bluewave

Yeah, October has been a pretty good indication of the Aleutian low strength for the winter since 1997 during super El Niño. Notice how large an area in the NEPAC during October 1997 was occupied by the Aleutian low. It actually had multiple centers. One area NW of Hawaii and the other over the EPO and PNA regions. The Southeast El Niño trough was already beginning to become established also. That winter went on to have one of the strongest and largest Aleutian low areas of all-time. In October 2015 and 2023 the Aleutian low was confined to a much smaller space in the NEPAC. Both of theses winters had smaller and more displaced Aleutian low locations than 1997-1998. This matches the 500 mb ridges becoming stronger and more expansive since 2015-2016 and the troughs becoming weaker relative to earlier years.

LGA came the closest at 99°. We could already begin to see the influence of the trees in Central Park after the new ASOS was installed in the shade in 1995. During the July 1991 heatwave Riverhead also made it to 100°. But the old Central Park station not under trees made it to 102°. Data for July 15, 1997 through July 15, 1997 Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 101 NJ TETERBORO AIRPORT WBAN 101 NY RIVERHEAD RESEARCH FARM COOP 100 NY LAGUARDIA AIRPORT WBAN 99 NJ HARRISON COOP 99 NY MINEOLA 1 NE COOP 99 NY MINEOLA COOP 98 NY SETAUKET STRONG COOP 98 NJ CANOE BROOK COOP 97 NY NY CITY CENTRAL PARK WBAN 97 CT DANBURY COOP 97 NY WESTCHESTER CO AP WBAN 97 CT NORWICH PUBLIC UTILITY PLANT COOP 97 NJ CRANFORD COOP 96 CT STAMFORD 5 N COOP 96 NY WEST NYACK COOP 96 NY UPTON COOP - NWSFO NEW YORK COOP 96 NY BRIDGEHAMPTON COOP 96 CT MOUNT CARMEL COOP 96 NY ISLIP-LI MACARTHUR AP WBAN 96 NJ LITTLE FALLS COOP 95 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 95 NY SEA CLIFF COOP 95 NY PORT JERVIS COOP 94 NY NEW YORK AVE V BROOKLYN COOP 94 NY JFK INTERNATIONAL AIRPORT WBAN 94 Data for July 21, 1991 through July 21, 1991 Click column heading to sort ascending, click again to sort descending. CT DANBURY COOP 105 NJ NEWARK LIBERTY INTL AP WBAN 102 NY NY CITY CENTRAL PARK WBAN 102 CT MIDDLETOWN 4 W COOP 102 NY BRIDGEHAMPTON COOP 102 CT MOUNT CARMEL COOP 101 NY ISLIP-LI MACARTHUR AP WBAN 101 CT GROTON COOP 101 CT NORWICH PUBLIC UTILITY PLANT COOP 101 NJ CANOE BROOK COOP 100 NY NY WESTERLEIGH STAT IS COOP 100 NY LAGUARDIA AIRPORT WBAN 100 NY MINEOLA COOP 100 CT NEW HAVEN COOP 100 NY RIVERHEAD RESEARCH FARM COOP 100

The 500 mb pattern during June and July across the Northern Hemisphere was the opposite of past developing super El Niño events. Had more in common with +SOI/ -PDO /La Niña June and July periods. Seasonsal forecast models from before the summer started missed this pattern.

Maybe it could reduce the highs on the days with more smoke by 1-2° from the model forecasts. Just glad that it’s significantly further away from our area than the record wildfires in Ontario back in mid-July. The smoke was so thick during that period that it resulted in 5-6° cooler high temperatures than model forecasts.

The ridge just doesn’t want to back down this summer. New run Old run

First time for NJ to have 9 consecutive years with over 30 days reaching 90°. Data for January 1, 2026 through August 11, 2026 Click column heading to sort ascending, click again to sort descending. ESTELL MANOR COOP 31 HARRISON COOP 31 Atlantic City Area ThreadEx 28 TETERBORO AIRPORT COOP 28 ATLANTIC CITY INTL AP WBAN 28 TETERBORO AIRPORT WBAN 28 New Brunswick Area ThreadEx 27 NEW BRUNSWICK 3 SE COOP 27 Newark Area ThreadEx 26 NEWARK LIBERTY INTL AP WBAN 26

That’s actually a NWS COOP station out in Baiting Hollow which gets included in the weather roundups across the area. It could be the warmest temperature ever recorded on Eastern Long Island. The big story this summer is how much warmer it is than past developing super El Niño summers. Some stations approached all-time highs back in early July. But the smoke prevented more 100° readings back in mid-July. Monthly Data for June 2025 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 103 NJ HARRISON COOP 103 NY BAITING HOLLOW COOP 103 NY JFK INTERNATIONAL AIRPORT WBAN 102 NJ TETERBORO AIRPORT COOP 101 NJ CANOE BROOK COOP 101 NY LAGUARDIA AIRPORT WBAN 101 NJ TETERBORO AIRPORT WBAN 101 NJ CALDWELL ESSEX COUNTY AP WBAN 101 NY ISLIP-LI MACARTHUR AP WBAN 101 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 101 CT NORWICH PUBLIC UTILITY PLANT COOP 101 NY FARMINGDALE REPUBLIC AP WBAN 100 NY WESTHAMPTON GABRESKI AP WBAN 100 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 100 Data for June 1, 2026 through August 11, 2026 Click column heading to sort ascending, click again to sort descending. NJ HARRISON COOP 106 NJ NEWARK LIBERTY INTL AP WBAN 105 NY LAGUARDIA AIRPORT WBAN 104 NY PORT AUTH DOWNTN MANHATTAN WALL ST HEL ICAO 103 NJ CALDWELL ESSEX COUNTY AP WBAN 102 NY STEWART FIELD WBAN 102 NY FARMINGDALE REPUBLIC AP WBAN 102 NY JFK INTERNATIONAL AIRPORT WBAN 102 NJ TETERBORO AIRPORT WBAN 101 NJ TETERBORO AIRPORT COOP 101 NY MONTGOMERY ORANGE COUNTY AP WBAN 101 NY CENTERPORT COOP 101 NY BAITING HOLLOW COOP 101 NY NY CITY CENTRAL PARK WBAN 100 Developing super El Niño summers since the 1990s Data for June 1, 2023 through August 31, 2023 Click column heading to sort ascending, click again to sort descending. NJ HARRISON COOP 97 NJ NEWARK LIBERTY INTL AP WBAN 96 NJ CANOE BROOK COOP 96 NJ CALDWELL ESSEX COUNTY AP WBAN 96 NY LAGUARDIA AIRPORT WBAN 95 NY WEST POINT COOP 95 Data for June 1, 2015 through August 31, 2015 Click column heading to sort ascending, click again to sort descending. NJ CRANFORD COOP 100 NJ NEWARK LIBERTY INTL AP WBAN 98 NJ HARRISON COOP 98 NJ TETERBORO AIRPORT WBAN 98 NJ TETERBORO AIRPORT COOP 98 NJ CANOE BROOK COOP 96 NY NY CITY CENTRAL PARK WBAN 96 Data for June 1, 1997 through August 31, 1997 Click column heading to sort ascending, click again to sort descending. NJ NEWARK LIBERTY INTL AP WBAN 101 NJ CANOE BROOK COOP 101 NJ TETERBORO AIRPORT WBAN 101 NY RIVERHEAD RESEARCH FARM COOP 100 NJ CRANFORD COOP 100

Some stations in NJ just set their May monthly maximum high temperature when they reached 100°. In early July multiple stations were within a few degrees of their monthly max for July and all-time high. Last June Baiting Hollow on Eastern LI reached 103° far from any urbanization and may have been the highest all-time temperature for that area. So all stations regardless of how urbanized they have been experiencing record heat. The drier pattern from the 1940s to early 2000s produced monthly maxes in August and September which haven’t been matched. Probably related to the early extreme summer heat in recent years turning wetter as we move into August and September. You will notice we had all-time record October heat as recently at 2019 in the mid 90s. That was the result of a flash drought which developed later in the season. February 2018 was probably our most extreme monthly max of any month reaching 80° for the first time at the areas away from the cooler ocean influence. A summer extreme of that magnitude would give the usual warm spots a reading in the 110° to 112° range.

Seasonal model forecasts for super El Niños usually have warmer temperatures across Canada and the Northern tier states into the Northeast. So in that general sense they usually end up correct. But they haven’t been correct with the magnitude of the warmth. Spots that wound up with +10 or more months have only been forecast to be something like +1 to 3 or maybe +2 to +4. Plus each of the 3 super El Niños since the late 90s had other variations in regard to where the ridge axis was located vs forecast. 1997-1998 was our only east based event of that era with a strong +PDO and no Maritime Continent forcing. But it started out cooler in the East during December and got progressively warmer during January and February. So it didn’t follow the general El Niño progression. It also had a strong -AO in January that linked up with the Southeast ridge even with such a strong STJ. The models had the stock El Niño composite for December 2015 as late as November 2023 with warmer north and cooler south. We wound up with the warmest December on record in the East greater than +13 in spots which were forecast to be something like +1 to +3. Strong +PDO that winter and a Maritime Cintinent influence in December 2023-2024 was forecast to be only something like +1 to 3 for places which verified more than +10. The event had a -PDO with Maritime Continent influence. This event is stronger than all three of those events. So the models probably won’t start showing the actual December pattern until into the first week of December. The January pattern probably won’t begin to show up until closer to New Years. And the actual February pattern until that month starts also.

Almost seems like an aspect of a more monsoonal type climate when the highest annual temperatures occur earlier before the heavier rains arrive.

Our 100° days have been occurring earlier than in the past. Spots in NJ had their earliest 100° day back on May 19th-20th. No 100° days after August 10th during the 2020s. We haven’t had a 100° day after August 10th since 2005. Maximum 1-Day Mean Max Temperature for HARRISON, NJ Earliest and Latest in Bold during the 2020s Click column heading to sort ascending, click again to sort descending. 1 106.0 2026-07-03 2 103.0 2026-07-04 - 103.0 2025-06-25 - 103.0 2025-06-24 3 102.0 2025-07-30 - 102.0 2022-07-25 4 101.0 2025-07-31 - 101.0 2024-07-17 - 101.0 2022-08-10 - 101.0 2022-07-24 - 101.0 2021-06-30 5 100.0 2026-07-02 - 100.0 2026-05-20 - 100.0 2025-07-26 - 100.0 2025-06-26 - 100.0 2024-08-02 - 100.0 2024-06-22 - 100.0 2022-07-23 - 100.0 2021-07-01 Time Series Summary for NEWARK LIBERTY INTL AP, NJ 100° days after August 10th Click column heading to sort ascending, click again to sort descending. 1 1953-09-30 5 0 2 1993-09-30 3 0 3 1948-09-30 2 0 - 1944-09-30 2 0 4 2005-09-30 1 0 - 2002-09-30 1 0 - 1973-09-30 1 0 - 1949-09-30 1 0 - 1881-09-30 1 0

Near record AMO rise helping to boost the dew points.

It just keeps climbing with the record breaking WWBs continuing.

The main reason the pattern was more favorable in 1995-1996 was the much more extensive and longer duration cold into April. Plus the -NAO patterns were able to lock in during those days from the late fall into the spring. This time around we got the fastAO/ NAO reversal in March shutting off the snows. No doubt 2025-2026 was the very best winter of the 2020s. So it’s good to know that we at least were able to get a weaker reflection of that season. This was the first time that a weak La Niña with the 3 ridge pattern over the Bering, Baja, and Greenland occurred in 30 years. But the ridges were much stronger limiting the cold. It also took two seasons following that one for a super El Niño to develop. This time the super El Niño was instantaneous right after the winter.