GaWx

Per the Cowan CDAS charts: Thanks to Nino 4 and despite Nino 3 having leveled off, the Niño 3.4 has once again had faster warming today after appearing to be stalling out with it up to +0.692 as of 18Z. On May 30th, I had thought it was stalling near +0.575 and then I thought the same near +0.65 yesterday. It has warmed on this chart 0.36 over the last 8 days. Whereas this is nowhere near a record fast warming for 8 days, which is about twice as fast, it is still notable. What would be even more notable would be if it were to continue warming at a similar rate over the next week or so and get to +1.0. This warming started 2.5 weeks following the May 9th start of the 19 day -SOI streak. Considering that in combination with the >+1 C anomaly of the OHC as well as five subsequent solid -SOI days, it isn't surprising and there could very well be more warming over the next week. The SOI appears to be heading to neutral to slightly positive during the next week or so. But then it looks to probably head back down again for much of mid June, which may last through late June. That along with a continued quite warm OHC could easily lead to additional significant warming in July.

After probably a slightly +SOI to neutral period averaged out over the next week, the EPS, GEFS, and CFS are all hinting at the next significant -SOI period in mid June. Meanwhile, the last 5 days have averaged -20.

Low OLR is correlated with enhanced convection. The OLR anomaly centered on the Dateline at the equator is negatively correlated with El Niño and they tend to be lowest during fall/winter. I consider a multimonth period of sub -10 to be a pretty good indicator of El Nino. Sub -30 OLRs months are strong indicators of El Niño. I'll be following the OLR to see how fast it drops, especially as we reach late summer and more so in fall. The stronger El Niño events tend to have good drops starting by summer. The most recent OLRa in the table is the +10 of April. But that's still a big drop from the +20+ of the prior 5 months and is the lowest in 2 years. The April drop is the 2nd largest for incoming El Niños since 1976-7. How does April of 2023 compare to other Aprils of incoming El Niño years from lowest to highest? 1997: -18 2014: -15 2004: -13 1994: -5 1991: 0 1982: 0 2002: +4 2006: +5 1979: +5 1986: +7 2023: +10 1976: +10 2009: +11 2018: +19 So, 2023 is exceeded only by 1976, 2009 and 2018. However, keep in mind that 2023, 1976, 2009, and 2018 were 4 of the 5 cases which immediately followed La Niña. The only other was 2006, which had a +5 (8th highest). And though 1986's +7 didn't immediately follow La Niña, 1985-6 barely missed La Niña. So, lag is likely having an influence. https://www.cpc.ncep.noaa.gov/data/indices/olr

This is the first time I checked out the CFSv2 weeklies for implied SOI predictions based on Darwin/Tahiti SLP progs. I have no idea how well it can predict these SLPs or if there are any significant biases. So, fwiw, here's the mean prediction of the last 48 runs of CFSv2 weeklies: 6/2-9: +5 6/9-16: -12 6/16-23: -16 6/23-30: -9 6/30-7/7: -8 7/7-14: -11 These would produce a complete June SOI of ~-9 and a first two weeks of July SOI of ~-9.5.

Per Don Sutherland "Summer has barely begun and Joe Bastardi is forecasting a cold and snowy Winter 2023-2024. His key assumption is that the evolving El Niño event will be a Modoki El Niño." @BigJoeBastardi • 5h Weatherbell using modoki enso analogs of 57-58,65-66,02-03,09-10 fir winter 23-24 colder snowier than ave implications in south/east oppsite last winter europe also El Niño 10... aces. El Niño Modoki Kos. @snowman19 and for that matter just about everybody wrote the script! Edit: not that it can't be a cold SE/E winter, of course, especially if it is a Modoki, but that's beside the point.

Arlene it is! https://www.nhc.noaa.gov/text/refresh/MIATCPAT2+shtml/021433.shtml Data from the Air Force Hurricane Hunters indicate that the depression has strengthened into a tropical storm. On the last leg of the current mission, the aircraft found maximum 925 mb flight-level winds of around 50 kt and SFMR surface winds of around 35 kt. Based on these data, Tropical Depression Two has been upgraded to Tropical Storm Arlene with estimated peak winds of 35 kt.

Thanks. It wouldn't surprise me if they do upgrade with those winds. But I think that the highest FL winds are ~40-60 miles N of the center. Am I looking at the data correctly? If so, would that matter in the decision about upgrading?

Fair enough but I've seen TDs with even less gradient get upgraded.

No upgrade with 11AM EDT advisory even with a SLP drop from 1007 to 1002 mb since the last advisory. 1002 is unusually low for a TD. This is from the NHC discussion: Convection has persisted throughout the morning, although the tropical cyclone remains highly asymmetric and poorly organized. The low-level center is located southwest of the large area of persistent deep convection. An Air Force Hurricane Hunter aircraft has found no evidence of intensification this morning, and the Dvorak satellite intensity estimate continues to support a steady current intensity of 30 kt for this advisory. The Hurricane Hunters will continue investigating the system for the next several hours, and a short-lived increase to tropical storm intensity cannot be ruled out. However, conditions are expected to become increasingly unfavorable for intensification later today and tonight.

The May OHC just came in at +1.08. Although this is slightly cooler than the +1.19 of April, 2023 actually moved up from 3rd warmest last month to 2nd warmest in May due to 2014 dropping sharply. So, how does May of 2023 compare to Mays preceding other incoming (new) El Niño events? From warmest to coolest May OHC: 1997 (super peak): +2.01 2023 (????????): +1.08 1982 (super peak): +0.96 2014 (weak peak): +0.95 2018 (weak peak): +0.88 2009 (strong peak): +0.87 1991 (strong peak): +0.76 2006 (weak peak): +0.54 1986 (moderate peak): +0.31 2004 (weak peak): +0.30 1994 (moderate peak): +0.16 2002 (moderate peak): +0.07 1979 (weak peak): +0.06 Based on 13 rankings back to 1979: - 2023 is notable as 2nd warmest vs 3rd warmest last month - Although much cooler than 1997, it is still slightly warmer than 1982. But 1982's warming finally accelerates in August and exceeds +2 in October. - Still a bit warmer than the 2 strongs - Still much warmer than the 3 moderates - 2014 fell sharply from 2nd warmest last month to 4th warmest now. (Its next two months continued the sharp fall to a negative value.) - So, overall there's still a pretty good correlation of May OHC to later peak ONI peak as all 4 strong to super are still in top half and bottom half are still all weak to moderate. - These May OHC rankings suggest that strong is still very much a possibility for 2023 and even super still can't at all be ruled out. Although 2014 will continue to fall off sharply in future monthly comparisons, 2018 held pretty steady in upcoming months just below +1.0 before rising to +1.47 in October telling me to not yet eliminate even weak as a small possibility. - Absent any significant cooling, 2023 will almost certainly be either 2nd, 3rd, or 4th warmest as of June. 1997 will almost certainly remain by far the warmest in June with either or both of 1982 and 2009 possibly being warmer than 2023 in June depending on what 2023 does. *Edit: I haven't been including 1987 and 2015 in these tables because they were not new El Niño events but rather a continuation of the prior year's event, which would make them apples to oranges in comparison to 2023 and other new El Niño events. But I will note that 2015 peaked at +1.97 in August. So, all three supers peaked near or above +2 by October. This implies that 2023 would probably need to warm at least to the high +1 area by October to have a chance for a super peak with +2+ preferred.

Thanks for posting that OSTIA chart. I realize it isn't easy but it sure would help if all organizations went by one SST dataset for all measures. Regardless, I assume that looking at just the trend on whatever SST dataset one looks at is useful info and it is clear that both CDAS and OSTIA have been steadily increasing recently. Also, next Monday's update, which will incorporate the current week, will be informative. - There's "CDAS" that Levi Cowan's site uses. I googled and couldn't find anything telling me what CDAS is or even just what it stands for! Do you or does someone else here know more about what CDAS is and who uses it? - There's "OISSTv2.1", which is used for the SSTa tables that are updated each Monday. - There's "ERSST.v5" that's used for the ONI Nino 3.4 three month averaged charts that NOAA uses to determine the official ENSO classifications. - There's "OSTIA" that you just posted from the UKMET office. Edit: When I googled "CDAS", the first on the list was this: https://cdas.com It is for a law firm with "Cowan" as the first listed name. Is that not an unbelievable coincidence?!? I also googled CDAS SST and other similar things and didn't find what I was hoping to see.

That's the first time I can recall Paul Tweeting explicitly about the chance for a super El Niño. So, he's going ~50-50 on a 2015-16 strength, which was a peak at +2.6 (stronger than any other since 1900). This implies Paul is at higher than a 50% chance for a super since super starts at +2.0.

I was wrong. I thought Niño 3.4 was leveling out near +0.575 C. However, it is now up to +0.62 per Cowan's CDAS chart after some re-acceleration in the warming. It rose 0.015 just during the last 6 hours. It has risen nearly 0.3 over just the last 5 days. The recent BoM model had a warming to +1.25 in June. I've been thinking it was significantly too warm because I had been figuring that June would start near +0.5 C and that it would have to get to a seemingly unreasonable ~+1.5 by June 15th to have a chance for +1.25 in June overall. I still think that's going to be very tough as +1.5 is still a long way up from +0.62. That would require the next 15 days warm as fast as the last 5 days, which I could find only one instance of since 1981 during an incoming El Niño (March of 2014). Regardless, with the significant warming still not having stopped, it will be interesting to see where this will actually level off.

The full May of 2023 SOI comes in at -15. How does this rank compared to other Mays since 1876? It comes in 8th lowest, which is a strong indicator for an upcoming moderate+ and a decent indicator for the chance for a strong+ El Niño in the absence of an ongoing/outgoing one as per this list: Lowest 20 May SOIs since 1876/Nino peak 1896 -39 (oncoming strong) 1905 -34 (ongoing/oncoming mod) 1953: -26 (ongoing/oncoming weak) 1972: -24 (oncoming super) 1987: -20 (ongoing mod/oncoming strong) 1997: -19 (oncoming super) 1991: -18 (oncoming strong) 2023: -15 (???) 1897: -15 (outgoing strong) 2002: -14 (oncoming mod) 2015: -13 (ongoing weak/oncoming super) 1940: -13 (ongoing mod/oncoming strong) 1947: -12 (outgoing warm neutral) 2005: -12 (outgoing weak) 1994: -12 (oncoming mod) 1957: -12 (oncoming strong) 1951: -12 (oncoming mod) 1912: -12 (outgoing mod) 1929: -11 (oncoming weak) 1946: -10 (oncoming warm neutral) ---------------------------- Edit: I'll now take out ongoing/outgoing El Niño years: 1896 -39 (oncoming strong) 1972: -24 (oncoming super) 1997: -19 (oncoming super) 1991: -18 (oncoming strong) 2023: -15 (???) 2002: -14 (oncoming mod) 1947: -12 (outgoing warm neutral) 1994: -12 (oncoming mod) 1957: -12 (oncoming strong) 1951: -12 (oncoming mod) 1929: -11 (oncoming weak) 1946: -10 (oncoming warm neutral) ------------------ Data source: https://data.longpaddock.qld.gov.au/SeasonalClimateOutlook/SouthernOscillationIndex/SOIDataFiles/MonthlySOIPhase1887-1989Base.txt

How does the current OHC compare to past oncoming El Niño events? I used the 3rd column from here and compared Aprils to give an apples to apples comparison to 2023: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt From warmest to coolest April OHC: 1997 (super peak): +2.17 2014 (weak peak): +1.41 2023 (????????): +1.19 1982 (super peak): +0.93 2018 (weak peak): +0.81 1991 (strong peak): +0.80 2009 (strong peak): +0.65 2006 (weak peak): +0.42 2002 (moderate peak): +0.32 2004 (weak peak): +0.21 1986 (moderate peak): -0.02 1994 (moderate peak): -0.14 1979 (weak peak): -0.21 Based on 13 rankings back to 1979: - 2023 is respectable 3rd warmest - Although much cooler than 1997, it is a little warmer than 1982. - A bit warmer than the 2 strongs - Much warmer than the 3 moderates - Much warmer than 3 of the weaks and a bit warmer than 1 of the weaks, but oddly enough a little cooler than 1 of the weaks (2014) - So, overall there's a pretty good correlation of April OHC to later peak ONI peak as all 4 strong to super are in top half and bottom half are all weak to moderate. - But the weak 2014 is way out of synch with its 2nd warmest OHC and 2018 is somewhat out of synch with its 4th warmest OHC - These April OHC rankings suggest that strong is very much a possibility for 2023 and even super can't at all be ruled out. But 2014 suggests that although highly unlikely that even a weak for 2023 is not out of the realm of reasonable possibilities.

Though far from perfect, I've found based on past cases that the 180-100W max OHC anomaly was often a decent leading indicator of about where an incoming El Niño ONI peak might end up a couple of months later. The tendency was for ONI peak to be a bit lower than the OHC peak. Thus, if this +1.2 maximum OHC were to not be exceeded later this year, then I might be looking for a low end moderate ONI peak a couple of months later as the most likely. However, it remains to be seen whether or not this +1.2 OHC holds up as the max. I expect it won't and that it will likely be exceeded this summer as May is almost always too early for it to peak. Most OHC peaks were in Oct or Nov. OHC by month: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt I'll now compare the OHC peak including timing, with ONI peak/timing for El Niño events since 1978-80: 1. 1979-80: OHC peak +1.1 Nov ONI peak +0.6 DJF Lag: 2 months 2. 1982-3: OHC peak +2.1 Oct ONI peak +2.2 DJF Lag: 3 months 3. 1986-8: OHC peak +1.2 Jan '87 ONI peak +1.7 JAS '87 Lag: 7 months 4. 1991-2: OHC peak +1.7 Dec ONI peak +1.7 DJF Lag: 1 month 5. 1994-5: OHC peak +1.2 Nov ONI peak NDJ +1.1 Lag: 1 month 6. 1997-8: OHC peak +2.6 Oct ONI peak +2.4 NDJ Lag: 2 months 7. 2002-3: OHC peak +1.7 Oct ONI peak +1.3 OND Lag: 1 month 8. 2004-5: OHC peak +0.9 Sep ONI peak +0.7 NDJ Lag: 3 months 9. 2006-7: OHC peak +1.4 Nov ONI peak +0.9 NDJ Lag: 1 month 10. 2009-10: OHC peak +1.8 Nov ONI peak +1.6 NDJ Lag: 1 month 11. 2014-6: OHC peak +1.9 Oct '15 ONI peak +2.6 NDJ Lag: 2 months 12. 2018-9: OHC peak +1.5 Oct ONI peak +0.9 OND Lag: 1 month --------------------- Summary: 1. Avg lag OHC to ONI peak: 2 months 2. ONI peak averaged 0.1 cooler than OHC peak though range was 0.6 cooler to 0.7 warmer; ONI cooler 8 of 12 times and warmer 3 of 12 times

I believe that on average that the # of May-June Gulf TS has been higher during oncoming/current El Niño vs other ENSO.

Based on the last 24 hours, it appears that per Levi's CDAS chart that Nino 3.4 is probably going to top out for the time being near +0.575. Of course, even if that occurs it could still resume warming within a few days for another step up. By the way, there still is no new long string of solid -SOIs yet being strongly suggested on the two week runs meaning that probably will need to wait til mid June at the earliest. Today is and tomorrow will be pretty solid negatives (perhaps also June 1st), but I think that's about it for the near future.

Wasn't 1969-70, another cold E US winter, also an east based weak El Niño? There have also been a good number of other weak to low end moderate El Niño winters (I don't know about east vs west) that were cold in much of the E US such as 1939-40* (frigid in SE), 1919-20 (frigid in NE), 1904-05* (frigid in most of E US), 1887-8* (frigid in NE), 1884-5, 1880-1 *(frigid in NE), and 1876-7. But recent weak ones have not been (as) cold overall in the E US. I suspect some of that is related to their respective RONI being only warm neutral. *immediately followed La Niña

Interesting Tweets from Paul. I'm guessing that when he talks about there being no reason there couldn't be a "major" event that he's more or less saying there's no reason there couldn't be a +1.5+ 3.4 SSTa or strong+. Technically, he's not actually explicitly predicting a strong+, but he's just saying that one may very well occur/don't bet against it.

The 0.2 C warming of 3.4 on the Cowan CDAS chart the last couple of days was fueled largely by warming in the western portion of 3.4 based on a 0.25 C warming the last 72 hours in Nino 4 (fastest there since April 11-14) to its warmest yet of +0.52 C per this: It appears that this burst of warming might be slowing. So, we'll soon see if it is about to level off for the time being.

10/5/2

As snowman19 just posted via a Tweet, this new sudden warming in 3.4 per Levi Cowan's chart is notable: This shows the fastest 48 hour warming (0.2 C) since way back during March 5-7! But is it merely a short term rise that will soon level off making it insignificant in the big scheme of things as sometimes happens? After all, this warming has only warmed it back up to near its May 16th high. Or is there more to it? Also, keep in mind that this chart is only one source and not necessarily the "gospel". One thing I said here last week based on the past is that there often is a delayed several tenths rise in 3.4 ~3-4 weeks after a sustained solid -SOI. The recent 19 day long solid -SOI started on May 9th. We're nearly 3 weeks after that. Could this be related? Who knows but it will be interesting to follow. Regardless, there's no followup string of solid -SOI days in sight (on the 2 week models) as of yet. *Edited for correction as that's a 48 hour rise

Looking back in this ENSO thread allowed me to finally find the Roundy Tweet that started generating the posts here referring to him predicting a super Nino: This, indeed, is quite a bullish Tweet, but it was done nearly two months ago (on April 8th) and he hasn't Tweeted anything explicitly bullish about the potential Nino strength since then. All I've seen since are some bullish WWB related Tweets. The strongest JAS Nino 3.4 SSTa on record back to 1950 is +1.9 C. So, this post is implying that "perhaps" we'll have a +2.0+ in JAS, meaning "perhaps" a super Nino already by JAS. Just saying this is admittedly quite bullish. However, he only said "perhaps" rather than outright predicting that and he also said: "But it still has a month or two for the forcing to break down before it gets there." And again, that was way back on April 8th. So considering all of this, is it accurate to say that he currently thinks that a super Nino is coming? Opinions? I posted this on April 17th in response to it being posted: "Doesn't he mean strongest 3.4 on record for the late summer, itself? I see almost no chance for strongest on record 3.4 by late summer. That would be well into the +2 range: +2.6 per 2015-6 and +2.9 per 1877-8. The strongest on record in JAS, alone, is +1.9. The model consensus is no warmer than the high +1 area by JAS and that's ignoring what I think is a warm bias."

I'm reposting this that I did in here on March 31st: These El Niño winters that quickly followed La Nina were significantly colder in the SE US than the prior winter: 1876-7 (cold), 1880-1 (cold), 1904-5 (very cold), 1911-2 (cold), 1925-6 (normal), 1939-40 (very cold), 1957-8 (cold), 1965-6 (cold), 1972-3 (normal), 1976-7 (very cold), 2009-10 (very cold) These weren't: - 1887-8 was slightly warmer than 1886-7 and near normal - 1918-9 was much warmer than 1917-8 and was near normal. It followed the very cold 1917-8, which was one of the coldest La Niña winters on record - 2006-7 was warmer than 2005-6 and warmer than normal - 2018-9 was warmer than 2017-8 and warmer than normal --------- Tally: - 11 of 15 were significantly colder than the prior winter - 9 of 15 were cold to very cold - 4 of 15 were near normal - 2 of 15 were warmer than normal, two of the three most recent cases Conclusion: As one living in the SE who prefers a cold winter, I'd take my chances with El Niño this winter on a normal or colder winter based on the above history despite two of the three most recent cases being warmer than normal, which would keep from betting heavily on it. I certainly would prefer it over other ENSO! Keep in mind that four of these 15 were historically cold. Although this analysis is centered on the SE US, much of this can be used for other areas as well. That includes seeing which were the 15 El Niño winters since the late 1800s that quickly followed La Niña and analyzing those 15 winters for one's own region.