Seasonal winter 2013/2014 forecast based on OPI index

[Absolute Humidity]

+0.45 DJF

-0.25 FMA

[The_Global_Warmer]

DJF: +0.65; DJFM: +0.45

 

 

Don,

 

you are going with the largest OPI bust on record.  what specifically do you see that would cause that?

 

I am just curious so I can better my knowledge of things.

[Jonger]

DJF +0.10

[skierinvermont]

DJ +1.4

DJF +1

DJFM +.8

FM +.2

[donsutherland1]

Don,

 

you are going with the largest OPI bust on record.  what specifically do you see that would cause that?

 

I am just curious so I can better my knowledge of things.

I'm hedging on the idea that one of the winter months could see enough blocking to dampen the three month average. That has often been the case following extreme November AO+ regimes. My figure would still be 13th highest on record.

 

Needless to say, even as I'd prefer a cold winter, I'm pulling for Ricardo and his team to be have as accurate a forecast as possible. Should their work be validated in a forecasting environment, that should increase odds that their work would become a valuable addition in winter season forecasting.

[The_Global_Warmer]

I'm hedging on the idea that one of the winter months could see enough blocking to dampen the three month average. That has often been the case following extreme November AO+ regimes. My figure would still be 13th highest on record.

 

Needless to say, even as I'd prefer a cold winter, I'm pulling for Ricardo and his team to be have as accurate a forecast as possible. Should their work be validated in a forecasting environment, that should increase odds that their work would become a valuable addition in winter season forecasting.

 

I am with you there.

[easternsnowman]

It takes more than the ao being positive to bring a mild winter, the pacific has something to say too. Although the ao being positive will affect  south of NYC much more. I'm with DT on this one about the winter, never heard of this ricardo guy!

[donsutherland1]

It takes more than the ao being positive to bring a mild winter, the pacific has something to say too. Although the ao being positive will affect  south of NYC much more. I'm with DT on this one about the winter, never heard of this ricardo guy!

I agree that it takes more than one variable. Nevertheless, having a reasonable idea about the AO adds a lot of value to winter forecasts. If one can skillfully forecast the state of one or more major teleconnections, one's seasonal forecasts will prove superior to forecasts that exclude the teleconnections. Hence, if Ricardo's work holds up, it will amount to an important contribution to winter seasonal forecasting.

 

If or when the paper is published we'll know more. If the work holds up in a forecasting environment, that would also be important.

[easternsnowman]

I agree that it takes more than one variable. Nevertheless, having a reasonable idea about the AO adds a lot of value to winter forecasts. If one can skillfully forecast the state of one or more major teleconnections, one's seasonal forecasts will prove superior to forecasts that exclude the teleconnections. Hence, if Ricardo's work holds up, it will amount to an important contribution to winter seasonal forecasting.

 

If or when the paper is published we'll know more. If the work holds up in a forecasting environment, that would also be important.

Don, my only question is how come no weatherman whether they be hobbyist or pros has figured this out... I mean most of us never heard of this guy. the ao and nao have always been the hardest to  figure out .

[donsutherland1]

Don, my only question is how come no weatherman whether they be hobbyist or pros has figured this out... I mean most of us never heard of this guy. the ao and nao have always been the hardest to  figure out .

Trying to forecast the teleconnections with a reasonable degree of accuracy is an extremely challenging proposition. There almost certainly are forecasting limits, as well.

 

Sometimes solving such problems require many steps and a lot of trial and error. One need not go back too far into the past to find SSTAs being promoted as perhaps the best indicator of whether or not there would be winter blocking. Later, Dr. Cohen found that Siberian snow cover had some correlation. He then refined that work with the Snow Advance Index (SAI) becoming a better indicator. From what was posted, Ricardo and the others who worked with him suggested that perhaps a pattern might be responsible for the outcomes seen in the SAI and subsequent wintertime blocking.

 

In any case, in the larger sweep of advances in understanding (far beyond meteorology), breakthroughs are not solely the result of efforts from the well-known. Often they do result from an accumulating foundation of incremental advances coupled with creative insight and/or new or improved technology.

 

Publication of the OPI paper would reveal how robust their work is. I'm not sure if Ricardo would be up for it, but I would certainly be willing to sign a non-disclosure agreement to have the chance to read his paper and safeguard his intellectual property. The paper would also give readers a much better understanding of that work. Success in forecasting would also validate the work.

 

For now, the posted correlations look promising. The idea that the pattern during transition to winter might hold clues about the upcoming winter is not implausible. The work appears to hold potential, but the key is whether that potential will be realized. Personally, I hope it will be, as there would be potentially large economic and social benefits from more accurate seasonal forecasting.  

 

In the end, I'm keeping an open mind and want to learn more (read the paper when it's ultimately published and to see how the OPI works in a forecasting environment). Of course, I would very much like to see Ricardo and his team succeed.

 

After having spent a lot of time over the past few years looking at extended range ideas (some successful, some not), I have a large appreciation for how much I don't know and a corresponding respect for uncertainty. Not surprisingly, I weighed many factors in the fun contest to guess the DJF AO (my guess was +0.65) and my guess was quite a bit less aggressive than the OPI result.

[uncle W]

It takes more than the ao being positive to bring a mild winter, the pacific has something to say too. Although the ao being positive will affect  south of NYC much more. I'm with DT on this one about the winter, never heard of this ricardo guy!

ever watch I love Lucy?...I'm with Don about having at least a period with a negative AO...I would bet on another period with a very positive AO sometime during the winter...1988-89 had only two days all winter with a negative ao...That's almost unbelievable...It also had a cold December...it had a very bad snow season from NY to Boston...

[Absolute Humidity]

ever watch I love Lucy?...I'm with Don about having at least a period with a negative AO...I would bet on another period with a very positive AO sometime during the winter...1988-89 had only two days all winter with a negative ao...That's almost unbelievable...It also had a cold December...it had a very bad snow season from NY to Boston...

I believe there were 2 events of 5 to 8" that winter.

[uncle W]

I believe there were 2 events of 5 to 8" that winter.

that was the year Atlantic City got a 15" snowstorm while NYC got nothing in February...I think there were two 3-5" storms in NYC that year...8.1" total for the season...

[Absolute Humidity]

that was the year Atlantic City got a 15" snowstorm while NYC got nothing in February...I think there were two 3-5" storms in NYC that year...8.1" total for the season...

Yes I remember that bust well. Had a dusting from it. The other two events were better down here, especially the one in March with 8" for that one.

[The_Global_Warmer]

Ricardo might be wrong. But it would be only in accidental error. Reading His posts and the forums where he is from you can tell he isn't full of bleep.

It's not like he is coming here only with correlation numbers and calling it proprietary.

That would be an instant red flag.

Plus the SAI Is calling for a .75 of so AO+ for DJFM.

Ricardo's is just DJF. So the descrrpency is likely March

[Absolute Humidity]

Ricardo might be wrong. But it would be only in accidental error. Reading His posts and the forums where he is from you can tell he isn't full of bleep.

It's not like he is coming here only with correlation numbers and calling it proprietary.

That would be an instant red flag.

Plus the SAI Is calling for a .75 of so AO+ for DJFM.

Ricardo's is just DJF. So the descrrpency is likely March

Funny that you bring him up after brief discussion of 1988, OPI's most off year as seen on chart on pg 1. I appreciate him coming here and reading his work, which is very insightful. like Don S and others, I hope his work is correct in predicting the AO state with such accuracy. It would indeed have big implications going forward with long range forecasting. However, I also appreciate DT's opposition. I am one who needs to see an oppositional viewpoint as well, such as DT's. Despite his language and colorful directness (which can be refreshing), he too has been correct in the past.

[skierinvermont]

I'm all for objection. But DT's has not made any sense whatsoever. 

[Jonger]

I believe what DT is referring to is the SAI and OPI's disregard for the rapid advance of snow cover during the last week of September as per his own winter outlook:

"The CONTRARY point of view on WHY the BIG OCT 2013 increase in Snow cover in Siberia doesn’t count

Their argument goes like this: If you Look at the SNOW Build up/ expansion from OCT 1 to NOV 1 in Siberia … the much above snowfall that fell in late SEPT undercuts the OCT snow cover build up. In other words the SEPT snow means that the OCT snow RATE OF CHANGE in building snow cover was NOT that impressive.

That argument is DELUSIONAL. The SAI is a Physical Process”

the rapid build up of Siberian snow cover in OCT which impacts the AO Phase in the Winter months. There is nothing special about OCT 1 vs say SEPT 25.

There is no possible reason WHY snow in late SEPT would mean a weaker SAI in OCT but IF the same snow in late Sept were to fall says 4 or 5 days later… it would enhance the SAI in October."

I know this controversy has been beat to a pulp here, but DT does have a very good point. Even if this winter turns out AO++, it good to see some mets argue against the norm and challenge what many here otherwise see as obvious.

DT, it's good to see you back. Keep posting.

 

Hard point to disprove.

[The_Global_Warmer]

Funny that you bring him up after brief discussion of 1988, OPI's most off year as seen on chart on pg 1. I appreciate him coming here and reading his work, which is very insightful. like Don S and others, I hope his work is correct in predicting the AO state with such accuracy. It would indeed have big implications going forward with long range forecasting. However, I also appreciate DT's opposition. I am one who needs to see an oppositional viewpoint as well, such as DT's. Despite his language and colorful directness (which can be refreshing), he too has been correct in the past.[/quote

Well the OPI has a 91% correlation. So some years will be off when factors like enso come into play.

In the 1988-89 winter ENSO was a major negative Nina.

[skierinvermont]

Hard point to disprove.

 

No it's not. It was already disproven in this thread.

 

The correlation is way stronger when the SAI is calculated from Oct 1 to 31. The correlation from Sept 25 to Oct 31 was moderate, but not nearly as good. In addition, there are a number of physical explanations for why this would be the case which a number of mets including HM have provided. 

 

This argument is nothing but weenie-casting. Basic math disproves it. Let's put it to rest.

[HM]

The November stratosphere continues to point to a strongly +AO winter. I have found a strong correlation between November east+central Asian stratosphere temperatures and the Dec-Jan AO (I would estimate R-squared of .8 or even .9 based on an ability to correctly predict the sign of the AO 9+ times out of 10). 

 

The stratosphere over eastern+central Asia has been frigid thus far. 

 

Thus the three best tools I know of to predict the winter AO (the OPI, SAI, and Nov. Asian stratopshere temps) all point to a strongly positive AO this winter.

 

I agree with this post. Any SSW potential, if at all, would be late-season and any cold into CONUS will be strictly from tropospheric wave positioning over the Pacific (as we've been seeing and will continue to see heading into December). 

 

 

As for the stratosphere, classic temperature structure of a very strong PV. The very cold parcels from Siberia are being advected into North America and our side's relatively warmer parcels are being advected to Siberia. These then go through irreversible heat transfer and rapidly cool over Siberia. Right now, the PV is doing a good job fighting off the pretty strong diabatic/Brewer Dobson Circulation and occasional wave disruption. From the snow cover-stratosphere standpoint and the physical relationships of SAI, wave positioning on the stratosphere, right now there is NO sign of disruptions to the NAM state. Early +AO/NAM signals look good. 

[NJwinter23]

I'm all for objection. But DT's has not made any sense whatsoever. 

 

Yup

 

Funny that you bring him up after brief discussion of 1988, OPI's most off year as seen on chart on pg 1. I appreciate him coming here and reading his work, which is very insightful. like Don S and others, I hope his work is correct in predicting the AO state with such accuracy. It would indeed have big implications going forward with long range forecasting. However, I also appreciate DT's opposition. I am one who needs to see an oppositional viewpoint as well, such as DT's. Despite his language and colorful directness (which can be refreshing), he too has been correct in the past.

 

I respect DT as well, but his read on the SAI going into this season (which he stated in his winter forecast ppt) is flat out incorrect. He even admits to using the SAI to make his outlook I believe, but his read into the state of snow cover advancement in Eurasia this October is wrong.

 

 

Edit: I just read the other OPI thread where DT is posting and he was actually using the snow cover extent more for his argument, or at least as a reason for caution in the ++AO winter forecasts. Okay I guess that is fair, the original correlation was SCE after all, but Cohen of course dug deeper and found a better correlation to the SAI. We shall see, i still roll with +AO from what I'm seeing.

[easternsnowman]

ever watch I love Lucy?...I'm with Don about having at least a period with a negative AO...I would bet on another period with a very positive AO sometime during the winter...1988-89 had only two days all winter with a negativ ao...That's almost unbelievable...It also had a cold December...it had a very bad snow season from NY to Boston...

I agree with Don about a period of -AO also and also feel there will be a +AO for awhile. The question is about the EPO and analog years of 2007-08 and 1993-94 may come into play for this year.

[HM]

There was some upward flux, albeit weak, from the eastern European High a week or so ago. It barely made a dent at 10mb. Currently, some of the East Asian MT waves are breaking to 10mb, but again...weak.

 

The latest 100mb poleward eddy heat flux is pretty much record low:

http://www.cpc.ncep.noaa.gov/products/stratosphere/polar/gif_files/time_series_cfsr_vt_100mb_2013_NH.gif

 

If the AO goes negative in the next 2-4 weeks, it won't be because of snow cover (well at least directly). All heat flux/temperatures are in the freezer in Asia. There may be enough of a NW Pacific-Aleutian Low by the start of December to get a wave 1 going. We'll see...

[donsutherland1]

I agree with Don about a period of -AO also and also feel there will be a +AO for awhile. The question is about the EPO and analog years of 2007-08 and 1993-94 may come into play for this year.

I suspect any periods of AO- early in the winter will likely be shorter than those later in the winter. The potential for longer periods of blocking could exist later in the winter, especially as the QBO approaches 0 (possibly February or March).

[sebastiaan1973]

http://www.centrometeotoscana.it/forum/index.php?topic=7709.0

 

The creators of the OPI have announced they will work together with no other than Judah Cohen. Please use the above link to read more details, suggestion use translate google if your Italian ain't that good.

[donsutherland1]

http://www.centrometeotoscana.it/forum/index.php?topic=7709.0

 

The creators of the OPI have announced they will work together with no other than Judah Cohen. Please use the above link to read more details, suggestion use translate google if your Italian ain't that good.

This is great news.

[Riccardo]

I confirm this news. We are very happy for this important collaboration. One of our main objectives will be to develop the themes related to the forecast of the winter subseasonal variations. At this regard we have already implemented on the software a specific algoritm which is able to calcolate (in October) the tropospheric wave activity development during the winter. The following figure shows this development about this winter (season 2013-2014):

 

As said, it shows the develompent of the wave activity during winter only at tropospheric level, so it shows directly the main winter phases at mid-latitudes (in particular North America and Europe).

By this graph we can see that there are two maximum tropospheric wave activity events: the first at the beginning of winter (end November-beginning of December) and the second almost at the end of winter (about 5-20 th of February).

 

About the first part of the winter already passed, we can note the high performance of our forecast. In fact we had predicted very strong advenctions of cold arctic air masses to the central-eastern areas of the North American continent due to a strong Aleutian anticyclone in elevation on the Gulf of Alaska at the end of november-first part of December. The following picture represents our forecast for this perid (end November-beginning of December) published at beginning of November:

 

 

 

Now we report the picture which shows the 500 hPa geopotential anomalies about the same period (end November-beginning of December):

 

 

 

After this first dynamic phase, we had predicted the start of the long zonal phase with a strong polar vortex. And this is the real development:

 

 

To conclude we can certainly note the good corrispondence between our forecast and the actual course of events about this first part of winter already passed.

About the future we believe that, after a very short stop (by first graph around end of December), the Tropospheric Polar Vortex (VPT) will reach again a new important compactness during January (especially the first half). In this way the mean quarterly AO would be very high and close to the value expected by the OPI (and also by the SAI).

The planetary tropospheric wave activity should resume in the second last part of Janary with restoring of winter season typical conditions. This new tropospheric wave activity should reach the best expession about at first half/central part of February (see again the graph), when they might occur other important cold arctic advenctions.

 

We wish you a marry Christmas

 

Riccardo Valente, Alessandro Pizzuti, Filippo Casciani and Andrea Zamboni   member of the Center for Study on Climate and Teleconnections of "Centro Meteo Toscana" 

[QcSevereWx]

So, is it possible to make a forecast for the storm season with this index ?

[sebastiaan1973]

Riccardo thanks for the update. I placed a link to the Dutch/ Belgium Website weerwoord.be as well. So the people from the Benelux can read it as well.

 

I have two questions. What does the vertical axis mean?

And secondly. This graph shows only troposferic wave-activity. Couldn't it be possible -hypothetically- that the maximum in february is forced by the stratosphere, i.e. by some sort of wave-induced event (either minor or major warming) in mid-january? So what is your opinion about warming of the stratosphere later on in januar and februar?

Thanks in advance!