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https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO

PDO is still hanging around +1 on the JISAO methodology -

2019-01-01T00:00:00Z    0.66
2019-02-01T00:00:00Z    0.46
2019-03-01T00:00:00Z    0.37
2019-04-01T00:00:00Z    1.07
2019-05-01T00:00:00Z    1.03
2019-06-01T00:00:00Z    1.09
2019-07-01T00:00:00Z    1.03

I got a response about the Jamstec Modoki data from Toru Miyama. On the link he gives, you can download the data. The Modoki value for the 2018-19 winter was +0.51, below 2009, 1968 and the other most Modoki winters. It was actually around +0.4 in Dec-Jan, but instead of lowering in February as my analogs had, it increased, which is why February went kind of nuts for the Plains (coldest month in Billings since 1936). The year I double weighted for the 2018-19 forecast, 1994-95, did have a Modoki value virtually identical to last winter, so I think the blend I had was pretty decent for the tropical pacific. 

 

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ENSO region 4 has cooled in the past week and is at its coolest since a month ago:

nino4.png

Likely due to a strong burst of easterly wind stress. The GFS forecast of a burst of westerly wind stress could help to bring the temperatures back up again:

u_anom_30.5S-5N.thumb.gif.811ea6e34eab724f20d78385d4311c9b.gif

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The August Jamstec has gone back to near-El Nino conditions again for winter, about 0.5C lower than what it forecast last August for 2018-19, when it correctly had the ONI peak around +1.0 (it was +0.9C).

Even so, the US is not depicted as particularly cold anywhere. The latest run has the East Coast slightly cold, the rest of the US warm. 

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I was kind of surprised at how close 2004 has been for SSTs globally for the past month. Fairly strong match for local weather here since Spring too. My hunch is the blue area off South America expands, and the deep reds by 180W shrink somewhat. PDO zone will likely fill in red around 180W too, as the waters by Alaska cool a bit, relative to normals.

Image

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Looking historically, it is fairly rare to get extended -NAO streaks (-0.3 or lower for more than three months). Will be interesting to what happens. August will be month four. If you match up the difference in the monthly NAO for May-Apr and Sept-Mar ahead of a given winter, you can usually get a pretty good sense of what the NAO will do in winter. The May-Apr and Sept-Mar readings last year for the NAO were near identical to 1975-76, a year near the solar minimum that had a positive NAO during winter. Will be interesting to see what September finishes with for the monthly NAO-reading. 

NAO Sept-Mar May-Apr DJF
1975 2.17 1.08 0.23
2018 2.60 0.88

0.50

I'm assuming the -NAO stays in September, but it comes up toward 0. If that is the case, 2017 and 1994 might be a good blend for the NAO in 2019. I selected these time periods because they have fairly high correlations to winter (each has an r-square near 0.1 individually for 1950-2018), and Sept/Mar represent the highest/lowest points for Atlantic heat, and May is usually a good indicator for how the Spring/Summer will setup in the Atlantic. 

1994 -2.58 -1.71 1.36
2017 -1.35 -3.64 1.30
Mean -1.97 -2.68        1.33
2019 -1.80 -3.09  

The subsurface is still pretty cold east of 120W, and even in the western part of Nino 3.4, there is a fair amount of cool water below the thin warm patch near the surface.

Equatorial Pacific Temperature Depth Anomalies Animation

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Maybe another back-loaded winter. Thanks for that research. Some Pacific help could mean a bit more of a favorable early season regime for the east coast relative to last season, though. IOW, while we may have to wait on any NAO help until later in the season, I think the PDO will be higher.

 

 

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Historically, out of every 3 month period from 1950-2018, only 8.7% see a -NAO (at or below -0.3) each month. The four month streaks are somewhat rarer (5.0%), and by six months it is down to 1.5% historically. So the NAO is fairly likely to go neutral/positive in Sept or Oct, which would be months five or six of the -NAO streak.

The math in winter is the same - 6/69 winters (8.7%) of Dec-Feb periods see each month at -0.3 or less.

My hunch is there is a big -NAO winter (overall maybe not each month) coming in the next two-three years, but I don't know that it is this one. I'd guess 2020-21, but we'll see. The 12 month sunspot mean was 5.5 for July 2018-June 2019, and we got down to 2.3 for July 2008-June 2009, centered around early 2009 for the absolute min. So early 2020 is the target with the current cycle, and then maybe a -NAO winter after that, like in 2009-10.

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14 hours ago, 40/70 Benchmark said:

What does this have to do with episodes of PNA during boreal winter?

The PAC jet is still raging due to Pacific Warmth spreading poleward and subsequently expanding Hadley Cells and strengthening the mid-Latitude cell (Pacific Jet). This isn't new, though. The Pacific overall has been warm for the past couple years to a decade. The question is how will the strong Pacific jet trend and/or affect the upcoming winter. Last year the Pacific was so hostile. Could we see a repeat?

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4 hours ago, Newman said:

The PAC jet is still raging due to Pacific Warmth spreading poleward and subsequently expanding Hadley Cells and strengthening the mid-Latitude cell (Pacific Jet). This isn't new, though. The Pacific overall has been warm for the past couple years to a decade. The question is how will the strong Pacific jet trend and/or affect the upcoming winter. Last year the Pacific was so hostile. Could we see a repeat?

I hope not...Could you clarify what you meant by "this isn't new"? Certainly the PAC hasn't been hostile all decade, right?

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1 minute ago, Maestrobjwa said:

I hope not...Could you clarify what you meant by "this isn't new"? Certainly the PAC hasn't been hostile all decade, right?

Courtesy to Isotherm, he and I had a small conversation on the disruption of the global jet stream patterns due to the emergence of changing Hadley Cell and Mid-Latitude Cell circulations. As SSTs continue to warm poleward due to the background state and changing climate, we see more convection which acts to disrupt the typical Hadley Cell circulations we know. Typically we see rising air at the ITCZ which spreads poleward and subsides around 30N which creates the Horse Latitudes. With convection being able to fire further north, the Hadley Cell circulations expand which create stronger gradients and subsequently strengthen the mid-Latitude cells. For the United States, that means the Pacific Jet stream becomes stronger. What I mean as "this isn't new" is the warmth of the Pacific and overall global oceans. We've seen warmth of our oceans for awhile now. However, are we finally entering the critical time where we truly do start to see global jet stream changes? Are winters going to be the same again? Or will we see more variability resulting in bigger and more extreme winter events? Have we already seen those changes? I don't know the answers to those questions, but I do know that in theory the global jet stream patterns should be or have already changed in the changing climate.

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4 hours ago, Newman said:

The PAC jet is still raging due to Pacific Warmth spreading poleward and subsequently expanding Hadley Cells and strengthening the mid-Latitude cell (Pacific Jet). This isn't new, though. The Pacific overall has been warm for the past couple years to a decade. The question is how will the strong Pacific jet trend and/or affect the upcoming winter. Last year the Pacific was so hostile. Could we see a repeat?

Thanks for the clarification.

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5 hours ago, Newman said:

The PAC jet is still raging due to Pacific Warmth spreading poleward and subsequently expanding Hadley Cells and strengthening the mid-Latitude cell (Pacific Jet). This isn't new, though. The Pacific overall has been warm for the past couple years to a decade. The question is how will the strong Pacific jet trend and/or affect the upcoming winter. Last year the Pacific was so hostile. Could we see a repeat?

Thanks for the clarification.

Maybe I am wrong, but I did not see the issue, at least not predominately, as a 2001-2002 type relentless PAC firehose that eradicates N America of cold, last year. We had plenty of cold, but in the absence of a pos PDO, the cold dumped west, and with no Atl blocking, there was nothing to hold it and prevent storms from displacing it.

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One thing about this winter that may be different from last year - the MJO has been kind of dead for a while. If it locks in as dead, the temporary incredible cold shots and heat waves that dominated last winter seem less likely - more consistent weather through the whole winter.

The pattern of late (cold middle) has been remarkably consistent, this August still looks a lot like last August in most of the US, and the Plains had the severe fall/winter/spring too.

VLIx6aJ.png

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                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA
 24JUL2019     21.1-0.2     25.5 0.0     27.6 0.4     29.8 1.0
 31JUL2019     20.6-0.5     25.2-0.2     27.5 0.5     29.8 1.0
 07AUG2019     20.3-0.6     25.3 0.1     27.3 0.4     29.6 0.9
 14AUG2019     20.0-0.7     24.7-0.3     27.0 0.1     29.5 0.8

Nino 4 is near record warm for August - 29.77C in 2015 is the highest it has been measured. I think it will finish around 29.55C in 2019.

We're "behind" (warmer) El Nino to La Nina years in Nino 4- so I remain in camp Neutral at this point, as Nino 4 will be able to fight off pulses of cold from the East and subsurface. The past month is like 2018 (Western areas) and 2017 (Eastern areas).

 26JUL1995     20.8-0.5     25.1-0.3     26.8-0.3     28.6-0.1
 02AUG1995     20.3-0.8     24.8-0.5     26.7-0.3     28.5-0.2
 09AUG1995     19.9-1.0     24.3-0.8     26.3-0.6     28.3-0.4
 16AUG1995     20.0-0.7     24.3-0.7     26.4-0.4     28.5-0.2
 29JUL1998     23.2 2.0     24.9-0.5     25.7-1.4     27.8-1.0
 05AUG1998     22.6 1.7     24.8-0.4     25.6-1.4     27.9-0.8
 12AUG1998     21.8 1.1     24.6-0.5     25.5-1.4     27.8-0.9
 27JUL2005     20.8-0.5     25.4 0.0     27.1 0.1     28.9 0.1
 03AUG2005     20.8-0.2     25.2-0.1     26.9-0.1     28.8 0.1
 10AUG2005     20.6-0.2     25.2 0.1     26.9 0.0     28.7 0.0
 17AUG2005     20.4-0.2     25.4 0.4     27.0 0.2     28.9 0.2
 25JUL2007     20.3-1.0     24.5-1.0     26.6-0.5     28.9 0.1
 01AUG2007     19.6-1.5     24.1-1.2     26.4-0.6     28.7 0.0
 08AUG2007     19.3-1.6     23.8-1.3     26.2-0.7     28.6-0.1
 15AUG2007     19.7-1.0     24.0-1.0     26.3-0.6     28.6-0.1
 28JUL2010     19.5-1.7     24.0-1.4     25.6-1.4     27.8-1.0
 04AUG2010     19.5-1.5     24.0-1.3     25.8-1.2     27.7-1.0
 11AUG2010     19.6-1.2     24.1-1.0     25.7-1.2     27.5-1.2
 18AUG2010     19.2-1.4     23.8-1.1     25.6-1.2     27.5-1.1
 26JUL2017     21.3 0.0     25.5 0.1     27.1 0.0     28.9 0.2
 02AUG2017     20.9-0.1     25.4 0.1     27.2 0.2     28.9 0.2
 09AUG2017     20.5-0.3     25.1 0.0     26.7-0.2     28.7 0.1
 16AUG2017     19.9-0.7     24.5-0.5     26.4-0.5     28.8 0.1
 25JUL2018     21.1-0.3     25.8 0.3     27.4 0.3     29.0 0.3
 01AUG2018     21.2 0.1     25.3 0.0     27.1 0.1     29.1 0.4
 08AUG2018     20.8-0.1     25.1-0.1     27.1 0.2     29.2 0.5
 15AUG2018     20.9 0.2     25.4 0.4     27.3 0.4     29.5 0.8

Long term, Nino 4 is warmth pretty strongly correlated to a cold October. It is a warm signal for the West and North in September - but weak.

Image

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On 8/18/2019 at 1:04 PM, 40/70 Benchmark said:

Thanks for the clarification.

Maybe I am wrong, but I did not see the issue, at least not predominately, as a 2001-2002 type relentless PAC firehose that eradicates N America of cold, last year. We had plenty of cold, but in the absence of a pos PDO, the cold dumped west, and with no Atl blocking, there was nothing to hold it and prevent storms from displacing it.

Yep...there was plenty cold over the CONUS, just not for most of the posters in here....pretty classic gradient with SE ridge in the east actually.

 

 

2018-2019 temps.png

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On 8/18/2019 at 12:18 PM, Newman said:

Courtesy to Isotherm, he and I had a small conversation on the disruption of the global jet stream patterns due to the emergence of changing Hadley Cell and Mid-Latitude Cell circulations. As SSTs continue to warm poleward due to the background state and changing climate, we see more convection which acts to disrupt the typical Hadley Cell circulations we know. Typically we see rising air at the ITCZ which spreads poleward and subsides around 30N which creates the Horse Latitudes. With convection being able to fire further north, the Hadley Cell circulations expand which create stronger gradients and subsequently strengthen the mid-Latitude cells. For the United States, that means the Pacific Jet stream becomes stronger. What I mean as "this isn't new" is the warmth of the Pacific and overall global oceans. We've seen warmth of our oceans for awhile now. However, are we finally entering the critical time where we truly do start to see global jet stream changes? Are winters going to be the same again? Or will we see more variability resulting in bigger and more extreme winter events? Have we already seen those changes? I don't know the answers to those questions, but I do know that in theory the global jet stream patterns should be or have already changed in the changing climate.

Really ...

Not looking for credit per se ... but, I haven't heard about the gradient hypothesis from anyone other than the person who proposed it five years ago ... and has been heavier about it over the last two.  Now, it's owned by someone else -

Heh... I suppose - fire was quasi implemented as a formal tool in human history at the same time every, too, so ...it's possible more than one person had the exact same to the letter ...inference regarding climate variations and large scale circulation forcing - 

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25 minutes ago, Typhoon Tip said:

Really ...

Not looking for credit per se ... but, I haven't heard about the gradient hypothesis from anyone other than the person who proposed it five years ago ... and has been heavier about it over the last two.  Now, it's owned by someone else -

Heh... I suppose - fire was quasi implemented as a formal tool in human history at the same time every, too, so ...it's possible more than one person had the exact same to the letter ...inference regarding climate variations and large scale circulation forcing - 

From 2009, talking about changing global circulations including Hadley Cell/Mid-Latitude Cell disruptions, etc.:

http://www.inscc.utah.edu/~reichler/publications/papers/Reichler_09_Widening.pdf

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54 minutes ago, Newman said:

From 2009, talking about changing global circulations including Hadley Cell/Mid-Latitude Cell disruptions, etc.:

http://www.inscc.utah.edu/~reichler/publications/papers/Reichler_09_Widening.pdf

I don't doubt there is/was relevant science and/or postulate content that predates the shenanigans that go in here   :)   

I mean ..it's a public forum ... to which a social media outlet certainly qualifies, and folks rarely cite their sources, anyway.  

That said ... this came up back in Eastern days... from which this site really owes it's heredity of users ... (initially anyway ...that's probably obscured by now), but unfortunately, content didn't follow.   

Also, I frankly wouldn't put it past anyone in the general ambit of research ... regardless of affiliation and rank, elsewhere ...to poach ideas from dialectical free-for-all sources ( like the Web when it's not degrading into vitriol ) and then run with it using the wherewithal they have at their disposal. 

Much of that wouldn't even be malfeasance ... not the point.  If I'm in a conversation with someone and it triggers a thought progression...and I science it and make discoveries... It's just where the 'idea zygote' took place. 

But like I said...like mindful quorums and consortia and who-knows-what intelligentsia ... they will tend to converge on similar ideas at the same time - this has taken place throughout human history.  I probably shouldn't have mentioned it as an afterthought .. .

 

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Se1yFOB.jpg

The scale is different in 2019, but it looks to me like the coolness in Nino 1.2/3 will peak in Fall, and then warm. The warmth in Nino 3.4/4 looks like it it will persist in fall, and then cool.

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In Albuquerque, we're going to be at six days with a high of 95F or hotter in the 8/15-9/30 period by the end of tomorrow. That's pretty rare since 1931. The composite of the six years to have that much heat late include two years after an El Nino - 1983, 1973, and also 1945, 1948, 1979 and 2011. Composite looks like this -

Image

1936 was a year with major heat waves in the US during Summer, and had the warm pool off Alaska with a cold Nino 1.2 - probably one of the better matches to this year pre-1950, but way too cold in Nino 4. August is starting to finally move away from Nino 3.4 warmth but it has been pretty slow.

Image

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2 minutes ago, AfewUniversesBelowNormal said:

N Pacific pattern doesn't match subsurface data again.. this first happened in March or May 2018. 

That's why last winter predictions busted so badly and is going to cause forecasting very challenging this winter. 

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