ENSO Updates (2007 thru 2023)

[cycloneye]

CPC May update has ended La Niña and Neutral conditions will prevail thru the fall with La Niña going up in % by the last months of the year. El Niño is with only 8% by ASO.

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

[Iceresistance]

CPC May update has ended La Niña and Neutral conditions will prevail thru the fall with La Niña going up in % by the last months of the year. El Niño is with only 8% by ASO.

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

https://i.imgur.com/ocQ9fFt.png

The Atlantic is going to have a another active season? And what will this coming winter will hold? Last one was NASTY!

[NotSparta]

Current trade burst is doing a good job in keeping the surface temps cooler than normal, but there's still very little upwelling at the subsurface.
https://i.imgur.com/RmkBC0v.gif

This is a "surface" La Nina/-ENSO presentation where the surface temperatures are cool and the subsurface is warm. This is the opposite of 2017's surface El Nino/+ENSO presentation, where the surface was much warmer than the subsurface.

Looking ahead, the models are coming into good agreement of another WPAC WWB during June. It'll likely trigger another downwelling KW if it occurs.
https://i.imgur.com/K3IiP1k.png

I'm not sure there's much model agreement, it being the CFS, a WWB towards the longer range is almost its default state. Though, I wouldn't be surprised to see weak trades when the MJO gets over to the WPAC

[Kingarabian]

Current trade burst is doing a good job in keeping the surface temps cooler than normal, but there's still very little upwelling at the subsurface.
https://i.imgur.com/RmkBC0v.gif

This is a "surface" La Nina/-ENSO presentation where the surface temperatures are cool and the subsurface is warm. This is the opposite of 2017's surface El Nino/+ENSO presentation, where the surface was much warmer than the subsurface.

Looking ahead, the models are coming into good agreement of another WPAC WWB during June. It'll likely trigger another downwelling KW if it occurs.
https://i.imgur.com/K3IiP1k.png

I'm not sure there's much model agreement, it being the CFS, a WWB towards the longer range is almost its default state. Though, I wouldn't be surprised to see weak trades when the MJO gets over to the WPAC

I agree the CFS is usually WWB biased. But it got the April WWB correct 45 days out, and was correct to keep the anomalies well west of the dateline. It's already showing up on the 2 week GFS and Euro 850mb wind forecasts. At the same time, it will be a MJO driven WWB (WWB driven MJO?) and the 46 day EPS has the same prolonged WPAC MJO setup as the CFS.

[Kingarabian]

This period of MJO activity will likely determine what happens in regards to ENSO. The active phase of the MJO will likely be over the WPAC in about a week or so. Current -VP200 pattern continues to favor anomalous rising motion near 150E, so MJO progression will likely be slow over the WPAC, and is opening the door for more westerly wind anomalies. The upcoming WWB will be more of the same. It'll likely be moderate strength at best and will be situated and prolonged (2-3 weeks probably) over 140E-160E. While this happens, enhanced trades will likely shift over to the EPAC. So this setup supports further downwelling KW activity but could keep the Nino 3 and Nino 1+2 warming rate very slow if any.

Something to keep an eye on: There's still time for upwelling to occur beneath the CPAC/EPAC and create some negative anomalies and start the reversal back -ENSO. But it still has not happened and as a result, the subsurface and 850mb winds are beginning to resemble a blend of 2009 and 2006 vs 2011.

[DorkyMcDorkface]

It really won't take much for the warm pool to surface...long-range Euro hovmoller is showing the MJO lingering in the WPAC up until the end of the month, which would likely be good enough to provide sufficient westerlies that may get the job done (particularly if it spawns a cyclone), and we could see a brief rise into +ENSO territory by next month. With that being said, however, I put emphasis on brief, as said hovmoller also depicts what appears to be the African Standing Wave kicking into high gear by mid-month, which will probably end up killing any further momentum towards further ENSO warming as it takes over as the dominant area of atmospheric forcing globally - you can also see sinking/positive VP returning to the Pacific as a result by the latter half of this graphic.

[Kingarabian]

It really won't take much for the warm pool to surface...long-range Euro hovmoller is showing the MJO lingering in the WPAC up until the end of the month, which would likely be good enough to provide sufficient westerlies that may get the job done (particularly if it spawns a cyclone), and we could see a brief rise into +ENSO territory by next month. With that being said, however, I put emphasis on brief, as said hovmoller also depicts what appears to be the African Standing Wave kicking into high gear by mid-month, which will probably end up killing any further momentum towards further ENSO warming as it takes over as the dominant area of atmospheric forcing globally - you can also see sinking/positive VP returning to the Pacific as a result by the latter half of this graphic.

[url]https://i.ibb.co/WWsTgLv/eps-chi200-anomaly-hov-equatorial-2021051700-MEAN.png[url]

The key thing here isn't much about the warm pool surfacing. It's the potential for it to remain warm. The upcoming WWB's main role here would be to keep the subsurface anomalies positive into JJA. This might open the door for last minute +ENSO development similar to 2009 and 2006. In the near future, the surface temperatures will warm by default since there will have been two downwelling KW's erupting. That 46 day EPS hovemoller is still not detrimental for a late +ENSO onset. While the Euro is forecasting for the WAM to kickoff, the forecast also shows very weak +VP200 anomalies near 150E-160E despite the presence of a suppressed MJO phase. Also a strong WAM doesn't mean +ENSO can't happen. Seen it in 2018, and the subsurface + 850mb snapshot for 2018 is also currently similar to 2021. So regardless, recent history tells us it's very likely we'll see an active Atlantic hurricane season since the basin responds well to the WAM.

My recent posts may seem +ENSO biased but the fact is... there's no upwelling going on despite two rounds of significant trade activity during March and most of May, and we're likely to see downwelling KW #3 in June.

[DorkyMcDorkface]

It really won't take much for the warm pool to surface...long-range Euro hovmoller is showing the MJO lingering in the WPAC up until the end of the month, which would likely be good enough to provide sufficient westerlies that may get the job done (particularly if it spawns a cyclone), and we could see a brief rise into +ENSO territory by next month. With that being said, however, I put emphasis on brief, as said hovmoller also depicts what appears to be the African Standing Wave kicking into high gear by mid-month, which will probably end up killing any further momentum towards further ENSO warming as it takes over as the dominant area of atmospheric forcing globally - you can also see sinking/positive VP returning to the Pacific as a result by the latter half of this graphic.

[url]https://i.ibb.co/WWsTgLv/eps-chi200-anomaly-hov-equatorial-2021051700-MEAN.png[url]

The key thing here isn't much about the warm pool surfacing. It's the potential for it to remain warm. The upcoming WWB's main role here would be to keep the subsurface anomalies positive into JJA. This might open the door for last minute +ENSO development similar to 2009 and 2006. In the near future, the surface temperatures will warm by default since there will have been two downwelling KW's erupting. That 46 day EPS hovemoller is still not detrimental for a late +ENSO onset. While the Euro is forecasting for the WAM to kickoff, the forecast also shows very weak +VP200 anomalies near 150E-160E despite the presence of a suppressed MJO phase. Also a strong WAM doesn't mean +ENSO can't happen. Seen it in 2018, and the subsurface + 850mb snapshot for 2018 is also currently similar to 2021. So regardless, recent history tells us it's very likely we'll see an active Atlantic hurricane season since the basin responds well to the WAM.

My recent posts may seem +ENSO biased but the fact is... there's no upwelling going on despite two rounds of significant trade activity during March and most of May, and we're likely to see downwelling KW #3 in June.

I'm not disagreeing with you in that +ENSO will develop, like you said the downwelling KWs are likely to surface soon with westerly wind anoms in the WPAC. My thing is, atmospherically, we still seem to be decently oupled with -ENSO overall, and really the sprouting of the ASW will likely reinforce this, so I feel it is best to err on the side of caution and expect any sort of warm-neutral-ish pattern to be confined to the June/July timeframe. It has basically been a quasi-permanent feature in recent years and it's definitely partially responsible for why our most recent +ENSO events have not climbed out of the weaker threshold.

Regarding 2018...the ASW still had a profound impact on ENSO that year. Had it not been there, there's a good chance the El Nino would have been stronger, but due to its presence it hindered significant development until that winter.

[Kingarabian]

It really won't take much for the warm pool to surface...long-range Euro hovmoller is showing the MJO lingering in the WPAC up until the end of the month, which would likely be good enough to provide sufficient westerlies that may get the job done (particularly if it spawns a cyclone), and we could see a brief rise into +ENSO territory by next month. With that being said, however, I put emphasis on brief, as said hovmoller also depicts what appears to be the African Standing Wave kicking into high gear by mid-month, which will probably end up killing any further momentum towards further ENSO warming as it takes over as the dominant area of atmospheric forcing globally - you can also see sinking/positive VP returning to the Pacific as a result by the latter half of this graphic.

[url]https://i.ibb.co/WWsTgLv/eps-chi200-anomaly-hov-equatorial-2021051700-MEAN.png[url]

The key thing here isn't much about the warm pool surfacing. It's the potential for it to remain warm. The upcoming WWB's main role here would be to keep the subsurface anomalies positive into JJA. This might open the door for last minute +ENSO development similar to 2009 and 2006. In the near future, the surface temperatures will warm by default since there will have been two downwelling KW's erupting. That 46 day EPS hovemoller is still not detrimental for a late +ENSO onset. While the Euro is forecasting for the WAM to kickoff, the forecast also shows very weak +VP200 anomalies near 150E-160E despite the presence of a suppressed MJO phase. Also a strong WAM doesn't mean +ENSO can't happen. Seen it in 2018, and the subsurface + 850mb snapshot for 2018 is also currently similar to 2021. So regardless, recent history tells us it's very likely we'll see an active Atlantic hurricane season since the basin responds well to the WAM.

My recent posts may seem +ENSO biased but the fact is... there's no upwelling going on despite two rounds of significant trade activity during March and most of May, and we're likely to see downwelling KW #3 in June.

I'm not disagreeing with you in that +ENSO will develop, like you said the downwelling KWs are likely to surface soon with westerly wind anoms in the WPAC. My thing is, atmospherically, we still seem to be decently oupled with -ENSO overall, and really the sprouting of the ASW will likely reinforce this, so I feel it is best to err on the side of caution and expect any sort of warm-neutral-ish pattern to be confined to the June/July timeframe. It has basically been a quasi-permanent feature in recent years and it's definitely partially responsible for why our most recent +ENSO events have not climbed out of the weaker threshold.

Regarding 2018...the ASW still had a profound impact on ENSO that year. Had it not been there, there's a good chance the El Nino would have been stronger, but due to its presence it hindered significant development until that winter.

Good points.

Yeah I think regardless of what happens with ENSO it'll only have 2018 effects at best. I doubt ENSO will be an inhibitor to the Atlantic hurricane season this year.

[Yellow Evan]

 https://twitter.com/wxjay/status/1395388623898353667

[NotSparta]

https://twitter.com/wxjay/status/1395388623898353667?s=21

This looks like the negative phase with stronger trade winds. Not sure how they'll get reduced equatorward of an anomalous ridge

[Kingarabian]

https://twitter.com/wxjay/status/1395388623898353667?s=21

This looks like the negative phase with stronger trade winds. Not sure how they'll get reduced equatorward of an anomalous ridge

I'm not sure but I think they're to trying say that the blocking high in the SP looks to be weakening due to SSTA warming in that spot. That area is typically cool in La Nina's. Still yet to see the NP warm at all though. I believe La Nina spawns twin blocking highs in the NP (also because of the -PDO) and SP.

[Kingarabian]

So far in May, the SOI has responded very well to the rising motion over the IO and has been dominantly positive with the 30 day average at times reaching +7. 12z Euro forecast shows a pretty negative SOI setup for the next 10 days.

[Category5Kaiju]

 https://twitter.com/cyclonicwx/status/1396514999070232581




This is a very interesting observation. I remember how some people in recent years were saying that super El Ninos would become more common, but what if it isn't?

[Kingarabian]

Pretty evident that for at least the next two weeks and likely through June, indicators are favoring warming over the Nino regions with a prolonged weak-moderate WWB centered west and over the dateline, as well as the CPAC. Latest 46 day EPS shows very little large scale subsidence just west of the dateline for the entire month of June.



Might come down to July and August to reverse things back to cool-neutral as we saw in 2017.

[GrayLancer18]

CPC May update has ended La Niña and Neutral conditions will prevail thru the fall with La Niña going up in % by the last months of the year. El Niño is with only 8% by ASO.

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

https://i.imgur.com/ocQ9fFt.png

Now the Mid-May CPC gives 31% of La Nina by OND and 21% for El Niño conditions by ASO. Neutral conditions dominate 55% for ASO.



https://iri.columbia.edu/our-expertise/ ... -iri_plume

[Kingarabian]

CPC May update has ended La Niña and Neutral conditions will prevail thru the fall with La Niña going up in % by the last months of the year. El Niño is with only 8% by ASO.

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

https://i.imgur.com/ocQ9fFt.png

Now the Mid-May CPC gives 31% of La Nina by OND and 21% for El Niño conditions by ASO. Neutral conditions dominate 55% for ASO.

[url]https://iri.columbia.edu/wp-content/uploads/2021/05/figure3.png[url]

https://iri.columbia.edu/our-expertise/ ... -iri_plume

Pretty big shift in two weeks. Neutral is clearly favored, but the type of neutral ENSO is key here. A persistent cool neutral of -0.4C like we saw in 2005 and 2017 would have big impacts for the Atlantic hurricane season compared to a warm-neutral that is +0.3C. Hard to say what will happen because even by ASO, La Nina and El Nino have very close odds.

[DorkyMcDorkface]

Latest BOM plume is slightly warmer than the last.

[GeneratorPower]

This projected cool neutral is one of the most favorable states for ATL landfalling hurricanes. Moreso than full-on La Nina. See 2005.

[Kingarabian]

NotSparta, are you using a different climo period than Mike Ventrice is using for the 850mb wind forecasts? The wind speeds look similar in the IO but different in the WPAC (7-9ms vs 10-15ms). Slight discrepancies just curious