GaWx

24 hour Nino 3.4 SSTa changes per Levi Cowan's CDAS graphs 6Z to 6Z: 5/29 to 5/30: +0.039 5/30 to 5/31: +0.023 5/31 to 6/1: +0.049 6/1 to 6/2: +0.009 6/2 to 6/3: +0.023 6/3 to 6/4: +0.036 6/4 to 6/5: +0.033 6/5 to 6/6: +0.084

Wow, the CDAS Nino 3.4 is zooming. It is up a whopping 0.037 over just the last 12 hours to +0.779! It has warmed 0.45 within the last 10 days. This implies that the average of the OISST and ERSST is probably currently up to near +0.9. If this keeps up, those two could be up near +1.0 within 2 days. I'm now starting to wonder if the BoM 3.4 is going to somehow get its +1.2 for June after all. Still not expecting it but I'm no longer dismissing it as extremely unlikely. Meanwhile, the SOI has finally risen almost to 0 just after a week that averaged -18. The 30 day has dropped to -20 and the 90 day has fallen to -7.5, indicative of El Niño.

I just took a walk with it near 70 and dewpoints in the mid 50s. It was similar last evening. It was very comfy for both walks. That's unusual for June down here.

But it (25) has so far been strongly over-performing per this and peak is likely still a ways out. Regardless, I no longer feel that there's much of a chance that individual solar cycle variations have much influence on our climate.

We'll see if it does. I'm educatedly guessing based on model biases and the very warm MC that it will. The GEFS/EPS do have a moderate move through 4/5. Some of the others don't even get it there outside of the circle as of now. Newly developing Nino events in 1986 (June), 1997 (May), 2002 (May and again in June), and 2004 (May) all had moderate or stronger moves through both phases 4 and 5 during May and/or June. Looking later: 1976 (Aug/Sep), 1979 (Sep/Oct), 2002 (Aug), and 2009 (Sep) had similar. That means that 7 of the 13 new El Niño events during the period covered by MJO historical data had a moderate or strong move through both 4 and 5 at some point(s) between May and Oct. So, there'd be nothing unusual if 2023 were to have a moderate or strong move through both 4 and 5 this month. http://www.bom.gov.au/climate/mjo/

I also think that a high end strong in autumn is increasing in probability vs how it looked a couple of weeks ago, when I thought it was decreasing. With the Euro's 6/1/23 run holding onto a similar SON to the prior run's +1.94 instead of cooling off, that supports an increased chance in my mind. But keep in mind that it remains well below the +2.7 of the BoM's SON, which I continue to feel is too high.

Per this morning's CPC weekly release, all four Nino regions' anomalies warmed 0.2-0.4 in the OISST based weeklies covering last week's significant warming centered on May 31st (keep in mind these are based on the prior calendar week and are rounded to the nearest 0.1): Nino 1+2: warmed 0.3 to +2.3 Nino 3: warmed 0.3 to +1.1 Nino 3.4: warmed 0.4 to +0.8 Nino 4: warmed 0.2 to +0.6 In Nino 3.4 for the average for the same period (last calendar week) in comparison, CDAS per Cowan's graph of dailies was only +0.57. As just mentioned, OISST for last week was +0.8, implying between +0.75 and +0.85 since it was rounded. So, OISST was at least 0.18 warmer than CDAS last week. It had averaged warmer by 0.13 for Mar-May overall per my earlier post. The 0Z 6/5/23 CDAS is still rising steadily and is up to +0.73. That means that the current OISST could be +0.9 and that the CFS' +1.0 for June is quite believable. The new BoM's +1.2 will still be tough to reach but we will see. OISST based weeklies: https://www.cpc.ncep.noaa.gov/data/indices/wksst9120.for CDAS for Nino 3.4 per Tropical Tidbits:

Due to a combination of several days of NE winds and the full moon, CHS had major and lower SC to GA had moderate coastal saltwater flooding Sun evening. This lead to US Highway 80 to Tybee being flooded and the 10th highest tide on record back to 1935 at Ft. Pulaski with 10.2'! I saw marsh grass that normally sticks out above the water even at high tide completely under water Sun evening!

The brand new BoM (6/3/23 run) has just been released and was initialized well with May. June cooled slightly from +1.3 in the prior run to +1.2. I feel that this is still too warm. Despite June's slight cooling, July remained at +1.7 and August-November all warmed 0.2 to +2.4, +2.6, +2.7, and +2.9, respectively! ASO surprisingly warmed from +2.4 to +2.6, which would be the warmest on record for ASO beating the +2.2 set both in 2015 and 1877! SON at +2.7 would also be a new record. Although the May BoM has had no net bias in predicting ASO the last 10 years averaged out, 3 of those 10 did miss 0.6 too warm (2022, 2017, and 2014). I continue to see little chance of it getting even close to being as warm as it has. The May Euro is only at +1.94 for SON vs the BoM's +2.7 and the May Euro hasn't been too cold for ASO since way back in 2004! http://www.bom.gov.au/climate/ocean/outlooks/index.shtml#tabs=Graphs&region=NINO34

That sub -1 area is centered in the middle of the monthly 100-180 W OHC that I track down to 300 meters. Despite that, the May OHC anomaly was still up at +1.08. That shows how warm the rest of that layer is.

1. Looking at the CFSv2 ensemble mean, it has April and May pretty close to the average of OISSTv2.1 and ERSSTv5. So, it is initialized pretty well and did well with May. 2. It has June close to +1.0. With June CDAS starting off near +0.7, this would require CDAS to reach ~+1.0 at midmonth and end at ~+1.3 per a smooth slope assumption to get +1.0 for the month. But keep in mind that CDAS has averaged ~0.1 cooler than OISST/ERSST per the analysis I just did. So, OISST/ERSST could already be up to ~+0.8. If so, the +1.0 for the June CFS would seem reachable (start at +0.8 and end at +1.2) unlike the +1.3 of the last BoM release (May 20th). 3. The CFS has July at +1.5. If July were to start at +1.2, it would probably have to end at ~+1.7 to +1.8. That would be a challenge but that's a good ways out. So, we'll see. 4. It has August at +1.75. If July gets to +1.5, that would be very doable. 5. It has ASO +1.95-2.00. That's much more reasonable than that last BoM's +2.5 but still more than likely too high imho.

It is a coincidence but the 1899 #s just happen to match my Atlantic tropical forecast for 2023.

1. I've been wondering and asking here how CDAS is calculated. Do you know that and also what CDAS stands for? Anyone know? 2. Whereas Cowan's charts are CDAS based, I want to make sure that those viewing this thread realize that the maps bluewave posted along with the official ENSO ONI updates are both based on ERSSTv5 and that the CPC weeklies issued on Mondays are based on OISSTv2.1. 3. I just did some comparisons of last 3 months for the 3 datasets in 3.4: a) Per Cowan CDAS daily graphs: - Mar -0.22 - Apr +0.06 - May +0.39 b) Per ERSSTv5 graphs used for ONI: - Mar -0.10 - Apr +0.15 - May +0.40 c) Per OISSTv2.1 based weekly #s: - Mar -0.04 - Apr +0.20 - May 1-27: +0.45 (CDAS May 1-27: +0.37) The above shows that Cowan's CDAS graphs have been the coolest for March-May with them averaging 0.07 cooler per month vs what's used for ONI and 0.13 cooler per month vs what's used for the weeklies issued on Mondays. So, based on Mar-May, the other datasets for early June are more likely running about the same to slightly warmer than CDAS rather than slightly cooler than CDAS. Based on this I'm educatedly guessing that the OISSTv2.1 based Nino 3.4 weekly to be released tomorrow, which will cover the average for May 28th-June 3rd, will be either +0.6 or +0.7. This compares to the prior weekly of +0.4.

Per Levi Cowan's Nino 3.4 CDAS based table, it has (as Leon just Tweeted) warmed to +0.7, which is a warming of 0.37 over just the last 9 days. Although the record fastest warming over the last 40 years during an incoming El Niño is ~twice that much, this is still a significant rise for just a 9 day period and it is still rising pretty steadily. Region 4 has also been warming pretty rapidly over the last three days (+0.05/day) and it has warmed 0.4 over just the last 9 days. Meanwhile, Nino 3 has stalled the last 3 days after warming 0.3 the prior 6 days. With Nino 3 stalled but already up at +0.975 and Nino 4 now up at +0.65 and still warming steadily, it would appear there's room for Nino 3.4 to warm from its current +0.7 up to +0.8 within a few days. Based on all of the above and although the ONI is based on a different SSTa dataset, there's a good chance as of now that MJJ will reach at least +0.6 with +0.7 not at all out of reach and even +0.8 reasonably possible. MAM came in at +0.1. For comparison back to 1950, the largest warming from MAM to MJJ has been 0.9, which occurred in 1997. Also, the warmest MJJ for an incoming El Niño was the +1.2 of 1997 with 1957's +1.1 next.

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.