GaWx

8 minutes ago, Stormchaserchuck1 said:

The last 5 years had -NAO Octobers. The last 5 years had +NAO Winters (CPC). 

Here’s the breakdown of Oct vs DJF NAO for +1.4+ Ninos since 1950:

2023: - +
2015: + +
2009: - -
1997: - N
1991: N +
1986: + -
1982: - +
1972: + +
1965: + -
1957: + -

 So, of the 5 +Oct, DJF was - thrice and + twice fwiw

4 minutes ago, Stormchaserchuck1 said:

23-24 is a good analog because we don't have enough data! I think you're the one who posted about every Strong+ El Nino since the 1800s having positive or neutral PDO until 2023. The PDO has surprisingly high correlation number with US conditions historically. For the whole year it's almost the same as ENSO! Giving ENSO 0.55 and PDO 0.45 makes 23-24 the best analog since the 1800s, not to mention that since 2012/2013, recent analogs have worked much better than far-away ones.

‘23 JJAS PDO -2.4
‘26 JJAS PDO -1.2

17 minutes ago, 40/70 Benchmark said:

God, I hope that grouping fails spectacularly moving forward....I'd just assume drive out to the desert's of Albuquerque and shot-gun a cactus than experience anything akin to the past four El Niño events during this coming season.

-2023 isn't a great analog because

1. its RONI peak of +1.4 pales in comparison to where 26 is headed and even where it already is

2. It was much less E based (cross between E based & basinwide) than 26 is progged to be

3. The only similarly strongly -PDO of any Niño of the last 150 years was 1951-2 and it’s RONI peaked at only +1.0

—————
-2019 is hardly an analog because it wasn’t even El Niño as it peaked at only +0.3 and was W based

———

-2018 isn’t a good analog because it peaked at only +0.8 and was slightly W based

————

-2015 is the only of these that’s a good analog but it was pretty much basin-wide, not E based

https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/v6/index/ersst.v6.pdo.dat

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/

12Z UKMET is 4th full run in a row with a Gulf TC and again maxes out in strong TS range but well to the W of the 0Z’s FL Pan with it coming into EC LA:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 78 HOURS
FORECAST POSITION AT T+ 78 : 21.8N 92.8W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 08.10.2026 84 22.1N 93.0W 1003 28
1200UTC 08.10.2026 96 23.3N 91.8W 1003 29
0000UTC 09.10.2026 108 23.0N 90.7W 1002 30
1200UTC 09.10.2026 120 24.8N 91.2W 1001 40
0000UTC 10.10.2026 132 26.2N 91.1W 997 44
1200UTC 10.10.2026 144 28.5N 90.3W 992 55
0000UTC 11.10.2026 156 31.3N 90.4W 994 30
1200UTC 11.10.2026 168 31.8N 90.3W 1006 25

On 10/1/2026 at 10:16 AM, WxWatcher007 said:

No hurricanes seems to be increasingly likely, but as for activity, the Gulf is starting to light up a bit on AI ensemble guidance.

0Z UK: high end 992 mb TS hits FL panhandle Sat AM and is the 3rd UK full run in a row with a Gulf TC:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 84 HOURS
FORECAST POSITION AT T+ 84 : 22.8N 94.2W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 07.10.2026 84 22.8N 94.2W 1005 27
0000UTC 08.10.2026 96 22.6N 93.1W 1002 28
1200UTC 08.10.2026 108 23.9N 91.7W 999 36
0000UTC 09.10.2026 120 25.0N 90.3W 997 41
1200UTC 09.10.2026 132 26.3N 89.4W 996 41
0000UTC 10.10.2026 144 27.9N 87.8W 992 53
1200UTC 10.10.2026 156 30.3N 86.6W 996 42
0000UTC 11.10.2026 168 32.6N 87.9W 1003 29

On 10/1/2026 at 1:16 AM, GaWx said:

Follow-up: As expected based on the model consensus having significantly warmer 2m maps on Sep 30th vs Sep 29th at 80N+, the DMI warmed notably yesterday (>1C) vs Sep 29th as it rose to the blue line (mean for 1958-2002). It should warm further tomorrow:

Follow-up: as expected per model progs, 80N+ warmed further since 9/30 with a total of a whopping 5C over just the last 4 days to solidly AN:

3 hours ago, OSUmetstud said:

NOAA Offical RONI ERSSTv6 released for September and JAS. 

2.08C and 1.69C

These both came in slightly lower than 1997’s 2.15/1.84

Sep OHC (keep in mind these aren’t relative) continues the record shattering of the prior 2 months with it at 3.38. The 2nd highest Sep is 2.38 (1997). Even if there were a relative version, it would still be a record.

11 minutes ago, EasternLI said:

Luckily there are some other ways to view the strength of enso besides SST related metrics and those are pointing at a record event as well. Record WWB's, record shear for the Atlantic hurricane season, VP anomalies that make all the other years pale in comparison. The MEI could be another and I'll be curious to see that once it updates with Sept included plus future updates. RONI vs ONI is an interesting conversation but I think both are likely useful in their own ways. 

Also the record summer -SOI 

 The NOAA ERSSTv6 Sep PDO was -0.74:

-As expected based on WCS, this was less negative than Aug’s -1.12

-This is the least neg Sep since 2019’s +0.44.

-2023 Sep was way down at -2.52!

-This is the 3rd month in a row that NOAA came in less negative than avg of WCS dailies, which was ~-1.0 in Sep

- The NOAA August PDO had come in at -1.12 vs the WCS avg of ~-1.55.

https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/v6/index/ersst.v6.pdo.dat

  Here I got rain since 12:45PM-1:30 moving NE with some of it very heavy. This is in addition to a quick shower this morning and moderate rain (few tenths) late yest. afternoon from popups. It appears I’dreceived 1.5”+ from all of this with most of it just since 12:45PM. This compares to ~2.55” for all of Sep!

 Update at 5: been getting additional mod to heavy rain since 4:45. I’m now likely at 2”+ since yest.

1 hour ago, LakePaste25 said:

RONI vs ONI are not important to me this year because both are well above the threshold for super on the daily index, and will be for the 3 month index eventually. 

for records, I only care about absolute SSTs. similar to how we measure record heatwaves based on setting the absolute temperature of say, 105 degrees, not the “record anomaly.” We are currently above record SSTs in the 3.4 region. 

 

 We agree that the absolute 3.4 temp has been blowing away its record since summer on OISST. But a portion of that difference from prior records is obviously due to the globe being near its warmest on record:

-Avg trop ocean warming since 1997 is ~0.6C. So, without any of that warming, 2026 OISST would still be warmer going back to Sep 1st. But the diff would be ~0.6 smaller.

-Avg warming since 1982 ~~0.8C. So, it would still be warmer than 82 w/o the GW since then but would be ~0.8 smaller diff.

-It has warmed ~0.3C since ‘15. So, even after taking into acct GW, it would still be blowing away ‘15.

-It is pulverizing ‘23 as that was a much weaker Nino at this point vs the other 3 and there’s been some GW since then.

-Also, keep in mind that cyclonicwx’s OISST graph has been ~0.4 warmer than NOAA’s OISST the last 2 months. They used to be within ~0.1 apart on avg. I don’t know why, but it’s possible Alex’s OISST has been skewed a few tenths higher due to a bug for all I know.

-Even after taking into account both a possible bug in Alex’s graph and GW, ‘26 looks like it would still be at a record in 3.4.

1 hour ago, bluewave said:

The original paper that RONI is based on discusses it mostly being developed to prevent weak La Nina’s from getting lost in the mix rather than some deficiency in measuring super El Niño events.

Plus the weaker El Niños not being able to fully couple. Both instances were also a function of the record WPAC warm pool. 

So the ONI and the absolute SSTs are a good measure of how intense this event is becoming.

My original ONI post was correct as the original ONIs we relied on for many years into the 2010s had the ONI with the 1972-1973 event peaking at the +2.0 to +2.1 range. So a lower end super El Niño event. 

 

1. The concept of RONI applies to all ENSO.

2. ONI is a good measure of the combo of GW and ENSO. RONI is a good measure of ENSO, alone.

3. NOAA officially currently has 1972-3 at +2.0.

30 minutes ago, JLPhill said:

 

How much is this complicated by the fact that some of the feedbacks reinforcing El Niño depend on absolute SST ? Convection becomes much more favorable once SSTs reach roughly 27–28C, and when that convection shifts eastward it can weaken the trade winds and reinforce El Niño.

 As the globe warms, the threshold for the SST becoming much more favorable for convection warms:

Significant Increase in Sea Surface Temperature at the Genesis of Tropical Mesoscale Convective Systems

“We show that this threshold (SSTG) has undergone a significant warming trend at a rate of ∼0.2°C per decade. The SSTG shows a remarkable correspondence with the tropical mean SST and upper-tropospheric temperature on interannual and longer timescales.”

“The development of tropical ocean showers and thunderstorms requires a warm ocean surface as an energy source fueling the storm.”

”Using satellite observations and a high-resolution global climate model, we show that this threshold has undergone a significant warming trend during the past several decades and will continue to increase in the future. This warming trend is closely related to the changes in the tropical mean SST. A constant relationship between the SST threshold and upper-tropospheric temperature is found in both the current climate and a warming climate, which corroborates the argument that tropospheric temperatures in the tropics approximately follow a moist adiabatic adjustment.”

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101950

58 minutes ago, bluewave said:

The old ONI that we used before the recent updates was also +2.1. It’s perfectly fine to use the ONI as a measurement of the actual intensity of the event. With an event as extreme as this RONI can make the event seem weaker than it actually is.

https://x.com/BenNollWeather/status/2105084471750037987

From a scientific perspective, part of the challenge is that weather patterns in different parts of the world are not equally sensitive to the same El Niño index. In South America, for example, Niño 1+2 is particularly important, while patterns across the U.S., Australia, Singapore and many other regions are more closely associated with conditions in Niño 3.4. Some rely on a blend of ocean-atmosphere indicators (e.g., ONI, RONI, SOI, EQSOI, OLR, MEI, etc.) to capture coupling. For the public, the minutiae of those indices matter much less. What's record-breaking in one index may not be record-breaking in another, and I think it's incumbent on the communicator to make that clear. At the very least, if a record is being claimed, then a reference to the index/data set being used is essential (see attached). Not everyone will read the fine print, but it's duty of care. I think there's an opportunity for a larger body to step in (e.g., WMO) to classify a record El Niño event, if there's sufficient evidence, like they would a global temperature record. Lastly, I think the RONI-ONI debate will go on for years. RONI is more closely tied to atmospheric responses. ONI informs absolute extremes. In the ONI space, every tenth of a degree matters to global water vapor levels and temperatures, and therefore, the weather. The best approach is up for debate, but I think showing both is a fair balance. One El Niño, many ways to measure it!

https://x.com/WeatherProf/status/2105064342441939064

On the other hand, if you are trying to communicate the absolute strength of this El Niño vs other historic El Nino’s, how global warming has impacted it, or how it may impact global temperatures in the coming months - then use the traditional ONI or raw sea surface temperature anomalies. Certainly it can be confusing to the public, but I’d argue the relative index inadvertently obscures the larger climate signal - it can be misleading because it basically subtracts the warming that has occurred in recent decades. So it’s unintentionally deceptive.

You said in your earlier post that I responded to:

“It was a+2.1 event up until a few years ago before the CPC dropped it to +1.8. So until very recently it was rated as a lower end super.”

1. The CPC officially now has 72-3 at +2.0, not +1.8, as I showed, because ONI hasn’t been official since Feb.

2. You said,

“With an event as extreme as this RONI can make the event seem weaker than it actually is.”

 No, it’s not RONI making the event seem weaker. It’s ONI making the current Nino seem stronger than it really is due to GW. That’s the reason the RONI exists.
 
 ONI isn’t per NOAA and BoM the absolute strength of the 26 Nino, itself, because that exaggerates the strength due to adding the increasing warming from GW to the warming from El Niño, itself. The warming from El Niño, itself, is what RONI measures.

 I’ll use a hypothetical example to illustrate better:

-Say that the avg worldwide tropical ocean 30 year SSTa is at +1.0 vs its prior 30 year avg. Now say that 3.4 is also at +1.0 vs its own 30 yr avg. Per ONI it’s a +1.0 Nino. But per RONI it’s at 0.0/neutral because it’s measuring the contrast of the 3.4 anom vs the anomaly of the tropical waters. NOAA and BoM at the least have determined that +1.0 is deceptively high in this example because 3.4 is up to +1.0 due to GW, not because of El Niño. 

 Measuring the true strength of ENSO means measuring the contrast with surrounding tropical waters. If 3.4 and avg tropical waters are both at +1.0c there’s essentially no contrast (no relatively warm tongue in 3.4) and thus no Nino. A contrast is needed to have a Nino (or a Niña) per the official RONI. With no contrast like in this example it is neutral.

@mitchnick

2 hours ago, chubbs said:

https://bsky.app/profile/khaustein.bsky.social/post/3mwqu6hrps22s

 

26 is also notably colder than 23 in the Arctic.

1 hour ago, MJO812 said:

People throwing in the towel in October make me laugh. Same people do this every winter.  There are so many factors to consider during the winter.  Its not just enso.

Even throwing in the towel just based on ENSO, alone, would seem to be awfully bold.

I know it is hard to accept because of Fay’s tenacity, but the 0Z UKMET actually dropped her coming back to being a TC. Poor Fay 

4 hours ago, bluewave said:

It was a+2.1 event up until a few years ago before the CPC dropped it to +1.8. So until very recently it was rated as a lower end super. 

In any event, it’s rare to get a +AO +EPO +WPO pattern in October regardless of the ENSO. We haven’t since this October combination since the 2011 La Niña. 

But this time around we are getting a stronger mid-latitude ridge across the CONUS than 2011 had. Unusual to get such a strong TPV this early in the season.

 The CPC has 1972-3 peaking at +2.0 in its most up to date RONI table linked just below. Since RONI is the official way of classifying (and has been since Feb), that’s the current CPC official peak for 1972-3 rather than +1.8:

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/

 More on the transition of CPC from ONI to RONI for official classification of ENSO (this was released in Feb 2026):

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/announcement.php

 From the link above:

“The Climate Prediction Center is making the shift to use the Relative Oceanic Niño Index (RONI) to better designate past events and predict future ENSO.”

———————

 The table at the link below, which is to the most up to date ONI, has 1972-3 peaking at +1.8. But ONI hasn’t been the official way for CPC to classify since Feb. At the top it says this:

This page will continue to be updated by the 5th of each month, but per NWS Public Information Statement 26-05, the Relative Oceanic Niño index (RONI) is used for official monitoring and prediction of the El Niño-Southern Oscillation (ENSO) phenomenon.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/oni/v6/

@Maestrobjwa

40 minutes ago, olafminesaw said:

Womp womp

 This like another map I saw this morning shows that I’d get within just the next few days at least as much as I got in all of pretty dry Sept., which was ~2.55”. So, I hope it verifies pretty closely for MBY. In reality due to the showery nature of some of this producing isolated heavy amounts, I realize there will likely be significant variations in totals within pretty short distances though.

15 hours ago, LakePaste25 said:

Beautiful! going to be a crappy winter regardless so might as well root for the highest possible 

I agree with most that a record strong RONI is likely at this point. But NOAA is ~0.4 cooler than this fwiw (low +2s). So, it very likely won’t get nearly as warm as some models, like the BoA (still way up near +3.8) are showing.

 Regardless, the strongest anomalies are going to continue to be in 1+2 and 3. This is now the most E based on record by a good margin over 1997, and that’s looking to continue down the road.

1 hour ago, Maestrobjwa said:

Now hang on...I was told in another thread that 72-73 didn't technically classify as a super. But was it?

1. Technically FYI, “super” is not an official category for NOAA. I think they call those with RONI max of +2.0+ “very strong” or something similar. But here we including myself usually call them “super”.

2. 72-3 barely qualifies as “super” or “very strong” per the RONI table:

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/

20 minutes ago, MANDA said:

I know 1914 has lowest ACE on record.  I consider anything not in the satellite era questionable.

In the satellite era what season has lowest ACE?  

17.4 (1983)

 Going back all the way to 1851, only 3 had lower ACE than 1983 and all of them could have been higher in reality due to being way before the satellite era: 1914, 1925, 1907

https://en.wikipedia.org/wiki/Accumulated_cyclone_energy

 I ended up getting only ~2.55” of rainfall in Sept, which is well below the longterm average of >4.5”. The upcoming progged significant rainfall in early Oct here would be most welcomed!

Tulsa, OK, was 84.3 F in Sep ‘26, which was in addition to being 10.1 warmer than the longterm Sep mean:

- 2.4 warmer than its 2nd warmest Sep

- 1.4 warmer than its longterm mean for July

- warmer than 69% of Julys, 74% of Augusts, and 98% of Junes on record (records back to 1905)

@donsutherland1