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2012 ENSO Thread


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I had a good WAG last year, so I'll take a shot this year.

My guess for ASO ONI is borderline neutral warm (+0.3-+0.5), and a little higher for DJF (+0.7-+0.9). We have seen a significant rise in ENSO 3.4, but that should level off in the short term, and maybe even cool a little, but I think we'll start to see some weak WWBs in Spring.

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I had a good WAG last year, so I'll take a shot this year.

My guess for ASO ONI is borderline neutral warm (+0.3-+0.5), and a little higher for DJF (+0.7-+0.9). We have seen a significant rise in ENSO 3.4, but that should level off in the short term, and maybe even cool a little, but I think we'll start to see some weak WWBs in Spring.

I agree for ASO... DJF seems sketchy. Cold PDOs have often featured third year Ninas, though the sample size isn't large. Descending -QBO would favor a Nina, too, wouldn't it?

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I agree for ASO... DJF seems sketchy. Cold PDOs have often featured third year Ninas, though the sample size isn't large. Descending -QBO would favor a Nina, too, wouldn't it?

Yeah, being in the cold phase of the PDO could throw a wrench in there, but what made me lean toward continued strengthening is that those 3 year Ninas usually were stronger during the 2nd year (1955-56, 1999-2000) or cooling during the spring (1974-75), which I don't expect this year.

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I'll say a weak Nino by late summer/early fall, with it possibly continuing to strengthen through the winter. How strong is certainly unknown at this point, but I think there is a fair chance it does get stronger than "weak".

The signs already pointed out in this thread are screaming that we are approaching a Nino.

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In Atlanta, there's no doubt that a weak El Nino is the most favorable ENSO phase as far as good cold/snow chances are concerned. Out of the 16 weak Nino's since the late 1800's, a whopping 13 averaged below the mean for DJF while only two were above. Nine of the 16 were at least two below normal and five of the 16 were very cold with five or more below normal. Only one of the 16 was two or more above normal and none were five or more above normal. The 16 together averaged nearly three below the normal for DJF!

Regarding S/IP, the 16 averaged nearly 3" vs. the longterm avg. of 2". Half of the 16 had 3.5"+ of S/IP. That compares to only a little over 25% of all winters on record having 3.5"+. So, that's pretty impressive. Major ZR storms occurred near the longterm avg. frequency. Needless to say, I'd love to see a weak Nino. I define weak as a Nino peak of no more than a +1.0 C anomaly trimonthly peak.

Edit: About one in every eight winters is a weak Nino.

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Yeah, being in the cold phase of the PDO could throw a wrench in there, but what made me lean toward continued strengthening is that those 3 year Ninas usually were stronger during the 2nd year (1955-56, 1999-2000) or cooling during the spring (1974-75), which I don't expect this year.

Thus far this La Nina regime has resembled the 1974-75 La Nina regime quite well and weather patterns as well.

If we observe some cooling in the Spring then my confidence will grow more towards another Nina regime next year but at this point in time I'm leaning towards a neutral ENSO. The PDO has been quite negative since last summer and remains persistent.

Models show a return of Low level Easterlies primarily across the central-western ENSO regions with the Kelvin Wave weakening out.

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I'm more interested in the NAO/AO state next winter honestly than anything. It seems every time the last 8-10 years we thought we were entering a long term negative phase of those indices we had a winter with a raging positive outcome for one or both. I'm beginning to think much like the winters as a whole we're going into a more volatile state of the AO/NAO than we are a persistently negative one.

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In Atlanta, there's no doubt that a weak El Nino is the most favorable ENSO phase as far as good cold/snow chances are concerned. Out of the 16 weak Nino's since the late 1800's, a whopping 13 averaged below the mean for DJF while only two were above. Nine of the 16 were at least two below normal and five of the 16 were very cold with five or more below normal. Only one of the 16 was two or more above normal and none were five or more above normal. The 16 together averaged nearly three below the normal for DJF!

I posted this in the meteorology 101 forum, but why does this happen? What is it about a weak ENSO that makes us so cold? Surely the NAO/AO cant have been negative for all those years, so the tropics must have played some role..right?

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I posted this in the meteorology 101 forum, but why does this happen? What is it about a weak ENSO that makes us so cold? Surely the

NAO/AO cant have been negative for all those years, so the tropics must have played some role..right?

Yes IMHO. I will post a detailed post later allowing me to make this conclusion.

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I'm more interested in the NAO/AO state next winter honestly than anything. It seems every time the last 8-10 years we thought we were entering a long term negative phase of those indices we had a winter with a raging positive outcome for one or both. I'm beginning to think much like the winters as a whole we're going into a more volatile state of the AO/NAO than we are a persistently negative one.

I'm in full agreement here. The NAO came in @ +2.52 (winter record) in December and +1.17 for January. Feb is a lock for a + monthly reading too. November was also + coming in at 1.36. If Feb comes in @ +1.0 or higher it will be the first time since 1950 that the 4 month stretch registered +1.0 or higher each month.

I invested some time this winter into researching the AO and there definitely a connection with a strong +AO in Dec and a warm winter overall. I'm just now started to do the same thing with the NAO. The NAO is much more volitile than the AO but based on what I saw this winter, I would say that it was the NAO that decided to cancel winter on this side of the globe moreso than the AO (the AO did plenty of damage though).

Dataset is small but there seems to be a pattern with -NAO Decembers. There have been 6 occurances of 3 or 4 year stretches of -NAO Decembers. I'm using the negative definition pretty loosely though and not setting the bar at a minimum. After each multi year stretch, a minimum of the next 2 Decembers came in positive. Following months are mixed. Probably means nothing but there is a pattern in the numbers at least.

There are a couple NAO analogs to this year where the index was positive from Nov - Feb: 93-94, 94-95. & 99-00. 82-83 isn't bad either. Anyway, I know all this stuff is off topic but I agree that the teleconnections are probably more important than enso to some extent.

Looking at previous multi year ninas makes it hard to decide which direction we go next year. 74-75 is a good match for this year but the nina held firm through the spring and summer of 75 and ended up going mod-strong in winter 75-76. Doesn't seem likely this year. The Nino's following multi year Nina's are pretty much in focus by the AMJ tri-monthly reading. Looking at the whole list of Nina's, 01-02 doesn't seem like a bad choice for an analog for the upcoming winter. Almost seems like equal chances for any outcome.

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I posted this in the meteorology 101 forum, but why does this happen? What is it about a weak ENSO that makes us so cold? Surely the NAO/AO cant have been negative for all those years, so the tropics must have played some role..right?

Yes, I say that the tropics, indeed, played a key role. Here is why I say this:

2/23/12: 11 Coldest (back to 1879-80) KATL Winters’ ENSO/PDO/NAO/AO

Winter……DJF Temp Anom…ENSO……..PDO*………NAO**….…AO***

1) 1976-7……….…..-7.6…………WEN…....+1.5………..-1.7………..-1.8

2) 1977-8…………...-6.2…………WEN…….+0.7……….-1.1………..-0.5

3) 1904-5……………-5.8………...WEN…….+1.3……….+0.8……….+0.8

4) 1962-3……………-5.8…………WLN……..+0.0……….-1.6………..-0.7

5) 1935-6……………-5.7………….NP………+1.5………-2.0………..-2.4

6) 1963-4……………-5.7…………WEN…….+0.4………-1.6………..-0.7

7) 1939-40………….-5.5…………WEN……..+1.7……...-1.9………..-1.9

8) 1901-2…………...-5.4………….NN………+1.5………-0.7………..-0.5

9) 2009-10………….-4.4…………SEN……..+0.1……..-2.9…………-2.6

10) 1885-6………….-4.3…………WEN……..+0.8……..-0.6…………N/A

11) 1969-70…….…..-4.1………….WEN……..+1.2…….-1.1…………-1.8

Findings:

A very impressive 7 of the 11 coldest (of the 133 winters) and 3 of the 4 coldest were weak Nino’s. Only about 1 in 8 winters is a weak Nino. So, only about 1-2 of the 11 coldest would be the “expected value” if there were no bias of weak Nino’s toward either warm or cold.

The PDO was positive for all 11 (1962-3 was barely above zero).

The NAO was -0.6 or more negative for all but one, 1904-5.

The AO was -0.5 or more negative for all but one, 1904-5. (I couldn’t find the AO for 1885-6.)

Based on the above stats, I’m fully aware that one can make the argument that it was the +PDO/-NAO/-AO combo that was a big reason for the cold for all but 1904-5. However, one could make the argument that the weak Nino phase, itself, also had a major influence. I’ll now explain:

I looked at all winters back to 1879-80 and found 26 that had the +PDO/-NAO/-AO combo, including the 9 noted above from the 11 coldest. A total of 6 of those 26 were weak Nino’s. An impressive 5 of those 6 weak Nino’s (83%) were within the 11 coldest. OTOH, 20 of those 26 +PDO/-NAO/-AO winters were NOT weak Nino’s. Only 4 of those 20 that were +PDO/-NAO/-AO and that weren’t weak Nino’s (20%) were within the 11 coldest. Furthermore, 10 of the 26 were moderate to strong Nino’s. Of those 10 mod. to strong Nino’s with +PDO/-NAO/-AO, only one of the 10 (10%) (2009-10) was within the 11 coldest.

So, to summarize regarding +PDO/-NAO/-AO winters since 1879-80:

- A whopping 83% of the weak Nino’s were in the 11 coldest

- Only 10% of the mod. to strong Nino’s were in the 11 coldest

- Only 20% of all winters that weren’t weak Nino’s were in the 11 coldest

- 40% of weak Nino’s and 47% of moderate to strong Nino’s since 1899-1900 were +PDO/-NAO/-AO….i.e., fairly similar %’s. Yet, weak Nino’s were much colder on average than moderate to strong Nino’s as a whole.

- Conclusion:

The weak Nino phase, itself, has a strong cold tendency for Atlanta independent of the cold tendency resulting from +PDO/-NAO/-AO. The moderate to strong Nino phase lacks this independent strong cold tendency.

---------------------------------------------------------------------------------------------------------------------------------------------------------

*PDO is DJF. 2/2010 was estimated based on this site:

http://jisao.washing.../pdo/PDO.latest

**NAO is DJF. I used a different data source for 1885-6

***AO is DJFM for all since that’s all I could find for pre-1950 and wanted all to be from same source

Datasources:

1) ENSO:

1950+ http://www.cpc.ncep....ensoyears.shtml

Prior to 1950 http://www.cgd.ucar....limind/TNI_N34/

2) DJF PDO:

ftp://ftp.ncdc.noaa.....1854.latest.ts

3) DJF NAO:

All but 1885-6: https://climatedatag.../nao_pc_djf.txt

1885-6:

http://www.cru.uea.a...ata/nao/nao.dat

4) DJFM AO: https://climatedatag...nam_pc_djfm.txt

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I agree for ASO... DJF seems sketchy. Cold PDOs have often featured third year Ninas, though the sample size isn't large. Descending -QBO would favor a Nina, too, wouldn't it?

I think I'm in agreement that the La nina could fade or even become a weak El nino and yet still

resume La nina conditions during winter '12 -'13.

I read that the consensus is the equatorial Pacific spends much time near neutral while another school of

thought insists that the equatorial Pacific exists in a state of forced choice where it is either in El nino state

or La nina with no true neutral.

Ideas in support of El nino rallying:

increasing sunspot state,

recent decadonal trends of shorter length La ninas and

multi-ENSO region warming (all but region 4)

Some thoughts from NWS climate site:

  • Is there such a thing as "normal", aside from El Niño and La Niña?*
  • Over the long-term record, sea-surface temperatures in the central and eastern tropical Pacific diverge from normal in a roughly bell-curve fashion, with El Niño and La Niña at the tails of the curve. Some researchers argue there are only two states, El Niño and non-El Niño, while others believe either El Niño or La Niña is always present to a greater or lesser degree. According to one expert, NCAR's Kevin Trenberth, El Niños were present 31% of the time and La Niñas 23% of the time from 1950 to 1997, leaving about 46% of the period in a neutral state. The frequency of El Niños has increased in recent decades, a shift being studied for its possible relationship to global climate change.

  • How often does La Niña occur?
  • El Niño and La Niña occur on average every 3 to 5 years. However, in the historical record the interval between events has varied from 2 to 7 years. According to the National Centers for Environmental Prediction, this century's previous La Niñas began in 1903, 1906, 1909, 1916, 1924, 1928, 1938, 1950, 1954, 1964, 1970, 1973, 1975, 1988, and 1995. These events typically continued into the following spring. Since 1975, La Niñas have been only half as frequent as El Niños

  • How long does a La Niña last?
  • La Niña conditions typically last approximately 9-12 months. Some episodes may persist for as long as two years.

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Thanks, Don!

To further illustrate my point, there have been 26 DJF's since 1899-1900 with a known +PDO/-NAO/-AO. Note these Atlanta temperature anomalies:

1) 6 Weak Nino's: all 6 had neg. anomalies that averaged a very impressively cold -5.0 F. A whopping 5 of 6 very cold.

2) 10 mod. to strong Nino's: 8 had neg. anom.'s and 2 had pos. anom.'s. The ten averaged -1.3 F. Only 1 of 10 very cold.

3) 6 neutral ENSO's: 3 had neg. anom.'s and 3 had pos. anom.'s. The 6 averaged -1.2 F. 2 of 6 very cold.

4) 4 Nina's: 2 had neg. anom.'s and 2 had pos. anom.'s. The 4 averaged -1.3 F. 1 of 4 very cold.

In summary for Atlanta, whereas the 6 weak Nino's averaged a very cold -5.0 F and 5 of 6 were very cold including the 2 coldest on record, the 20 others averaged only a modestly cold -1.3 F or about 25% of the weak Nino's negative anomaly magnitude and only 4 of 20 were very cold. So, it is quite evident to me that the weak Nino state, itself, is associated with a strong tendency toward cold winters at Atlanta that tends to pile onto the cold that tends to already be associated with +PDO/-NAO/-AO and is unlike any other ENSO state including stronger Nino's. In other words, nothing comes close to beating the weak Nino/+PDO/-NAO/-AO combo coldwise.

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Today's released weekly 3.4 SST negative anom. shows a reduction from -0.6 the prior week to the latest week's -0.4. It was -1.2 just three weeks back. This virtually insures that DJF won't be colder than -1.0, thus almost insuring that this La Nina peak will verify as a weak one based on common definitions. Actually, DJF could easily be -0.9 or perhaps even -0.8 making the trimonthly peak -0.9.

Fwiw (probably not much predictive power right now), the four regions are warmer than they were one year ago with 3.4 being 0.8 warmer. Region 3 is 0.9 warmer. It is still anyone's guess what next fall/winter will bring ENSOwise.

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Thanks, Don!

To further illustrate my point, there have been 26 DJF's since 1899-1900 with a known +PDO/-NAO/-AO. Note these Atlanta temperature anomalies:

1) 6 Weak Nino's: all 6 had neg. anomalies that averaged a very impressively cold -5.0 F. A whopping 5 of 6 very cold.

2) 10 mod. to strong Nino's: 8 had neg. anom.'s and 2 had pos. anom.'s. The ten averaged -1.3 F. Only 1 of 10 very cold.

3) 6 neutral ENSO's: 3 had neg. anom.'s and 3 had pos. anom.'s. The 6 averaged -1.2 F. 2 of 6 very cold.

4) 4 Nina's: 2 had neg. anom.'s and 2 had pos. anom.'s. The 4 averaged -1.3 F. 1 of 4 very cold.

In summary for Atlanta, whereas the 6 weak Nino's averaged a very cold -5.0 F and 5 of 6 were very cold including the 2 coldest on record, the 20 others averaged only a modestly cold -1.3 F or about 25% of the weak Nino's negative anomaly magnitude and only 4 of 20 were very cold. So, it is quite evident to me that the weak Nino state, itself, is associated with a strong tendency toward cold winters at Atlanta that tends to pile onto the cold that tends to already be associated with +PDO/-NAO/-AO and is unlike any other ENSO state including stronger Nino's. In other words, nothing comes close to beating the weak Nino/+PDO/-NAO/-AO combo coldwise.

Nice research. I put together a list of the 20 coldest weeks in NYC since 1960 and the Nino 3.4 temperatures.

16 out of the 20 coldest weeks were during weak or neutral ENSO phases. The most recent week to make the

list back in 2005 was a weak Nino.

Week/Average Temperature(F)/Nino 3.4

1/6-1/12........1968....12.2..-0.7

2/12-2/18......1979....12.7..0.0

1/15-1/21......1994....13.9..0.2

1/20-1/26......1961....15.5..-0.2

1/12-1/18.....1977.....15.9..0.6

1/8-1/14........1981....16.4..-0.5

12/21-12/27...1989....16.7..-0.1

1/18/-1/24......2005....17.1..0.7

1/28-2/3........1961.....17.2..-0.2

1/10-1/16......2004.....17.4...0.4

1/12-1/18......1982.....17.6..0.0

1/18/-1/24.....1976.....18.1..-1.6

1/28/-2/3.......1971.....18.2..-1.3

1/19-1/25......1970.....18.4..0.5

2/1-2/7..........1996.....18.6..-0.7

1/18-1/24.......2003....18.7..1.2

1/23-1/29.......2004....18.9..0.4

1/15-1/21.......1971....19.1..-1.3

1/14-1/20......1965.....19.4..-0.8

2/5-2/11........1979.....19.5..0.0

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Nice research. I put together a list of the 20 coldest weeks in NYC since 1960 and the Nino 3.4 temperatures.

16 out of the 20 coldest weeks were during weak or neutral phases. The most recent week to make the

list back in 2005 was a weak Nino.

Week/Average Temperature(F)/Nino 3.4

1/6-1/12........1968....12.2..-0.7

2/12-2/18......1979....12.7..0.0

1/15-1/21......1994....13.9..0.2

1/20-1/26......1961....15.5..-0.2

1/12-1/18.....1977.....15.9..0.6

1/8-1/14........1981....16.4..-0.5

12/21-12/27...1989....16.7..-0.1

1/18/-1/24......2005....17.1..0.7

1/28-2/3........1961.....17.2..-0.2

1/10-1/16......2004.....17.4...0.4

1/12-1/18......1982.....17.6..0.0

1/18/-1/24.....1976.....18.1..-1.6

1/28/-2/3.......1971.....18.2..-1.3

1/19-1/25......1970.....18.4..0.5

2/1-2/7..........1996.....18.6..-0.7

1/18-1/24.......2003....18.7..1.2

1/23-1/29.......2004....18.9..0.4

1/15-1/21.......1971....19.1..-1.3

1/14-1/20......1965.....19.4..-0.8

2/5-2/11........1979.....19.5..0.0

here are the winters coldest 30 day periods and DJF enso...

winter.....coldest 30 days...DJF enso...

1976-77.......21.9.......0.6

1980-81.......22.2......-0.3

2003-04.......22.5.......0.4

1993-94.......23.5.......0.2

1969-70.......24.0.......0.5

1970-71.......24.2......-1.3

1960-61.......24.6......-0.2

1967-68.......25.1......-0.7

1981-82.......25.2.......0.0

1989-90.......25.3.......0.1

2006-07.......25.8.......0.8

1962-63.......25.9......-0.6

2002-03.......25.9.......1.2

1978-79.......26.0......-0.1

1983-84.......26.1......-0.4

1977-78.......26.2.......0.6

1999-00.......26.2......-1.6

1975-76.......27.1......-1.6

1984-85.......27.5......-0.9

1955-56.......27.6......-1.3

1995-96.......27.7......-0.7

1956-57.......27.8......-0.5

2008-09.......27.9......-0.8

1964-65.......28.0......-0.8

1957-58.......28.1.......1.7

2010-11.......28.1......-1.3

..............................................................................................................................................................................

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  • 4 weeks later...

At the very least, this MJO pulse ought to kill off the Nina through the spring and summer. Obviously, it's looking more Nino for fall/winter right now, but a lot of people thought that last year at this time, too.

Pretty large westerly wind event now (time sensitive):

WMBas270.png

Agree that it is certainly the end of La Nina, and to me, it heralds the arrival of El Nino in a few months. I say this because the tropical forcing is expected to remain in Phase space 7/8 for quite some time if you believe the forecasts. This should cause a significant oceanic Kelvin wave, and a large increase in eastern EPac SSTs within 4-6 weeks.

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Bluewave,

Thanks for the research! Interesting.

Local statistician at KHOU-TV 11 forum ("Ptarmigan") did similar research. El Niño years following Niña years tend to be some of the most interesting Winters in SETX.

Waiting for sunshine and onshore flow to return.

No fun-derstorms in the immediate future' date=' but the SST loop from AOML, March 10 through March 19th, killed all the sub 20ºC shelf water, and reduced most of the sub 21º shelf water. Yesterdays rain and clouds and runoff might set us back a bit, and I wish the Mexican highlands would have gotten more rain this late Winter, for an even cooler and more humid (ie, weaker) capping inversion, but I think, if it comes, we have built it, and this Spring won't be the dreadfully dull Cap Fest 2011 was. Maybe beyond the Day 10 range, animating the Euro ensembles from the ECMWF page we'll drift back into a stormy pattern.

And way long range, next Winter may be exciting. Now, fewer long tracked Atlantic storms, but really, we don't need something destroying freshly rebuilt vacation homes in Jamaica Beach this year, and, of course, a long tracked Atlantic storm that hits South of Miami as a Cat 5 and hits new Morgan City as a Cat 3 can still happen in a warm ENSO, and think of all the added cell phone and video cameras in Florida in the last 20 years.

http://www.ecmwf.int/products/forecasts/d/getchart/catalog/products/forecasts/seasonal/forecast/eurosip/nino_plumes_euro_public!3!201202!chart.gif

I think we could see an El Nino by the end of the year. Winters that occurred in years that went from La Nina to El Nino tend to be cold and some of the coldest on record.

La Nina To El Nino Years

1972

1976

2006

2009

Upper Texas Coast

1971-1972 58.37°F 103rd La Nina

1972-1973 51.03°F 10th El Nino

1973-1974 55.73°F 72nd La Nina

1974-1975 56.00°F 79th La Nina

1975-1976 55.63°F 69th La Nina

1976-1977 50.23°F 6th El Nino

1977-1978 48.90°F 1st El Nino

1978-1979 50.70°F 9th Neutral

1979-1980 54.00°F 38th Neutral

2001-2002 55.50°F 64th Neutral

2002-2003 53.90°F 35th El Nino

2003-2004 54.60°F 52nd Neutral

2004-2005 56.60°F 90th El Nino

2005-2006 56.20°F 82nd La Nina

2006-2007 54.17°F 43rd El Nino

2007-2008 57.47°F 99th La Nina

2008-2009 57.33°F 97th La Nina

2009-2010 49.63°F 3rd El Nino

2010-2011 54.03°F 39th La Nina

2011-2012 57.70°F 100th La Nina

Bold denotes La Nina to El Nino year.

Interesting to note for Houston, years that went from La Nina to El Nino produced some of the coldest winters on record. 1972-1973 had three snowfall events, while 2009-2010 had two snowfall events, including the earliest on record. The late 1970s was cold.

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Pretty large westerly wind event now (time sensitive):

Agree that it is certainly the end of La Nina, and to me, it heralds the arrival of El Nino in a few months. I say this because the tropical forcing is expected to remain in Phase space 7/8 for quite some time if you believe the forecasts. This should cause a significant oceanic Kelvin wave, and a large increase in eastern EPac SSTs within 4-6 weeks.

Agree, though I think it will be a very gradual process...probably not an El Niño until close to autumn. This WWB is not gonna weaken ENSO substantially, methinks, but could setup the table for a follow up wave in the time range you mention (4-6 weeks).

u.anom.30.5S-5N.png

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Agree, though I think it will be a very gradual process...probably not an El Niño until close to autumn. This WWB is not gonna weaken ENSO substantially, methinks, but could setup the table for a follow up wave in the time range you mention (4-6 weeks).

u.anom.30.5S-5N.png

You thinking weak Nino next Winter? Stronger?

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