bluewave

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

The shallow nature is what makes it such an interesting phenomenon. I radiate much better here by a wooded area just north of the sound. You really notice the temperature falling pretty quickly when the sun goes down. My old area back on the South Shore didn't radiate very well. So I had to rely more on strong CAA and the winds staying strong for my colder mornings near the ocean and bays.

It’s pretty wild how shallow those radiational cooling inversions are. The low was only 57° at 50 meters up just above the treetops. That’s what the urban areas experienced this morning due to UHI around NYC.

LGA remains the cool spot as we get a warmer pattern to close out the month. LGA….-1.8 BDR….-1.4 NYC….-1.1 JFK…..-1.1 HPN….-0.3 EWR…..0.0 SMQ….+0.1 ISP……+0.2 FWN…+0.6 HVN….+1.0

We’ll see if a piece of the over the top warm up in Canada near the end of September can build down into the Northeast in October.

This summer was much drier in New England than 2010 was leading to the record low streamflows that some areas are experiencing.

Mid to perhaps upper 80s Tuesday as the models are slowing the front down. New run Old run

The recent summer pattern across the U.S. is a reversal of the Dust Bowl. The record heat has been located in the West and East with cooler and wetter in the middle. This is the opposite of the Dust Bowl with record heat and drought focused in the middle. https://journals.ametsoc.org/view/journals/clim/36/20/JCLI-D-22-0716.1.xml Abstract A cooling trend in summer (May–August) daytime temperatures since the mid-twentieth century over the central United States contrasts with strong warming of the western and eastern United States. Prior studies based on data through 1999 suggested that this so-called warming hole arose mainly from internal climate variability and thus would likely disappear. Yet it has prevailed for two more decades, despite accelerating global warming, compelling reexamination of causes that in addition to natural variability could include anthropogenic aerosol–induced cooling, hydrologic cycle intensification by greenhouse gas increases, and land use change impacts. Here we present evidence for the critical importance of hydrologic cycle change resulting from ocean–atmosphere drivers. Observational analysis reveals that the warming hole’s persistence is consistent with unusually high summertime rainfall over the region during the first decades of the twenty-first century. Comparative analysis of large ensembles from four different climate models demonstrates that rainfall trends since the mid-twentieth century as large as observed can arise (although with low probability) via internal atmospheric variability alone, which induce warming-hole-like patterns over the central United States. In addition, atmosphere-only model experiments reveal that observed sea surface temperature changes since the mid-twentieth century have also favored central U.S cool/wet conditions during the early twenty-first century. We argue that this latter effect is symptomatic of external radiative forcing influences, which, via constraints on ocean warming patterns, have likewise contributed to persistence of the U.S. warming hole in roughly equal proportion to contributions by internal variability. These results have important ramifications for attribution of extreme events and predicting risks of record-breaking heat waves in the region.

Still looks pretty warm to me since the Atlantic is currently the 5th warmest on record for the date. We also have to remember that this is the warmest 1991-2020 climo. So the actual historical ranking is pretty high. The cold pool west of Ireland is from the locally stronger winds there with the deep low pressure.

I had 1.78 spread out over 3 days. My wettest single day was only .76. The last 1.02” in a day was way back on May 5th. 3-23-24 was my last 2.92” in one day. This was my 5th driest summer at only 4.99”. It was also my 4th warmest summer here. So all the vegetation and grass was on the brown side. But July 99 back on the South Shore of LI still holds the record for the brownest vegetation that I have seen. Nearly all the lawns and the parkways were completely brown.

Hoping the cutoff low to the SW can finally end the 13th longest daily streak with under 1.00” here since early May. Number of Consecutive Days Precipitation < 1.00 for NEW HAVEN TWEED AP, CT Click column heading to sort ascending, click again to sort descending. 1 244 2014-12-10 through 2015-08-10 2 240 1964-12-05 through 1965-08-01 3 200 2001-10-10 through 2002-04-27 4 194 1965-08-03 through 1966-02-12 5 171 2013-06-09 through 2013-11-26 6 160 1971-02-09 through 1971-07-18 7 159 1960-11-02 through 1961-04-09 8 151 2015-08-12 through 2016-01-09 9 148 1962-04-02 through 1962-08-27 10 146 1957-05-15 through 1957-10-07 11 142 2007-09-12 through 2008-01-31 - 142 1955-03-23 through 1955-08-11 12 138 1966-10-20 through 1967-03-06 13 137 2025-05-06 through 2025-09-19 14 132 1955-11-05 through 1956-03-15 15 131 2009-01-29 through 2009-06-08

Yeah, from the 60s to early 90s within a few inches of 25” was very common. There were a few seasons of near 30”+ and a few 20” and below. So a very balanced snowfall pattern during that stable colder era. The snowfall became all or nothing since 93-94. Most seasons have been over 30” or under 20” since then as the winters have continued to warm. The storm tracks remained cold enough to our south for many 30”+ seasons from 09-10 to 17-18. The warmer storm tracks since 18-19 have resulted in most seasons ending up with under 20” of snow. So it has been challenging to get a 30”+ season. Plus NYC hasn’t had a season near 25” since 12-13. So losing the higher end 30”+ seasons and continuing the decline in the near 25” seasons has resulted in the under 20” season becoming most common. NYC snowfall seasons near 25” 12-13….26.1” 08-09…27.6” 92-93…24.5” 90-91….24.9” 86-87….23.1” 84-85….24.1” 83-84….25.4” 82-83…..27.2” 81-82……24.6” 78-79…..29.4” 76-77…..24.5” 73-74…..23.5” 71-72…..22.9” 69-70….25.6” 64-65….24.4”

The lowest 10 year for JFK was 18.0” from 83-84 to 92-93. So this 7 year stretch has been lower that 10 year. The 7 year got down to 15.8” vs the current 14.5”. The key difference is that snow drought ended with 93-94 and 95-96 since the climate was so much colder than our modern 2020s climate. Unlikely we see a 50”+ season and a 70”+ season during the remainder of the 2020s within 2 years apart to break this snow drought without the greatest volcanic eruption in hundreds to thousands of years. Unfortunately, we don’t have a reliable long range volcanic forecast system.

Record heat to our west yesterday with temperatures only missing 90° by 1°. This is why I have been discussing the potential for 85°-90°heat since late August even when models weren’t showing it. Models often underestimate the heat potential during flash droughts. 443 CDUS41 KCTP 190624 CLIIPT CLIMATE REPORT NATIONAL WEATHER SERVICE STATE COLLEGE PA 224 AM EDT FRI SEP 19 2025 ................................... ...THE WILLIAMSPORT PA CLIMATE SUMMARY FOR SEPTEMBER 18 2025... CLIMATE NORMAL PERIOD 1991 TO 2020 CLIMATE RECORD PERIOD 1895 TO 2025 WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST VALUE (LST) VALUE VALUE FROM YEAR NORMAL ................................................................... TEMPERATURE (F) YESTERDAY MAXIMUM 89R 351 PM 88 1964 75 14 78

Will be intersting to see if Walpack, NJ actually has a colder August monthly minimum temperature than September. They made it down to 37° on 8-31. The lowest so far this month has been 38°. After some cooler temperatures this weekend the pattern warms up again next week. Walpack NJ 2025-08-31 Mesonet 79 37 Walpack NJ 2025-09-09 Mesonet 75 38

I think the warm blobs can begin to exert some influence on the pattern when they become anchored to the subsurface like we are seeing now across most of the WPAC to North of Hawaii. Last winter we had one of the deepest troughs for the last 20 years emerge to the east of Japan. The surface SSTs didn’t cool very much compared to past deep trough instances since the subsurface had accumulated to much heat. So the strong gradient remained between the area east of Japan and Siberia. This lead to frequent jet extensions. Plus when the record SSTs are located near the Kuroshio Current in the WPAC and Gulf Stream in the Atlantic, they can help to initiate Rossby wave breaking which have a big influence on hemispheric circulation patterns. https://www.cpc.ncep.noaa.gov/products/GODAS/ocean_briefing_gif/global_ocean_monitoring_current.pdf

It’s pretty wild how fast we dried out after that record deluge last August.

The 1980s snowfall averaged about 6” higher than the last 7 seasons. Monthly Total Snowfall for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Mean T 0.1 2.6 8.2 5.9 2.7 1.0 20.4 1979-1980 T 0.0 2.5 3.0 2.3 3.2 T 11.0 1980-1981 0.0 0.2 1.7 7.7 T 6.9 0.0 16.5 1981-1982 0.0 T 3.1 12.5 0.8 0.3 8.2 24.9 1982-1983 0.0 0.0 4.8 1.0 24.7 0.1 1.5 32.1 1983-1984 0.0 T 1.2 9.9 T 10.9 T 22.0 1984-1985 0.0 T 5.5 12.4 9.0 0.4 T 27.3 1985-1986 0.0 T 2.8 3.0 13.5 T T 19.3 1986-1987 0.0 0.4 1.0 11.8 7.9 2.0 0.0 23.1 1987-1988 0.0 0.4 3.0 15.7 0.5 0.1 0.0 19.7 1988-1989 0.0 0.0 0.7 4.7 0.1 2.7 0.0 8.2 Monthly Total Snowfall for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Mean 0.0 0.7 1.8 3.7 7.3 1.0 T 14.5 2024-2025 0.0 0.0 3.0 2.5 6.5 0.0 0.0 12.0 2023-2024 0.0 T T 2.4 10.4 T 0.0 12.8 2022-2023 0.0 T T T 1.7 0.4 0.0 2.1 2021-2022 0.0 T 0.2 17.8 3.2 0.5 0.0 21.7 2020-2021 0.0 0.0 7.2 0.9 26.4 T T 34.5 2019-2020 0.0 T 1.9 1.9 T T T 3.8 2018-2019 0.0 4.8 T 0.7 3.1 6.1 0.0 14.7