2026 ENSO Updates

[cycloneye]

 https://x.com/webberweather/status/2028979292873605153



 https://x.com/webberweather/status/2028980372814328194

[cycloneye]

The BoM latest outlook of ENSO has the headline "La Niña is close to it's end.



https://www.bom.gov.au/climate/enso/?ni ... iod=weekly

https://www.bom.gov.au/climate/ocean/ou ... abs=Graphs

[jconsor]

Pretty deceiving in my view because this chart averages 15S-15N latitude. Vast majority of the strong westerly anomalies are from about 7.5 to 15N from second week of Mar heading into mid-Mar, with easterly anomalies in the central Pacific from near the equator to 15S.

Given the MJO progression EPS weeklies are showing in late Mar (8 to 1 to 2), would expect the westerly anomalies that are near/west of the dateline to progress into the Eastern and central Pacific, but be forecast outside the tropics than during the second week of Mar.

Dang.

https://i.imgur.com/BaICekJ.jpeg

[mixedDanilo.E]

Pretty deceiving in my view because this chart averages 15S-15N latitude. Vast majority of the strong westerly anomalies are from about 7.5 to 15N from second week of Mar heading into mid-Mar, with easterly anomalies in the central Pacific from near the equator to 15S.

Given the MJO progression EPS weeklies are showing in late Mar (8 to 1 to 2), would expect the westerly anomalies that are near/west of the dateline to progress into the Eastern and central Pacific, but be forecast outside the tropics than during the second week of Mar.

Dang.

https://i.imgur.com/BaICekJ.jpeg

Yep this is a look at the EPS anomalies at 360 hours out. Strong westerlies but north of the EQ.

[cycloneye]

RONI for DJF is down to -0.9C.



https://www.cpc.ncep.noaa.gov/products/ ... atest-data

PDO for Febuary is down to -1.01.

https://www.ncei.noaa.gov/pub/data/cmb/ ... v5.pdo.dat

[cycloneye]

 https://x.com/BenNollWeather/status/2029210270388895794

[DorkyMcDorkface]

RONI for DJF is down to -0.9C.

https://i.imgur.com/LRSQKqb.jpeg

https://www.cpc.ncep.noaa.gov/products/ ... atest-data

PDO for Febuary is down to -1.01.

https://www.ncei.noaa.gov/pub/data/cmb/ ... v5.pdo.dat

As long as the warm plume extending from Japan to S of the Aleutians remains, the index will have a hard time rising, despite the beginnings of +PMM arising. If anything, said waters have actually gotten warmer since last month. Is it just me or is the index more heavily dependent on that region than the horseshoe off the Pacific NA coast?

[Kingarabian]

RONI for DJF is down to -0.9C.

https://i.imgur.com/LRSQKqb.jpeg

https://www.cpc.ncep.noaa.gov/products/ ... atest-data

PDO for Febuary is down to -1.01.

https://www.ncei.noaa.gov/pub/data/cmb/ ... v5.pdo.dat

As long as the warm plume extending from Japan to S of the Aleutians remains, the index will have a hard time rising, despite the beginnings of +PMM arising. If anything, said waters have actually gotten warmer since last month. Is it just me or is the index more heavily dependent on that region than the horseshoe off the Pacific NA coast?
https://i.imgur.com/VbOiOF2.png

Well that region is half of the calculation and it's much more positive than the horseshoe off of the WCONUS. In prior decades we didn't see this issue where the waters east of Japan remain stubbornly warm.

[Kingarabian]

RONI for DJF is down to -0.9C.

https://i.imgur.com/LRSQKqb.jpeg

https://www.cpc.ncep.noaa.gov/products/ ... atest-data

PDO for Febuary is down to -1.01.

https://www.ncei.noaa.gov/pub/data/cmb/ ... v5.pdo.dat

As long as the warm plume extending from Japan to S of the Aleutians remains, the index will have a hard time rising, despite the beginnings of +PMM arising. If anything, said waters have actually gotten warmer since last month. Is it just me or is the index more heavily dependent on that region than the horseshoe off the Pacific NA coast?
https://i.imgur.com/VbOiOF2.png

Well that region is half of the calculation and it's much more positive than the horseshoe off of the WCONUS. In prior decades we didn't see this issue where the waters east of Japan remain stubbornly warm.

I wonder if it's correlated to the SOI as the SOI has also been disconnected in terms of ENSO phase, similar to the PDO when it's not La Nina.

[cycloneye]

The next CPC important update will be on march 12th when they will have a complete analysis of how things are in ENSO and the probabilities of El Niño how will they be. Stay tuned for that but in the meantime, there will be models releasing their march runs from today like ECMWF and NMME on the 8th.

[cycloneye]

Boom from ECMWF.

[Ntxw]

RONI for DJF is down to -0.9C.

https://i.imgur.com/LRSQKqb.jpeg

https://www.cpc.ncep.noaa.gov/products/ ... atest-data

PDO for Febuary is down to -1.01.

https://www.ncei.noaa.gov/pub/data/cmb/ ... v5.pdo.dat

As long as the warm plume extending from Japan to S of the Aleutians remains, the index will have a hard time rising, despite the beginnings of +PMM arising. If anything, said waters have actually gotten warmer since last month. Is it just me or is the index more heavily dependent on that region than the horseshoe off the Pacific NA coast?
https://i.imgur.com/VbOiOF2.png

We had a discussion a few page back how the PDO EOF has shifted more towards EOF2. NPAC SSTs are warming rapidly and the gradient is shifting much further north thus the persistent warmth east of Japan. Past historical references isn't helping much using the old method. How the PDO is effecting other regions is ever so changing, as is with other warming oceans. Much like ONI/RONI needed the adjustment so will the PDO.

[Yellow Evan]

Post-February 2026 analog list
1957
1963
1982
1986
1997
2002
2014

Based primarily on February sea surface temperature configurations (specifically looking for years with +PMM, low amplitude PDO, and years that exited -ENSO but are also started to develop a costero and/or +SPMM), late winter/early spring trade wind pattern (both at and above the equator) and the sub surface. Both the February and September composite are a little too +PDO happy for my tastes but otherwise seem reasonable. A few years like 1968, 2018 and 2023 barely missed the cut and could merit inclusion depending on how the PMM or PDO behave next month.

[Kingarabian]

Post-February 2026 analog list
1957
1963
1982
1986
1997
2002
2014

Based primarily on February sea surface temperature configurations (specifically looking for years with +PMM, low amplitude PDO, and years that exited -ENSO but are also started to develop a costero and/or +SPMM), late winter/early spring trade wind pattern (both at and above the equator) and the sub surface. Both the February and September composite are a little too +PDO happy for my tastes but otherwise seem reasonable. A few years like 1968, 2018 and 2023 barely missed the cut and could merit inclusion depending on how the PMM or PDO behave next month.

https://i.imgur.com/GwsQeze.jpeg
https://i.imgur.com/V8mfczv.jpeg

2014 is probably the most feasible option IMO.

[mixedDanilo.E]

Post-February 2026 analog list
1957
1963
1982
1986
1997
2002
2014

Based primarily on February sea surface temperature configurations (specifically looking for years with +PMM, low amplitude PDO, and years that exited -ENSO but are also started to develop a costero and/or +SPMM), late winter/early spring trade wind pattern (both at and above the equator) and the sub surface. Both the February and September composite are a little too +PDO happy for my tastes but otherwise seem reasonable. A few years like 1968, 2018 and 2023 barely missed the cut and could merit inclusion depending on how the PMM or PDO behave next month.

https://i.imgur.com/GwsQeze.jpeg
https://i.imgur.com/V8mfczv.jpeg

I can't get myself to believe that the Atlantic will be that cold as it shows on the anomaly maps. It just seems impossible in the era that we are in, and especially if that doesn't happen, I wonder how that would impact the Atlantic's ability this year.

[Yellow Evan]

Post-February 2026 analog list
1957
1963
1982
1986
1997
2002
2014

Based primarily on February sea surface temperature configurations (specifically looking for years with +PMM, low amplitude PDO, and years that exited -ENSO but are also started to develop a costero and/or +SPMM), late winter/early spring trade wind pattern (both at and above the equator) and the sub surface. Both the February and September composite are a little too +PDO happy for my tastes but otherwise seem reasonable. A few years like 1968, 2018 and 2023 barely missed the cut and could merit inclusion depending on how the PMM or PDO behave next month.

https://i.imgur.com/GwsQeze.jpeg
https://i.imgur.com/V8mfczv.jpeg

I can't get myself to believe that the Atlantic will be that cold as it shows on the anomaly maps. It just seems impossible in the era that we are in, and especially if that doesn't happen, I wonder how that would impact the Atlantic's ability this year.

1982/1986 is probably skewing the MDR down a bit.

[cycloneye]

 https://x.com/DylanFedericoWX/status/2029606747040522576

[cycloneye]

Good point from Andy.

@AndyHazelton
This is a key point. At this point, it appears we will have a classic Wavenumber 1 (subsidence over the Atlantic and Africa, rising over the Pacific) El Niño. This means that shear and dry air across the Atlantic will likely be more like 1997, 2009, or 2015 than 2023, which was a highly unusual year with an extremely warm Atlantic that seems unlikely to repeat.

 https://x.com/AndyHazelton/status/2029739425005985918

[cycloneye]

 https://x.com/BenNollWeather/status/2029901123948323276



 https://x.com/BenNollWeather/status/2029901128612336065



 https://x.com/BenNollWeather/status/2029901134794772831

[cycloneye]

Here is a great thread from Eric Webb about the IOD and it's effects on ENSO.

 https://x.com/webberweather/status/2030005880394240404



 https://x.com/webberweather/status/2030007138656079922



 https://x.com/webberweather/status/2030007987625202014



 https://x.com/webberweather/status/2030008637368979874



 https://x.com/webberweather/status/2030009534153118165



 https://x.com/webberweather/status/2030011129548919107