bluewave

This 26-27 forecast is significantly warmer than the forecast for 23-24 was especially across the Northern States. Not a surprise given how much stronger this super El Niño is than 23-24. That forecast was much too cool for what verified. Kept the same scale stopping at just +2C. We can see how much warmer the actual winter was than the forecast. Included a 2nd verification in F below as it was the warmest winter on record for the CONUS. The biggest miss that winter was the Upper Midwest and Plains which was forecast as near normal and verified +10°F. In ° F which turned out to be the warmest winter on record for the CONUS.

It’s a really good question. The very end of the CFS run next June continues the Nino in 3 and 1+2 due to the WWBs shifting the warm pool east. We can also see the model showing a significant subsurface warm pool in the EPAC at the end of the run. Plus the current CFS is much too cool for its initialization of 1+2 this week. So its forecasts are already too weak. We are in uncharted territory with how extreme the warming is becoming with this El Niño. So we really don’t have any similar analogs to draw from. All we can say is that 82-83 was a significantly weaker event and managed to linger into early July in the Nino 1+2 regions. There has never been a +30C warm pool pushed this far to the east in the Pacific before. So we don’t really know for sure how quickly the record WWBs will relax heading into next June. All the models keep the WWBs going until the end of their runs next June. But it’s interesting that they are all saying the same thing including the recent extended Euro runs. These models aren’t really designed to see much past the spring forecast barrier and we are still only in the fall. Plus there isn’t any data on events this strong and how they might influence the pattern once we get past the spring.

There aren’t really any inverse temperature correlations between October and the winter. When relationships do exist, it’s more on a CONUS and North American level of similar October to winter temperatures. For instance very warm Octobers across the CONUS and North America sometimes continue into the winter. Same for very cold Octobers continuing into the winter. Our last much weaker super El Niño in 2023 -2024 had a very warm October in the Northeast and this continued for the winter. Other times the October pattern doesn’t continue into the winter. So it’s mostly magnitude dependent across a larger area.

All-time records continue to increase. This was the first +5.3 week ever for Nino 1+2 ONI. Nino 3 and 3.4 records are also being set. Highlighting 1+2 due to how low the models have been here. While the Euro is much better than the CFS, they both missed how east based this has become. The interesting thing about both models is that they start to show a second rise in Nino 1+2 heading into next spring on the Euro and early summer on the CFS. The Euro October update was just issued. Nino 3 staying above +4 into February would also be a first . The previous Nino 3 February record was +2.8 in 1998. So it’s possible that the +30C warm pool makes it as far east as Nino 3 for the first time. https://www.cpc.ncep.noaa.gov/data/indices/ 30SEP2026 26.1 5.3 29.0 4.0 29.9 3.2 29.9 1.2 04FEB1998 28.0 2.4 28.9 2.8 28.9 2.3 28.8 0.7

Last month was N to a little AN for most stations with the exception of the immediate Long Island Sound stations like BDR and LGA. All the other months back to March were also some degree of AN. With such extensive ridging and record CONUS warmth, there wasn’t much cooler air around. So the few cooler spots last month like LGA and BDR had to rely on lower daytime highs rather than cooler minimums. May managed to finish a little above even with the cooler conditions just to our West. The record warm day where parts of the area reached 100° for the first time in May put that month over the top. So the theme has been back and forth with the warmer departures being more impressive than the cooler ones. October looks like a continuation of the same theme. Very warm start to the month with a cool down this week. But we warm right back up into the 70s again. Whether we reach 80° again by mid-October will be contingent on sky conditions, wind direction, and how far north the moisture near the Gulf gets.

No need to search very far since it has been the dominant pattern since March.

Models shifting to a much stronger Southeast ridge in around a week. So we could continue the drier pattern. More 80° days would be possible with enough sun and SW flow. New run Old run

You would have loved the 1960s with snowy winters and drought conditions the rest of the year. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean T 0.4 8.3 7.1 10.1 6.1 0.1 32.0 1959-1960 0.0 0.5 15.8 2.5 1.9 18.5 0.0 39.2 1960-1961 T 0.0 18.6 16.7 18.2 1.2 T 54.7 1961-1962 0.0 T 7.7 0.6 9.6 0.2 T 18.1 1962-1963 T T 4.5 5.3 3.7 2.8 T 16.3 1963-1964 0.0 T 11.3 13.3 14.1 6.0 T 44.7 1964-1965 0.0 0.0 3.1 14.8 2.5 2.8 1.2 24.4 1965-1966 T 0.0 T 11.6 9.8 T 0.0 21.4 1966-1967 0.0 0.0 9.1 1.4 23.6 17.4 T 51.5 1967-1968 0.0 3.2 5.5 3.6 1.1 6.1 0.0 19.5 1968-1969 0.0 T 7.0 1.0 16.6 5.6 0.0 30.2

Subsurface warmth continuing to increase. Getting close to +12 now in spots. The +30C warm pool shifting further east is also a first.

JMA has a great site with many different ENSO composites. https://ds.data.jma.go.jp/tcc/tcc/products/clisys/enso_statistics/index.html

October is showing overlapping influences compared to past El Nino climatology. The typical -EPO blocking ridge is displaced further south than usual into the Western US. This is a continuing theme from last spring with enhanced mid-latitude ridges. It’s developing a little more south of 2015 which would be the closest match. The North Pacific low looks displaced or stretched into a +WPO position.

Unfortunately, the arrival of spring warmth is coming earlier while the date of the last freeze has held more steady over time.

The Euro was fairly close this month. It had forecast a global mean average temperature of 1.67 C in September. The September average came in a +1.63 C.

The original paper that RONI is based on discusses it mostly being developed to prevent weak La Nina’s from getting lost in the mix rather than some deficiency in measuring super El Niño events. Plus the weaker El Niños not being able to fully couple. Both instances were also a function of the record WPAC warm pool. So the ONI and the absolute SSTs are a good measure of how intense this event is becoming. My original ONI post was correct as the original ONIs we relied on for many years into the 2010s had the ONI with the 1972-1973 event peaking at the +2.0 to +2.1 range. So a lower end super El Niño event.

The planet doesn’t care about squabbles based on how humans define things. It just responds to the actual temperatures. So the headline story for the planet right now is that we are exceeding past super El Niño events by a wide margin and it’s still only early October. All-time SST records are increasing from Nino 3.4 to 1.2.