bluewave

Yeah, the ridge axis was to our west. This is why JFK only has around half as many 90° days as NJ this year so far. The warm spots in NJ may very well top 40 days reaching 90° again this year. While the number to the east of NYC with the sea breeze will be much lower. The ridge axis has been located to the east of New England again this summer. 90° Day Data for January 1, 2025 through July 11, 2025 Click column heading to sort ascending, click again to sort descending. Newark Area ThreadEx 18 OCEAN COUNTY AIRPORT WBAN 18 NEWARK LIBERTY INTL AP WBAN 18 TETERBORO AIRPORT COOP 16 HIGHTSTOWN 2 W COOP 16 TETERBORO AIRPORT WBAN 16 CALDWELL ESSEX COUNTY AP WBAN 16 HARRISON COOP 16 PHILADELPHIA/MT. HOLLY WFO COOP 14 90° Day Data for January 1, 2025 through July 11, 2025 Click column heading to sort ascending, click again to sort descending. LAGUARDIA AIRPORT WBAN 13 New York-LGA Area ThreadEx 13 BAITING HOLLOW COOP 11 PORT JERVIS COOP 10 SARATOGA SPRINGS 4 SW COOP 10 POUGHKEEPSIE/HUDSON VALLEY REGIONAL AIRPORT WBAN 10 STONYKILL NEW YORK RAWS 10 Poughkeepsie Area ThreadEx 10 ST. JAMES COOP 10 DANSVILLE MUNICIPAL AIRPORT WBAN 9 JFK INTERNATIONAL AIRPORT WBAN 9 New York-Kennedy Airport Area ThreadEx 9 SARA NEW YORK RAWS 9 VICTOR 2NW COOP 8 LANSING MANOR COOP 8 WEBSTER 2 NE COOP 8 GANG MILLS NEW YORK RAWS 8 SHERBURNE NEW YORK RAWS 8 ISLIP-LI MACARTHUR AP WBAN 7 HUDSON CORRECTIONAL FACILITY COOP 7 DANSVILLE COOP 7 SYRACUSE HANCOCK INTL AP WBAN 7 WESTCHESTER CO AP WBAN 7 SHIRLEY BROOKHAVEN AIRPORT WBAN 7 Islip Area ThreadEx 7 Syracuse Area ThreadEx 7 FARMINGDALE REPUBLIC AP WBAN 6 NY CITY CENTRAL PARK WBAN 6 SHRUB OAK COOP 6 MONTGOMERY ORANGE COUNTY AP WBAN 6

The ridge during that 10 day heatwave in Central Park from 7-7-93 to 7-16-93 was centered in SE PA. Lower heights and pressures over New England kept the flow W to SW here. So no onshore flow influence back then like we are getting now.

Our longest heatwave around the area was 20 days from 7-29-88 to 8-17-88 at Newark. The ridge axis and strongest 500mb height anomaly was centered over the Great Lakes. At the surface the Bermuda high was pressed to our south with lower pressure over New England keeping the flow more SW. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 1988-07-29 95 1988-07-30 99 1988-07-31 90 1988-08-01 91 1988-08-02 94 1988-08-03 93 1988-08-04 92 1988-08-05 90 1988-08-06 90 1988-08-07 93 1988-08-08 90 1988-08-09 92 1988-08-10 93 1988-08-11 97 1988-08-12 95 1988-08-13 98 1988-08-14 98 1988-08-15 99 1988-08-16 92 1988-08-17 90

When the WAR pushes into New England from the east we get more high pressure there leading to onshore flow here. Back in the old days we would get a strong ridge over the Great Lakes leading to more westerly flow here. But these days that area gets more troughs over the summer.

Strong WAR pattern setting up over the next week to 10 days. So plenty of onshore flow and cooling afternoon sea breezes east of NYC at the beaches. This will push the sea breeze front west of NYC keeping the strongest heat there. It will also keep the best convection west of Long Island. So plenty of lawn watering on tap to prevent the brown lawn syndrome which has become common on Long Island with these dry July patterns. July 14-21 forecast

Some newer studies are backing off those older predictions.

That’s the composite for the old days. Our new El Nino back in 23-24 had the mid-latitude marine heatwaves from Japan across the Atlantic to near Spain. So it resulted in a record warm pattern for North America even though the ONI was much weaker than 15-16 and 97-98.

While our summers here have become much warmer since 2010, at least they aren’t warming at the rate that Western Europe is.

The reason the 1995 summer was so humid with the nearly 130° heat index around 7-15 was due to corn sweat pooling under the inversion and getting transported to the East Coast.

Yeah, that’s why I posted it since it went into more detail on the same paper that you posted. This new -PDO is defined more by a warmer Western Pacific and stronger Aleutian Ridge from the older days. This leads to a further north storm tracks during the winter through the Great Lakes with warmer and less snowy conditions for our area. The older -PDO with a cooler Eastern Pacific and less WPAC warming had a weaker Aleutian Ridge. So we would often get colder and snowier winters under that -PDO regime from the last 40s into mid 70s. Plus the background climate has warmed so much more in general since then. This is why the Southeast Ridge has expanded so much over the last decade and it was often not even a factor back in those days. In addition, warming of the Atlantic resembling a +AMO is also probably boosting the 500 mb heights near the East Coast. This new pattern of mid-latitude rising 500mb heights and SSTs resembles a mid-latitude El Niño while the tropics have been more in La Niña mode.

More onshore flow due to the rising 500mb heights to the north and east of New England since around 2018. Those older summers had higher 500mb heights over the Great Lakes. So we would get more persistent westerly flow during those summers.

The ridge to the east of New England during the summers has been giving us more onshore flow. But it’s located further to the west during the winter. So we get more SW to W flow then with all the Great Lakes cutters.

This paper below explains why the circulation pattern shift is related to the warming and it focuses more on the Pacific side. But we have been seeing similar shifts in the Atlantic leading to more ridging east of New England. It results the repeating weather patterns we have been experiencing over the last decade. Don just posted this in the La Niña thread in the main forum. I added this link below. https://scienmag.com/north-pacific-climate-shifts-drive-southwest-us-drought/

Thanks for posting that paper which really confirms how significant a shift has occurred in the North Pacific. There was another article recently published on this paper which expands on the one that you posted. While this wasn’t what many of us on the forum wanted to hear, at least the team of researchers were clever enough to tie together paleoclimate reconstructions together with advanced climate modeling for a more coherent picture of what has been going on. https://scienmag.com/north-pacific-climate-shifts-drive-southwest-us-drought/ In recent years, the American Southwest has been gripped by one of the most prolonged and severe droughts in recorded history. While variations in precipitation and temperature have long challenged water resource management in this already arid region, the ongoing drought has raised alarm bells for scientists, policymakers, and residents alike. Understanding what drives these shifts in water availability is critical to anticipating future risks and developing adaptive strategies. A groundbreaking new study published in Nature Geoscience now provides compelling evidence that warming in the Northern Hemisphere, particularly in the North Pacific, plays a pivotal role in shaping drought patterns over the Southwest United States through complex ocean-atmosphere interactions. This research combines innovative paleoclimate reconstructions with advanced climate modeling to unravel how moderate warming episodes in Earth’s past—specifically during the mid-Holocene, around 6,000 years ago—triggered oceanic and atmospheric responses that closely mirror modern drought conditions. By studying leaf-wax stable isotopes preserved in sediment cores, the authors reconstructed ancient rainfall patterns with unprecedented precision. These reconstructions revealed that subtle changes in ocean temperatures off the North Pacific coast led to atmospheric circulation shifts that suppressed precipitation across the Southwest, a mechanism remarkably similar to currently observed drought drivers. What makes this work especially illuminating is its identification of the Pacific Decadal Oscillation (PDO) as a critical mediator in this process. The PDO is a naturally occurring climate phenomenon characterized by long-term fluctuations in sea surface temperatures and atmospheric pressure in the North Pacific Ocean that profoundly influence weather and climate patterns across North America. The study’s findings indicate that moderate hemispheric warming can excite a PDO-like state—specifically its negative phase—resulting in sustained drying conditions in the Southwest. This conclusion challenges prior assumptions that natural oscillations would eventually reverse and alleviate drought conditions, instead implying that external forcings such as global warming may stabilize drought-inducing patterns. The implications for future climate projections are sobering. Simulations of twenty-first century climate pathways, driven by anthropogenic greenhouse gas emissions, demonstrate that similar ocean-atmosphere dynamics are likely to emerge and endure. These simulations forecast persistent reductions in winter precipitation over the Southwest through at least the mid-century, exacerbating the region’s already critical water scarcity issues. Given that winter rains supply a substantial portion of the region’s annual precipitation and recharge vital aquifers, prolonged deficits pose significant threats to agriculture, urban water supplies, and natural ecosystems. However, the study also reveals that current climate models may underestimate the severity of these precipitation deficits. The authors suggest that the ocean-atmosphere coupling—how strongly and accurately models simulate the interaction between ocean warmth and atmospheric circulation—is likely too weak in existing frameworks. This underestimation means that official drought risk assessments and water management strategies may not be adequately prepared for the intensity or duration of future dry spells dictated by North Pacific variability under a warming climate. This advances a growing body of evidence underscoring the Pacific Ocean’s outsized influence on terrestrial climate variability in the western United States. The North Pacific’s role is multifaceted, involving the modulation of storm tracks, alterations in jet stream position and strength, and changes in moisture transport pathways. By illuminating the mechanisms through which relatively moderate warming perturbs this system, the research offers a nuanced understanding of regional climate dynamics that transcends simplistic attributions to long-term warming or random variability alone. Perhaps most compellingly, the paleoclimate perspective grants the study an unparalleled vantage point. Utilizing ancient environmental archives to calibrate and validate model simulations bridges the gap between historical climate fluctuations and future projection scenarios. This approach ensures that the conclusions are firmly rooted in empirical evidence, helping to surmount some of the uncertainties that plague climate prediction in complex transitional zones like the Southwest. The mid-Holocene period serves as a natural analog for how the contemporary Earth climate system might respond to ongoing warming trends. The study’s methodology highlights the innovative use of leaf-wax isotopes, a biomarker that preserves signals of past hydrological conditions through changes in hydrogen isotope ratios. This technique captures past rainfall variability integrated over plant growing seasons and provides a proxy record that can be spatially and temporally correlated with model outputs. Such high-resolution paleoclimate data strengthen confidence in attributing Southwest drought episodes to ocean-driven atmospheric circulations rather than isolated terrestrial or stochastic factors. In practical terms, these findings emphasize the need for water managers, urban planners, and policymakers to incorporate dynamic ocean-atmosphere feedbacks into drought risk models and resource allocation strategies. Static assessments based solely on historical precipitation trends could lead to dangerously optimistic assumptions. Instead, adaptive frameworks must account for the possibility that warming seas off the Pacific Northwest and Alaska may sustain drying influences for decades, intensifying competition for scarce water supplies across municipal, agricultural, and ecological sectors. Scientists are also calling for an urgent refinement of climate models to better replicate the subtle but critical feedbacks identifying the ocean’s influence on atmospheric patterns that steer precipitation regimes. Such improvements are crucial, as underestimating these processes risks downplaying the Southwest’s vulnerability to exacerbated drought conditions and the cascading socioeconomic impacts that follow. Enhanced model sophistication will also improve the reliability of seasonal and decadal forecasts, crucial for water allocation decisions in drought-prone regions. Furthermore, this research situates the Southwest drought within the broader context of anthropogenic climate change, illustrating that natural variability modes like the PDO can be amplified or modulated by human-driven warming. This intersection complicates predictions but also stresses the urgency of climate mitigation efforts. Without substantial reductions in greenhouse gas emissions, these drought-favoring ocean-atmosphere states may become increasingly entrenched, imperiling water security for millions of residents and straining fragile ecosystems. The findings also contribute to the growing discourse on climate resilience and the need for sustainable water use practices. Recognizing that intensified drought risk is not merely cyclical but potentially a forced response to anthropogenic warming highlights the importance of diversified water portfolios, investments in conservation technologies, and reforms in water rights systems. Communities in the Southwest must prepare for a future where drought is not an anomaly but a persistent stressor shaped by global climate dynamics. In summary, this landmark study integrating paleoclimate evidence and future climate modeling transforms our understanding of the Southwest United States drought by pinpointing the North Pacific ocean-atmosphere system as a central driver modulated by Northern Hemisphere warming. It challenges prevailing assumptions about the transitory nature of current drought conditions and suggests that external forcing is capable of sustaining drought-inducing oceanic patterns similar to the negative phase of the Pacific Decadal Oscillation. This new insight demands meaningful recalibrations in climate prediction frameworks and resource management policies to adequately prepare for a potentially drier future under continued global warming. The message is unequivocal: the interplay between warming seas and atmospheric circulation cannot be overlooked if we aim to understand and combat the growing risks of drought in one of America’s most vulnerable regions. As the Southwest grapples with dwindling water supplies amidst cities and landscapes dependent on reliable precipitation, this research underscores the urgent need to enhance predictive capabilities and strengthen societal resilience in the face of a changing climate punctuated by powerful ocean-driven droughts.

Don’t know if we can repeat 2010 east of NYC since the summer circulation patterns have shifted so much since then. Prior to 15-16 we would often get ridges over the Great Lakes and westerly flow summers. Since then we get a ridge over New England and the Rockies. This leaves a trough closer to the Great Lakes and more onshore flow here. So getting 30 days reaching 90° at JFK will be a challenge with onshore flow.