bluewave

I like to rely more on the ECMWF Nino plumes model than the CFS but we only get one update a month. My guess is that it will show another increase in ONI with the May 5th release as it initializes the current near record OHC for so early in the season. It may be that the Nino 1+2 regions not fully cooling off from the last very strong event in 2023-2024 could have something to do with the El Niño coming in so strong with only a 3 year gap between events. Notice that 2025 was the first full year following an El Niño so strong that stayed warm off of South America. Go back to the previous higher end events since the early 1970s and you will see they all significantly cooled compared to what happened in 2025. Also note how much warmer the entire North Pacific remained.

The climate has had three shifts to the warmer since 2009-2010. Our summers became warmer beginning with the 2010 summer. We haven’t had any cooler summers against the long term average like in 2009 or earlier since then which we would normally get every several years. The only three cooler summers since then against the recent much warmer means like 2023, 2017, and 2014 have been closer to or a little warmer than the older long term average. Most of the summers since then have been near the top rankings for warmth. Starting with December 2015, the U.S. winters have become much warmer to the point where we have seen many new top warmest winters for the CONUS and no significantly colder ones since then. The most recent temperature jump in 2023-2024 produced the #1 warmest CONUS winter on record that winter and the #2 warmest winter this year in 2025-2026. The concern going forward is that we will get another baseline temperature jump with this developing very strong El Niño for 2026-2027 that will just add to the previous ones since 2015-2016. I can fully understand your point of view that the climate has not rapidly changed. Since it’s human nature to normalize the recent 3-7 of weather as nothing unusual. Plus it may not be that obvious when we get used to more Mid-Atlantic style temperatures like used to be normal for VA.

We can see why the recently initialized models like the CFS are going higher. This is the first time since 1997 with an OHC reading reaching over 2.0° in April. Remember, 1982 didn’t reach this level of heat until October. Plus even 2015-2016 only peaked at 1.91 and not until October. My guess is that the ECMWF release on May 5th will increase its forecast over the April 5th levels once this record kelvin wave and OHC is initialized. So it appears we are on track for our first two El Nino events with a peak over +2.0 only separated by 3 years. We may not know what the ceiling is on this one until we get into late May or June. But it looks higher than 2023-2024 due to how strong this is becoming early on. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

It does look like May will at least start out cooler than average with all the blocking and the upper low parked over the Northeast. Will be interesting to see if we can get some improvement heading out toward Memorial Day. Still beyond the reach of the models.

2009 would probably be too big of an ask in this much warmer climate. It was the 2nd coolest June and July on record at spots like Islip. 2023 was our last summer with a developing El Niño that became very strong. Was cooler overall than the other 2020s summers so far but still not really cool by historical standards. Time Series Summary for Islip Area, NY (ThreadEx) 10 Coolest June 1 to July 31 Periods Click column heading to sort ascending, click again to sort descending. 1 1965-07-31 67.9 0 2 2009-07-31 68.2 0 3 1978-07-31 68.5 0 4 1979-07-31 68.7 0 - 1968-07-31 68.7 0 5 1992-07-31 68.9 0 6 1982-07-31 69.0 0 7 1964-07-31 69.2 0 8 1972-07-31 69.3 0 9 1985-07-31 69.4 0 10 2000-07-31 69.6 0 - 1996-07-31 69.6 0

You usually have to go back a day before to get the broader set to update. On the Xmacis2 site it’s easier to display. Islip had their 12th warmest spring average spring high through the 25th with Philly coming in 3rd place. Time Series Summary for ISLIP-LI MACARTHUR AP, NY mean max temp Mar 1 through Apr 25 Click column heading to sort ascending, click again to sort descending. 1 2012-04-25 58.9 0 2 2010-04-25 58.1 0 3 2025-04-25 56.7 0 4 1976-04-25 56.5 0 5 2023-04-25 56.1 0 - 2016-04-25 56.1 0 6 2002-04-25 55.9 0 7 1977-04-25 55.6 0 8 2024-04-25 55.5 0 9 1973-04-25 55.3 0 10 2021-04-25 55.2 0 11 1999-04-25 54.8 0 - 1991-04-25 54.8 0 12 2026-04-25 54.3 0 - 2008-04-25 54.3 0 13 2022-04-25 54.2 0 14 1987-04-25 54.0 0 15 2020-04-25 53.8 0 Time Series Summary for Philadelphia Area, PA (ThreadEx) mean max temp Click column heading to sort ascending, click again to sort descending. 1 1921-04-25 65.7 0 2 1945-04-25 65.0 0 3 2026-04-25 64.5 0 4 1977-04-25 64.1 0 5 2012-04-25 63.8 0

It mostly comes down to the warmest high temperatures staying closer to the interior rather than the coast. So even though Long Island is still having warmer highs than normal for this time of year, It’s around 10° cooler than the Philly to interior NJ corridor. Very strong onshore flow influence with the SSTs still cooler during the spring.

Big average high temperature spread between the LI and CT Shorelines and NJ since March 1st. AEROFLEX-ANDOVER AIRPORT WBAN 65.4 ESTELL MANOR COOP 63.9 PENNSAUKEN 1N COOP 63.3 MILLVILLE MUNICIPAL AIRPORT WBAN 63.0 SALEM COOP 62.8 SOUTH JERSEY REGIONAL AIRPORT WBAN 62.8 MOORESTOWN 4 E COOP 62.4 MCGUIRE AFB WBAN 62.4 PHILADELPHIA/MT. HOLLY WFO COOP 62.1 Atlantic City Area ThreadEx 61.8 OCEAN COUNTY AIRPORT WBAN 61.8 ATLANTIC CITY INTL AP WBAN 61.8 SOMERSET AIRPORT WBAN 61.7 New Brunswick Area ThreadEx 61.5 Data for March 1, 2026 through April 24, 2026 Average High temperature Click column heading to sort ascending, click again to sort descending. NJ CALDWELL ESSEX COUNTY AP WBAN 61.2 NJ NEWARK LIBERTY INTL AP WBAN 60.7 NJ TETERBORO AIRPORT WBAN 60.5 NY PORT AUTH DOWNTN MANHATTAN WALL ST HEL ICAO 60.3 NJ TETERBORO AIRPORT COOP 60.1 NJ HARRISON COOP 59.5 NY NY CITY CENTRAL PARK WBAN 59.4 NY LAGUARDIA AIRPORT WBAN 58.3 NY MONTGOMERY ORANGE COUNTY AP WBAN 58.3 CT DANBURY MUNICIPAL AP WBAN 57.8 NY SHRUB OAK COOP 57.6 NJ CHARLOTTEBURG RESERVOIR COOP 57.3 CT DANBURY COOP 56.8 NY WESTCHESTER CO AP WBAN 56.7 NY RIVERHEAD RESEARCH FARM COOP 56.5 NY STEWART FIELD WBAN 56.4 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 56.3 NY PORT JERVIS COOP 56.2 CT NORWICH PUBLIC UTILITY PLANT COOP 55.8 NY JFK INTERNATIONAL AIRPORT WBAN 55.5 NY BAITING HOLLOW COOP 55.5 NJ CANOE BROOK COOP 55.2 NY FARMINGDALE REPUBLIC AP WBAN 55.0 NY SYOSSET COOP 55.0 NY ST. JAMES COOP 54.8 NY ISLIP-LI MACARTHUR AP WBAN 54.3 CT OXFORD WATERBURY WBAN 54.2 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 53.8 NY CENTERPORT COOP 53.8 NY CARMEL 4N COOP 53.4 CT GUILFORD COOP 53.4 NY UPTON COOP - NWSFO NEW YORK COOP 53.2 CT NEW HAVEN TWEED AP WBAN 53.1 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 52.3 NY ORIENT POINT STATE PARK COOP 52.1 CT GROTON NEW LONDON AP WBAN 51.3 NY WESTHAMPTON GABRESKI AP WBAN 50.7 NY BRIDGEHAMPTON COOP 50.3 NY MONTAUK AIRPORT WBAN 48.9

Classic onshore flow pattern with waves of low pressure bringing rainfall as they move through. Tomorrow could have afternoon temperatures struggling to get out of the low 40s with clouds and rain. Blocking pattern set to continue right into May.

The Western Pacific warm pool was so overpowering that we got a La Niña pattern instead of the classic weak El Niño. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall

Everyone has their own subjective likes and dislikes when it comes to the weather. I liked cooler and wetter in the summer when it used to keep the big beach crowds away from Long Beach. Since finding parking spaces was always a challenge there. So 1996 and 2009 are two of my favorite summers living in Long Beach. I didn’t mind having several days which were compete washouts since all the perfect days in the 70s and low 80s made up for it.

There are a few ways of looking at this. If you use a linear model, then you would be correct. But a non-linear process involving threshold temperarures of marine heatwaves potentially driving the forcing leading to that record breaking ridge would be a different case. The ridge out West was much stronger from November to March this year than the similar weak La Niña in 1995-1996. Such an increase could be the result SST forcing thresholds being met and the pattern becoming much more amplified and locking in over a longer duration. So rather than a gradual increase in temperatures and 500mb ridging, the warmer background pattern resulted in more of a jump. The CONUS was actually slightly colder in 1995-1996 instead of the warmest November to March on record in 2025-2026. There wasn’t the extended record warmth out West over the same period back in 1995-1996. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101499 Circus Tents, Convective Thresholds, and the Non-Linear Climate Response to Tropical SSTs Using model simulations, we demonstrate that the climate response to localized tropical sea surface temperature (SST) perturbations exhibits numerous non-linearities. Most pronounced is an asymmetry in the response to positive and negative SST perturbations. Additionally, we identify a “magnitude-dependence” of the response on the size of the SST perturbation. We then explain how these non-linearities arise as a robust consequence of convective quasi-equilibrium and weak (but non-zero) temperature gradients in the tropical free-troposphere, which we encapsulate in a “circus tent” model of the tropical atmosphere. These results demonstrate that the climate response to SST perturbations is fundamentally non-linear, and highlight potential deficiencies in work which has assumed linearity in the response.

Both the 2023 and 2026 early developing El Niños are having spring crop damage from cold following early record warmth. Newark Area, NJPeriod of record: 1843-05-01 through 2026-04-22DateHighest maximum temperatures (degrees F) Top Record 2nd Record 3rd Record 4/13 92 in 2023 86 in 1977 84 in 2018+ 4/14 93 in 2023 89 in 2026 88 in 2022+ 4/15 91 in 2026 88 in 1960 87 in 1941 4/16 92 in 2002 90 in 2026 89 in 1896

Models correcting stronger with the blocking to start May as this El Niño is developing at a record pace for this time of year. So the growing El Niño combining with other elements will cap the high end warmth potential for a while. We saw something like this back in the spring of 2023 following the April record 90°+ heat with that El Niño which formed early also. New run Old run

In effect that is what happened with the El Niño in 2018-2019 which had La Niña elements preventing it from fully coupling. Perhaps if the RONI and ONI can come into closer alignment it could suppress the Southeast ridge more than we saw back in 2023-2024. But that is really speculative at this point. It looks like we are headed for over +2.0 again on at least ONI and can use this as another test case. None of the seasonal models back in 2023-2024 were able to correctly forecast the stronger ridge building down into the Mid-Atlantic. As they all had the stock El Niño composite.