bluewave

Several stations had a warmer departure than Newark did this month. HVN…+2.2 PHL….+2.1 FWN….+2.0 ISP…….+1.7 SMQ…..+1.4 MPO….+1.4 EWR…..+1.3 HPN…..+1.1 TTN…..+0.6 POU…..+0.5 NYC……+0.3 JFK……..0.0 LGA…….-0.4 BDR…….-0.5

Multiple record warm high and low temperatures at Islip in late September have raised it to the 5th warmest September on record. Numerous top 10 warmest finishes in recent years. Since the new 1991-2020 climate normals are so warm, it only took a +1.7 departure to reach a top 10 warmest ranking. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 0432 PM EDT FRI SEP 26 2025 ...RECORD HIGH TEMPERATURE SET AT ISLIP NY... A RECORD HIGH TEMPERATURE OF 85 DEGREES WAS SET AT ISLIP NY TODAY. THIS TIES THE OLD RECORD OF 85 DEGREES SET IN 1970. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 234 AM EDT THU SEP 25 2025 ...RECORD DAILY HIGH MINIMUM TEMPERATURE SET AT ISLIP NY... THE LOW TEMPERATURE WAS ONLY 70 DEGREES WEDNESDAY, SEPTEMBER 24 AT ISLIP MACARTHUR AIRPORT. THIS BREAKS THE OLD RECORD HIGH MINIMUM OF 69 DEGREES, SET IN 1970. RECORDS FOR THE ISLIP NY AREA GO BACK TO 1963. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 0433 PM EDT FRI SEP 19 2025 ...RECORD HIGH TEMPERATURE SET AT ISLIP NY... A RECORD HIGH TEMPERATURE OF 85 DEGREES WAS SET AT ISLIP NY TODAY. THIS TIES THE OLD RECORD OF 85 DEGREES SET IN 1983. RECORDS GO BACK TO THE YEAR 1963 AT THIS CLIMATE STATION. Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Sep Click column heading to sort ascending, click again to sort descending. 1 2015 70.9 0 2 2005 70.2 0 3 2018 69.8 0 4 2021 69.6 0 - 1980 69.6 0 5 2025 69.3 4 6 2017 69.0 0 - 2011 69.0 0 7 2016 68.9 0 8 2023 68.6 0 - 1998 68.6 0 9 2010 68.3 0 10 2022 68.2 0

Yeah, those surface SSTs are very impressive. They recently helped to drive the 4 sigma jet streak near the Aleutians when combined with the record cold in Siberia. Just a tremendous thermal gradient. So we are currently getting the big EPO and PNA volatile swings as the shortwaves are racing through the very fast Pacific flow. But they are only the tip of the iceberg since there is so much stored heat below the surface. This deep reservoir of warmth contributed to the record Pacific Jet last winter even though there was the deepest trough in 25 years east of Japan. Past instances of strong troughs east of Japan had much colder SSTs and a much weaker Pacific Jet. But the surface SSTs hardly cooled which maintained the strong SST gradient and faster Pacific flow with the record cold in Siberia. So it gave us the warm storm track through the Great Lakes. Going forward I am trying to find other areas which can offset this dominant climate feature since 2018-2019. But it’s still a work in progress. The last time we were able to push back against this feature was in January 2022. It took the MJO 8 tropical forcing to disrupt the pattern for a month. I will be happy if we can find another competing source of forcing in the coming years to help the snowfall bounce even a little above the 2019 to 2025 record seven year lows. But it may be a challenging task with that massive WPAC heat engine. This cutter, hugger, and suppressed Southern Stream storm track has become very persistent since the 2018-2019 winter when the rapid SST warming took of in the WPAC.

The one certainty is that the global temperatures will continue to rise as China keeps burning so much coal. For now, the world isn’t performing an energy transition but an energy addition, where renewables top up oil, gas and coal. Regardless of well-intended green aspirations, that will remain the case for years, if not decades, unless governments impose significant changes. https://www.smh.com.au/business/markets/the-end-of-fossil-fuel-era-it-s-nowhere-near-20250911-p5mudo.html

Many stations had two consecutive lows of 70° on the 24th and 25th. This is the 2nd latest on record for spots like Islip. The lastest was 10-08 and 10-09 back in 2017. Islip Area, NYPeriod of record: 1963-09-05 through 2025-09-25 Highest minimum temperatures (degrees F)Top Record 2nd Record 3rd Record 9/24 70 in 2025 69 in 1970 67 in 2011+ 9/25 72 in 1970 71 in 2025 67 in 2011 10/8 72 in 2005 71 in 2017 67 in 1990 10/9 71 in 2017 69 in 1990 62 in 2018+

100° days have been arriving earlier in recent years making June 100° heat more common than late August into September.

Yeah, it was just something that you got used to living in Long Beach being right under the approach to JFK. The planes ultimately will have to flyover someone’s neighborhood with how busy JFK and LGA are. I hope they can change things up a bit to make the noise a little lower in your area.

The new RRFS A has been maintaining that trajectory for days now with the heaviest focused to our NW. It’s still considered an experimental forecast so doesn’t really get included in the mix during forecast discussions. It could be that the warmer conditions with the record 70° lows resulted in the front stalling a little more to the NW of the very wet models like the Canadian suite focusing the max right through our area. So the stalled front would up further north than the wetter models.

Why do you think I am talking about your forecasts? If I had a question for you then I would ask you directly. The negative modes of those indices weren’t strong enough last winter to prevent the storm tracks on the wettest .20+ precipitation days from Philly to Boston from cutting through the Eastern Great Lakes. Your perception of those modes were from a colder era when they were more effective at driving colder storm tracks to our south when the Pacific Jet was weaker. For the general pattern since 18-19 to change we would need to see the Pacific Jet relax and stop producing the cutter, hugger, and suppressed Southern Stream storm tracks. Hard to believe our last effective wide scale relaxation of this pattern was in January 2022 with the great MJO 8 pattern.

It’s certainly underperforming model forecasts as this dry pattern since last fall has been very persistent.

This was the 7th latest 70° minimum at Islip. 269 SXUS71 KOKX 250637 RERISP RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 234 AM EDT THU SEP 25 2025 ...RECORD DAILY HIGH MINIMUM TEMPERATURE SET AT ISLIP NY... THE LOW TEMPERATURE WAS ONLY 70 DEGREES WEDNESDAY, SEPTEMBER 24 AT ISLIP MACARTHUR AIRPORT. THIS BREAKS THE OLD RECORD HIGH MINIMUM OF 69 DEGREES, SET IN 1970. RECORDS FOR THE ISLIP NY AREA GO BACK TO 1963. ALL CLIMATE DATA ARE CONSIDERED PRELIMINARY UNTIL REVIEWED BY THE NATIONAL CENTERS FOR ENVIRONMENTAL INFORMATION (NCEI). First/Last Summary for ISLIP-LI MACARTHUR AP, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. 1990 06-23 (1990) 70 10-13 (1990) 70 111 2018 06-19 (2018) 70 10-11 (2018) 70 113 2017 06-23 (2017) 71 10-09 (2017) 71 107 2005 06-14 (2005) 70 10-08 (2005) 72 115 2010 06-24 (2010) 73 09-30 (2010) 70 97 1970 07-10 (1970) 70 09-25 (1970) 72 76 2019 06-29 (2019) 73 09-24(2025) 70 85

We maintained the -EPO and -WPO throughout the 13-14 and 14-15 seasons. The Pacific Jet was much weaker so frequent shortwaves weren’t constantly lowering heights in the region. Notice how much lower the -EPO and -WPO domain 500mb heights were in 2025 than 2014 with the much stronger Pacific Jet. Also look how the subtraction of 2025 from 2014 resembled 2024. Much stronger ridge last winter near Hudson Bay than 2014. This is exactly where the ridge was during 2024.

I would spend half the time looking out of the windows of Lindell School which was right on the bay and under the flight landing path to JFK near the edge of Lawrence Marsh. We would also have the really big barges going by since that was such a busy waterway. I thought it was the coolest thing when the bay was nearly frozen across during all the cold winters growing up back in Long Beach.

I actually got used to being right under the flight path for planes landing at JFK when I was back in Long Beach. But it was hard to ignore the Concorde which flew over my house every morning shortly after 9am coming into JFK. But kids think that kind of stuff if pretty cool anyway. I live near a much smaller airport now and the flight path doesn’t go directly over my house. But it’s really cool walking around the airport and seeing all the takeoffs and landings. There is a dirt lot where the locals park to watch all the flights landing and taking off. I still enjoy the low flyovers when walking on the sidewalk which crosses directly under the planes just off the end of the runway. I have noticed that the Boeing 737 is a much louder jet than the Airbus A 220. The airbus has more of a higher pitched whine and the Boeing is more of a deep roar. Had friends in the aviation business that would get to ride the jump seats on flights.

You are a very funny guy and appreciate the levity. But it’s been difficult to sustain any wall to wall DJF -EPO -WPO patterns since 2018-2019. It was much easier to lock in the -EPOs and -WPOs from December to March in 2013 to 2015 when the WPAC was much colder and the jet stream weaker. This allowed the NEPAC blocking to extend through the season since the weaker jet wasn’t constantly lowering heights with repeated shortwaves eroding the ridge from the west. As long as we have the enormous WPAC warm pool above and below the surface, the gradient between Siberia and the WPAC will drive these faster jet streams and frequent extensions. So what we are beginning to see now with the big EPO reversal this month is just a microcosm of the larger pattern since 2018-2019. The EPO reversal last year from late November into December was much more impressive. It’s actually been easier to sustain the NEPAC blocking during the summers since 2018 than during the winters. My guess is that this is due to the gradient between Siberia and the WPAC being much weaker during the summer. November 2024 into December 2024 -EPO couldn’t lock in and the daily +EPO max in late December was more impressive than the -EPO min in late November. Major Jet max and extension sent multiple shortwaves into the EPO domain lowering heights. 2024 11 20 -168.33 2024 11 21 -243.29 2024 11 22 -258.96 2024 11 23 -229.99 2024 11 24 -222.98 2024 11 25 -212.57 2024 11 26 -174.73 2024 11 27 -153.02 2024 11 28 -130.16 2024 11 29 -105.10 2024 11 30 -81.63 2024 12 01 -43.78 2024 12 02 -14.50 2024 12 03 -35.60 2024 12 04 -34.12 2024 12 05 -14.08 2024 12 06 28.23 2024 12 07 49.16 2024 12 08 -27.22 2024 12 09 -137.55 2024 12 10 -149.44 2024 12 11 -49.79 2024 12 12 35.08 2024 12 13 64.11 2024 12 14 70.96 2024 12 15 -21.55 2024 12 16 -72.62 2024 12 17 -59.81 2024 12 18 -48.59 2024 12 19 -98.46 2024 12 20 -88.76 2024 12 21 -9.80 2024 12 22 99.09 2024 12 23 112.77 2024 12 24 186.45 2024 12 25 280.91 2024 12 26 310.29 2024 12 27 225.40 2024 12 28 135.47 2024 12 29 75.67 2024 12 30 11.94

I think the record cold in Siberia creating the tight gradient between the record SSTs south of the Aleutians is helping this very strong shift to +EPO. This is following a similar pattern of recent years. Currently the Aleutians are experienceing a 4 sigma jet max helping to dig the +EPO trough and pump the warm ridge over North America. So as we have seen in recent years it tough to maintain a -EPO indefinitely. This EPO reversal was among the strongest we have seen from September into October. 4 sigma jet max near Aleutians Strong EPO reversal https://downloads.psl.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt 025 09 01 -195.59 2025 09 02 -217.86 2025 09 03 -189.23 2025 09 04 -134.91 2025 09 05 -108.24 2025 09 06 -90.21 2025 09 07 -71.66 2025 09 08 -37.71 2025 09 09 3.25 2025 09 10 39.61 2025 09 11 71.15 2025 09 12 90.96 2025 09 13 97.24 2025 09 14 92.25 2025 09 15 53.53 2025 09 16 -6.59 2025 09 17 -20.75 2025 09 18 -29.60 2025 09 19 33.92 2025 09 20 133.17 2025 09 21 158.66

This looks like our best rainfall potential in a while. Good signal from the CAMs for a widespread 1.5”+ with pockets of 3”+ possible. Just had brief heavy downpour here.

Yeah, looks like all the real cold is limited to Siberia.

Very challenging seasonal forecast that winter for anyone that was making an attempt in the early days of forecasting. Pretty much unprecedented up until time for parts of the CONUS to have a -15 December followed by a +15 January in other spots. Still the coldest December at 25.9° that I have ever experienced which was colder than all of our Januaries since 2004.

Very rare occurrence this August and September. Several stations are on track for a colder August monthly minimum temperature than in September. First time at Allentown since 1982. Looks like a warmer pattern to close out the month. Monthly Lowest Min Temperature for Trenton Area, NJ (ThreadEx) Click column heading to sort ascending, click again to sort descending. 2025 49 50 49 2024 52 45 45 2023 57 50 50 2022 58 41 41 2021 58 49 49 2020 58 40 40 Monthly Lowest Min Temperature for PHILADELPHIA/MT. HOLLY WFO, NJ Click column heading to sort ascending, click again to sort descending. 2025 48 49 48 2024 51 44 44 2023 54 49 49 2022 57 44 44 2021 59 49 49 2020 58 40 40 Monthly Lowest Min Temperature for SOMERSET AIRPORT, NJ Click column heading to sort ascending, click again to sort descending. 2025 44 46 44 2024 48 40 40 2023 52 45 45 2022 53 37 37 2021 53 45 45 2020 54 34 34 Monthly Lowest Min Temperature for Allentown Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1986 41 38 38 1934 41 43 41 1927 42 40 40 1982 43 47 43 1976 43 38 38 1944 43 38 38 1940 43 34 34 2025 45 47 45

I mostly remember how cold it was waiting for the school bus every morning during those late 70s winters.

Still the record for number of days with lows at or below 0° at Islip. Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Dec through Feb Days with low temperature at or below 0° Click column heading to sort ascending, click again to sort descending. 1 1978-1979 6 0 2 1964-1965 4 0 3 1967-1968 3 0 - 1966-1967 3 0 4 1987-1988 2 0 - 1983-1984 2 0 - 1981-1982 2 0 - 1980-1981 2 0 5 2015-2016 1 0 - 2013-2014 1 0 - 1984-1985 1 0 - 1976-1977 1 0 - 1975-1976 1 0 - 1973-1974 1 0 - 1969-1970 1 0 - 1963-1964 1 2 Data for December 1, 1978 through February 28, 1979 Days with low temperature at of below 0° Click column heading to sort ascending, click again to sort descending. NY WALDEN 1 ESE COOP 16 NJ CANOE BROOK COOP 11 NJ CHARLOTTEBURG RESERVOIR COOP 11 NY YORKTOWN HEIGHTS 1W COOP 11 NY CARMEL COOP 10 CT NORWALK GAS PLANT COOP 9 NY WESTCHESTER CO AP WBAN 9 NY PORT JERVIS COOP 8 NJ CRANFORD COOP 8 NJ LITTLE FALLS COOP 8 NJ WANAQUE RAYMOND DAM COOP 8 NY SUFFERN COOP 8 CT MIDDLETOWN 4 W COOP 8 CT NORWICH PUBLIC UTILITY PLANT COOP 8 NJ JERSEY CITY COOP 7 NY MIDDLETOWN 2 NW COOP 7 CT STAMFORD 5 N COOP 7 CT DANBURY COOP 7 NY SCARSDALE COOP 7 CT MOUNT CARMEL COOP 7 CT GROTON COOP 7 NJ PLAINFIELD COOP 6 NY WEST POINT COOP 6 NY PATCHOGUE 2 N COOP 6 NY ISLIP-LI MACARTHUR AP WBAN 6 NJ NEWARK LIBERTY INTL AP WBAN 5 NY DOBBS FERRY-ARDSLEY COOP 5 NY VANDERBILT MUSEUM COOP 5 CT NEW HAVEN COOP 5 NY SETAUKET STRONG COOP 5 Data for December 1, 1978 through February 28, 1979 Days with low temperature at or below 0° Click column heading to sort ascending, click again to sort descending. PA BELTZVILLE DAM COOP 16 PA TOBYHANNA POCONO MOUNTAIN ARPT WBAN 14 NJ LONG VALLEY COOP 13 NJ NEWTON COOP 13 NJ SUSSEX 1 NW COOP 13 PA COATESVILLE 1 SW COOP 10 NJ FLEMINGTON 5 NNW COOP 10 PA READING 4 NNW COOP 10 NJ HIGH POINT PARK COOP 10 NJ FREEHOLD-MARLBORO COOP 9 NJ SOMERVILLE 4 NW COOP 9 NJ MORRIS PLAINS 1 W COOP 9 PA EAST STROUDSBURG COOP 9 NJ BELVIDERE COOP 9

Areas closer to Southern NJ did. Data for February 18, 1979 through February 19, 1979 Click column heading to sort ascending, click again to sort descending. TUCKERTON 2 NE COOP 21.0 ESTELL MANOR COOP 19.4 CAPE MAY 2 NW COOP 18.2 FLEMINGTON 5 NNW COOP 18.0 RAHWAY COOP 18.0 ATLANTIC CITY INTL AP WBAN 17.1 Atlantic City Area ThreadEx 17.1 WOODSTOWN PITTSGROV 4E COOP 17.0 PLAINFIELD COOP 17.0 NEWARK LIBERTY INTL AP WBAN 16.6 Newark Area ThreadEx 16.6 AUDUBON COOP 14.0 BELVIDERE COOP 14.0 Belvidere Area ThreadEx 14.0 MORRIS PLAINS 1 W COOP 12.5 MILLVILLE MUNICIPAL AIRPORT WBAN 12.0 PEMBERTON COOP 12.0 MOORESTOWN 4 E COOP 12.0 LAMBERTVILLE COOP 12.0 INDIAN MILLS 2 W COOP 11.6 CRANFORD COOP 11.0 CANOE BROOK COOP 11.0 MIDLAND PARK COOP 11.0 FREEHOLD-MARLBORO COOP 10.5 SANDY HOOK COOP 10.0

Still the coldest 14 day period at Islip. Minimum 14-Day Mean Avg Temperature for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Period of record: 1963-09-05 to 2025-09-21 1 11.4 1979-02-06 through 1979-02-19 0 2 11.5 1979-02-07 through 1979-02-20 0 3 11.9 1979-02-05 through 1979-02-18 0 4 12.5 1979-02-08 through 1979-02-21 0 5 13.4 1979-02-04 through 1979-02-17 0 6 13.8 1979-02-09 through 1979-02-22 0 7 14.6 1967-12-31 through 1968-01-13 0 8 14.8 1967-12-30 through 1968-01-12 0 9 15.0 1979-02-03 through 1979-02-16 0 10 15.4 1979-02-10 through 1979-02-23 0 11 15.5 1968-01-01 through 1968-01-14 0 12 15.9 1979-02-02 through 1979-02-15 0 13 16.0 1967-12-29 through 1968-01-11 0 14 16.3 1968-01-02 through 1968-01-15 0 15 16.3 1968-01-04 through 1968-01-17 0 16 16.5 1979-02-01 through 1979-02-14 0 - 16.5 1968-01-05 through 1968-01-18 0 17 16.8 1968-01-03 through 1968-01-16 0 18 17.2 1977-01-11 through 1977-01-24 0 19 17.4 2017-12-26 through 2018-01-08 0 20 17.4 1981-01-01 through 1981-01-14 0 21 17.5 1981-01-03 through 1981-01-16 0 - 17.5 1981-01-02 through 1981-01-15 0 22 17.7 1980-12-31 through 1981-01-13 0 - 17.7 1967-12-28 through 1968-01-10 0 1979-02-06 25 13 19.0 -12.9 46 0 0.00 0.0 0 1979-02-07 22 13 17.5 -14.5 47 0 0.65 6.5 0 1979-02-08 30 17 23.5 -8.6 41 0 0.03 0.3 7 1979-02-09 19 8 13.5 -18.7 51 0 0.00 0.0 6 1979-02-10 15 -1 7.0 -25.4 58 0 0.00 0.0 5 1979-02-11 11 -2 4.5 -28.0 60 0 0.00 0.0 4 1979-02-12 15 -6 4.5 -28.2 60 0 0.09 0.9 2 1979-02-13 12 5 8.5 -24.3 56 0 T T 3 1979-02-14 13 -1 6.0 -27.0 59 0 0.00 0.0 3 1979-02-15 20 9 14.5 -18.6 50 0 T T 2 1979-02-16 18 8 13.0 -20.3 52 0 0.02 0.2 1 1979-02-17 10 0 5.0 -28.5 60 0 0.00 0.0 1 1979-02-18 14 -2 6.0 -27.7 59 0 0.00 0.0 1 1979-02-19 24 10 17.0 -16.9 48 0 0.88 8.8 2

Especially in places like the Adirondacks. I remember wondering as a kid how Old Forge made it down to -52° in February 1979. The Arctic high settled right over that region for perfect radiational cooling. Data for February 18, 1979 through February 18, 1979 Click column heading to sort ascending, click again to sort descending. OLD FORGE COOP -52 STILLWATER RESERVOIR COOP -44 WANAKENA RNGR SCHOOL COOP -41 HINCKLEY 2 SW COOP -40