ENSO Updates (2007 thru 2023)

[LarryWx]

I believe that El Nino conditions must persist for a full 3 months before an El Nino is declared.

But the CPC already declared it last month, which was earlier than I expected:

https://www.cpc.ncep.noaa.gov/products/ ... disc.shtml

[wxman57]

I believe that El Nino conditions must persist for a full 3 months before an El Nino is declared.

But the CPC already declared it last month, which was earlier than I expected:

https://www.cpc.ncep.noaa.gov/products/ ... disc.shtml

That website looks like they issued an El Nino advisory, that the warm temperatures would continue through the summer. It didn't say the current status has reached the El Nino classification level.

[LarryWx]

I believe that El Nino conditions must persist for a full 3 months before an El Nino is declared.

But the CPC already declared it last month, which was earlier than I expected:

https://www.cpc.ncep.noaa.gov/products/ ... disc.shtml

That website looks like they issued an El Nino advisory, that the warm temperatures would continue through the summer. It didn't say the current status has reached the El Nino classification level.

Isn't this them saying there was already a weak El Niño?

"In June, a weak El Niño was associated with above-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean."

[Ntxw]

CPC criteria is SSTA trimonthly. AMJ was 0.5C enough for El Nino threshold is likely why they declared with some confidence by their metric. For sure MJJ will, those months have passed. Now if you're talking atmospheric response that's another story.

Retroactively you need 5 consecutive trimonthly in a database, but for the purpose of advisory, warnings that wouldn't make sense to wait that long after it has already occurred.

[dexterlabio]

Just curious, was there a weak El Nino where the atmospheric coupling was undebatable? 2006 maybe?

[Ntxw]

Just curious, was there a weak El Nino where the atmospheric coupling was undebatable? 2006 maybe?

MEI is a decent proxy to use. Also depends on when we're looking at. For early in the season it's not likely to happen prior to July for the weak events. 1994-1995 was probably the best case borderline moderate.

https://psl.noaa.gov/enso/mei/

[cycloneye]

[wxman57]

Isn't this them saying there was already a weak El Niño?

"In June, a weak El Niño was associated with above-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean."

I think that they mean weak El Nino temperatures. There was no El Nino in June, if it takes 3 consecutive months of temperature anomalies of 0.5C or greater.

[dexterlabio]

^I'm sorry but I thought Nino 3.4 has been hitting >= 0.5C since April? So that makes June the third consecutive month with El Nino temp reading.

[xtyphooncyclonex]

Isn't this them saying there was already a weak El Niño?

"In June, a weak El Niño was associated with above-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean."

I think that they mean weak El Nino temperatures. There was no El Nino in June, if it takes 3 consecutive months of temperature anomalies of 0.5C or greater.

An El Niño advisory has long been understood as a declaration of El Niño, or the presence of El Niño conditions, in this forum and by the media. Hence the headlines catch on to it.

The official NOAA website confirms it.
https://www.weather.gov/news/230706-ElNino

[Ntxw]

OLR anomalies 10N/10S for the past few months shows the La Nina lingering influence. However that is in the process of changing. You can see the gradual shift of -OLR progressing from the MC towards the dateline, which prior was heavily sinking motion. As it shifts from the IDL east, will favor coupling of the El Nino background state.

[Hybridstorm_November2001]

This is only my opinion based upon decades of weather watching, there is little chance we get a greatly above-average Hurricane Season as predicted if El Nino keeps developing.

[Kingarabian]

ENSO is compromised of the ocean and atmosphere. So if one or the other isn't in sync then it should be declared "neutral" until there's a full cooperation. In 2019, the CPC refused to call El Nino, even though the atmosphere was behaving like El Nino because the ocean response was underwhelming. I do believe the atmosphere will eventually get there but I think the same criteria should apply here.

[cycloneye]

ENSO is compromised of the ocean and atmosphere. So if one or the other isn't in sync then it should be declared "neutral" until there's a full cooperation. In 2019, the CPC refused to call El Nino, even though the atmosphere was behaving like El Nino because the ocean response was underwhelming. I do believe the atmosphere will eventually get there but I think the same criteria should apply here.

ENSO at Neutral right now is your take?

[cycloneye]

 https://twitter.com/TylerJStanfield/status/1687108015596711936

[dexterlabio]

ENSO is compromised of the ocean and atmosphere. So if one or the other isn't in sync then it should be declared "neutral" until there's a full cooperation. In 2019, the CPC refused to call El Nino, even though the atmosphere was behaving like El Nino because the ocean response was underwhelming. I do believe the atmosphere will eventually get there but I think the same criteria should apply here.

I must say El Nino's prediction has become too complicated nowadays. Before, we were just looking at the SSTs in the Nino regions, or the coastal waters of Ecuador and Peru, which is where El Nino's very name comes from. It is a warm phase of the equatorial Pacific Ocean. Perhaps this is the same reason why 2019 wasn't declared an El Nino because this criterion wasn't met.

I know there are also atmospheric factors at play and apparently, SST configuration in other parts of the globe (PDO, AMO) matters in the El Nino status, but I guess when the Nino regions are anomalously warm, then we should call it what it is.

[zzzh]

Latest ONI up to 0.8. Let's see what the MEI shows.

[cycloneye]

Latest ONI up to 0.8. Let's see what the MEI shows.

When does MEI has the next update?

[zzzh]

Usually on the 5th. No later than 10th.

[LarryWx]

1) The July OISST for 3.4 based on averaging the dailies calculated to be +1.10.

2) The July ERSST for 3.4, which is direct input into ONI, was just released and was +1.00. So, ERSST continues to come in slightly cooler than OISST in 3.4, which has been the case since December of 2022.

3) The MJJ ONI (ERSST based) was calculated to be/released at +0.77.

4) The MJJ RONI was released at +0.33. That means MJJ RONI was 0.44 cooler than MJJ ONI.

5) RONI-ONI: trending down since JJA of 2022, when it was only -0.01. Here are them since DJF:

DJF: -0.14

JFM: -0.17

FMA: -0.26

MAM: -0.34

AMJ: -0.41

MJJ: -0.44