bluewave

We have plenty of time to watch this one develop. Remember, these ENSO plume forecasts are just basically repeater models. They extrapolate the current conditions going forward. They are correct when the actual conditions repeat. When changes occur they exhibit errors. So if these record WWBs continue, then we have a shot at what they are showing. All I can say is that the models did a great job on the plumes from April of 2023. We would probably need a wind reversal on the order of June 2014 to avoid a +2.0 or greater ONI outcome. Once we verify the June conditions then things will come into better focus. The big story in 2023-2024 was the models underestimating the Nino ridge and warmth along the Northern Tier and overestimating the Aleutian low and troughing in the South and East. So it will be interesting to see how things go with this event.

The cooler Euro Mid 80s in the warmer spots in Central NJ is probably the floor and the Canadian low 90s is the high end potential. Will probably come down to frontal timing and clouds. But the signal is there for the warmest readings of the year so far.

The forecast 850 mb temperatures next week would potentially support the first 85-90° range of the season for the usual warm spots across the region.

They have done detailed reanalysis from that era. That may be the earliest case of a a El Niño above +2.0 C that we have. Notice the record warmth that winter in the Upper Midwest. Time Series Summary for Minneapolis-St Paul Area, MN (ThreadEx) Warmest Winters with ONI above +2.0 C bolded Click column heading to sort ascending, click again to sort descending. 1 2023-2024 29.9 0 2 1877-1878 29.0 0 3 1930-1931 26.9 0 4 2001-2002 26.8 0 5 2011-2012 26.3 0 6 1881-1882 26.1 0 7 1997-1998 25.9 0 8 1986-1987 25.8 0 9 2016-2017 24.3 0 10 2015-2016 24.2 0 11 1982-1983 24.0 0 12 1991-1992 23.7 0 13 1943-1944 23.5 0 14 1920-1921 23.2 0 15 1999-2000 23.1 0 https://psl.noaa.gov/data/20thC_Rean/ 20th Century Reanalysis and PSL Four-dimensional historic weather reconstructions, or reanalyses, provide a crucial instrument-based link between long paleoclimate reconstructions and climate model forecasts. But until recently, the earliest reanalyses began with the year 1948, leaving out many important 20th century climate events, such as the 1930’s Dust Bowl. To expand the coverage of global gridded reanalyses, the 20th Century Reanalysis Project is an effort led by NOAA's Physical Sciences Laboratory (PSL) and CIRES at the University of Colorado, supported by the Department of Energy, to produce reanalysis datasets spanning the entire 20th century and much of the 19th century. These reanalyses assimilate only surface observations of synoptic pressure into NOAA's Global Forecast System and prescribe sea surface temperature and sea ice distribution in order to estimate e.g., temperature, pressure, winds, moisture, solar radiation and clouds, from the surface to the top of the atmosphere throughout the 19th and 20th centuries. 20CR uses an ensemble filter data assimilation method which directly estimates the most likely state of the global atmosphere for each three-hour period, and also estimates uncertainty in that analysis. The most recent version of this reanalysis, V3, provides 8-times daily estimates of global tropospheric variability across 75 km grids, spanning 1836 to 2015 (with an experimental extension from 1806 to 1835.) There are three previous versions of the reanalysis: V1, V2, and V2c. The project has greatly benefited from international cooperation under the Atmospheric Circulation Reconstructions over the Earth (ACRE) initiative, which undertakes and facilitates the recovery of historical instrumental surface terrestrial and marine global weather observations to underpin 4D weather reconstructions spanning the last 200 to 250 years. Additional support has been provided by the Global Climate Observing System and the World Climate Research Programme. https://journals.ametsoc.org/view/journals/clim/33/11/jcli-d-19-0650.1.xml How Significant Was the 1877/78 El Niño? 5. Conclusions The ERSSTv5 analysis clearly shows a strong El Niño during 1877/78. The ranking of El Niño strength will vary depending on the SST dataset, the Niño regions examined, and the climatology that is used. Here, we attempt to quantify how strong it was in the SST record using the monthly 2° × 2° ERSSTv5 (Huang et al. 2017). To compare the strength of El Niño events, the uncertainty of the Niño indices should be taken into account (Huang et al. 2016a). To date, the uncertainty has rarely been considered in comparing the strength of El Niño events. In ERSST, the SST uncertainty consists of parametric and reconstruction uncertainties (Huang et al. 2016b, 2020). For a regionally averaged SST such as Niño indices, the parametric uncertainty dominates over the reconstruction uncertainty. A 1000-member ensemble analysis of ERSSTv5 (Huang et al. 2020) is used to quantify the parametric uncertainty of Niño indices, which depends on the 2–7 selections of 28 parameters. Our initial analysis of the 1000-member ensemble shows that the ensemble averaged Niño-3 over 1877/78 is lower (1.8°C) than the value from ERSSTv5 standard run while the uncertainty is large (2.8°C). In contrast, the uncertainty range in the Niño-3 and Niño-3.4 indices during 1982/83, 1997/98, and 2015/16 is much smaller (0.1°–0.2°C). The reasons for the small Niño-3 index value and large uncertainty among the ensemble members over 1877/78 has been investigated using factor analysis here among the 28 ERSSTv5 parameters. We find two of the 28 parameters are especially critical in representing El Niño events when observational data are sparse. In particular, the selections of 1-month high-frequency filter and 20% EOT acceptance criterion appear to reduce the Niño indices by 0.6°–0.8°C and increase the uncertainty by approximately 1.1°C. By removing these members within the 1000-member ensemble, a reassessment of the data confirms a strong El Niño during 1877/78 (with averaged Niño-3 value of 2.8°C and reduced uncertainty of 0.5°C). However, with these adjustments, the Niño indices and their uncertainty do not change much during 1982/83, 1997/98, and 2015/16, suggesting that the selections of those two parameters do not exert a large influence on the SST reconstruction across the tropical Pacific in the modern era. The reason for a more stable SST reconstruction in the modern era is due to the better observational coverage after the 1960s (80%) than during the 1870s (10%). The strong 1877/78 El Niño in ERSSTv5 is consistent with independent SOI index derived from sea level pressure measurements in Darwin and Tahiti (Trenberth 1984). This El Niño event in ERSSTv5 is also consistent with the precipitation and temperature proxy data derived from tree rings and coral reefs and from the great famine record in southeastern Asia and Africa (Kiladis and Diaz 1986; Allan et al. 1991; D’Arrigo et al. 2008; Garden 2008; Hao et al. 2010; Räsänen et al. 2016; Singh et al. 2018; Lough et al. 2018). For example, Singh et al. (2018) used the Palmer drought severity index (PDSI) in Asia and demonstrated a record-breaking El Niño during 1877/78. D’Arrigo et al. (2008) used the PDSI in Australia and Lough et al. (2018) used the degree heating month index (DHMI) derived from coral reef in the tropical oceans; both showed a strong El Niño event during 1877/78. The strong 1877/78 El Niño in ERSSTv5 is consistent with that in HadSST1 (Fig. 2c; dotted blue) (Rayner et al. 2003). The Niño-3 index is approximately 0.5°C lower in HadISST1 than in ERSSTv5 from January 1877 to February 1878, which is in the range of the uncertainty of ERSSTv5 as indicated in Fig. 5d and Table 1. The temporal correlation between ERSSTv5 and HadISST1 Niño-3 indices between January 1877 and January 1879 is high (approximately 0.94). The consistency between the 1997/98 El Niño events in ERSSTv5 and HadSST1 is very good with strong correlations (0.99) between January 1997 and January 1999 (Fig. 2f). In conclusion, the strength (2.8°–3.5°C) and uncertainty (0.5°C) of the 1877/78 El Niño event are quantified by evaluating the selection of certain parameters in the ERSSTv5 ensemble. The strength of the 1877/78 El Niño appears approximately equal to those during 1982/83, 1997/98, and 2015/16.

Looks like this week will feature some of our coolest temperatures until next fall before our next rebound warmer.

Perhaps if the RONI is in better alignment with the ONI next winter than 2023-2024 there will be a stronger Aleutian Low and trough in the SE and MA. But I am really not sure about that yet since even 2015-2016 had weaker troughing compared to 1997-1998. Could also be a function of the warm pool in the North Pacific expanding outside the traditional -PDO and +PDO bounds with the record 2nd EOF. 2023-2024 Nino ridge to north in super mode like 1997-1998 but the Aleutian Low and SE and MA trough showing a Niña-like influence with big RONI and ONI spread. 2015-2016 Aleutian Low well developed but the SE and MA trough in the East very weak. Perhaps reflecting the record WPAC warm pool leading to the Niña-like record MJO 5. 1997-1998 last traditional looking super El Niño both to the north and south across North America with strong ridge and trough development. 1877-1878 super El Niño more traditional like 1997-1998.

Back in 2023-2024 there was a pretty big spread between ONI and RONI. The ONI peaked at +2.1 C and the RONI at +1.5 C .Yet the 500 mb pattern across the Northern Tier and Canada was similar to 1997-1998 with the CONUS setting the warmest winter on record. Perhaps the weaker RONI was related to the lack of a robust Nino trough across Mid-Atlantic and Southeast and weaker Aleutian Low. Plus we got a big global temperature super El Niño baseline jump even higher than 1997-1998 and 2015-2016. Also note the global temperatures hardly fell in 2025.

Gorgeous cherry blossoms around NYC.

The April update is stronger than its forecast at the same time in 2023. My guess this is due to the initialization of the OHC and near to record current WWB. So it will be interesting to see if we continue these WWBs into the summer. Since we are still in the spring forecast barrier period. In any event, this would be a very significant development for the planet to have 2 events of +2.0 ONI or greater only 3 years apart. So the El Nino progress will have potentially much wider ramifications than just what happens next winter.

I would say that the cold this winter in parts of North America was uneventful compared to what we used to get in the past. Sure some localized areas did see intervals of record cold. But the areas of record warmth overpowered the colder ones so North America still finished with a significantly warmer winter than the old days at +1.522 C during DJF 2025-2026. This winter was the 5th warmest on record for North America.The record highs were of a greater ranking and number than the areas of record cold. The last colder winter for North America occurred back in 1994. This is why numerous cold and snow records set that winter still stand to this day. The warmest winter on record was 2023-2024 with 2024-2025 experiencing the 2nd warmest winter. So our warmest winters are becoming warmer with a shrinking winter cold pool. Each jump in global temperatures like we saw in 2015-2016 and 2023-2024 raises the bar for record warmth even higher. This is why the warming acceleration over the last decade is so significant. https://climatereanalyzer.org/research_tools/monthly_tseries/

Even though we are averaging out on the warmer side, this is still a very active backdoor pattern for this time of year. Big spread on the highs between NJ and the CT Shoreline. Looks like this back and forth with the warmer days being more impressive than the cooler days will continue. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 2026-03-08 73 24.7 2026-03-09 73 24.5 2026-03-10 82 33.2 2026-03-11 82 32.9 2026-03-12 64 14.6 2026-03-13 45 -4.7 2026-03-14 53 3.0 2026-03-15 46 -4.4 2026-03-16 67 16.3 2026-03-17 47 -4.0 2026-03-18 37 -14.3 2026-03-19 44 -7.7 2026-03-20 66 14.0 2026-03-21 60 7.6 2026-03-22 64 11.3 2026-03-23 52 -1.1 2026-03-24 50 -3.5 2026-03-25 55 1.2 2026-03-26 77 22.8 2026-03-27 65 10.4 2026-03-28 45 -10.0 2026-03-29 58 2.6 2026-03-30 73 17.2 2026-03-31 82 25.8 2026-04-01 81 24.4 2026-04-02 54 -3.0 2026-04-03 67 9.6 Data for IGOR I SIKORSKY MEMORIAL AIRPORT, CT Click column heading to sort ascending, click again to sort descending. 2026-03-08 57 12.0 2026-03-09 64 18.7 2026-03-10 59 13.5 2026-03-11 58 12.2 2026-03-12 55 8.9 2026-03-13 40 -6.3 2026-03-14 49 2.4 2026-03-15 39 -7.9 2026-03-16 56 8.8 2026-03-17 55 7.5 2026-03-18 35 -12.8 2026-03-19 38 -10.1 2026-03-20 50 1.6 2026-03-21 54 5.3 2026-03-22 48 -1.0 2026-03-23 49 -0.4 2026-03-24 46 -3.7 2026-03-25 47 -3.1 2026-03-26 64 13.6 2026-03-27 57 6.2 2026-03-28 44 -7.1 2026-03-29 49 -2.5 2026-03-30 65 13.1 2026-03-31 72 19.8 2026-04-01 70 17.4 2026-04-02 49 -4.0 2026-04-03 55 1.6

All these early 70°+ and 80°+ days makes the average days for this time of year feel much colder than they really are especially with onshore flow and clouds.

Probably due to the lower local resolution when trying to show regional snowfall. It would be nice if they were able to develop a map with local zooming capability. These types of maps are nice for broad overviews but not necessarily great locally.

The record WWBs got going back in January which is pretty early for an El Niño leading to speculation early on that this one has pretty good potential if follow up WWBs become established next few months to keep the ball rolling so to speak.