ENSO Updates (2007 thru 2023)

[Kingarabian]

Doesn't look like the February event to me. Still further west, reminds me of the March event (but a bit east). It is stronger than the last but not as much as February. In addition, if the forecast verifies, the duration will leave much to be desired.

It's much stronger and coherent than what we saw in March. I don't even think what we saw in March counts as a true westerly burst. So far this event has similar Ms speeds near the dateline to the February WWB and with due time it likely to continue correct east. CFS has this WWB as strong or stronger than the February WWB

Yeah, for sure. The March WWB was anemic. This one does have those huge anomalies coming, but what made the February event was having more long-lived & larger areas. In addition, this WWB still is a bit too far west. It doesn't really get much past the dateline, while the February WWB was centered near it, & even got as far as 150°W.

[url]https://i.imgur.com/r9PKePl.gif[url]

It's no surprise that the CFS shows a stronger WWB - it's the strongest w/ the MJO - much more so than the Euro or GFS

And the March WWB looks even worse when filtered for raw westerly winds.

GFS, Euro, and CFS all have the same sigma when the MJO enters phase 8. Main difference now in the long range forecasts is that the GFS and CFS go into phase 1 with good amplification wile Euro goes back to the null phase.

[NotSparta]

It's much stronger and coherent than what we saw in March. I don't even think what we saw in March counts as a true westerly burst. So far this event has similar Ms speeds near the dateline to the February WWB and with due time it likely to continue correct east. CFS has this WWB as strong or stronger than the February WWB

Yeah, for sure. The March WWB was anemic. This one does have those huge anomalies coming, but what made the February event was having more long-lived & larger areas. In addition, this WWB still is a bit too far west. It doesn't really get much past the dateline, while the February WWB was centered near it, & even got as far as 150°W.

[url]https://i.imgur.com/r9PKePl.gif[url]

It's no surprise that the CFS shows a stronger WWB - it's the strongest w/ the MJO - much more so than the Euro or GFS

And the March WWB looks even worse when filtered for raw westerly winds.

GFS, Euro, and CFS all have the same sigma when the MJO enters phase 8. Main difference now in the long range forecasts is that the GFS and CFS go into phase 1 with good amplification wile Euro goes back to the null phase.

I'm interested in which MJO fcast verifies. I've been seeing a lot of divergence between the GFS & CFS and I'm guessing MJO differences are responsible. The changes in WWB strength, at this point, could make big differences

[NotSparta]

The WWB will need to work its magic soon - subsfc doesn't look healthy currently

[NotSparta]

Not by much, but a true WWB:

[Hurricaneman]

Looking at current subsurface anomalies the WWB doesn’t seem to be causing a downwelling kelvin wave but we will see in the next update or 2 before making that declaration

[Kingarabian]

Looking at current subsurface anomalies the WWB doesn’t seem to be causing a downwelling kelvin wave but we will see in the next update or 2 before making that declaration

2 weeks at least. This WWB could go on for the rest of May if the GFS verifies.

[NotSparta]

Looking at current subsurface anomalies the WWB doesn’t seem to be causing a downwelling kelvin wave but we will see in the next update or 2 before making that declaration

It's a bit early to look for downwelling KWs, since the WWB started pretty recently

[cycloneye]

EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
9 May 2019

ENSO Alert System Status: El Niño Advisory


Synopsis: El Niño is likely to continue through the Northern Hemisphere summer 2019 (70% chance) and fall (55-60% chance).

During April, above-average sea surface temperatures (SSTs) persisted across most of the equatorial Pacific Ocean [Fig. 1], reflecting the ongoing El Niño. All of the latest weekly Niño indices were near +0.8°C, except for Niño-1+2 index, which was at +0.3°C [Fig. 2]. While surface indicators were relatively unchanged during the month, the anomalous upper-ocean subsurface temperatures (averaged across 180°-100°W) decreased through April [Fig. 3]. Subsurface temperature anomalies remained positive close to the surface across the equatorial Pacific Ocean, but were increasingly negative at depth [Fig. 4]. Suppressed tropical convection was evident near Indonesia and enhanced convection continued near the Date Line, though weaker compared to the last two months [Fig. 5]. Low-level wind anomalies were weak over the tropical Pacific Ocean, with easterly anomalies evident over the western Pacific. Upper-level wind anomalies were easterly over the western Pacific and westerly over most of the eastern Pacific. Overall, oceanic and atmospheric conditions were consistent with El Niño.

The majority of models in the IRI/CPC plume predict El Niño to continue through 2019, with SST anomalies in the Niño-3.4 region clustering between +0.5°C and +1.0°C [Fig. 6]. However, model predictions made during the spring tend to be less accurate relative to the rest of the year, so uncertainty remains whether this outcome will occur. In the shorter term, a recent increase in westerly wind anomalies over the west-central Pacific Ocean portends the possible development of another downwelling oceanic Kelvin wave, which could build up the above-average subsurface temperatures needed for El Niño to persist. In summary, El Niño is likely to continue through the Northern Hemisphere summer 2019 (70% chance) and fall (55-60% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

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

[cycloneye]

Here is the ENSO Blog about their thinking on how are things going with ENSO:

Over the past year, subsurface waters (from the surface down to about 1,000 feet) have remained warmer-than-average overall, but with some substantial increases and decreases, resembling a particularly brutal stage of the Tour de France. If the recent weakening in the trade winds does lead to a downwelling Kelvin wave and increases the subsurface anomalies, it could provide fuel to help this El Niño event to persist. Bikers beware, another uphill climb may be ahead of you.

https://www.climate.gov/news-features/b ... ea%C3%B1os

[Kingarabian]

If no downwelling Kelvin wave is generated I think those numbers should come down considerably by the next update.

But there's a good chance that this WWB presently, is generating a downwelling Kelvin wave that will be evident in a week or so. And it looks like this WWB might be a half month/month long and appears to be slowing down the trades across the central and eastern Pacific. So even without a downwelling Kelvin wave there's a high chance that SST's over the Nino regions will maintain themselves at least through May and June.



CFS continues to have a much stronger WWB but that's likely because it's now an outlier compared to the Euro/GFS and shows more amplification of the MJO in phases 8/1.

[CyclonicFury]

May NMME is out. CFSv2 and NASA are warm and cold outliers, respectively, showing a strong El Nino and cool neutral ENSO. Most of the other models are in between, showing continuation of weak/moderate El Nino conditions through fall. It's not surprising to see CFSv2 much warmer than the other models considering it is the strongest with the WWB. Is there a chance the NASA model is onto something because of the cool subsurface, or is it just a cold biased model?

[Kingarabian]

May NMME is out. CFSv2 and NASA are warm and cold outliers, respectively, showing a strong El Nino and cool neutral ENSO. Most of the other models are in between, showing continuation of weak/moderate El Nino conditions through fall. It's not surprising to see CFSv2 much warmer than the other models considering it is the strongest with the WWB. Is there a chance the NASA model is onto something because of the cool subsurface, or is it just a cold biased model?
[url]https://i.imgur.com/U53JiZm.png[url]

To be honest don't know of any track record when it comes to this model and ENSO. First time I hear of it.

[CyclonicFury]

I decided to do some research by looking at past plumes. It did very well in 2015 projecting a Super Nino, it did well in 2016 showing a weak La Nina, in 2017 it was actually too warm (but so was pretty much every model), but in 2018 it was far too cold (showing a cool neutral ENSO) when a weak Nino developed by late fall in reality. Only in 2018 did it show a significant cold bias, but I think the model may have been upgraded which may have given it a cold bias.

[Kingarabian]

I decided to do some research by looking at past plumes. It did very well in 2015 projecting a Super Nino, it did well in 2016 showing a weak La Nina, in 2017 it was actually too warm (but so was pretty much every model), but in 2018 it was far too cold (showing a cool neutral ENSO) when a weak Nino developed by late fall in reality. Only in 2018 did it show a significant cold bias, but I think the model may have been upgraded which may have given it a cold bias.

Interesting. Too bad the update may have ruined it.

[NotSparta]

:uarrow: If no downwelling Kelvin wave is generated I think those numbers should come down considerably by the next update.

But there's a good chance that this WWB presently, is generating a downwelling Kelvin wave that will be evident in a week or so. And it looks like this WWB might be a half month/month long and appears to be slowing down the trades across the central and eastern Pacific. So even without a downwelling Kelvin wave there's a high chance that SST's over the Nino regions will maintain themselves at least through May and June.

https://i.imgur.com/3WATbC6.gif

CFS continues to have a much stronger WWB but that's likely because it's now an outlier compared to the Euro/GFS and shows more amplification of the MJO in phases 8/1.
https://i.imgur.com/LFOK0yQ.png

The WWB isn't all that impressive so I'd expect a more minor downwelling KW, but still one.

You should also ignore the westerlies to the east, a lot of it is from the GFS/GEFS bias of pumping up the MJO there. It's apparent in the VP200 plots.

Either way, it'll be interesting to see what happens. The subsfc looks increasingly anemic, but this WWB could reverse that trend

[Kingarabian]

:uarrow: If no downwelling Kelvin wave is generated I think those numbers should come down considerably by the next update.

But there's a good chance that this WWB presently, is generating a downwelling Kelvin wave that will be evident in a week or so. And it looks like this WWB might be a half month/month long and appears to be slowing down the trades across the central and eastern Pacific. So even without a downwelling Kelvin wave there's a high chance that SST's over the Nino regions will maintain themselves at least through May and June.

https://i.imgur.com/3WATbC6.gif

CFS continues to have a much stronger WWB but that's likely because it's now an outlier compared to the Euro/GFS and shows more amplification of the MJO in phases 8/1.
https://i.imgur.com/LFOK0yQ.png

The WWB isn't all that impressive so I'd expect a more minor downwelling KW, but still one.

You should also ignore the westerlies to the east, a lot of it is from the GFS/GEFS bias of pumping up the MJO there. It's apparent in the VP200 plots.

Either way, it'll be interesting to see what happens. The subsfc looks increasingly anemic, but this WWB could reverse that trend

It's not one of those 2014/2015 WWBs but as long as a WWB is measured > +10Ms and near the dateline I would say its meaningful. Does not have to be directly over the dateline or completely over the CPAC for it to influence the subsurface. I've seen similar WWB's in early 2017 and early 2018 warm the subsurface.

Weak trades are expected when there's a WWB near the dateline. Plus the MJO is forecast to get into phase 1 which is basically the EPAC so I would assume there would be relaxed easterlies by default.

[NotSparta]

:uarrow: If no downwelling Kelvin wave is generated I think those numbers should come down considerably by the next update.

But there's a good chance that this WWB presently, is generating a downwelling Kelvin wave that will be evident in a week or so. And it looks like this WWB might be a half month/month long and appears to be slowing down the trades across the central and eastern Pacific. So even without a downwelling Kelvin wave there's a high chance that SST's over the Nino regions will maintain themselves at least through May and June.

https://i.imgur.com/3WATbC6.gif

CFS continues to have a much stronger WWB but that's likely because it's now an outlier compared to the Euro/GFS and shows more amplification of the MJO in phases 8/1.
https://i.imgur.com/LFOK0yQ.png

The WWB isn't all that impressive so I'd expect a more minor downwelling KW, but still one.

You should also ignore the westerlies to the east, a lot of it is from the GFS/GEFS bias of pumping up the MJO there. It's apparent in the VP200 plots.

Either way, it'll be interesting to see what happens. The subsfc looks increasingly anemic, but this WWB could reverse that trend

It's not one of those 2014/2015 WWBs but as long as a WWB is measured > +10Ms and near the dateline I would say its meaningful. Does not have to be directly over the dateline or completely over the CPAC for it to influence the subsurface. I've seen similar WWB's in early 2017 and early 2018 warm the subsurface.

Weak trades are expected when there's a WWB near the dateline. Plus the MJO is forecast to get into phase 1 which is basically the EPAC so I would assume there would be relaxed easterlies by default.

I don't disagree about the first part, it definitely could warm the subsfc a good bit. Just need to wait & see

I didn't quite mean completely ignore the westerlies near South America, but in that fcast they are very overblown due to the GFS bias, as the westerlies & low VP200 are in the same area.



Also note the signal retrograding, that means something is wrong w/ the forecast

[Kingarabian]

The WWB isn't all that impressive so I'd expect a more minor downwelling KW, but still one.

You should also ignore the westerlies to the east, a lot of it is from the GFS/GEFS bias of pumping up the MJO there. It's apparent in the VP200 plots.

Either way, it'll be interesting to see what happens. The subsfc looks increasingly anemic, but this WWB could reverse that trend

It's not one of those 2014/2015 WWBs but as long as a WWB is measured > +10Ms and near the dateline I would say its meaningful. Does not have to be directly over the dateline or completely over the CPAC for it to influence the subsurface. I've seen similar WWB's in early 2017 and early 2018 warm the subsurface.

Weak trades are expected when there's a WWB near the dateline. Plus the MJO is forecast to get into phase 1 which is basically the EPAC so I would assume there would be relaxed easterlies by default.

I don't disagree about the first part, it definitely could warm the subsfc a good bit. Just need to wait & see

I didn't quite mean completely ignore the westerlies near South America, but in that fcast they are very overblown due to the GFS bias, as the westerlies & low VP200 are in the same area.

[url]https://i.imgur.com/ZwpYS9b.gif[url]

Also note the signal retrograding, that means something is wrong w/ the forecast

Certainly does look odd. But the Euro has a big -VP200 pulse in the same area starting may 13 as well.


PC: Weatherbell

[NotSparta]

I feel like I may be looking at these too much, but the GFS trended slightly weaker w/ the WWB - now showing the 5 m/s anomalies ending.

However I think this may be a bit underdone as it also shows EWB activity in the Indian Ocean, an El Niño pattern

[Kingarabian]

A great way to view raw westerly winds and see if they're verifying, is through the buoys. Sharp long arrows pointing from west to east (longer the stronger) are beginning to appear just west of the dateline.


Here's a comparison with the WWB we saw in mid march and for same time period in 2005: