bluewave

If the models are still showing something similar with the June updates, then our first 2.0°+ ONI El Niño events within 3 years would become more likely.

Similar to the Euro which is what you would expect if these record WWBs continue past the spring forecast barrier.

There was very heavy rain and flooding early that July before the warmer conditions arrived as the El Niño first began to take hold. The late spring that year was defined by the record warmth in Canada and drought leading to all the wildfires and the record poor air quality conditions in NYC in early summer. That being said, each year is different which variation from previous El Niños. While it was a cooler summer relative to the 2020s, it was still warmer than most summers in the earlier decades. The progress of “cooler” summers since the 1990s

The summer of 2023 wasn’t really that cool at all. But relative to the other recent years it seemed that way. I guess the new definition of a cool summer in the 2020s is under 30 days reaching 90° at a warm spot like Newark as was the case in 2023. An actual cool summer like 2014 and 2009 had 15 or fewer days. A really cool summer like 1996 had under 10 days. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Days Reaching 90° Click column heading to sort ascending, click again to sort descending. 2025 39 0 2024 33 0 2023 29 0 2022 49 0 2021 41 0 2020 31 0 Coolest summers since 1961 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Days Reaching 90° Click column heading to sort ascending, click again to sort descending. 1 1967 7 0 2 1996 9 0 3 1985 11 0 4 1982 12 0 - 1975 12 0 5 2004 13 0 6 2009 14 0 - 1962 14 0 7 2014 15 0 - 1976 15 0 - 1969 15 0 The thing to watch as we head into the summer is if a much wetter pattern than we have been experiencing can develop. Since we had some record rainfall and flooding events going into the summer in 2023. Hard to tell at this early stage if this El Niño will respond with that much wetness. Long range precipitation forecasting is very low skill.

The Nino regions have been steadily warming over the years. So it takes a lower ONI departure in a modern climate to record the same actual SSTs. The atmospheric forcing responds to the actual SSTs especially when getting close to the threshold temperatures. This is why we had such a strong El Niño response with regard to the 500mb and ridge over Canada and the Northern States with record warmth back in 2023-2024 with a lower ONI than 1997-1998. The totality of the SST warmth from Nino 1+2 to Nino 4 extending west of the Dateline was among the highest ever recorded for the actual SSTs during an El Niño. ONI and RONI values for just 3.4 won’t always reflect this. The lower RONI values may have been a result the lack of a significant El Niño trough in the East and South and weaker Aleutian low than normal. So we didn’t need ONI or RONI values as strong as 1997-1998 or 2015-2016 to create similar effects. So if this event can max out at around 2.0° ONI or higher in Nino 3.4, then it possible it can have an effect closer to 2.3° to +2.5° in the old days especially with the Nino ridge and warmth to the north. The actual SSTs may be more important than the specific departures in measuring the actual magnitude necessary to initiate a strong El Niño atmospheric response. Nino 3.4 got to 28.57° during the early winter back in 2023. https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt NDJ 2023 28.57 2.06 Notice how much mare expansive the +30C warm pool was in the Central Pacific in December 2023 than 1998 which lead to the record global temperature jump and warmth that winter. ONI and RONI values won’t always capture this.

Long range models are moving toward more blocking during the last week of April. This was what happened following the mid-April record warmth back in 2023 during the developing El Nino. So it will be interesting to see if the models like the EPS continue with the blocking as we get closer in time since these week 2 forecasts aren’t always the most reliable.

Developing El Niños in April have pretty reliably resulted in near to record highs over 90° around the area like we most recently experienced in mid-April 2023. Newark Area, NJPeriod of record: 1931-01-01 through 2026-04-11 Developing El Niños bolded Highest maximum temperatures (degrees F)Top Record 2nd Record 3rd Record 4/1 82 in 1978 81 in 2026 80 in 2016 4/2 83 in 1967 80 in 1963 78 in 1946 4/3 81 in 1967 80 in 1981 77 in 2002 4/4 82 in 1950 79 in 1974 78 in 2010 4/5 83 in 1985 81 in 2010 75 in 1974 4/6 83 in 2023 80 in 1947 77 in 2010+ 4/7 92 in 2010 85 in 1991 84 in 1942 4/8 88 in 1991 84 in 2010 84 in 1959 4/9 85 in 2013 84 in 1991 78 in 1970 4/10 82 in 2017 82 in 1955 77 in 2008 4/11 87 in 2011 84 in 2017 84 in 1955 4/12 90 in 1977 87 in 2023 82 in 1996 4/13 92 in 2023 86 in 1977 84 in 2018+ 4/14 93 in 2023 88 in 2022 88 in 1941 4/15 88 in 1960 87 in 1941 85 in 1949 4/16 92 in 2002 88 in 2012 88 in 2003 4/17 97 in 2002 88 in 1976 83 in 1941 4/18 93 in 2002 93 in 1976 85 in 1964 4/19 92 in 1976 91 in 2002 89 in 1985 4/20 91 in 1941 88 in 2005 85 in 1938 4/21 88 in 1957 84 in 1985 84 in 1936 4/22 87 in 1985 86 in 2001 86 in 1973+ 4/23 88 in 1996 86 in 2007 82 in 1990+ 4/24 87 in 2001 84 in 2011 83 in 1994 4/25 91 in 1960 90 in 2009 87 in 1939 4/26 93 in 2009 85 in 2011 83 in 1985 4/27 94 in 1990 92 in 1994 90 in 1962 4/28 90 in 2009 90 in 1990 89 in 2021+ 4/29 91 in 1974 86 in 2024 86 in 2017+ 4/30 91 in 1942 87 in 1985 85 in 1941

Great write up from ECMWF on how to interpret the recent El Nino forecast so early in the development process. https://www.ecmwf.int/en/about/media-centre/science-blog/2026/el-nino-2026

Looks like the usual NJ warm spots can see their first 90° readings of the season this week.

There was a great weather observer living in Newark back in those days. The NJ climate office added all the data to the climate record recently. The beauty of these records is that it matches other overlapping accounts from that era. The average snowfall during that era was 44.0” with a DJF average temperature of 30.4°. While this winter was the coldest and snowiest at Newark and other stations in over a decade, the temperatures were still warmer than 30 year average for that era. The snowfall this winter was a little higher than the 30 year mean for that era. Plus they measured snowfall less frequently in the old days compared to today. So the actual seasonal totals could have been around 15 to 20 percent higher if they used the current snowfall measurement techniques. https://news.ucar.edu/14009/snowfall-measurement-flaky-history Monthly a seasonal Total Snowfall for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Mean 0.1 0.8 9.4 12.1 12.6 7.3 1.8 44.0 1872-1873 0.0 4.0 25.1 14.1 23.3 2.2 3.0 71.7 1871-1872 0.0 T 8.5 2.0 5.0 8.5 T 24.0 1870-1871 0.0 T 5.0 16.0 16.1 1.3 2.0 40.4 1869-1870 T T 8.1 1.8 8.5 11.0 3.0 32.4 1868-1869 T 0.0 9.5 11.0 12.0 5.0 0.6 38.1 1867-1868 0.0 T 15.5 23.8 14.0 15.0 7.0 75.3 1866-1867 0.0 T 7.0 23.5 15.5 17.5 T 63.5 1865-1866 0.0 0.0 13.1 11.8 8.0 1.5 T 34.4 1864-1865 0.0 0.3 26.0 10.5 12.5 T 0.0 49.3 1863-1864 0.0 T 4.3 7.0 1.0 7.0 T 19.3 1862-1863 0.0 6.5 8.0 10.0 13.0 10.9 1.8 50.2 1861-1862 0.0 1.0 1.0 12.0 25.5 4.6 6.0 50.1 1860-1861 0.0 T 7.0 20.6 1.3 17.0 2.0 47.9 1859-1860 3.0 0.0 5.1 11.3 25.0 2.5 T 46.9 1858-1859 0.0 5.5 6.5 12.3 15.8 6.0 T 46.1 1857-1858 0.0 T 4.5 1.8 10.5 10.5 T 27.3 1856-1857 0.0 0.5 4.3 28.1 2.1 17.0 0.0 52.0 1855-1856 0.0 T 9.0 32.8 5.0 11.0 0.0 57.8 1854-1855 0.0 T 8.0 18.5 16.0 2.5 T 45.0 1853-1854 0.0 M 14.5 15.0 23.5 2.8 13.5 69.3 1852-1853 0.0 T T 15.5 2.3 7.0 T 24.8 1851-1852 0.0 2.0 7.0 20.0 14.0 16.0 4.3 63.3 1850-1851 0.0 0.0 6.0 2.5 3.5 10.5 2.0 24.5 1849-1850 0.0 0.0 11.0 3.0 T 9.0 8.0 31.0 1848-1849 0.0 1.3 24.0 T 13.0 6.0 0.0 44.3 1847-1848 0.0 T 6.0 T 8.0 5.0 T 19.0 1846-1847 0.0 1.5 12.0 10.0 21.0 4.3 0.5 49.3 1845-1846 0.0 T 8.5 16.5 28.0 T T 53.0 1844-1845 0.0 0.5 6.5 5.5 20.5 5.5 T 38.5 1843-1844 0.0 1.3 9.5 5.5 13.5 1.8 0.0 31.6 Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ December to February Click column heading to sort ascending, click again to sort descending. Mean 31.9 28.8 30.4 30.4 1872-1873 24.7 25.1 27.4 25.7 1871-1872 28.4 29.3 29.7 29.1 1870-1871 33.6 26.5 28.6 29.6 1869-1870 32.9 35.8 30.7 33.1 1868-1869 28.2 32.8 33.3 31.4 1867-1868 26.7 26.3 21.7 24.9 1866-1867 30.7 22.9 36.4 30.0 1865-1866 35.2 25.2 29.9 30.1 1864-1865 31.9 22.8 29.2 28.0 1863-1864 31.4 29.5 32.6 31.2 1862-1863 32.7 32.9 31.4 32.3 1861-1862 33.6 27.6 30.0 30.4 1860-1861 28.8 27.8 34.2 30.3 1859-1860 29.3 29.9 28.9 29.4 1858-1859 32.7 29.6 32.6 31.6 1857-1858 37.0 36.0 26.4 33.1 1856-1857 29.8 19.0 35.7 28.2 1855-1856 33.6 21.4 24.0 26.3 1854-1855 28.8 32.3 25.8 29.0 1853-1854 32.8 28.8 30.6 30.7 1852-1853 39.7 30.5 34.9 35.0 1851-1852 27.2 25.5 31.5 28.1 1850-1851 33.8 33.3 36.9 34.7 1849-1850 33.1 34.4 35.1 34.2 1848-1849 39.9 25.8 24.9 30.2 1847-1848 36.3 32.8 30.5 33.2 1846-1847 31.5 30.4 29.7 30.5 1845-1846 27.6 30.2 27.1 28.3 1844-1845 33.0 33.2 31.3 32.5 1843-1844 33.4 25.1 31.3 29.9

Bounce back to warmer again following the colder temperatures this week.

Not really sure yet what would happen to benchmark storm tracks following another rapid warming event so soon after 2023-2024. Would probably depend on the SST state across the rest of the ocean basins. The record early SSW back in November really got the ball rolling in the right direction this past winter. Around NYC metro we have been in an all or nothing snowfall regime since the mid 1990s. So every year with a benchmark KU like this past winter has gone to at or above the long term average snowfall. Very few 18-30” seasons anymore which were common from the 1960s to 1990s. Most years without a benchmark event like 22-23, 23-24, and 24-25 finished up with under 18” across multiple locations. Back in the 1840s to early 1870s a recently discovered excellent set of long term weather observations showed the average annual snowfall at Newark in the low 40s over a 30 year period. This gradually declined into the mid 20s by the early 1990s. We had a big bounce back decade during the 2010s which was built on a record number of benchmark KU snowstorms. From 2019 to 2025 the benchmark track was largely absent so we had numerous very low snowfall years. This winter started out with an outstanding clipper pattern in December which pretty much maxed out the potential of what the Northern Stream could do if everything went just right. Then the Northern Stream finally relaxed for around 30 days from late January until late February. So only one month of relaxation yielded the record KU event in late February. March reverted to the dominant Northern Stream pattern which had resulted in the lowest March snowfall over 7 consecutive seasons around NYC Metro from 2020-2026. So taking the very long view has given us a steady decline since the 1840s in seasonal snowfall around NYC Metro with bounce back periods from time to time. No matter how warm this El Niño gets next winter, I will never give up hope for bounce back seasons and potential benchmark events from time to time. The big question is what type of interval of reoccurrence will we be looking at? Warm winters like 2015-2016 and 2016-2017 were proof of concept that we could get great benchmark storms even in a warm season. So it will just come down to having the benchmark tracks pushing back from time to time against the strong Northern Stream tendency we had since 2019.

Upper ocean heat is getting off to a record start for March. So the model forecasts of an ONI getting above +2.0° would make sense if the El Niño continues on a similar trajectory into June past the spring forecast barrier. This could be the first ONIs above 2.0° only 3 years apart which could have major ramifications for the global climate well beyond what happens next winter. Since we never had this rapid a global temperature increase over such a short period. With the big temperature jump in 2023-2024 the CONUS has had the #1 warmest winter in 2023-2024 and the #2 warmest winter in 2025-2026. Plus all the record warm winters following the 2015-2016 El Niño.

We just don’t want a repeat of the west based -WPO like we had in March which could allow too much of a +EPO Aleutian low position with El Niño forcing. Climatologist49 ‪@climatologist49.bsky.social‬ Follow As impressive as the southwestern U.S. mega-ridge was in March, the eastern Siberia mega-ridge was even more anomalous!

While Canada had its coldest March since the late 1980s and Alaska back to the 2000s, the warmest CONUS March allowed North America to finish warmer than average.