ENSO Updates (2007 thru 2023)

[cycloneye]

Kingarabian, any effects from this cyclone about ENSO or will not have any?

[Kingarabian]

Kingarabian, any effects from this cyclone about ENSO or will not have any?

It formed due to MJO/CCKW passage and is influencing the 850mb winds between 5N-5S:


It is a similar scenario although not quite in past seasons where strong WPAC typhoons were spawned in relation to a WWB near the dateline.

It's still too far south to trigger a full blown WWB, but some maps that factor 850mb winds between 15N-15S show a bigger WWB.

[cycloneye]

Kingarabian. Moved the above 2 posts from the Tropical Cyclone Harold thread to here where more members can see my question and your reply as at this moment, everything is important about ENSO as we figure out how will it be by ASO.

[Kingarabian]

March 2015 850mb zonal winds:


It's not un-common to see Typhoons in the WPAC or Cyclones in the SPAC during a WWB event if the right ingredients are in place. However the effects towards ENSO depends. I think it's agreed that the Kelvin wave generation area is between 120E-180 latitude. However for longitude, some say the regions ENSO is sensitive the most to is 5N-5S, while some say its 7N-7S -- which would mean that this event will be focused too far south for any ENSO influence.. But some say its 10N-10S which would have much more impacts toward ENSO. We won't know until we're in May.

[Kingarabian]

PMM seems to be warming. Probably due to the EPO being more negative in the last 4 weeks.





PC: Weathermodels.com and Cyclonicwx.com

[Kingarabian]

April Euro seasonal is out. It's running similar to the March update, if not cooler.

[cycloneye]

April Euro seasonal is out. It's running similar to the March update, if not cooler.

This is important news as ENSO is being watched closely. Any graphic?

[Kingarabian]

April Euro seasonal is out. It's running similar to the March update, if not cooler.

This is important news as ENSO is being watched closely. Any graphic?

ASO:

PC: Weathermodels.com

[cycloneye]

Yikes,indeed cooler than the March update.

[Hurricaneman]

The fact that the euro shows this is very concerning as it usually shows the opposite

[Shell Mound]

PMM seems to be warming. Probably due to the EPO being more negative in the last 4 weeks.
https://i.imgur.com/Uz1GDyQ.png
https://i.imgur.com/jkGkKBG.png

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

PC: Weathermodels.com and Cyclonicwx.com

It is interesting to note that the MDR has actually begun to cool significantly ever since the NAO flipped strongly negative, starting in particular around 1 April. This is contrary to what one would normally expect. Similarly, up until this point, the NAO has been strongly positive throughout most of the winter, yet because the large-scale synoptic features were displaced farther to the north than is usual for typical +NAO events, the enhanced low-level easterlies due to strong subtropical ridging largely stayed north of the MDR, while anomalous low-level westerlies persisted farther south, closer to the Equator. So the overall effects on the MDR were more like those of a -NAO/+AMM rather than a +NAO/-AMM, serving to counter the cold North Atlantic and keeping the MDR warm. Yet this has proven a double-edge sword, since the oncoming -NAO period has acted more like a +NAO/-AMM than a -NAO/+AMM, since the anomalous westerlies are now occurring north of the MDR, with shortwave ridging and easterlies farther south, resulting in the recent cooling. It is possible to speculate that climate change is shifting large-scale features northward and is producing unusual outcomes relative to specific patterns.

[Shell Mound]

April Euro seasonal is out. It's running similar to the March update, if not cooler.

This is important news as ENSO is being watched closely. Any graphic?

ASO:
https://i.imgur.com/Xo3IQgD.png
PC: Weathermodels.com

Interestingly, while the latest EC has a colder -ENSO by peak season, it also shows a cooler MDR with a more pronounced -AMO signature than on the last run.

[Kingarabian]

PMM seems to be warming. Probably due to the EPO being more negative in the last 4 weeks.
https://i.imgur.com/Uz1GDyQ.png
https://i.imgur.com/jkGkKBG.png

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

PC: Weathermodels.com and Cyclonicwx.com

It is interesting to note that the MDR has actually begun to cool significantly ever since the NAO flipped strongly negative, starting in particular around 1 April. This is contrary to what one would normally expect. Similarly, up until this point, the NAO has been strongly positive throughout most of the winter, yet because the large-scale synoptic features were displaced farther to the north than is usual for typical +NAO events, the enhanced low-level easterlies due to strong subtropical ridging largely stayed north of the MDR, while anomalous low-level westerlies persisted farther south, closer to the Equator. So the overall effects on the MDR were more like those of a -NAO/+AMM rather than a +NAO/-AMM, serving to counter the cold North Atlantic and keeping the MDR warm. Yet this has proven a double-edge sword, since the oncoming -NAO period has acted more like a +NAO/-AMM than a -NAO/+AMM, since the anomalous westerlies are now occurring north of the MDR, with shortwave ridging and easterlies farther south, resulting in the recent cooling. It is possible to speculate that climate change is shifting large-scale features northward and is producing unusual outcomes relative to specific patterns.

These are some very good observations and points you make. And it's just all over the place right now. The large-scale synoptic features are not behaving as they traditionally do. We've been stuck in this weird pattern since May-June 2019.

So far it's obvious that a moderate upwelling wave with -2.0/-2.5C anomalies is pushing east into the EPAC below 150 meters. Above that, is a downwelling Kelvin wave from late winter, that continues to push into the EPAC and continues to receive warm anomalies from the WPAC. The thermocline remains suppressed with even the 28C isotherm mean still holding @ 155W. We know that the rising branch over the dateline has broken down and last weeks easterly burst should mean that the transition towards cool neutral has started. But then the SHEM mid-latitudes get active, SOI tanks, a WWB centered below 5S in the SPAC triggers a major TC, and westerly anomalies set to linger for 2 weeks over the CPAC and EPAC.

We know El Nino and most warm neutral seasons favor active Pacific hurricane seasons. We know La Nina and cool neutral seasons favor active Atlantic seasons. Maybe a situation we're in triggers a 2006/2013 type situation? Stay tuned. I'm still really favoring an active Atlantic hurricane season.

[WeatherEmperor]

All Nino indices rose this week

1+2 is + 0.8c
3 is up to +0.6C
3.4 is up to +0.6C
4 is up to +0.7c

The enso models continue to show a decline in Nino regions....but with the numbers staying the same or rising slightly each week, how confident are we that Enso will become neutral or even cool-neutral like the models show?


Sent from my iPhone using Tapatalk

[Shell Mound]

PMM seems to be warming. Probably due to the EPO being more negative in the last 4 weeks.
https://i.imgur.com/Uz1GDyQ.png
https://i.imgur.com/jkGkKBG.png

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

PC: Weathermodels.com and Cyclonicwx.com

It is interesting to note that the MDR has actually begun to cool significantly ever since the NAO flipped strongly negative, starting in particular around 1 April. This is contrary to what one would normally expect. Similarly, up until this point, the NAO has been strongly positive throughout most of the winter, yet because the large-scale synoptic features were displaced farther to the north than is usual for typical +NAO events, the enhanced low-level easterlies due to strong subtropical ridging largely stayed north of the MDR, while anomalous low-level westerlies persisted farther south, closer to the Equator. So the overall effects on the MDR were more like those of a -NAO/+AMM rather than a +NAO/-AMM, serving to counter the cold North Atlantic and keeping the MDR warm. Yet this has proven a double-edge sword, since the oncoming -NAO period has acted more like a +NAO/-AMM than a -NAO/+AMM, since the anomalous westerlies are now occurring north of the MDR, with shortwave ridging and easterlies farther south, resulting in the recent cooling. It is possible to speculate that climate change is shifting large-scale features northward and is producing unusual outcomes relative to specific patterns.

These are some very good observations and points you make. And it's just all over the place right now. The large-scale synoptic features are not behaving as they traditionally do. We've been stuck in this weird pattern since May-June 2019.

So far it's obvious that a moderate upwelling wave with -2.0/-2.5C anomalies is pushing east into the EPAC below 150 meters. Above that, is a downwelling Kelvin wave from late winter, that continues to push into the EPAC and continues to receive warm anomalies from the WPAC. The thermocline remains suppressed with even the 28C isotherm mean still holding @ 155W. We know that the rising branch over the dateline has broken down and last weeks easterly burst should mean that the transition towards cool neutral has started. But then the SHEM mid-latitudes get active, SOI tanks, a WWB centered below 5S in the SPAC triggers a major TC, and westerly anomalies set to linger for 2 weeks over the CPAC and EPAC.

We know El Nino and most warm neutral seasons favor active Pacific hurricane seasons. We know La Nina and cool neutral seasons favor active Atlantic seasons. Maybe a situation we're in triggers a 2006/2013 type situation? Stay tuned. I'm still really favoring an active Atlantic hurricane season.

Interestingly, that Cat-5 TC in the South Pacific, Harold, is currently the strongest on record in the South Pacific since Pam and Winston (2015), both of which immediately preceded the record-breaking El Niño of 2015–6. High ACE production in the South Pacific tends to be positively correlated with ACE in the EPAC/CPAC but negatively correlated with ACE in the Atlantic, since +ENSO favours stronger storms in these regions vs. the Atlantic.

[Chris90]

Interestingly, that Cat-5 TC in the South Pacific, Harold, is currently the strongest on record in the South Pacific since Pam and Winston (2015), both of which immediately preceded the record-breaking El Niño of 2015–6. High ACE production in the South Pacific tends to be positively correlated with ACE in the EPAC/CPAC but negatively correlated with ACE in the Atlantic, since +ENSO favours stronger storms in these regions vs. the Atlantic.

Pam and Winston didn't occur during the same year. Pam occured in March 2015, and preceded the Niño and the 2015 season in the N. Hemisphere. Winston occurred February 2016 when the Niño was on the way down, after the 2015 season in the N. Hemisphere, preceding the 2016 season in the N. Hemisphere.

It might be an indicator, but there is also a lot of +SST anomalies north and south of the equator, and to the west of 180°. I'm inclined to believe this is simply a storm taking advantage of good conditions and being in the right place at the right time. ACE generation in the SPAC hasn't exactly been off the charts this year.

[aspen]

Interestingly, that Cat-5 TC in the South Pacific, Harold, is currently the strongest on record in the South Pacific since Pam and Winston (2015), both of which immediately preceded the record-breaking El Niño of 2015–6. High ACE production in the South Pacific tends to be positively correlated with ACE in the EPAC/CPAC but negatively correlated with ACE in the Atlantic, since +ENSO favours stronger storms in these regions vs. the Atlantic.

Pam and Winston didn't occur during the same year. Pam occured in March 2015, and preceded the Niño and the 2015 season in the N. Hemisphere. Winston occurred February 2016 when the Niño was on the way down, after the 2015 season in the N. Hemisphere, preceding the 2016 season in the N. Hemisphere.

It might be an indicator, but there is also a lot of +SST anomalies north and south of the equator, and to the west of 180°. I'm inclined to believe this is simply a storm taking advantage of good conditions and being in the right place at the right time. ACE generation in the SPAC hasn't exactly been off the charts this year.

I’d have to agree. Harold seems to be a lucky storm that finally managed to take hold of the warm SSTs in its area. Every other SW Pacific storm has been a disorganized tropical storm/Cat 1 that formed out of a very broad precursor disturbance; Harold was lucky to have formed out of something more compact, and have a path taking it through the optimal environment for intensification.

[cycloneye]

 https://twitter.com/BenNollWeather/status/1247173465695817730

[Kingarabian]

All Nino indices rose this week

1+2 is + 0.8c
3 is up to +0.6C
3.4 is up to +0.6C
4 is up to +0.7c

The enso models continue to show a decline in Nino regions....but with the numbers staying the same or rising slightly each week, how confident are we that Enso will become neutral or even cool-neutral like the models show?


Sent from my iPhone using Tapatalk

But OHC is now dropping:

[aspen]

https://twitter.com/BenNollWeather/status/1247173465695817730

What would a negative Indian Ocean Dipole do to activity in the Atlantic and the NIO/SWIO/SPac basins?