ENSO Updates (2007 thru 2023)

[Kingarabian]

Simply looking at the CHI200 on the GFS and Euro, the models still show sinking motion left over the EPAC. But in regards to the SOI, the SOI technically lags a bit and the positive daily's should've been much more and prolonged with the MJO now over the MC.

Yeah SOI is really noisy so it might not reflect what you think it will

While it is true the SOI is noisy, especially the daily, it can give you some hints if taken in context over longer periods and trends. It's not useless per say. If the negatives continue to weigh heavily against positives (when forecast says otherwise) there is a disconnect which means one should re-evaluate if the totality of the atmosphere is cooperating with the surface winds and/or SSTA. About 1-2 months ago many were ready to write off the Nino, but the long term SOI told us to hold up and hold steady.

I find the SOI to be more noisy during late winter through April as it becomes very prone to noise caused by seasonal changes and TC's or low pressure systems. It becomes pretty solid through the month of May, as it starts to correctly reflect current conditions, while SOI forecasts also give an idea on what is likely to happen in regards to ENSO. I remember in 2017, Larry correctly called an El Nino cancel before anything happened just by utilizing SOI numbers. At this time of the year its very important to pay attention to the SOI especially when things are seesawing back and forth.

[Kingarabian]

I thought the suppressed MJO had already left the Pacific?

Yes, but the east wind meeting west meaning llvl convergence, which leads to the rising air. Also, that is true, but only thru the SSTAs changing the wind pattern to favor rising/sinking air.

Simply looking at the CHI200 on the GFS and Euro, the models still show sinking motion left over the EPAC. But in regards to the SOI, the SOI technically lags a bit and the positive daily's should've been much more and prolonged with the MJO now over the MC.

Yeah SOI is really noisy so it might not reflect what you think it will

IMO at some point when the SOI repeatedly refuses to budge and defies model forecasts it means that El Nino or La Nina forcing from somewhere else is overriding MJO or Kelvin activity.

[Kingarabian]

Beneath the Pacific ocean at 100 meters, we can see a very solid upwelling Kelvin wave pushing east and has moved into the EPAC. Above 100 meters we still see a present downwelling Kelvin wave that has weakened due to strong trades dominating since the beginning of June.



If the forecast for relaxed trades west of the dateline, relaxed east of 120W but strong trades over the CPAC verifies, I think there's a chance the warm pool will be fragmented or broken apart right below the CPAC and we start to see cooler anomalies mixing in.

[WAcyclone]

Here's a graphic comparing the 12z ECMWF sea level pressure forecast for Darwin and Papeete.

[cycloneye]

The plume.

 https://twitter.com/climatesociety/status/1141781704111198208

[Kingarabian]

Mike Ventrice tweeted this today, but the CFS since about mid May, has been persistent on a standing wave developing over the EPAC by the beginning of July.
 https://twitter.com/MJVentrice/status/1141701513397571585




I wonder as evidenced by the -SOI, that It's possible the ongoing trade burst over the CPAC is not tied to the atmosphere attempting to go against El Nino and has more to do with a rogue Rossby wave.

[NotSparta]

Mike Ventrice tweeted this today, but the CFS since about mid May, has been persistent on a standing wave developing over the EPAC by the beginning of July.
https://twitter.com/MJVentrice/status/1141701513397571585

I wonder as evidenced by the -SOI, that It's possible the ongoing trade burst over the CPAC is not tied to the atmosphere attempting to go against El Nino and has more to do with a rogue Rossby wave.

Yeah, it would be difficult for the CFS to not show an EPAC standing wave if we are not in -ENSO. Eric Webb noted a Pacific bias w/ the model (absolutely not surprised there, it's been trying to show WWB activity that hasn't verified), and the complete destruction of a very strong African wave is dubious.

(ignore the specifics of this tweet)

 https://twitter.com/webberweather/status/1018144362885275649




Yes this EWB is mostly due to a rogue ERW, but the fact that we're going this long w/o forcing favorable for El Niño is proof that subseasonal forcing is needed now to get appreciable +ENSO forcing, so yes it is weakening. The subsfc can also tell us a lot (I remember you were all over that last yr), and it's not exactly making me bullish for El Niño as the values are rather meager as of late

[Kingarabian]

Mike Ventrice tweeted this today, but the CFS since about mid May, has been persistent on a standing wave developing over the EPAC by the beginning of July.
https://twitter.com/MJVentrice/status/1141701513397571585

I wonder as evidenced by the -SOI, that It's possible the ongoing trade burst over the CPAC is not tied to the atmosphere attempting to go against El Nino and has more to do with a rogue Rossby wave.

Yeah, it would be difficult for the CFS to not show an EPAC standing wave if we are not in -ENSO. Eric Webb noted a Pacific bias w/ the model (absolutely not surprised there, it's been trying to show WWB activity that hasn't verified), and the complete destruction of a very strong African wave is dubious.

(ignore the specifics of this tweet)

https://twitter.com/webberweather/statu ... 2885275649

Yes this EWB is mostly due to a rogue ERW, but the fact that we're going this long w/o forcing favorable for El Niño is proof that subseasonal forcing is needed now to get appreciable +ENSO forcing, so yes it is weakening. The subsfc can also tell us a lot (I remember you were all over that last yr), and it's not exactly making me bullish for El Niño as the values are rather meager as of late

I'm fully aware that the CFS has bias problems. Not just over the Pacific, but globally. I used to dog on the CFS all the time. Its forecast range goes out further than the operational Euro and GFS so naturally it will be very susceptible to errors, so we should give it credit in that it did pickup on a large trade burst well in advance. Correct Its over doing the stage of relaxed trades and is showing westerly anomalies which is correctly false as you stated, but IMO it doesn't mean its wrong in every other area as well.

But the Euro and GFS hovemoller's from Ventrice show the models look to be picking up on an extended period of -VP200 anomalies building east of the dateline and over the EPAC and I think this is the reason why Ventrice shared that CFSv2 hovmoller because it has more detail.

[NotSparta]

Mike Ventrice tweeted this today, but the CFS since about mid May, has been persistent on a standing wave developing over the EPAC by the beginning of July.
https://twitter.com/MJVentrice/status/1141701513397571585

I wonder as evidenced by the -SOI, that It's possible the ongoing trade burst over the CPAC is not tied to the atmosphere attempting to go against El Nino and has more to do with a rogue Rossby wave.

Yeah, it would be difficult for the CFS to not show an EPAC standing wave if we are not in -ENSO. Eric Webb noted a Pacific bias w/ the model (absolutely not surprised there, it's been trying to show WWB activity that hasn't verified), and the complete destruction of a very strong African wave is dubious.

(ignore the specifics of this tweet)

https://twitter.com/webberweather/statu ... 2885275649

Yes this EWB is mostly due to a rogue ERW, but the fact that we're going this long w/o forcing favorable for El Niño is proof that subseasonal forcing is needed now to get appreciable +ENSO forcing, so yes it is weakening. The subsfc can also tell us a lot (I remember you were all over that last yr), and it's not exactly making me bullish for El Niño as the values are rather meager as of late

I'm fully aware that the CFS has bias problems. Not just over the Pacific, but globally. I used to dog on the CFS all the time. Its forecast range goes out further than the operational Euro and GFS so naturally it will be very susceptible to errors, so we should give it credit in that it did pickup on a large trade burst well in advance. Correct Its over doing the stage of relaxed trades and is showing westerly anomalies which is correctly false as you stated, but IMO it doesn't mean its wrong in every other area as well.

But the Euro and GFS hovemoller's from Ventrice show the models look to be picking up on an extended period of -VP200 anomalies building east of the dateline and over the EPAC and I think this is the reason why Ventrice shared that CFSv2 hovmoller because it has more detail.

Yeah it does appear that the MJO is coming into the Pacific which will temporarily reignite forcing in the area.

Also I do understand the dilemma, the model has a known bias but it goes out far

[Ntxw]

Daily SOI: -35.29

[cycloneye]

 https://twitter.com/hurricanetrack/status/1142101543279353862

[Kingarabian]

Suprised the daily value for June 22 came in at -42. Much lower than what the Euro showed a couple days ago.

[Ntxw]

Suprised the daily value for June 22 came in at -42. Much lower than what the Euro showed a couple days ago.

-40s is a big number without influence of a tropical cyclone.

[NotSparta]

-SOI is so low mainly due to mid-latitude low activity near Tahiti that acts like a nearby tropical cyclone onto SOI. One reason why an off equatorial index like this can be misleading.

I'm not surprised, as if SOI was really that low w/ ENSO alone, we'd be looking at respectable WWB activity now

[Ntxw]

-SOI is so low mainly due to mid-latitude low activity near Tahiti that acts like a nearby tropical cyclone onto SOI. One reason why an off equatorial index like this can be misleading.

I'm not surprised, as if SOI was really that low w/ ENSO alone, we'd be looking at respectable WWB activity now

https://uploads.disquscdn.com/images/32c0ffa01fd1a46788df718c8f908fbc2358dff573ef7a66778eca844bbbb113.png

Right, but that is telling us the mid latitude forcings are more Nino like currently than others. On the other side of the Pacific a similar event (East of Japan -> Aleutian low) is cooling waters there.

It is telling us the long term SOI trend will continue to be negative. That the outward influence of the EWB has been rather limited to the equatorial central and eastern Pacific.

It is not the daily soi itself, but that it continues below the forecast.

[NotSparta]

-SOI is so low mainly due to mid-latitude low activity near Tahiti that acts like a nearby tropical cyclone onto SOI. One reason why an off equatorial index like this can be misleading.

I'm not surprised, as if SOI was really that low w/ ENSO alone, we'd be looking at respectable WWB activity now

https://uploads.disquscdn.com/images/32c0ffa01fd1a46788df718c8f908fbc2358dff573ef7a66778eca844bbbb113.png

Right, but that is telling us the mid latitude forcings are more Nino like currently than others. On the other side of the Pacific a similar event (East of Japan -> Aleutian low) is cooling waters there.

It is telling us the long term SOI trend will continue to be negative. That the outward influence of the EWB has been rather limited to the equatorial central and eastern Pacific.

It is not the daily soi itself, but that it continues below the forecast.

True, but that EWB is hitting where it counts for ENSO. We'll have to see what happens though

[Kingarabian]

-SOI is so low mainly due to mid-latitude low activity near Tahiti that acts like a nearby tropical cyclone onto SOI. One reason why an off equatorial index like this can be misleading.

I'm not surprised, as if SOI was really that low w/ ENSO alone, we'd be looking at respectable WWB activity now

https://uploads.disquscdn.com/images/32 ... bbb113.png

Pretty much what Ntxw said. These type of lows typically are by products of El Nino or La Nina depending on where they're located. We see quite a bit of these pass Australia that weaken high pressure near Darwin during La Nina's.

[Kingarabian]

-SOI is so low mainly due to mid-latitude low activity near Tahiti that acts like a nearby tropical cyclone onto SOI. One reason why an off equatorial index like this can be misleading.

I'm not surprised, as if SOI was really that low w/ ENSO alone, we'd be looking at respectable WWB activity now

https://uploads.disquscdn.com/images/32c0ffa01fd1a46788df718c8f908fbc2358dff573ef7a66778eca844bbbb113.png

Right, but that is telling us the mid latitude forcings are more Nino like currently than others. On the other side of the Pacific a similar event (East of Japan -> Aleutian low) is cooling waters there.

It is telling us the long term SOI trend will continue to be negative. That the outward influence of the EWB has been rather limited to the equatorial central and eastern Pacific.

It is not the daily soi itself, but that it continues below the forecast.

True, but that EWB is hitting where it counts for ENSO. We'll have to see what happens though

Yeah its put in good work so far as all Nino regions are down based on CDAS.

[NotSparta]

Right, but that is telling us the mid latitude forcings are more Nino like currently than others. On the other side of the Pacific a similar event (East of Japan -> Aleutian low) is cooling waters there.

It is telling us the long term SOI trend will continue to be negative. That the outward influence of the EWB has been rather limited to the equatorial central and eastern Pacific.

It is not the daily soi itself, but that it continues below the forecast.

True, but that EWB is hitting where it counts for ENSO. We'll have to see what happens though

Yeah its put in good work so far as all Nino regions are down based on CDAS.

And it's leaving a mark in the subsurface as well. For the persistence of the Niño we'll need a WWB soon

[Kingarabian]

True, but that EWB is hitting where it counts for ENSO. We'll have to see what happens though

Yeah its put in good work so far as all Nino regions are down based on CDAS.

And it's leaving a mark in the subsurface as well. For the persistence of the Niño we'll need a WWB soon

Agreed.

Well we're entering the last week of June so its time to do some comparisons with this years closest ENSO analogs. In regards to the 2004 Modoki comparisons, we're really losing that analog now. At this time in 2004, there was a separate upwelling Kelvin wave taking over the EPAC while a strengthening downwelling Kelvin wave was emerging west of the dateline:
.

Based on the buoys, 2017 is still a solid subsurface analog. But based on PENTAD imagery, around this time in June 2017, the subsurface had no coherent downwelling Kelvin wave:


Also very important to note is that the atmosphere in 2017 was very supportive of La Nina with repeated trade bursts over the dateline and a strong La Nina standing wave over the MC. Here's some comparisons, though I don't have the same exact graphics to match, the idea is there.

Zonal winds:
2017:
 https://twitter.com/BenNollWeather/status/889078735105806336



2019(I don't have a graphic that goes back to January, but we do know there were strong dateline WWB's in January and February 2019:


Standing wave(I don't have the same exact images to match but red and orange is sinking motion and blue/purples indicate rising motion:
2017:

2019:

I don't have a graphic that goes back 120 days, but rising motion has been placed over or just west of the dateline since the start of 2019.

OLR:
2017:

2019: