral?

I'm leaning towards the former as surely some months have started say on +1 and ended up -1....

I'm a complete novice when it comes to weather so do bear with my incredible stupidity.

I completely agree with all the praise given to those who have contributed so fabulously to this thread. Sounds like the OPI could be quite significant in having a vague idea at what winter may have in store. Can't wait for the (winter) MOD to get up and running as many others have already said :)

Edited by SW Saltire

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Have to say I hadn't heard about the OPI but the evidence presented does look quite compelling.

 

you're really late Gavin, it's been over a year since we discussed it and you did not notice ?? OPI index works much better than just watching anomalies Stt as you usually do every year, that's not how it works. I think you should look at what is actually OPI before saying that there is no convincing evidence  :)

Edited by neige57

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you're really late Gavin, it's been over a year since we discussed it and you did not notice ?? OPI index works much better than just watching anomalies Stt as you usually do every year, that's not how it works. I think you should look at what is actually OPI before saying that there is no convincing evidence  :)

I think Gavin said that the evidence does look compelling - perhaps you misread! And the SST anomalies are important, especially ENSO, Arctic, and another piece of the jigsaw.

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Something to note with the OPI, is that while it appears useful at predicting the winter AO, it has no strong correlation with the November AO and so we shouldn't expect the cold to arrive in November even with a very -ve OPI this month.

 

Some better news! The OPI itself appears to have a stronger correlation with the winter CET than the AO does since 1976, at 0.68 compared to 0.66. These correlations are better, and almost identical during -ve QBO years, at just over 0.7.

 

Below is a graph of the winter CET anomaly (compared to 81-10 average) and the OPI

 

LLdmtJ5.jpg

 

They appear to drift away a little during the 90s, but are very closely tied during all other decades. The correlation since 2000 is up to 0.82.

The 90's were much reduced in the number of strat warmings as well....,

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A question to those who understand this:

Secondly, does the OPI take into account that the PV would naturally strengthen by the end of the month?

This is similar to my thoughts Saltire, that surely how the OPI is trending towards month end that may be more important than how it begins.

 

Only time and further research will answer that I suppose.

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Only time and further research will answer that I suppose.

True.

My question perhaps should have been worded less 'Does the OPI take the natural increase into account' but more 'to what extent is that the case' ie how does it do so?

As you have said, that's why this theory is in it's infancy.

It seems like the OPI has strong evidence behind it, practically irrefutable (that there is at least SOME link to how the winter may pan out - in conjunction with other well known factors) IMO.

However, further evidence should continue to improve it as an indicator further, as well as other indicators of course.

Exciting times :)

Edited by SW Saltire

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tomorrows update will be interesting- could get to -4!!!

 

Rolling average out to 9th -1.96

Edited by Steve Murr

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Riccardo and his team aren't excepted to work with Judah Cohen this past year ? I read it on his blog few days ago.

 

Sorry for my bad English.

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What are the chances of the opi going positive into November though strengthing the polar vortex.?

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