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.

The other thing is that we are starting to see more of these record breaking 500mb ridges even when ENSO isn’t as overwhelming. This winter was one of the rare weak La Niña winters like 1995-1996 with 500mb ridges over the Bering Sea, Baja California, and Greenland. Notice how much more overpowering the 500mb ridges were this winter leading to the record warmth out West producing the 2nd warmest winter on record for the CONUS.

Once we get near or above +2.0° on ONI with near a 28.5C Nino 3.4 SST, a warmer winter pretty much becomes baked in since the early 1980s. Snowfall is highly dependent on whether we get decent blocking or not. 1982-1983 was one of the milder winters of that era but we had the great February 1983 snowstorm with the blocking. The 1997-1998 was one of the warmest 1990s winters and we couldn’t really get decently positioned blocking. So the snowfall was disappointing as the Nino ridge build into the Northeast. Fast forward to 2015-2016 and the record MJO 5 for such a strong El Niño produced the ridiculous +13.3 December which was warmer than most Novembers in the Northeast. But once we got into January and February we got the historic NYC snowstorm and a nice follow up event a few weeks later. Also the first below 0° reading in NYC on Valentine’s Day since 1994. The Nino ridge near the Great Lakes during 2023-2024 was so overpowering that it was one of the warmest and least snowy winters on record for many. The one bright spot in February was the narrow band in NJ with the record STJ streak but it was part of a one week pattern which quickly shifted.

https://science.nasa.gov/earth/arctic-winter-sea-ice-2026/#:~:text=End of dialog window.,Flight Center in Greenbelt%2C Maryland. For the second consecutive year, winter sea ice in the Arctic reached a level that matches the lowest peak observed since satellite monitoring began in 1979. On March 15, Arctic sea ice extent reached 5.52 million square miles (14.29 million square kilometers), very close to the 2025 peak of 5.53 million square miles (14.31 million square kilometers). Scientists with NASA and the National Snow and Ice Data Center (NSIDC) at the University of Colorado, Boulder, note that the two years are statistically tied. Along with the overall extent, researchers are also observing changes in ice thickness. “Based on what we’re seeing with NASA’s ICESat-2 satellite, much of the ice in the Arctic is thinner this year, especially in the Barents Sea northeast of Greenland.,” said Nathan Kurtz, chief of the Cryospheric Sciences Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The Sea of Okhotsk that borders northern Japan and Russia also had relatively low ice this year — a region that naturally experiences significant year-to-year variability.” Scientists with NASA and NSIDC found that this winter’s peak Arctic ice coverage continues the long-term trend observed over the past several decades. This year, peak ice cover was below the average levels between 1981 and 2010 by roughly half a million square miles (about 1.3 million square kilometers). Sea ice extent is defined as the total area of the ocean with at least 15% ice concentration. The area of the Arctic Ocean covered in ice expands in the cold of winter. Although much of the sea ice melts in warmer months, some ice remains throughout the year. Recently, less new ice has been forming. As a result, less multi-year ice has accumulated. “A low year or two don’t necessarily mean much by themselves,” said NSIDC ice scientist Walt Meier. But viewed within the long‑term downward trend since 1979, Meier added, they contribute to the overall picture of change in Arctic sea ice throughout the seasons.

The Summer of 2012 which followed was the 3rd warmest on record for the CONUS.

They recently found out that was an error. https://journals.ametsoc.org/view/journals/bams/107/1/BAMS-D-24-0313.1.xml The world record hottest near-surface air temperature of 134°F recorded at Greenland Ranch, Death Valley, California on 10 July 1913 is demonstrated to be approximately 14°F hotter than what likely occurred on that date. Using July data from non–Death Valley stations during 1923–2024, we compute a range of temperature lapse rates diagnosed from the differences between Greenland Ranch station and the average of higher-elevation stations’ maximum temperatures (TMAX) and elevation. The range of lapse rates from those 102 years of July data is then used to estimate Greenland Ranch temperatures during the early years (1911–22). The first 2 weeks of July 1913 are shown to be spuriously hot and other years at Greenland Ranch exhibit anomalous July temperature behavior as well. Despite the establishment of a U.S. Weather Bureau instrumented shelter at Greenland Ranch in 1911, based upon historical accounts, we believe some of the shelter readings in the early years were replaced with hotter values, possibly taken from the veranda of the ranch house using a thermometer of unknown provenance. As a result of these findings, we recommend that the 134°F world record status be rescinded and that many of the Greenland Ranch temperature reports during the early years be more closely evaluated for data quality.

The Hofstra student garden in Hempstead made it to 81°.

We should still be able use ERA 5 now for 500MB reanalysis dataset which first becomes available about 5 days after the month ends. https://psl.noaa.gov/data/atmoswrit/map/

Will be interesting to see if the Euro April 5th release turns out to be as reliable as its El Niño forecast issued back in April 2023. https://iri.columbia.edu/our-expertise/climate/forecasts/enso/2023-April-quick-look/?enso_tab=enso-sst_table

Yeah, looks like another warmer month coming up as the Western and Eastern ridges merge like we saw in March.

Yeah, we have been at daily record levels since the 23rd. https://bsky.app/profile/climatecasino.net/post/3mhv47nbqqk2j Earth's global 2m surface temperature just posted the hottest March 23rd on record, and likely the hottest March 23rd in the last 120,000+ years. 8:38 AM · Mar 25, 2026