bluewave

The new micronet stations in Queens give us a wider understanding of the local sea beeeze influences. Stations closer to the water have fewer 90° and 100° days. So interior portions of Queens are closer to the type of heat which places like Newark and Harrison regularly experience. 2025 days reaching 90° and 100° JFK……………..…90 days…15…100 days…2 Ozone Park……..90 days…17….100 days…2 Maspeth………….90 days..23…100 days…2 LGA…………………90 days…25…100 days..2 Astoria……………..90 days…25…100 days 3 Corona…………….90 days…30...100 days…6 Queensbridge….90 days…31….100 days..3 Harrison…………..90 days…35…100 days…6 Newark…………….90 days…37….100 days..7

My guess is that the stronger sea breeze in recent years has been also playing a role reducing the 90° days relative to the increases at other areas. Stronger sea breeze circulation South Shore of NYC and LI. Plus there have been several equipment moves at JFK since 1948. So it appears that the observations prior to 1995 were at warmer parts of the airport a little further from Jamaica Bay. Making it easier to record 90° days further from the sea breeze. The current location of the ASOS since 1995 is right on the water. JFK is so large that there is a significant difference in temperatures closer to the Ozone Park side than the current ASOS near the cooler 5 towns right on the Bay. See the full location history for this station using the Historical Observing Metadata Repository. Latitude Longitude History LATITUDE LONGITUDE PRECISION BEGIN DATE¹ END DATE¹ 40.63915 -73.7639 DDddddd 1996-05-01 Present 40.63915 -73.76401 DDddddd 1995-05-01 1996-05-01 40.65 -73.78333 DDMM 1948-07-01 1995-05-01 40.65 -73.783333 DDMM 1948-06-01 1948-07-01 Elevation History ELEVATION ELEVATION TYPE BEGIN DATE¹ END DATE¹ 2.7 GROUND 1996-05-01 Present 3.4 GROUND 1995-05-01 1996-05-01 4.9 GROUND 1982-01-01 1995-05-01 10.1 GROUND 1958-01-01 1982-01-01 9.1 GROUND 1951-01-01 1958-01-01 6.1 GROUND 1948-07-01 1951-01-01 4.9 GROUND 1948-06-01 1948-07-01 9.8 BAROMETRIC 1996-05-01 Present Relocation History RELOCATION DATE¹ .3 mi S 1957-12-18 Location Descriptions DESCRIPTION BEGIN DATE¹ END DATE¹ E SIDE JFK INTL AP MIDWAY BTWN RWYS 4L-22R/4R-22L AND RWYS 13L-31R/13R-31L 1995-06-27 Present ROOF OF INTL ARRIVALS BLDG WITHIN AND 1 MI S OF PO AT JFK AIRPORT 1991-06-13 1995-06-27 0 OF PO 1948-06-01 1948-07-01 Topography Descriptions TOPOGRAPHY BEGIN DATE¹ END DATE¹ JAMAICA BAY WITH NUMEROUS SMALL MARSH ISLANDS TO THE SOUTH AND SOUTHWEST. ATLANTIC OCEAN IS 5 MILES TO THE SOUTH SEPARATED BY A BARRIER SAND PENINSULA HOME TO THE ROCKAWAYS. TERRAIN AT AIRPORT COMPLEX IS FLAT WITH MUCH OF IT SANDFILL. HEAVILY POPULATED WITH CONGESTED CAR TRAVEL TO THE NORTH AND EAST. 1996-05-01 Present JAMAICA BAY W NUMEROUS SMALL MARSH ISLANDS. TERRAIN FLAT AND SANDFILL. HEAVILY POPULATED AND CONJESTED CAR TRAVEL TO N AND E 1991-06-13 1996-05-01

Here on the CT Shoreline there has been a much steeper increase in 90° days than JFK. We are currently in 2nd place on the all-time 90° day list at 15 days so far reaching 90° or higher. This heat combined with the 5th driest summer so far has turned most of grassy areas brown. Was glad to get a brief shower yesterday. Time Series Summary for NEW HAVEN TWEED AP, CT Driest June 1st to August 14th Periods Click column heading to sort ascending, click again to sort descending. 1 2000-08-14 2.64 62 2 1957-08-14 2.77 0 3 1966-08-14 3.42 0 4 2017-08-14 3.50 3 5 2022-08-14 4.12 0 6 2025-08-14 4.18 0 7 1949-08-14 4.27 0 8 2016-08-14 4.82 0 9 1970-08-14 5.05 0 10 1965-08-14 5.09 0

90° days have been increasing at a slower rate than the 86° days at JFK. If the summer high temperatures rise another 2-4°, then the 90° days will begin to increase more sharply. The summer average high is still too low for a big increase in 90° days like areas west of the sea breeze in NJ have experienced.

Next week looks like what the surfers have been waiting for all summer. The best August hurricane swell that we have seen in years. The unusual part with the set up is how much smoke pools just to our SW as the Erin recurves OTS. So rather than much rain, we could see the smoke move into the area as Erin phases with the 50/50 low and another upper low from Hudson Bay heads for SE Canada. https://atmosphere.copernicus.eu/charts/packages/cams/products/aerosol-forecasts?base_time=202508150000&layer_name=composition_aod550&projection=classical_north_america&valid_time=202508200000

Mostly driven by the cooler minimums as we are finally getting lower dewpoints.

This new study really isn’t a surprise given the rapid warming of SSTs in North Pacific. But it’s good to see this new attribution technique correct the climate model errors. Similar shift in the North Atlantic so rapidly warming the climate leads to more persistent -PDO and +AMO patterns. https://www.colorado.edu/today/2025/08/14/human-emissions-drove-megadrought-western-us Greenhouse gas and aerosol emissions from human activity have been driving the prolonged drought in the western United States through a complicated connection with the Pacific Ocean, according to a new CU Boulder-led study. For more than two decades, an extreme dry spell has drained the Colorado River, devastated local farms, and intensified wildfires across the American Southwest. The new prediction, published August 13 in Nature, could help water managers region develop better water use plans or invest in infrastructure accordingly, with relief potentially still decades away. “Our results show that the drought and ocean patterns we’re seeing today are not just natural fluctuations—they’re largely driven by human activity,” said Jeremy Klavans, postdoctoral researcher in CU Boulder’s Department of Atmospheric and Oceanic Sciences and lead author of the study. Worst drought in 12 centuries The drought hitting the Colorado River Basin states and California is directly linked to a climate pattern of the north Pacific Ocean, known as the Pacific decadal oscillation (PDO). The PDO is a natural fluctuation of the Pacific that waxes and wanes every two decades or so. In its positive phase, waters in the eastern Pacific Ocean along the U.S. West Coast tend to be warmer, whereas waters near Japan are colder. In its negative phase, the pattern flips, bringing cold water to the eastern Pacific. Since the 1990s, the PDO has been stuck in a negative phase, an unusually long stretch for a typical cycle, Klavans said. That has had profound impacts on the United States. The cold air and water along the U.S. West Coast hold less moisture than warm air, causing a reduction in precipitation. This extended cool phase also pushed storms that would have brought water to the region farther north. As a result, scientists estimated that about 93% of the western United States is experiencing drought, with 70% facing severe dry conditions. Prior studies have shown that the past two decades have been the driest in the American Southwest in at least 1,200 years. Scientists had long thought that the PDO was entirely determined by natural forces, such as the heat exchanges between the ocean and the air. Even the latest report from the Intergovernmental Panel on Climate Change (IPCC), a body of experts convened by the United Nations, said the PDO is controlled by natural forces with high confidence. If that theory was correct, the PDO should have flipped from negative to positive in 2015 after a strong El Niño event warmed the Pacific. Instead, the PDO shifted positive for a short time following the El Niño before reverting to the negative phase again. New reality To understand why the PDO has been stuck, Klavans and his team used a large collection of climate simulation programs to predict what would happen in the future. Using a new suite of over 570 simulations, the team found that between 1870 and 1950, changes in the PDO were almost entirely driven by internal forces. But since the mid-20th century, greenhouse gas and aerosol emissions have accounted for more than half of the variations in the PDO. The team discovered that existing climate models tend to overestimate the role of internal factors on the PDO while underestimating the influence of external factors, such as emissions. After correcting the imbalance, the team found that emissions, and their impacts on the PDO, have been responsible for nearly all of the precipitation decline in the western United States over the past three decades. “People have been trying for a long time to find out why this part of the country is so dry, and we have an answer for that finally,” Klavans said. Because the same imbalance has been shown in other regions, Klavans said the study’s implications could go far beyond the Pacific. For example, the North Atlantic Oscillation, a similar fluctuation over the Atlantic Ocean, is driving drought in places like Spain. He added that improving climate models to capture the role of external forces could help scientists predict future changes in precipitation across the globe. As for the American Southwest, the outlook is grim. If greenhouse gas emissions continue to rise, the PDO will likely remain in its negative phase, and the drought will persist for at least the next three decades, Klavans said. “With this information, water planners could set new expectations and make proper investments in water infrastructure now, knowing this drought is here to stay,” Klavans said. For example, some Californian cities are already building desalination plants to turn seawater into drinking water. “This study can allow us to better quantify the costs of continued greenhouse gas emissions for Americans,” Klavans said. “That can only help our region plan for a better future.” https://www.nature.com/articles/s41586-025-09368-2 This anthropogenic influence was previously undetected because the current generation of climate models systematically underestimate the amplitude of forced climate variability. A new attribution technique that statistically corrects for this error suggests that observed PDO impacts—including the ongoing multidecadal drought in the western United States—can be largely attributed to human activity through externally forced changes in the PDO. These results indicate that we need to rethink the attribution and projection of multidecadal changes in regional climate.

The summer high tempersrures at JFK and Newark are rising at a similar rate. But JFK is still 4° cooler for summer highs than Newark since it’s right on the water with more sea breezes. But if this current rate of warming continues, then JFK will start seeing a big increase in 90° days as the summer average gets closer to 90°. So the equivalent to Newark 90° days at JFK is 86°. JFK number of 86° days since 1996 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. 2025 29 139 2024 28 0 2023 23 0 2022 41 0 2021 35 0 2020 37 0 2019 35 0 2018 31 0 2017 28 0 2016 41 0 2015 49 0 2014 13 0 2013 24 0 2012 36 0 2011 36 0 2010 55 0 2009 15 0 2008 26 0 2007 20 0 2006 22 0 2005 32 0 2004 7 0 2003 22 0 2002 38 0 2001 18 0 2000 16 0 1999 27 0 1998 28 0 1997 25 0 1996 10 0

Heading for another season of 40 or more 90° days at the usual NJ warm spots. This is the first decade with so many 90° days through the first 6 summers of the 2020s. The last cooler summer in NJ with most spots staying under 20 days was 2009. Have to go back to 1996 for Newark, Harrison, and SMQ to have under 10 days in the same season. Data for January 1, 2025 through August 14, 2025 90° Click column heading to sort ascending, click again to sort descending. NEWARK LIBERTY INTL AP WBAN 35 Newark Area ThreadEx 35 TETERBORO AIRPORT WBAN 33 HARRISON COOP 33 HIGHTSTOWN 2 W COOP 32 TETERBORO AIRPORT COOP 32 Data for January 1, 2024 through December 31, 2024 Click column heading to sort ascending, click again to sort descending. HIGHTSTOWN 2 W COOP 41 HARRISON COOP 41 CANOE BROOK COOP 37 SOMERSET AIRPORT WBAN 35 Newark Area ThreadEx 33 NEWARK LIBERTY INTL AP WBAN 33 CALDWELL ESSEX COUNTY AP WBAN 33 INDIAN MILLS 2 W COOP 31 TETERBORO AIRPORT WBAN 31 PENNSAUKEN 1N COOP 30 TETERBORO AIRPORT COOP 30 Data for January 1, 2023 through December 31, 2023 Click column heading to sort ascending, click again to sort descending. ESTELL MANOR COOP 34 HARRISON COOP 33 HIGHTSTOWN 2 W COOP 31 Newark Area ThreadEx 29 NEWARK LIBERTY INTL AP WBAN 29 SOMERSET AIRPORT WBAN 24 Data for January 1, 2022 through December 31, 2022 Click column heading to sort ascending, click again to sort descending. SOUTH JERSEY REGIONAL AIRPORT WBAN 53 HIGHTSTOWN 2 W COOP 49 Newark Area ThreadEx 49 NEWARK LIBERTY INTL AP WBAN 49 CANOE BROOK COOP 47 SOMERSET AIRPORT WBAN 46 HARRISON COOP 44 NEW BRUNSWICK 3 SE COOP 43 New Brunswick Area ThreadEx 43 FREEHOLD-MARLBORO COOP 42 ESTELL MANOR COOP 41 INDIAN MILLS 2 W COOP 40 Data for January 1, 2021 through December 31, 2021 Click column heading to sort ascending, click again to sort descending. FREEHOLD-MARLBORO COOP 43 Newark Area ThreadEx 41 NEWARK LIBERTY INTL AP WBAN 41 HIGHTSTOWN 2 W COOP 41 HARRISON COOP 38 CALDWELL ESSEX COUNTY AP WBAN 37 New Brunswick Area ThreadEx 36 SOUTH JERSEY REGIONAL AIRPORT WBAN 36 NEW BRUNSWICK 3 SE COOP 36 SOMERSET AIRPORT WBAN 33 Data for January 1, 2020 through December 31, 2020 Click column heading to sort ascending, click again to sort descending. HIGHTSTOWN 2 W COOP 42 FREEHOLD-MARLBORO COOP 40 HARRISON COOP 39 CANOE BROOK COOP 37 CALDWELL ESSEX COUNTY AP WBAN 37 ESTELL MANOR COOP 36 HAMMONTON 1 NE COOP 32 Atlantic City Area ThreadEx 31 Newark Area ThreadEx 31 NEWARK LIBERTY INTL AP WBAN 31 ATLANTIC CITY INTL AP WBAN 31 New Brunswick Area ThreadEx 30 NEW BRUNSWICK 3 SE COOP 30 FLEMINGTON 5 NNW COOP 30 Data for January 1, 2009 through December 31, 2009 Click column heading to sort ascending, click again to sort descending. WRIGHTSTOWN COOP 22 CANOE BROOK COOP 18 MOORESTOWN 4 E COOP 16 PENNSAUKEN 1N COOP 16 CRANFORD COOP 16 SOMERDALE 4 SW COOP 16 NEW BRUNSWICK 3 SE COOP 15 New Brunswick Area ThreadEx 15 TETERBORO AIRPORT WBAN 15 HARRISON COOP 15 TETERBORO AIRPORT COOP 15 HIGHTSTOWN 2 W COOP 14 Newark Area ThreadEx 14 NEWARK LIBERTY INTL AP WBAN 14 Data for January 1, 1996 through December 31, 1996Click column heading to sort ascending, click again to sort descending. Newark Area ThreadEx 9 CRANFORD COOP 9 NEWARK LIBERTY INTL AP WBAN 9 GLASSBORO 2 NE COOP 8 HARRISON COOP 8 ATLANTIC CITY INTL AP WBAN 7 NEW BRUNSWICK 3 SE COOP 7 New Brunswick Area ThreadEx 7 Atlantic City Area ThreadEx 7 FLEMINGTON 5 NNW COOP 5 PHILLIPSBURG-EASTON BRIDGE COOP 5 ESSEX FELLS SERVICE BLDG COOP 5 BOONTON 1 SE COOP 5 EWING 3 WNW COOP 4 Trenton Area ThreadEx 4 JERSEY CITY COOP 4 LITTLE FALLS COOP 4 WANAQUE RAYMOND DAM COOP 4 LONG BRANCH-OAKHURST COOP 3 SANDY HOOK COOP 3 SOMERVILLE 4 NW COOP 3

We have been leaning more on RONI in recent years reflecting the much warmer global oceanic state. Plus record WPAC warm pool north of the tropics has lead to the record low -PDO enhancing the La Niña background state. So the 2020s have been serving up a new type of La Niña background where it has been more defined by the WPAC warm pool than how cool the Nino 3.4 SSTs have been. It’s also interesting that the weaker RONI winters have been warmer in the multiyear La Ninas groups since 2010. 22-23 featured only a -0.83 weaker RONI and it was the warmest winter of the 3 year group. 16-17 had a weaker positive-0.73 RONI and it was the warmest winter of that two year event. Same for the 11-12 weaker RONI of -0.82 coming in as a warmer winter than 10-11 was. Multiyear La Ninas and DJF RONI https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt 25-26…….? 24-25….-1.12 22-23…..-0.83 21-22……-1.21 20-21…...-1.17 17-18……..-1.10 16-17……..-0.73 11-12…..-0.82 10-11……-1.42

Yeah, that is my early guess based on past multiyear La Ninas since the late 90s. There is usually one year with a strong +PNA December mismatch. The other surrounding Decembers had either a weaker positive or a negative PNA. So I will go lower on the PNA for December 2025 than the +1.70 we had in December 2024. But not sure yet whether it’s just a weaker positive or the PNA dips negative. Multiyear La Ninas and December PNA 2025…….? 2024….+1.70 2022….-0.66 2021….-2.56 2020…+1.58 2017…..+0.89 2016….-0.35 2011….+0.36 2010….-1.78 2008….-1.41 2007…..+0.14 2000…..+1.23 1999…..+0.21 1998…..-0.09

The Northeast finally got the drought update due to the lack of rainfall this summer.

There has been a new relationship between the -PDO and PNA especially during the 2020s summers. This was our first July streak of 5 consecutive -2 to -4 -PDOs. There has been a very strong +PNA signal leading to the record wildfires, record heat, and drought up in Canada. Past instances of -2 -PDOs in July were more -PNA. My guess is that this is related to the -PDO being more driven by the warmer SST anomalies than the colder ones which used to dominate -PDOs in the past. Recent July -2 to -4 -PDOs have been more +PNA Older -PDO below -2 in July were more -PNA

Yeah, remarkable subsurface warmth well beyond anything that we have seen before. So these record low -PDO values are just scratching the surface. We saw how quickly the SSTs rebounded after last winter. So this new dynamic helps this pattern to really persist.

Well June 20th through July 31st was top 3 warmest for many locations. Since that covers the typical peak heating period of the year, then by extension this will be remembered as an impressively warm summer. Especially with the record high dew points adding to the heat. The 10-11 winter didn’t have any memorable cold and snow before Christmas and after February 2nd. But record 60” snows in spots from 12-26 to 1-27 made it one of our snowiest winters. Even though the snowy period didn’t last that long.

The upper ridge in late June was able to build into the Great Lakes and Ohio Valley. This allowed the Bermuda high at the surface to expand back west through the Apps. So it created westerly flow to the coast. This current event had the upper ridge east of New England. So the Bermuda high expanded too far north to the east of ACY allowing onshore flow. So we can probably say this was a hybrid summer alternating between 2010-2013 patterns and 2018-2024 patterns.

The original idea of the heat this week coming in under June and July levels turned to be correct. This is what the models were originally showing before shifting to 102° heat in later runs. We haven’t had any 100° heat after August 13th since 1993. We also haven’t had 100° heat after August 10th since 2005. First/Last 100° Day Summary for NEWARK LIBERTY INTL AP, NJ Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. 1993 06-19 (1993) 102 09-03 (1993) 100 75 1953 06-21 (1953) 100 09-02 (1953) 105 72 1973 08-28 (1973) 100 08-28 (1973) 100 0 1948 08-26 (1948) 103 08-28 (1948) 102 1 2005 07-27 (2005) 101 08-13 (2005) 102 16 2002 07-04 (2002) 100 08-13 (2002) 100 39 1944 08-04 (1944) 100 08-13 (1944) 100 8 1949 07-03 (1949) 100 08-11 (1949) 102 38 2022 07-20 (2022) 100 08-09 (2022) 101 19 2001 08-07 (2001) 100 08-09 (2001) 105 1 2006 08-01 (2006) 100 08-03 (2006) 101 1 1955 07-05 (1955) 101 08-02 (1955) 100 27 2024 06-21 (2024) 100 08-01 (2024) 100 40

The Bermuda high has been shifting much further north during recent summers leading to more onshore flow here and record heat going to our north were the deep SW flow sets up.

Yeah, this has been the theme during this decade with the PDO values rising into the winter and spring. https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat Oct 2021….-3.13……..Mar 2022….-1.67 Jul 2022....-2.64…….Jan 2023…..-1.24 Sep 2023…-2.99…….Feb 2024…..-1.33 Oct 2024…..-3.80……Mar 2025…..-1.15

I think what we have been seeing from that record warm pool east of Japan in the 2020s is a seasonal shift from the summer into the fall and winter. The SST anomalies have been peaking there during the summers. Then declining as we have moved into the winter. Notice how the -PDO readings have also been following this pattern. The summer into fall 2021, 2022, and 2024 displayed a similar process. The lowest -PDO readings have occurred in the summer and fall and have risen into the winter. So the 21-22, 22-23, and 24-25 winters were all rising PDO patterns off the strongly negative values of the summer and fall. The main theme is that this seasonal pattern has kept repeating. So the winter values can’t get high enough to reverse the PDO when it starts declining again into the summers. The SSTs are marker for the 500mb ridging which keeps returning to the same areas. So even when we had a weaker trough east of Japan last winter, the SSTs couldn’t fully cool down. This could be related to the deep subsurface warmth there. Then there could be a feedback process between the atmosphere and SSTs perpetuating the 500mb pattern and extended record SSTs and -PDOs.

Return to more comfortable temperatures next week into late August as the Erin recurve merges with the trough and keeps the 500 mb heights lower over the Northeast. August 18-25 August 25-31

Familiar pattern in recent years as the all-time record heat went to our north in Canada.

While we are only 6 summers into the 2020s, it’s been significantly warmer than the Philly to Newark corridor was back in the 1990s. If we continue this level of summer warmth for the next 4 summers, then it will have the highest number of 90° days on record. The previous leader for 90° days was the 2010s. Philly to Newark corridor average annual number of 90° days by decade 2020s….Philly….35…..Hightstown….39…..Newark….36 2010s…. 34….33…32 2000s….23…..21…23 1990s…..31…..20…29 1980s…..26….21….26 1970s……22….14….20 1960s……17…..20….21 1950s…..26……23…25 1940s…..26…..23….25

The record high of 98° at Augusta, Maine was two degrees under the August all-time high. They got the all-time June monthly record earlier this summer. Through August 11th this has been their driest summer on record. Also their first year reaching 98° or higher twice. Time Series Summary for AUGUSTA STATE AIRPORT, ME - Month of Aug Warmest High Temperature Click column heading to sort ascending, click again to sort descending. 1 1955 100 0 2 2025 98 20 - 1948 98 0 3 2001 97 0 - 1975 97 0 4 2002 96 0 - 1987 96 0 5 1953 95 0 - 1949 95 0 Time Series Summary for AUGUSTA STATE AIRPORT, ME - Month of Jun Click column heading to sort ascending, click again to sort descending. 1 2025 100 0 2 1995 98 0 3 2024 97 0 - 1988 97 0 - 1971 97 0 4 1955 95 0 - 1953 95 0 5 2021 94 0 - 2020 94 0 - 2005 94 0 - 1984 94 0 - 1963 94 0 - 1956 94 0 Time Series Summary for AUGUSTA STATE AIRPORT, ME June 1st through August 11th Lowest Rainfall Click column heading to sort ascending, click again to sort descending. 1 2025-08-11 3.00 3 2 1999-08-11 3.57 0 3 1949-08-11 3.80 0 4 1994-08-11 3.82 0 5 1952-08-11 4.31 0 6 2017-08-11 4.77 0 7 1965-08-11 4.80 0 8 1995-08-11 4.81 0 9 1950-08-11 5.06 0 10 1966-08-11 5.15 0

Both urban and rural NJ sections weren’t consistently as warm as they have been since 2010. Getting 30+ and 40+ days reaching 90° only happened from time to time with many cooler seasons under 20 days and even 10 days. These days most of the seasons are over 30 days with the cooler seasons under 20 or 10 days hard to come by anymore.