GaWx

I'm remaining open-minded about how much of the excess heat since 2023 can be connected to Hunga Tonga since it still hasn't been explained. The atmosphere is way too complex and Hunga Tonga was quite unique with regard to the volume of water vapor added to the stratosphere,

Just because we're about to have La Nina doesn't say anything about 2025-2029. And the paper's idea about a POSSIBLE multiyear El Nino before 2030 doesn't exclude La Nina in 2024-5. I'm at least going to wait to see what 2025-6 brings. Of course, even if we do have a multiyear Nino then, that wouldn't prove the connection to Hunga Tonga.

This same paper was put out in Aug of 2023 as per my 8/9/23 post quoted above. It appears the same one was just re-released on 5/27/24 and that's what Ryan is referring to. So, although Ryan refers to this as new, he doesn't realize it was first released 8 months ago. It is an interesting paper as it suggests that the significant effects may last til 2030 as Ryan says. Looking ahead to the possible effects on US winters 2025-6 through 2028-9 from the January of 2022 Tonga volcano, the chance of a multiyear El Niño MAY be enhanced while the volcano still has influence. Note how the DJF temperature anomaly pattern over the US comes rather close to a typical El Niño, including the cool SE and warm NW. Also, note especially figure 11d (see my link to August 2023 paper), which shows an El Ninolike Pacific SSTa pattern. From the paper: "Thus, it is possible that the SWV forcing from the eruption would favor a positive phase of ENSO on a multi-year timescale, but further work is required to confirm this, in particular with a model including fully interactive ocean and cloud feedbacks."

The WCS daily PDO as of 5/28/24 has plunged further to -2.66, the lowest since at least late Oct of 2022 (not just since Sep of 2023, which dipped as low as ~-2.63 as this graph shows). That means that the equivalent NOAA daily PDO would likely be in the general vicinity of -3.4 to -3.7! The May 2024 NOAA PDO is likely going to be down to the -2.5 to -2.9 range as the WCS May 2024 PDO drops to ~-1.8 to -1.9.

21/10/5

1. Latest (5/25/24) BoM model run sticking with only down to -0.07 for lowest ONI (not RONI) in autumn (SON): But keep in mind that it had a large warm bias last year. Its 5/20/23 run had SON ONI way up at +2.53 or 0.75 warmer than +1.78 actual: The next BoM run (6/3/23) had SON ONI even warmer (+2.73), which verified 0.95 too warm! 2. In stark contrast, the UKMET May of 2024 run has ASO ONI way down at -1.01 (though that’s actually significantly warmer than its prior run for JAS of -1.28): But unlike the way too warm BoM, the May of 2023 UKMET run for ASO ONI was nearly spot on with its +1.84 prog, a mere 0.06 too warm: 3. So, between the latest BoM and UK, I heavily favor the latest UK to end up the closer of the two for this fall’s ONI. Not necessarily nearly spot on but at least closer. And keep in mind that RONI would undoubtedly be significantly cooler than ONI.

No, it is the opposite because RONI looks at the contrast better with the surrounding extra warm waters that were caused by GW. With this last El Nino, RONI peak was only high end moderate vs ONI peak of borderline strong/super-strong. So, RONI was ~0.5C cooler than ONI. For the upcoming La Nina, there's a good chance for a similar relationship where ONI dips only to, say, -1.0 or -1.4 while RONI dips to, say, -1.5 or -1.8 meaning RONI once again cooler.

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

Chuck, 1. The record NOAA -PDO is -2.61 (1948-9). (Interestingly, that winter was neutral ENSO rather than La Niña.) This month has been near that avg. But I think it will still be a big challenge for the upcoming winter to avg near that strong even with the help of La Niña since 1948-9 was so phenomenally strong. The next strongest is -2.34 (2021-2)(moderate La Niña), 3rd strongest is -2.25 (1955-6)(strong La Niña, and 4th is -2.09 (1872-3)(weak La Niña). So, four sub -2 PDO winters over the last 170 years or one every 42.5 winters on avg. Could we get the 5th sub -2 PDO this winter? Yes, but the odds would be higher for -1.5 to -2.0 based on the data showing 16 winters in that range (4 times the frequency of sub -2) or ~one every 11 winters. That’s my educated guess as of now. We’ll see! 2. When you say “warmer winter”, do you mean warmer than last winter or just warmer than normal?

Another thunderstorm here late this afternoon. Only light rainfall (~0.10”).

- The equivalent current RONI is likely already down to ~-0.5 vs the equivalent ONI of ~+0.1. - There have been 21 sub -1.75 NOAA PDO Mays on record. Of those, 19 of the subsequent winters had a -PDO. The other 2, 1880-1 (Nino) and 1922-3 (neutral) had a neutral PDO. Edit: - There have been 22 +1.25+ NOAA PDO Mays on record. Of those, only 3 of the subsequent winters had a -PDO (all 3 followed mod+ El Niños and lead to cold neutral winters) vs 6 neutral and 13 +PDO. - So, correlation of May to winter PDO strong. - Thus with almost certain La Niña upcoming, -PDO this winter very likely

The WCS PDO for May is headed for ~-1.8. Based on the avg ratio between the PDO of WCS and NOAA, I’m projecting the NOAA May PDO will come out to ~-2.7 (-2.5 to -2.9), easily the lowest in May since 1950. Even a -2.45 would be the lowest May since 1950:

Thunderstorms with very heavy rain and lots of CTG lightning here the last 45 minutes. Rainfall really adding up with the typical street flooding. Severe warned nearby. I estimate a little over an inch.

The following tweet’s image clearly illustrates the idea of RONI, which is already nearing the -0.5 threshold of La Niña (look at all of the blue along the equator in the E and C Pacific) vs the equivalent to ONI, which is still only down to ~+0.2 per OISST and CRW. https://x.com/BenNollWeather/status/1793981601132798393 “This map compares current sea surface temperature anomalies with the global average anomaly. Rather than using a 30-year normal to compute anomalies, this method more clearly reveals areas that are unusually warm or cool relative to the rest of the planet. This is important”

This GW over-exaggerated the strength of this last El Niño as it made it appear to peak at borderline strong/super (per ONI) vs it for all practical purposes really peaking at borderline moderate/strong (per RONI). In other words, the contrast with surrounding tropical waters wasn’t as large as the ONI suggested. The MEI suggested an even weaker Nino peak.

No, it doesn't change my analysis at all as that analysis wasn't predicting the upcoming La Nina strength. Nothing in this Noll tweet is surprising except that I had never seen a prog of RONI until now. Of course, this is just a multimodel avg prog and thus we'll obviously need to see if it verifies well. But this prog of a moderate RONI based La Nina in ASO (-1.15) doesn't surprise me at all as I had already been thinking good chance for RONI based moderate La Nina by ASO.

Check this tweet out from met. Ben Noll as it actually has a prog of RONI, the first I’ve ever seen: https://twitter.com/BenNollWeather/status/1793235394219434190 ”In a warming world, it's becoming increasingly difficult to disentangle El Niño events from the climate change signal. In other words, when the entire equatorial Pacific Ocean is anomalously warm -like it was in recent months- it can be hard to distinguish the signal from the noise! The Relative Niño 3.4 Index is calculated by subtracting the tropical mean sea surface temperature anomaly (20˚N-20˚S) from the Niño 3.4 Index and multiplying by a scaling factor. The relative index describes the onset of convection better, is not contaminated by global warming, and can be monitored and forecast in real-time. This suggests that La Niña-like atmospheric patterns may build in the months ahead, likely starting before an official La Niña event is classified by most international centers. This is of significance to hurricane season in the Atlantic Ocean and weather patterns across the planet. ————————————— This ONI/RONI prog is from the C3S, an average of most of the major models of the world (see image below). It’s showing RONI-ONI to be -0.67 in May (near what it was in FMA) and -0.55 in Oct. Based on this graph, it’s showing a prog of ASO ONI to be ~-0.60 (weak La Niña) but ASO RONI to be ~-1.15 (moderate La Niña), a truer reflection of the predicted strength of La Niña since it is negating the surrounding tropical waters’ warming: RONI retrospectively calculated back to 1950: https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

Check this tweet out from met. Ben Noll as it actually has a prog of RONI! https://twitter.com/BenNollWeather/status/1793235394219434190 ”In a warming world, it's becoming increasingly difficult to disentangle El Niño events from the climate change signal. In other words, when the entire equatorial Pacific Ocean is anomalously warm -like it was in recent months- it can be hard to distinguish the signal from the noise! The Relative Niño 3.4 Index is calculated by subtracting the tropical mean sea surface temperature anomaly (20˚N-20˚S) from the Niño 3.4 Index and multiplying by a scaling factor. The relative index describes the onset of convection better, is not contaminated by global warming, and can be monitored and forecast in real-time. This suggests that La Niña-like atmospheric patterns may build in the months ahead, likely starting before an official La Niña event is classified by most international centers. This is of significance to hurricane season in the Atlantic Ocean and weather patterns across the planet. ————————————— This is the first time I’ve ever seen a model prog for RONI! It is the C3S, an average of most of the major models of the world. (See image below) It’s showing RONI-ONI to be -0.67 in May (near what it was FMA) and -0.55 in Oct. Based on this graph, it’s showing a prog of ASO ONI to be ~-0.60 (weak La Niña) but ASO RONI to be ~-1.15 (moderate La Niña), a truer reflection of the predicted strength of La Niña since it is negating the surrounding tropical waters’ warming: RONI retrospectively calculated back to 1950: https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

From met. Ben Noll, this is consistent with what I’ve been posting about S FL/Keys recently: A strong-to-severe marine heatwave has developed in South Florida's coastal waters amid the recent wave of noteworthy heat and humidity... The extremely warm water will likely form a positive feedback loop, with above average sea temperatures causing above average air temperatures and vice versa - a cycle that looks unlikely to be broken in the weeks ahead A pattern of persistent and strong high pressure over Mexico is driving the situation. When superimposed with the long-term warming trend, it creates some downright oppressive conditions. Simply put, such widespread and severe marine heatwaves are a sign of the warming climate. They are only expected to become stronger and last longer in the years and decades ahead. This event is a glimpse at what the future holds. It's not just Florida that's being affected: a category 5 "beyond extreme" marine heatwave is active near Port-au-Prince, Haiti, where it recently soared to 100˚F, a few degrees shy of the annual record. Santo Domingo, Dominican Republic, reached 101˚F this month, a degree shy of its annual record. The story has been similar for San Juan, Puerto Rico. Nighttime temperatures have been 5-10˚F above average in these areas, offering little or no reprieve from the heat. However, these locations can't hold a candle to Campeche, Mexico, which had a 26-day run of high temperatures exceeding 100˚F from April 23rd to May 18th. This included a ridiculous 113˚F reading on May 17th and a low of 83˚F that night, qualifying as 13˚F above average for the day as a whole. https://x.com/BenNollWeather/status/1792877963052261488?ref_src=twsrc^google|twcamp^serp|twgr^tweet

I just did an analysis of CONUS landfalls for RONI ASO -0.50 to -1.00 vs sub -1.00. E = east coast and G = Gulf coast including FL Keys; if storm landfalled on both as a H, I counted it as 1/2 E and 1/2 G (1995’s Erin and 2022’s Ian) ASO RONI -0.50 to -1.00: every season at least 1 1954: 3 (3E) 1955: 2 (2E) 1964: 4 (2E, 2G) 1970: 1 (1G) 1983: 1 (1G) 1995: 2 (0.5E, 1.5G) 1999: 3 (1E, 2G) 2011: 1 (1E) 2017: 3 (3G) 2021: 2 (2G) AVG: 2.20 (0.95E, 1.25G) ASO RONI sub -1.00: less active avg despite 2020 1973: 0 1975: 1 (1G) 1988: 1 (1G) 1998: 3 (1E, 2G) 2007: 1 (1G) 2010: 0 2016: 2 (1E, 1G) 2020: 6 (1E, 5G) 2022: 2 (1.5E, 0.5G) AVG: 1.78 (0.50E, 1.28G) Analysis of ASO RONI wk vs mod+: -sig. more CONUS H landfalls (100%/70% had 1+/2+) -sig. more E coast landfalls (60%/30% had 1+/2+) -slightly fewer G coast landfalls due to 2020 being active -E being nearly as active as G for wk is relatively high for E -2020 ASO is mod+ per RONI but is only wk per ONI H tracks: https://www.nhc.noaa.gov/data/ RONI: https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

5 of the 16 LIV players (31%) MC per this: https://golfweek.usatoday.com/lists/2024-pga-championship-how-all-16-liv-golf-players-fared-valhalla/ The 31% is actually pretty good considering that 50% of all 156 players MC or WD.

Thanks for posting this. This shows a dynamic model average ONI low of ~-0.9C in OND/NDJ. I’d probably conservatively subtract ~0.5C to estimate RONI, which would mean ~-1.4C for the implied dynamic model avg RONI prog.

Though severe warned for potential 60 mph wind gusts and 1” hail, I fortunately never saw anything close to that unlike the 4 hour power outage causing prior severe warned storm of 10 days prior (5/9). Also the CTG lightning wasn’t bad. But the rain was very heavy for ~30 minutes producing the typical localized street flooding. Rain fell for ~2 hours total due to followup convection. I received a total of ~1.25” of beneficial rain.

I’ve been following the Key West (KW) buoy data closely again recently to see how it is comparing to last year. Keep in mind that this buoy’s water temp is legit since it’s over deep water unlike the buoys over shallow FL Bay/just S of the S tip of FL. During 5/15-18/24, KW water averaged an insanely warm 30.5C! That was warmer than 5/15-17/23, which was “only” 29.1C. And then today (5/19), the KW avg rose to 31.0C! Last year around this date, KW started warming significantly and was up to 30.5C on 5/19/23. It didn’t fall back to that level til late August. The peak was on 8/10/23, when the avg was ~33.5C and one reading just touched 34.0C/93.2F!! There is a coral reef in this deep water near and I believe just S of the Keys chain. It suffered severe, extensive, and very longlasting bleaching much of last summer. I’ll be closely following this again this summer. If the most recent water temps are any indication, it isn’t looking encouraging. In addition to a significant increase in the warmth of the planet overall and more specifically in the N Atlantic Ocean in 2023 vs 2022, the Keys and nearby had a lengthy dry/sunny spell during July-early Aug, which exasperated the ocean heat. Will it be as bad there this summer? Key West latest buoy data: https://www.ndbc.noaa.gov/station_page.php?station=kywf1 2023 KW buoy data: https://www.ndbc.noaa.gov/view_text_file.php?filename=kywf1h2023.txt.gz&dir=data/historical/stdmet/

Strong thunderstorms approaching my area. Edit: Now severe warned.