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

[Blessed Weather]

So the OPI follows the GFS output? So we are happy the heights are back therefore the OPI stays negative........I thought the GFS wasn't rated compared to the ECM?

 

So if the ECM was being used the OPI could be in the positive?

 

Hi MPG.

The OPI calculations are far more complicated than just looking at the Nth Hemisphere heights for a 3 day period. I've shown that chart because it's an indicator of how the heights profile might be looking out at the end of the GFS 10 day forecast period that the OPI model includes in its' calculations. Bear in mind that the final OPI is based on "actuals" for the month, once it has finished (i.e. 31st Oct). So there shouldn't be any difference between ECM and GFS once you get to the months end, as either would give you the "actuals".

 

Also, bear in mind the post from Interitus yesterday, that the inclination of the vortex against an imaginary line drawn between the two major oceans has more weight (certainly at this stage of the month) than the actual geopotential heights.

 

Anyway, for now it's promising because we have a calculation based on 17 days actual results and another 10 days forecast added. The Index will be gradually firming up.

[mountain shadow]

More than half way through the month and the decently negative OPI continues.

Can't help but feel a wee tinge of excitement.

[SomeLikeItHot]

I am really hoping we get a really solid negative number (ie <-2) as a nice clear signal like this should be a good test of the model and will build more confidence  going forward (or much less should it bust).

[Midlands Ice Age]

Yes bluearmy, a very encouraging Index of -3.36 from the GFS 0z run.

 

Yesterday I posted the ECM/GFS 8-10 day Nth Hemisphere mean height anomaly from Weds 12z runs and the heights had disappeared from the Pole. I'm glad to say that last night's 12z output have the heights back again, as well as (to my eye) better positioning of anomalies in relation to the top ten -ve OPI composite chart.

 

I have no idea what signal the GFS had picked up to drop the heights on Weds, then have them back on Thurs (bearing in mind this is a 3 day mean chart out at days 8 to 10). But a wise post from John Holmes yesterday saying not to worry, you shouldn't take just one run!

 

Height Anomaly for 24th - 26th Oct: ECM-GFS 8-10 Mean 500 Hgt Anomaly on 12z 16Oct2014.gif

 

Edit: Meant to say GFS has heights back, ECM remains reluctant. 

 

It really is quite staggering the difference in the northern profile between the two models at this stage.

 

Perhaps one shouldn't be surprised that our weather is so variable. Presumably the huge anomaly difference over the pole itself is caused by a very small difference in reported data somewhere rather than any differences in the code. Perhaps the GFS has picked up a signal from one of its long term trend adjustment features such as a change in the forecast nino   or an Indian Ocean anomaly. Or maybe the ECM has cahnged somewhere. We don't/won't know probably, but to me it encapsulates how very large changes can be produced in the models on our atmosphere, by just a small change somewhere. Butterfly principle?

 

The profile for the rest of the northern hemisphere is similar, and the ECM would still probably produce a negative OPI, but I think not a large one as per the GFS

 

MIA.

Edited October 17, 2014 by Midlands Ice Age

[bluearmy]

It's not that surprising - those charts are derived from operationals which have a verification below 50% by day 10.

Yesterdays ECM 12z op was out of kilter wrt previous and subsequent output.

You need to check the op anomolys against the ens mean anoms to check that's it's a reasonable stab In the 6/10 day timeframe.

[TonyH]

I suspect this may be a fuss over nothing

[Midlands Ice Age]

It's not that surprising - those charts are derived from operationals which have a verification below 50% by day 10.

Yesterdays ECM 12z op was out of kilter wrt previous and subsequent output.

You need to check the op anomolys against the ens mean anoms to check that's it's a reasonable stab In the 6/10 day timeframe.

 

Thanks BA

It still brought it home how quickly things can change!

 

MIA

[Mapantz]

I suspect this may be a fuss over nothing

I'm afraid I agree with you Tony. The OP has posted this across every weather-related forum/site I could find, he hasn't replied on them either. Over the years, I've seen random posts like the OP's, appear on another forum I go to.

[Gogoslo]

Gogoslo Good Morning all.    Please excuse my ignorance if this is a really stupid question.     Historically,  have there been large swings in terms of - and + IPO during the month or have they been relatively consistent ?   Has there been situations in the past mid-month that has seen a significant - IPO only for it to end up + at the month end.

[KyleHenry]

I'm afraid I agree with you Tony. The OP has posted this across every weather-related forum/site I could find, he hasn't replied on them either. Over the years, I've seen random posts like the OP's, appear on another forum I go to.

No polite way to say this but a reasonable person would use their intelligence and say that the OP has done this to flag up any possible errors that may have been missed prior to releasing the final paper for peer review.

This is the future of paper release by sending it through all forums for feed back. There won't be any replies forthcoming for this reason.

If the theory is has flaws it will be taken apart.

I leave the most recent example of OPI 2013 was +1.6 and we all observed the results. 2014's will be soon here and by Spring 2015 everyone can make their own mind up.

[Mapantz]

No polite way to say this but a reasonable person would use their intelligence and say that the OP has done this to flag up any possible errors that may have been missed prior to releasing the final paper for peer review.

This is the future of paper release by sending it through all forums for feed back. There won't be any replies forthcoming for this reason.

If the theory is has flaws it will be taken apart.

I leave the most recent example of OPI 2013 was +1.6 and we all observed the results. 2014's will be soon here and by Spring 2015 everyone can make their own mind up.

Or they posted it to try and get some coverage?

And before you or anyone gets on the defensive, just remember, I'm entitled to my opinion.

Edited October 17, 2014 by Mapantz

[KyleHenry]

Or they posted it to try and get some coverage?

And before you or anyone gets on the defensive, just remember, I'm entitled to my opinion.

I'm open minded so yes that's a possibility and by releasing the concept onto the forums it is for Riccardo's benefit.

As I said before I wish him success. From what I see so far, I see the theory as honourable and papers written by Judah Cohen make him also the same.

[neige57]

Still a lot of high pressure over the Arctic in the 6Z GFS, both say that the OPI index will remain very negative. It was a big step and chances are now very high for the OPI index will be largely negative final

[mountain shadow]

Or they posted it to try and get some coverage?

And before you or anyone gets on the defensive, just remember, I'm entitled to my opinion.

You can see the work that has gone into it and there are enough brains on here to see that there may be something in it.

 

It could be we have a very negative OPI, in which case we will not have long to wait to see if it verifies to a cold winter.

Edited October 17, 2014 by Paul

[LomondSnowstorm]

It may well come to nothing, but it would be remiss of us not to at least give the OPI serious consideration, particularly because of the correlation it shows with the AO and NW European winter temperatures. If people weren't willing to put forward hypotheses to improve seasonal forecasting then the science will never improve. Just look at the work that's been done on the stratosphere and how much our understanding of that has improved in such a short space of time. 

If it is a bust then we'll disregard it for future years, and if not then we'll have taken a very signficant step forward in long range forecasting. It seems pretty clear to me though that a huge amount of research has gone into this -  it isn't like that time that  stock market analyst came on and predicted a North Sea storm surge and the destruction of Hamburg a month out on the basis of him looking through the archive charts 

[Mapantz]

I think too many people on here are under the assumption that a negative OPI will bring a cold winter. If you want to look at numbers, the OPI was a bust in predicting the AO for the states.

I don't wish to be labeled as having 'no sense' for having a different opinion. There is a flaw with it, like many papers! This is now a tool for the cold-brigade to lose the plot over- (not everybody of course, as I like cold too) I'd like some balance in it, perhaps predicting an AO for the Summer too? Until then, I'll take this with a large pinch of salt.

Edited October 17, 2014 by Mapantz

[Yarmy]

I think too many people on here are under the assumption that a negative OPI will bring a cold winter. If you want to look at numbers, the OPI was a bust in predicting the AO for the states.

I don't wish to be labeled as having 'no sense' for having a different opinion. There is a flaw with it, like many papers! This is now a tool for the cold-brigade to lose the plot over- (not everybody of course, as I like cold too) I'd like some balance in it, perhaps predicting an AO for the Summer too? Until then, I'll take this with a large pinch of salt.

 

The AO was very positive last winter:

 

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

 

Thus agreeing with the OPI which is only trying to predict the AO and not the weather at mid-latitudes.

 

But I agree we should remain sceptical until we have a few more years of forecast to go with the 40 years of hindcast.

[SMU]

I think too many people on here are under the assumption that a negative OPI will bring a cold winter. If you want to look at numbers, the OPI was a bust in predicting the AO for the states.

I don't wish to be labeled as having 'no sense' for having a different opinion. There is a flaw with it, like many papers! This is now a tool for the cold-brigade to lose the plot over- (not everybody of course, as I like cold too) I'd like some balance in it, perhaps predicting an AO for the Summer too? Until then, I'll take this with a large pinch of salt.

 

Where do you get the united states from in terms of AO?

 

Also the forecast from Riccardo last year for the US on Eastern US was pretty much 100% Spot on...

[Interitus]

The AO was very positive last winter:

 

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

 

 

 

To be fair it wasn't very positive, the CPC monthly values were +1.475, -0.969 and 0.044 giving an average about 0.18

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table

[Tamara]

Or they posted it to try and get some coverage?

And before you or anyone gets on the defensive, just remember, I'm entitled to my opinion.

 

We should remember that the working mechanisms underpinning the direction of travel of the OPI are derived from peer reviewed research into seasonal atmospheric feedbacks. This much is already apparent from Riccardo, and Cohen's Eurasian snow advance feedback template is well identified in terms of its importance and relevance in the stratosphere thread. 

 

Stratospheric research contributing to seasonal forecasting only relatively recently come under the spotlight within the echelons of the likes of the METO.  We should remember that this was being discussed on humble pages such as these before it gained any respected credence and recognition from the METO and other meteorological organisations and then fed into the public domain  .

 

So I think our Italian friends introduced this topic of reference for all the right reasons and have added a much welcomed further avenue of research into the complexity of determining the pre-winter pattern jigsaw. In that sense, and with an open mind, there is very much more to benefit from this thread than simply riding with the highs and lows of intra day GFS output that give us the statistical figures of the index.

 

As a bare minimum, the OPI will provide a litmus test over time for accuracy of measuring how seasonal feedbacks might already be affecting the state of the polar stratospheric field (vortex development and stability) and as a consequence are already in the process of shaping up provisional indications of the type of winter season ahead. It is with that in mind, that we should analyse the final end month figure. The OPI simply offers a starting benchmark to pitch and manage future expectations, and its final figure can be (ongoing) assessed and checked for accuracy within the stratosphere and other threads from November and as we head closer and closer to the short season.

 

My own post earlier in the thread alluded to many of the various factors driving the current patterns that are evolving catalysts to kick-start important feedbacks in the coming months that will determine the character of the winter that lies in front of us . I gave very basic explanations as to how and why they might be relevant to what is underpinning (and conceivably we very much hope hampering!) vortex development.

 

As far as I am concerned progress continues quite satisfactorily along the lines as suggested in that post and the associated threads operating in tandem to this one (especially the stratosphere thread) endorse and reflect in excellent technical detail the general simple overview/analysis I attempted to provide in that post

 

I think we should approach this thread with the view that the OPI is at the very least, a starting measure of determining the direction of travel of the tropospheric/stratospheric relationship this year. It is not the answer on its own, but it does represent, at the very least, a provisional indication of whether we are dealing with a stable or unstable trending vortex.

 

We know from repeated experience of in depth stratospheric analyses/ monitoring of previous years that to stand any chance of blocking establishing at higher latitude we rely on favourable destabilising feedbacks to be operating on the polar stratospheric vortex first and foremost. The OPI doesn't guarantee a UK snow fest or even guarantee that we will directly benefit from any blocking that does arise from an unstable stratospheric profile, should we have one, but it does give us at least some idea as to whether or not those vortex ammunition feedbacks are present at seasonal 'initialisation' (i.e in the weeks before official winter begins).

 

It is from this perspective that I think we should take at least some faith in the OPI accuracy correlation

 

We already know that the base state of the QBO is strongly easterly (primed to assist Rossby wave breaking from trop > strat and DBC poleward transport of ozone to assist warming). We are seeing very promising progress, thus far, of Eurasian snow advance - the mechanism that will enhance wave 2 responses during the winter and assist retrograde of the Siberian High. Tentatively and theoretically, there is also the very cautious possibility of early wave activity initiating a faster track trop/ lower strat response to give interest to the earlier part of the winter. No further repetition of other relevant factors as given previously, and examined elsewhere, required for purposes of this reply

 

While progress remains indicative of a weaker vortex, and all that might entail for the winter, then lets continue to have faith that the sum of the feedbacks in play are doing their work. Time to sit back, not fuss over intra day descrepencies and non compliant seasonal models which appear to conflict the evidence at this time, and watch and enjoy the show

 

@ Mapantz - you are welcome, and thanks

Edited October 17, 2014 by Tamara תָּמָר

[Mapantz]

Great post Tamara תָּמָר, as always. Thank you for taking the time to write an informative reply.

[easton888]

06z -3.37!

[A.J]

A very well balanced and informative post from Tamara above, pretty much summed up my thoughts and then some (although I could never have posted it as eloquently)

 

Any attempt to improve long range forecasting is surely a good thing, and I for one, applaud the OP in having the courage of conviction to develop this particular tool, and from a non-biased viewpoint, I wish him and his methodology every success

[Yarmy]

To be fair it wasn't very positive, the CPC monthly values were +1.475, -0.969 and 0.044 giving an average about 0.18

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table

 

Ha, yes. That's what happens when you just look at the pretty graph instead of the actual numbers.

December was a monster though and the States were buried.

[Interitus]

06z -3.37!

 

Strange, the angle values are exactly the same as the 0z