bluewave

We had some good discussions on this topic over the years. My guess is that the 500 mb ridging associated with the ABNA ridge during 2024-2025 and 2025-2026 winters was effectively pulled south due to the record mid-latitude marine heatwaves across the North Pacific. So a much stronger subtropical ridge influence than 2013-2014 and 2014-2015. This lead to lower heights across the -WPO region in 2024-2025 and 2025-2026 relative to 2013-2014 and 2014-2015. So this stronger subtropical ridge influence may have also contributed to the weaker TPV in the Great Lakes and Northeast and much warmer winters than we got those years. Notice that the warm pool extending from Japan to California didn’t let the PDO index show a strongly +PDO reading even with the record SSTs off the California Coast for this time of year. This also makes it more difficult to have a one to one comparison with the PDO readings of the past that didn’t have the record mid-latitude warm pool east of Japan and south of the Aleutians.

Areas like the CT Shoreline have been nearly 10° lower for the average highs compared to NJ this month with the backdoor pattern. Coastal areas are normally colder this time of year. But the stalling warm fronts near NYC have enhanced the gradient. Monthly Data for March 2026 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NJ CALDWELL ESSEX COUNTY AP WBAN 54.8 NJ NEWARK LIBERTY INTL AP WBAN 54.4 NJ TETERBORO AIRPORT WBAN 53.9 NJ TETERBORO AIRPORT COOP 53.9 NY PORT AUTH DOWNTN MANHATTAN WALL ST HEL ICAO 53.7 NJ HARRISON COOP 52.9 NY NY CITY CENTRAL PARK WBAN 52.5 NY LAGUARDIA AIRPORT WBAN 51.8 NJ CHARLOTTEBURG RESERVOIR COOP 51.6 CT DANBURY MUNICIPAL AP WBAN 51.4 NY MONTGOMERY ORANGE COUNTY AP WBAN 51.3 NY RIVERHEAD RESEARCH FARM COOP 50.6 CT NORWICH PUBLIC UTILITY PLANT COOP 50.3 CT DANBURY COOP 50.2 NY WESTCHESTER CO AP WBAN 50.2 NY SHRUB OAK COOP 50.1 NY BAITING HOLLOW COOP 50.0 NY CENTERPORT COOP 49.8 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 49.5 NY PORT JERVIS COOP 49.1 NY SYOSSET COOP 49.0 NY FARMINGDALE REPUBLIC AP WBAN 48.8 NY JFK INTERNATIONAL AIRPORT WBAN 48.7 NY ISLIP-LI MACARTHUR AP WBAN 48.3 NY ST. JAMES COOP 48.2 CT OXFORD WATERBURY WBAN 48.1 NY BRIDGEHAMPTON COOP 48.1 NY UPTON COOP - NWSFO NEW YORK COOP 47.9 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 47.7 CT GUILFORD COOP 47.5 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 46.8 NY ORIENT POINT STATE PARK COOP 46.7 CT NEW HAVEN TWEED AP WBAN 46.6 CT GROTON NEW LONDON AP WBAN 46.0 NY CARMEL 4N COOP 45.5

The atmospheric response in 23-24 was a full super El Niño when viewed through the intensity and location of the 500mb ridge in North America and warmth along the Northern Tier. The troughs across the South and East along with the Aleutian low were much weaker than we typically see with stronger El Niños. It’s a similar effect to what we have seen the last two winters with the ridges becoming more expansive than 13-14 and 14-15 leading to a much smaller trough across the Great Lakes and Northeast So we didn’t get the magnitude of the cold or snow experienced during the 13-14 and 14-15 winters during 24-25 and 25-26. Goes to the shrinking Northern Hemisphere cold pool relative to similar teleconnections during the past. So metrics like ONI, RONI, and PDO need to be filtered through this newer expression of the ridges and troughs to arrive at the sensible weather.

Even the ONI has been having issues due the warming baseline updating every 5 years. So a +1.5 ONI today can have the same actual SSTs and heat release to the atmosphere as a 1.7 to +2.0 ONI did back in the old days. It’s a bit like relying on departures for temperatures as the same temperature these days as the older era will have a smaller departure due to the warming baseline. This can lead to super El Niño winters in actuality like 23-24 appearing weaker on the ONI and RONI due to the warming baseline shrinking the departure. But we saw how strongly the global temperatures spiked with that event along with the warmest winter on record for the CONUS with lower ONI and RONI values than 97-98 had. The all important 500 mb atmospheric response was very close to 97-98. Plus the 23-24 event was so spread out from Nino 1+2 to just west of the dateline that the collective heat release was very impressive than just looking at the actual Nino 3.4 SSTs.

I don’t think RONI is a relevant metric for measuring El Niños since 2023-2024 had an even warmer North American atmospheric response than 1997-1998 did with a very similar 500 mb pattern.

Early April looks like a battle between 80° warmth trying to push north vs the backdoor cold front. Notice the classic split high structure between Southeast Canada and Bermuda. My guess is that we will have a day or several that the 80° warmth pushes into NJ. But still uncertain how warm points north and east of NYC will be able to get.

Looks like NYC will finish the season at 43.4”, LGA at 45.6”, and JFK 45.4”.

It’s like someone flipped a switch after March 2019. March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 0.5 0.5 2026 0.2 0.2 2025 0.0 0.0 2024 0.0 0.0 2023 1.6 1.6 2022 1.6 1.6 2021 T T 2020 T T March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 8.2 8.2 2019 4.1 4.1 2018 31.9 31.9 2017 7.4 7.4 2016 3.2 3.2 2015 19.7 19.7 2014 5.4 5.4 2013 7.4 7.4 2012 T T 2011 2.1 2.1 2010 0.4 0.4 March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 5.4 5.4 2009 13.6 13.6 2008 T T 2007 3.8 3.8 2006 3.2 3.2 2005 13.3 13.3 2004 5.7 5.7 2003 3.7 3.7 2002 T T 2001 10.3 10.3 2000 0.2 0.2 March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 5.8 5.8 1999 9.1 9.1 1998 1.6 1.6 1997 3.7 3.7 1996 12.0 12.0 1995 T T 1994 5.0 5.0 1993 13.3 13.3 1992 7.6 7.6 1991 1.9 1.9 1990 4.2 4.2 March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 3.0 3.0 1989 3.0 3.0 1988 3.4 3.4 1987 1.7 1.7 1986 0.1 0.1 1985 T T 1984 13.0 13.0 1983 T T 1982 T T 1981 7.1 7.1 1980 2.0 2.0 March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 3.1 3.1 1979 T T 1978 10.4 10.4 1977 4.0 4.0 1976 3.9 3.9 1975 1.2 1.2 1974 8.0 8.0 1973 T T 1972 1.0 1.0 1971 1.0 1.0 1970 1.0 1.0 March Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 6.9 6.9 1969 11.0 11.0 1968 3.0 3.0 1967 21.7 21.7 1966 0.0 0.0 1965 4.5 4.5 1964 1.0 1.0 1963 M M 1962 M M 1961 M M 1960 M M

Have only had three 60°+ days here while it’s been like a different season in NJ. Climatological Data for NEW HAVEN TWEED AP, CT - March 2026 Click column heading to sort ascending, click again to sort descending. 2026-03-01 41 26 33.5 -1.2 31 0 T 2026-03-02 27 15 21.0 -13.9 44 0 0.00 2026-03-03 34 15 24.5 -10.6 40 0 0.41 2026-03-04 48 28 38.0 2.6 27 0 0.10 2026-03-05 40 28 34.0 -1.6 31 0 0.75 2026-03-06 39 35 37.0 1.2 28 0 0.31 2026-03-07 41 34 37.5 1.4 27 0 0.09 2026-03-08 55 35 45.0 8.7 20 0 T 2026-03-09 64 30 47.0 10.4 18 0 0.00 2026-03-10 63 31 47.0 10.2 18 0 0.00 2026-03-11 60 41 50.5 13.4 14 0 0.30 2026-03-12 53 32 42.5 5.2 22 0 0.22 2026-03-13 39 31 35.0 -2.6 30 0 0.00 2026-03-14 47 30 38.5 0.7 26 0 0.00 2026-03-15 42 29 35.5 -2.6 29 0 0.00 2026-03-16 55 40 47.5 9.1 17 0 1.68 2026-03-17 53 31 42.0 3.3 23 0 0.01 2026-03-18 35 26 30.5 -8.4 34 0 0.00 2026-03-19 38 28 33.0 -6.2 32 0 0.00 2026-03-20 49 27 38.0 -1.5 27 0 0.08 2026-03-21 53 41 47.0 7.2 18 0 0.00 2026-03-22 48 40 44.0 3.9 21 0 0.17 Climatological Data for NEWARK LIBERTY INTL AP, NJ - March 2026 Click column heading to sort ascending, click again to sort descending. 2026-03-01 44 29 36.5 -1.8 28 0 T T 1 2026-03-02 34 21 27.5 -11.0 37 0 0.00 0.0 1 2026-03-03 38 30 34.0 -4.8 31 0 0.42 T T 2026-03-04 47 37 42.0 2.9 23 0 T 0.0 0 2026-03-05 44 39 41.5 2.2 23 0 1.62 0.0 0 2026-03-06 43 37 40.0 0.4 25 0 0.16 0.0 0 2026-03-07 50 37 43.5 3.7 21 0 T 0.0 0 2026-03-08 73 48 60.5 20.4 4 0 T 0.0 0 2026-03-09 73 44 58.5 18.1 6 0 0.00 0.0 0 2026-03-10 82 46 64.0 23.3 1 0 0.00 0.0 0 2026-03-11 82 53 67.5 26.6 0 3 0.35 0.0 0 2026-03-12 64 35 49.5 8.3 15 0 0.07 T 0 2026-03-13 45 30 37.5 -4.0 27 0 0.00 0.0 0 2026-03-14 53 34 43.5 1.7 21 0 0.00 0.0 0 2026-03-15 46 36 41.0 -1.1 24 0 T 0.0 0 2026-03-16 67 45 56.0 13.6 9 0 0.60 0.0 0 2026-03-17 47 31 39.0 -3.7 26 0 T 0.0 0 2026-03-18 37 25 31.0 -12.0 34 0 0.00 0.0 0 2026-03-19 44 32 38.0 -5.3 27 0 0.00 0.0 0 2026-03-20 66 35 50.5 6.9 14 0 0.07 0.0 0 2026-03-21 60 48 54.0 10.1 11 0 0.00 0.0 0 2026-03-22 64 44 54.0 9.7 11 0 0.08 0.0 0

Yeah, the CT Shoreline has been on the cooler side of the backdoor for much of this month. EWR…+4.7° NYC….+3.8° BDR….+0.8°

The AIFS has 70° potential also in NJ on Thursday and takes middle ground between the Euro and GFS. But the warmth struggled to get much further north yesterday. So it’s possible that NYC and points north and east doesn’t get as warm as the 0z OP Euro. I will gladly take a AIFS compromise and get warmer than the GFS but not as warm here on the CT Shore as the OP Euro.

Looks like the warm front will come north again this Thursday for the next 70° potential at the usual spots. Would be nice if the warm sector can push further north than yesterday. Had the marine layer all day yesterday here on the CT Shoreline while NJ mad it to 70°+. Then another a cooldown for a few days as Canada and the Northeast briefly gets colder. It’s possible that some of the local warm spots could make a run on 75°-80° during the first week of April as the Southeast ridge flexes and trough tries to dig into the West.

Evolution of winters around 32° and colder in NYC since the 1970s showing the expansion of warmth to our west.