ENSO Updates (2007 thru 2023)

[Ntxw]

Ntxw,trade winds are weak right now right? Do you think the final El Nino advisory was right to be released by CPC on June 9 or it was a little bit premature?

http://i.imgur.com/23YSTr2.png

Trades have been weak the first week of June. In fact it has been anomalous westerly. Another trade burst is coming though, they were right to end the Nino advisory as the weeklies no longer reflect them. La Nina is taking it's time though. As with any ENSO event, the longer they take to go the less likely they are to be big events. We just haven't seen the huge bursts of trades like in 1998/2007/2010

[stormwise]

First clear indication of a noticeable pressure rising over Tahiti with the incoming la-nina as it should be.

[Dean_175]

Trades have been weak the first week of June. In fact it has been anomalous westerly. Another trade burst is coming though, they were right to end the Nino advisory as the weeklies no longer reflect them. La Nina is taking it's time though. As with any ENSO event, the longer they take to go the less likely they are to be big events. We just haven't seen the huge bursts of trades like in 1998/2007/2010

Yes. In fact CFS is showing that subsurface anomalies are likely to get weaker near Nino3.4 late this summer. If we are going to see a moderate to strong La Nina, as opposed to a weak one- it would help to see some big easterlies now when there is a significant cool pool below the surface.

[Ntxw]

Warmed up to +0.1C this week

[cycloneye]

Text of CPC 6/13/16 update that has Nino 3.4 up to +0.1C.

http://www.cpc.noaa.gov/products/analys ... ts-web.pdf

[Hunabku]

Ntxw,trade winds are weak right now right? Do you think the final El Nino advisory was right to be released by CPC on June 9 or it was a little bit premature?

Seems that EPAC westerly winds were kicked in by our most recent MJO. With it gone, winds will get going easterly - for how much and how long is the key question.

We clearly can see how things heat up without the easterlies driving the currents. Look at all these hot pool eddies along the equator.

[cycloneye]

And the weak trade winds continue to cause the rise of the Nino 3.4 index.As of 12z on June 14 is up to El Nino category once again,this after CPC a few days ago issued their last El Nino advisory and said Neutral conditions are present.

[cycloneye]

ECMWF June forecast is at cool neutral for the peak of the North Atlantic season. Graphic from Phil Klotzbach.

[Ntxw]

Interesting the Euro has the peak of this Nina the next two months. In terms of ONI that may not be enough for official Nina. 5 trimonthlies, wouldnt it be crazy if cfsv2 scores a coup from months ago? PDO has definitely been a factor.

[Yellow Evan]

ENSO forecasts tend to be conservative around June and December. MJO should surge trades in a few weeks anyhow.

[Hunabku]

ECMWF June forecast is at cool neutral for the peak of the North Atlantic season. Graphic from Phil Klotzbach.
...

ECMWF has been showing July as the lowest for a while now - some dismissed it but I thought it might be accurate, especially given the relatively smaller size and minimal temp anomalies of the cold tongue. One thing to consider about the trades is that not only do they draw the cold tongue to the surface they also help to replenish or even grow it by bringing cooler water up from depth and hence extend the magnitude and length of the nina. I suspect ECMWF is picking up on atmospheric processes that are diminishing the trades.

These atmospheric responses are also the primary factors creating a +PDO, so it's important to remember that the PDO does not cause anything but rather is caused by a combination of processes - some of which directly connect to ENSO – especially the Aleutian Low.


from The Pacific Decadal Oscillation – revisited - see - [url]http://www.clivar.org/news/pacific-decadal-oscillation-–-revisited[/url]

… since much of the PDO represents the oceanic response to atmospheric forcing, care should be taken when using the PDO as a forcing function of non-oceanic responses without a convincing argument for the physical forcing mechanism.

Also see The Relationship Between the PDO and ENSO https://bobtisdale.wordpress.com/2014/04/20/the-201415-el-nino-part-5-the-relationship-between-the-pdo-and-enso/

[cycloneye]

The mid-June plume of ENSO models has as consensus (Yellow line) Weak La Nina thru ASO and beyond.

[Ntxw]

ECMWF June forecast is at cool neutral for the peak of the North Atlantic season. Graphic from Phil Klotzbach.
...

ECMWF has been showing July as the lowest for a while now - some dismissed it but I thought it might be accurate, especially given the relatively smaller size and minimal temp anomalies of the cold tongue. One thing to consider about the trades is that not only do they draw the cold tongue to the surface they also help to replenish or even grow it by bringing cooler water up from depth and hence extend the magnitude and length of the nina. I suspect ECMWF is picking up on atmospheric processes that are diminishing the trades.

These atmospheric responses are also the primary factors creating a +PDO, so it's important to remember that the PDO does not cause anything but rather is caused by a combination of processes - some of which directly connect to ENSO – especially the Aleutian Low.


from The Pacific Decadal Oscillation – revisited - see

… since much of the PDO represents the oceanic response to atmospheric forcing, care should be taken when using the PDO as a forcing function of non-oceanic responses without a convincing argument for the physical forcing mechanism.

Also see The Relationship Between the PDO and ENSO

These are good valid points. But we can also infer that cause or effect, the very +PDO is an indicator that the atmosphere is not yet primed to enhance this La Nina. It is a very slow process, we are already approaching the second half of the year. If you look back in history, significant ENSO events (strong La Nina/El Nino) such as last year the extratropical waters often are preconditioned. We would at least liked to have seen a neutral to slightly warm PDO to start but instead we had the record spring strong +PDO and looking at latest SST data over the North Pacific is still prevalent.

[Hunabku]

But we can also infer that cause or effect, the very +PDO is an indicator that the atmosphere is not yet primed to enhance this La Nina.

Oh yes thanks for the clarification, there is cause and effect stemming directly from the warmer east and cooler west ocean areas of +PDO. To be clear, i'm not sure how those warmer and cooler waters directly or indirectly effect or support ENSO. However, there is general consensus behind the idea/observation that the processes that drive ENSO also in part drive the PDO.

[cycloneye]

Text of CPC weekly update of 6/20/16 has Nino 3.4 up to +0.2C.

http://www.cpc.noaa.gov/products/analys ... ts-web.pdf

[cycloneye]

What swing up and down Nino 3.4 has been going thru in the first three weeks of June.

[cycloneye]

CPC update of 6/27/16 has Nino 3.4 down to -0.4C.

http://www.cpc.noaa.gov/products/analys ... ts-web.pdf

[Hunabku]

Found out more about what is going on with the eddies along the equator. They're called Tropical Instability Waves (TIWs), they tend to suppress the nina and are primarily driven by differences between equatorial and subtropical SSTs - which are quite pronounced right now.

I read about TIWs and more regarding our developing nina in this excellent blog recently posted on the Weather Underground https://www.wunderground.com/blog/JeffMasters/a-gallery-of-tropical-influences--mjo-cckw-tiw-and-la-nia

[stormwise]

Anybody have a idea on the warm anom in the pacific on the 30 day change.

[Darvince]

Looks to me like the beginning of a transition to a -ve PDO phase.