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

[Barry12]

How are we back to square one?

 

The correlation is a negative OPI = a negative NAO.

[Hocus Pocus]

So after 52 pages of ups and downs it appears we are back to square one. You couldn't write it really. Suppose I will just stick with the met office after all.

Maybe you should read it before drawing your conclusions as even though their findings are mixed it's a work in progress which they admit on the above link, so like any new area in science there will be up's and downs until they are happy with their own research themselves.

[chionomaniac]

Effectively, what he is saying is that the new experimental index, the IZE, differs from the OPI and the SAI forecasts this year. The IZE is suggesting a neutral winter AO, whereas the OPI and SAI (as far as we know up to this point) are suggesting a negative AO. But they emphasize that this work is still in its infancy and therefore should not be relied on until there is some sort of verification that only time will allow.

[Catacol]

Well - the article freely admits that there is no "forecast" being made at this point and that they will collaborate with Cohen and the SAI along with their 2 indices... and use this coming winter season to adjust their work according to errors that occur. And there must be errors somewhere - cos their 2 chosen indices of OPI and IZE have both proven accurate in hindcast (IZE only since 2011 though - OPI goes back to 1976) and that one of them presumably is going to come unstuck this winter as their signals are contradictory.

 

Based purely upon sample size surely its gotta be the IZE which will be inaccurate!!! Please??? :-0

[SW Saltire]

Suppose I will just stick with the met office after all.

and still be wrong....

Just because the Met Office's very experimental model (which is in it's infancy) is showing mild this year doesn't mean all 52 pages of optimism are misplaced.

This new information just means (as we all know) there are many pieces to the jigsaw....

At the end of the day, I'd rather be sitting here with an OPI of nearly -2.5 than +2.5

[Hocus Pocus]

I think the main problem here is some want clairvoyant answers as to whether it will snow IMBY this winter, until someone cracks that one I expect lots of toys being thrown out of the pram.

[Yarmy]

It's claimed in the blog that the IZE can make AO predictions at the resolution of 3-day averages through the winter (as opposed to the OPI making a 3 month average forecast). That sounds almost too incredible to be true. Anyway it will be verified one way or the other as soon as we get through the first couple of weeks of December. 

[LomondSnowstorm]

My reading of it is that the IZE only goes out, so far, to the end of January, so if the final third were to come in negative (by that I mean the AO forecast comes in negative, which I think means the index is actually +ve) it wouldn't be too far off the SAI/OPI?

Certainly wouldn't say we're back to square one on anything, this is a fascinating area of research and I'd far rather have the wealth of competing indices and indicators, no matter how mixed the picture it gives (and I'd still say it's broadly leaning more towards cold than not in simplistic terms FWIW) than relying either on long range forecast models or, as we used to, wild stabs in the dark.

Edited October 27, 2014 by LomondSnowstorm

[radiohead]

I think the important thing to remember is that the OPI is just one tool which can be used to try to get an impression of the coming winter. It's new, experimental, still not fully understood or tested and therefore shouldn't be used in isolated but instead as part of a broader outlook with things like this new IZE index we are hearing about, the SAI, SEI, seasonal computer models, ENSO, QBO, solar activity etc....

 

It wouldn't be as much fun if we knew exactly what was going to happen anyway would it?

[Met4Cast]

"We're back to square one"

No we're not. The correlation between a -OPI & a -AO still exists.

People have said throughout this thread that the OPI has a small data set & remains experimental and by no means proven.

The iZE is a new index and one that could prove interesting in the future. The fact that it's at odds with the OPI will surely mean both indicies will be tested this winter, an interesting winter from a scientific point of view is coming up, anyway.

The iZe is also going for "neutral" AO and not positive, so that's something

[mcweather]

Here's a thing.

 

We all know that even in mild winters the usual suspects can still get snow often due to being close to windwards coasts or altitude.

 

But what about a relatively snow free location like mine in Central south Dorset?

 

Looking back through the OPI table for the last 36 years every one of the years with a reading of minus 1 or below has produced a spell/spells of heavy snow and/or intense cold.

 

Sometimes we didn't even need to get as low as minus 1. The great Blizzard of Feb 1978 in southwest England came on the back of and OPI of-0.95 for October 1977 and even a reading of -0.85 in October 2010 was followed by the coldest December on record in much of Dorset.

 

So I for one am certainly looking forward as we home in on a sub minus 2 OPI. It will be a good test.

[egret]

I think the important thing to remember is that the OPI is just one tool which can be used to try to get an impression of the coming winter. It's new, experimental, still not fully understood or tested and therefore shouldn't be used in isolated but instead as part of a broader outlook with things like this new IZE index we are hearing about, the SAI, SEI, seasonal computer models, ENSO, QBO, solar activity etc....

 

It wouldn't be as much fun if we knew exactly what was going to happen anyway would it?

And if we knew 6 months in advance with accuracy we would start looking forwards 18 months and be guilty of ramping or writing off the following winter. Such is human nature!

The great thing with the digital age is being able to explore vast amounts of data and to openly consider the ideas and work of others as they explore emerging trends and associated hypotheses.

For me the solar cycle patterns remain compelling and the OPI appears to paint a similar pattern albeit over a shorter set of records.

[Dancerwithwings]

Translated from 'The OPI Team' https://forum.netweather.tv/topic/81494-october-pattern-index-opi-monitoring-winter-season-2014-2015/page-51#entry3060632    http://translate.google.com/translate?ie=UTF8&prev=_t&tl=en&u=http://www.climatemonitor.it/%3Fp%3D36712&sandbox=0&usg=ALkJrhjMi8248Baz6iMGQ9nWUYmZM3GZKg

 

Also click on, OUTLOOK....It starts: first Outlook for Winter 2014-2015.

Edited October 27, 2014 by Dancerwithwings

[Gael_Force]

"We're back to square one"

No we're not. The correlation between a -OPI & a -AO still exists.

People have said throughout this thread that the OPI has a small data set & remains experimental and by no means proven.

The iZE is a new index and one that could prove interesting in the future. The fact that it's at odds with the OPI will surely mean both indicies will be tested this winter, an interesting winter from a scientific point of view is coming up, anyway.

The iZe is also going for "neutral" AO and not positive, so that's something

 

Last winter was a good example of a near neutral winter achieved through a blend of both positive and negative months.

 

The IZE can be right as well as the OPI.

 

None of these indices, however accurate, can be a forecast for a small, specific point on the very large dome, which is the northern hemisphere.

[Man With Beard]

Hi all, happy to be back and sorry for the delay.

Ok, we're almo si done actually, almost not quite of course. But, yes, there is high confidence that we won't see many differences at the end of this week. I see that some of you is willing to put this work Under scrutiny in order to check its reliability. This is exactly what we are waiting for as well, but please, keep in mind a few things:

1) A three months mean value cannot be used for a forecast;

2) Hindcasts have been satisfactory so far, but the correlation is not as high as needed to avoid episodes of error, and unless we (or anybody else) will be able to turn it in a causality there won't be way to understand where the error lies;

3) Winter, as well as every other season, is much more than AO, the latitude of the polar jet, just to say one.

I am writing this before the end of the calcolation because we don't want to turn this thing in a challenge, will it be right or wrong? By the way, just to let you know that there is a long way to go, let me show you something else we are working on. it's still an index and it's still based on the similarity between October and winter patterns, but it's focused on zonality. Check it out here: http://www.climatemonitor.it/?p=36712

Sorry it's still in Italian but I am confident that you will find the graphics self explanatory. And you will also see that we have a problem, to differs from OPI and SAI quite a lot.

It's going to be challenging!

gg

Thank you OPI team, a very helpful comment. I guess you've realised that many of us had gone too far in calling a cold winter based on your preliminary findings - I'm afraid the sound of the word "snow" and "cold" reverts some people on this forum back to the age of 5!!! 

 

Just this very evening I've been looking at past winters with -1.5C OPIs (yet again, the 5 year old in me coming out!!) and to be honest, there really was no guarantee of cold in those winters, it's just that the PV just becomes more unpredictable. In a strong PV year of course, the PV is very predictable, but in a weak PV year, it just acts like a bit of jelly. It increases the odds of cold getting here, but it's still rather random, and often we just got the odd week or two of severe cold - but there's equally a chance that the jelly will never quite shape itself to bring cold weather to us. It wouldn't be a failing in the OPI - it's not the "UK snow" index, after all!

 

BUT ... I'm sure you don't want us to say "back to square one" either, though? There obviously must be something in the OPI, going by Riccardo's initial post, its success with North America last year (and to be frank, its success in predicting an absence of cold in NW Europe when many including the Met were leaning in the cold direction), and the correlations posted by SM and BFTP still tell me there is "something in it".

 

So I'm still going to give the OPI time of day, but I won't be ordering extra whiskey for the end of February just in case it doesn't blanket the UK in snow.

[nick sussex]

I think some undue worry may occur in here because of the IZE.

 

The polar front research however seems very interesting, the inference from reading the article was that last year the IZE and OPI correlated well and one can understand why Riccardo et al are scratching their heads as to why theres an apparent disconnect this time.

 

One could perhaps presume that the problem maybe more with the IZE than the OPI, even with the hindsight aspect of the base of knowledge re the AO correlation, its clear that there is a strong correlation.

 

The issue might be in the cold light of day that we might see a tipping point aspect with the degree of neg/pos of the OPI which supercedes the IZE, the IZE may well be more important in more neutral outcomes. That's something we might learn as these areas are researched further.

 

It's understandable that the OPI team want to develop another index on which to test the OPI because then you have two measures that can be compared, also then if the measures disagree you can see with time which seems to be the better guide and then you go onto find out why?

 

I think people need to realize that scientific understanding only comes through this type of research, its especially difficult with meteorology and its attendant vast array of variables.

 

What one wants to see is researchers in a sense trying to deconstruct a theory, you want a theory to be robust and solid and also you want to solidify that foundation.

 

Remember here the more things you test the OPI against the more respected that measure might become. Alternatively with time you might find out the IZE is more worthwhile.

[Isolated Frost]

Just read what the very useful OPI team response, and then the replies saying 'back to square one' and 'gutted'.

As far as I can tell, the post simply confirmed a lot of what we thought, along with adding the IZE (which could also be useful for future), but the OPI-AO/CET correlation hasn't actually changed. Sub -1.5 OPIs have still provided pretty cold winters, and it's currently -2.43? Bon nuit.

[NorthernRab]

Without meaning to stir anything up, I find it surprising how astoundingly rude and dismissive people can be just because some one's work isn't giving them a cast-iron guarantee of a record breaking cold winter. A lot of hard work has been put into the OPI and we should be thankful for both its existence and the interaction we've been lucky enough to enjoy with it's research team.

[Chris K]

Without meaning to stir anything up, I find it surprising how astoundingly rude and dismissive people can be just because some one's work isn't giving them a cast-iron guarantee of a record breaking cold winter. A lot of hard work has been put into the OPI and we should be thankful for both its existence and the interaction we've been lucky enough to enjoy with it's research team.

 

I do not care if it stirs something up. Those are exactly my thoughts and I knew from the start this was never to be treated as a concrete factor to determine what our winter will be like...it is still being analysed and worked on after all. Plus there are many other pieces of the winter jigsaw puzzle that still need to be taken into account.

 

Some people need reduce expectations from the OPI to be honest and equally the evident trolls of the forum need to stop flaring things up...it's obvious who they are!

 

Again as others have said - thank you for the update OPI team. Your work is valued by many here.

Edited October 27, 2014 by Chris K

[Vorticity0123]

One cans say that the OPI is a really interesting measure, especially given the very high correlation with the AO. However, it does raise some questions to me (sorry for asking a lot of questions, but I am trying to understands the concepts somewhat better   ). 

 

Relation of AO-index to blocking

 

First, as the OPI-index is actually an indicator of the AO-index (if I am correct), does a negative AO-index frequently relate to a cold winter in Western Europe? Or does it strongly depend on the regions where (in longitudinal sense) the cold air flows out toward (as related to blocking)?

In other words: does a negative AO favor blocking over Scandinavia, for instance, which often leads to a cold easterly flow over western Europe (due to land-ocean positioning etc.)? Or are the blocks more or less randomly placed during a negative AO?

 

SAI- and OPI-index

 

Second (and last): Is there any relation between the OPI- and the SAI-index? Since both seem to be related to events occurring on the northern latitudes, and both are mostly being influenced by the month October, one could argue that some kind of a feedback or relation exists between them.

 

The SAI-index seems to be related to the rate of increase of snow cover over Eurasia, giving the following feedback loop:

 

Feedback loop occurring during a positive- or negative SAI. The left hand side of the image applies to a negative SAI, while the right-hand side applies to a positive SAI. 

 

More about it can be read in the excellent post from Chionomaniac in the Strat-thread:

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

 

Since a negative OPI-index implies a negative AO-index, it generally also indicates a weak polar stratospheric vortex (correct me if I'm wrong). As can be seen from the SAI-feedback loop, a positive SAI-index also indicates a weakened polar vortex. 

 

A second piece of evidence (though not very strong) shows up when locating the origins of both indices. The theory used for the OPI-index is a piece of a post of Steve Murr in the same thread, given below:

 

 

I do believe this is in relation to the ever changing arctic & how the Taymyr region in particular produces a feedback that has an inverse impact on the height anomaly which is-  the more negative the sea anomaly to the Norm the more positive the height anomaly is. This manifests across late September & early October where this region at sea level is warmer than the average so the ice growth at the edges recedes further to the pole & takes longer to grow back.

Because the overall mechanism that is creating this feedback is becoming self perpetuating & the signal for melt becomes larger each year ( over the period of time ) my thoughts on this feedback is that we are yet to see the full extent how 'deep' this anomaly will get. 

 

As can be deduced from the theory/suggestion given (in bold), the OPI-index itself possibly originates near the north pole (with all precautions applicable here). The SAI itself originates from the Eurasian part close to the north pole. These regions are quite close together, and do very likely influence each other as well. 

 

Many thanks in advance  . 

 

Sources:

http://en.wikipedia.org/wiki/Arctic_oscillation

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

Edited October 27, 2014 by Vorticity0123

[Cheshire Freeze]

Of course it's highly possible that the IZE index could be right in essence but comes unstuck following an SSW in December or January. Surely given the feedback nature of the OPI measurement and direct relationship with tropospheric synoptic patterns, it should in theory prove more useful in -QBO years with SSW potential? The IZE may have its uses but perhaps precluding certain years where certain variables are more likely to skew the expected trajectory?

[neige57]

Of course it's highly possible that the IZE index could be right in essence but comes unstuck following an SSW in December or January. Surely given the feedback nature of the OPI measurement and direct relationship with tropospheric synoptic patterns, it should in theory prove more useful in -QBO years with SSW potential? The IZE may have its uses but perhaps precluding certain years where certain variables are more likely to skew the expected trajectory?

 

 

I completely agree with you. In my opinion, the IZE could be lost if a SSW would be realized for example early in the season for example late December or mid-January. That is why I have big doubts about this index and very little back up because only until 2011 (while the OPI index goes back to 1976). Personally, I would rather use the IPO index and ISC without hesitation

[Cheshire Freeze]

I completely agree with you. In my opinion, the IZE could be lost if a SSW would be realized for example early in the season for example late December or mid-January. That is why I have big doubts about this index and very little back up because only until 2011 (while the OPI index goes back to 1976). Personally, I would rather use the IPO index and ISC without hesitation

Exactly. Who knows, such a discrepancy with low OPI and differing IZE could even indicate a high liklihood of an SSW at some point during winter. We just don't know at present.

Edited October 27, 2014 by CreweCold

[Duane S.]

Maybe you should read it before drawing your conclusions as even though their findings are mixed it's a work in progress which they admit on the above link, so like any new area in science there will be up's and downs until they are happy with their own research themselves.

Ignore him, he's starting early this year, any sniff of a spoiler / downgrade / disappointment and he's straight on his keyboard...

Not really sure why the sudden despondency from some others though. So there appears to be a contradiction between the OPI and this new index (well, new to me anyway). But the bottom line is the OPI when strongly negative (as October 14 WILL be) hindcast or not, has a proven correlation with not only -AO DJF months but subsequently colder than average winters for the UK as well.

Of course... there remains the possibility it may have been 'chance' in what is admittedly a fairly small data set and that the correlation is much weaker than it looks. We know drivers such as QBO, ENSO, MJO, GLAAM etc can have vastly varying effects year to year with their degrees of coupling ( or disconnection) with the atmosphere and the extent to which they interact with proceedings.

I guess Riccardo and the team are concerned many years of work on this are potentially under threat if we have another zonal European winter but I am confident the errors are not with the OPI and meandering jets are going to appear aplenty in the coming winter months!

[Skyraker]

So after 52 pages of ups and downs it appears we are back to square one. You couldn't write it really. Suppose I will just stick with the met office after all.

Splendid idea, you go do that quietly, while the rest of us do that boring science thing.

We promise to come and get you if anything "good" happens or if there is any "colouring in".

Edited October 28, 2014 by Skyraker