WHY the +AO = WARM WINTER argument is in deep Doo

[Isotherm]

Any question now as to what is more important for CONUS cold, the AO or EPO?

 

 

30dTDeptUS.png

 

 

 

Also if you notice elsewhere in the northern hemisphere, the EPO is a cold producer for the CONUS but not for Europe. The past couple years have seen the negative AO benefit the Eurasian side of the globe, but a -AO doesn't always translate into CONUS cold if the NPAC signal is unfavorable. The EPO in my view has a higher correlation w/ temps at this time of year than the AO, across most of the US. As we progress into mid/late winter, the AO/NAO increase in importance, but even then, the EPO is just as if not more important.

[DTWXRISK]

 dude    Your forecasting  skills are so bad  you should be  in jail   

 

  SERIOUSLY... you  keep talking about  the   +AO  as If   that has ANYTHING  to do with this ..it does not... 

 

 

 

I think the AO is set in stone.  The OPI is predicting a 1.64 AO+.  Which is quite ridiculously high.  Now the GFS ensembles are showing around a 2-3SD AO+ at the start of December.  We know pattern changes are typicallty modeled to fast. 

 

I don't know about your neck of the woods.  But during the record AO+ in the 88-89 season we had 24" which is 5" above normal.  Which is pretty interesting.  I believe we also went down to -20F as well(all time record low) in December of that year.

 

 

 

 

This is years with a AO+ of 1.5 or more for the DJF period.  Interestingly they both featured a large HP over the GOA.  But also a trough over the West coast.  This goes back to 1948.  So it looks like it has only happened twice.

 

 

Here is the AO+ of 1.0 or higher years.  Much more muted SE ridge. 

As far as the ONI.  I totally agree. Sub-surface OHC is way above 12 month highs.  We can see the sub-surface warmth making it's way to the surface between 120-140W.

 

TAO is a bit cooler which is probably more reaslistic than the CPC charts.  As far as winds or trends I certainly cannot talk about them. 

 

 

[skierinvermont]

 dude    Your forecasting  skills are so bad  you should be  in jail   

 

  SERIOUSLY... you  keep talking about  the   +AO  as If   that has ANYTHING  to do with this ..it does not... 

 

I don't think he said that anywhere in your quoted section. In fact, he said the exact opposite in your quoted section by pointing out the 5" above average he had in a +AO winter as well as a -20F reading. 

[DTWXRISK]

There are  TWO key  features  driving the overall pattern  and BOTH of them are in  the northern Pacific.  and for those who cannot Admit they  totally misread  the pattern and the data ...  it   has  NOTHING     to  do with the + AO and + NAO

 

 

 

 

1.    One is  the   Omega BLOCK   (shaped like the Greek letter omega) which has developed between Alaska and eastern Siberia.  This feature in the weather business is refer to as the  Negative phase of the  WPO  (-WPO).  

 

 

2.    The other feature is the Alaska   ridge    (which is known in the weather business as the  Negative phase  of the Eastern Pacific Oscillation  of
 -EPO)..  This is not something new. The data is overwhelming that when these two features are strongly negative the pattern is quite cold over much of the country but especially east the Rockies.  For reasons that I cannot explain  some of     forecasters  ignored these key parts of the weather pattern. 

 

 

These two images show that these features ... the -WPO and the -EPO… are  NOT going to break down or go away anytime soon.  This first image shows a huge pool of very warm water temperatures relative to normal in the gulf Alaska and the Northern Pacific Ocean.  It is this very large and very warm pool of ocean where temperatures which is feeding and locking into  the two features keeping the cold pattern in place  ...  the -WPO and the -EPO.

 

 

In addition if you look at the trend with the regard  to the ocean where temperatures ...  If anything the ward temperatures in the Northern Pacific Ocean are actually increasing !!!

 

Thus it can be argued that unless this large pool of except we warm ocean where temperatures breaks down or weekends are dissipates the current cold pattern for the central and eastern  US  will remain in place.

[DTWXRISK]

  um sure  whatever   dude. 

 

 

I don't think he said that anywhere in your quoted section. In fact, he said the exact opposite in your quoted section by pointing out the 5" above average he had in a +AO winter as well as a -20F reading. 

[uncle W]

if you are just forecasting a positive AO this winter you are off to a good start...whether or not it continues is another issue...it's forcast to rise to +4 again...

 

[WEATHER53]

Good posts WxRisk.  People will lock onto a position and work alphabet soup to try and have it come true. Your assessment of this pattern has been stellar and the idea I have had since mid October that this would be a cold winter, especially Dec and Jan, is coming true.

[scottmartin49]

Good posts WxRisk.  People will lock onto a position and work alphabet soup to try and have it come true. Your assessment of this pattern has been stellar and the idea I have had since mid October that this would be a cold winter, especially Dec and Jan, is coming true.

You guys do realize that this model is aggregated; i.e.; not just CONUS, right?

[Typhoon Tip]

Any question now as to what is more important for CONUS cold, the AO or EPO?

 

 

30dTDeptUS.png

Yes the EPO is the primary loading pattern for cold into western N/A ... then nuances in the circulation overall dictates how it will spread - if at all - S of the 45th parallel.  This is known.  

 

The AO is a cold domain.  A kind of miss-conception exists that a +AO mean "warm."  WRONG.  Above 60 N it is cold, regardless of the mode of the AO.  If the WPO relay into the EPO are negative (double A phase of the NP), you have a tipped flow from above 60 N into the Canadian prairies, and it snags large parcels of the AO domain space air mass bringing those air masses S.  

[HM]

 pretty  much self  explanatory

 

The exceptional warmth across the SE / Mid Atlantic and ultimate plus departures for their December shows the danger of using the WPO correlation. Since a majority of the -WPO Decembers were also -AO, they ended up putting the coldest anomalies over the eastern US. In the end, the monthly temps ended up pretty typical and most outfits had the correct idea (SE ridge / cold western 2/3s). The EPO led the way here and nothing more.

 

We are about to see the opposite happen in early Jan. A not so impressive WPO on the way but a very nice transpolar ridge and PNA ridge delivering cold air into the East.

 

My point? The WPO is .... well, it's easily trumped. That's me being nice.

[NJwinter23]

A pretty classic looking -EPO/+NAO Dec at the end of the day.. 

 

[NJwinter23]

The exceptional warmth across the SE / Mid Atlantic and ultimate plus departures for their December shows the danger of using the WPO correlation. Since a majority of the -WPO Decembers were also -AO, they ended up putting the coldest anomalies over the eastern US. In the end, the monthly temps ended up pretty typical and most outfits had the correct idea (SE ridge / cold western 2/3s). The EPO led the way here and nothing more.

 

We are about to see the opposite happen in early Jan. A not so impressive WPO on the way but a very nice transpolar ridge and PNA ridge delivering cold air into the East.

 

My point? The WPO is .... well, it's easily trumped. That's me being nice.

 

 

Yeah. The North Pac ridging was always stretching well into the EPO domain, and I was simply confused why some were calling this a -WPO driven pattern. That's like saying (in a hypothetical case), it's actually the ridging over Scandinavia/Europe driving a cold East U.S. pattern when there is also ridging in the NAO/Greenland domain... 

[Typhoon Tip]

These domain spaces are not disconnected, folks.  -WPO correlates with a -EPO (positively) because of R-wave decay spacing.  -WPO is a "transitive" (you may need to look that term up...) correlation to the eastern Pacific circulation.  Fact remains, -WPO correlates to -EPO via/through the NP teleconnector: 

 http://journals.ametsoc.org/doi/pdf/10.1175/2007JCLI2048.1  (AA vs AB)

 

One should not discount the WPO.   Because of that transitive nature of the correlation, it won't show up very cleanly in the the linear comparison, which might make one think that it is too far removed to be a factor -- you would be mistaken.  Teleconnections need to be created that show this transitive effect ( the first series effects the third, but the first series does not as much effect upon the second), because otherwise remains somewhat like hidden. 

 

-WPO and -EPO is the balanced state over the long haul, as much as the positive variance of those two domains also correlate.  

 

As to the AO's recent involvement, that is more irrelevant, because the WPO and EPO have large portions of their domains spaces in the mid latitudes, which means their phase states are influenced too strongly by subtropical/tropical forcing. 

[HM]

These domain spaces are not disconnected, folks.  -WPO correlates with a -EPO (positively) because of R-wave decay spacing.  -WPO is a "transitive" (you may need to look that term up...) correlation to the eastern Pacific circulation.  Fact remains, -WPO correlates to -EPO via/through the NP teleconnector: 

 

One should not discount the WPO.   Because of that transitive nature of the correlation, it won't show up very cleanly in the the linear comparison, which might make one think that it is too far removed to be a factor -- you would be mistaken.  Teleconnections need to be created that show this transitive effect ( the first series effects the third, but the first series does not as much effect upon the second), because otherwise remains somewhat like hidden. 

 

-WPO and -EPO is the balanced state over the long haul, as much as the positive variance of those two domains also correlate.  

 

As to the AO's recent involvement, that is more irrelevant, because the WPO and EPO have large portions of their domains spaces in the mid latitudes, which means their phase states are influenced too strongly by subtropical/tropical forcing. 

 

No one is discounting the WPO and the AO is not irrelevant. I know your post was near the holidays and I'm late to responding, but try to keep up with the conversation in this thread and its context. There was never an issue other than the WPO correlation graphic for December from the CDC. In fact, the AO was very relevant, since the SE / Mid Atlantic ended up on plus side for December.

[NJwinter23]

These domain spaces are not disconnected, folks.  -WPO correlates with a -EPO (positively) because of R-wave decay spacing.  -WPO is a "transitive" (you may need to look that term up...) correlation to the eastern Pacific circulation.  Fact remains, -WPO correlates to -EPO via/through the NP teleconnector: 

 http://journals.ametsoc.org/doi/pdf/10.1175/2007JCLI2048.1  (AA vs AB)

 

One should not discount the WPO.   Because of that transitive nature of the correlation, it won't show up very cleanly in the the linear comparison, which might make one think that it is too far removed to be a factor -- you would be mistaken.  Teleconnections need to be created that show this transitive effect ( the first series effects the third, but the first series does not as much effect upon the second), because otherwise remains somewhat like hidden. 

 

-WPO and -EPO is the balanced state over the long haul, as much as the positive variance of those two domains also correlate.  

 

As to the AO's recent involvement, that is more irrelevant, because the WPO and EPO have large portions of their domains spaces in the mid latitudes, which means their phase states are influenced too strongly by subtropical/tropical forcing. 

 

Sure ok, but clearly there are many cases when the WPO is negative and the EPO positive. For example, this lovely MJO phase 5 composite which leads to absolute CONUS torch.........

 

[DTWXRISK]

 

 

[needbiggerboat]

Drew, how is that a "winner" for US? Haven't you seen the jB's tweets on the coming doom and expensive cold wave?

[Jonger]

Hopes of a warm winter verifying are donezo.

[The_Global_Warmer]

Hopes of a warm winter verifying are donezo.

 

Who hoped for a warm winter?