donsutherland1

My thoughts on what will become Imelda, while recognizing that there is still some uncertainty:

Courtesy of the Fujiwhara Effect, my thinking is that the stronger Humberto will pull what will become Imelda away from the coastline before U.S. landfall can occur and before ridging can rebuild overhead to break down the steering currents and later redirect Imelda toward U.S. landfall. The Bahamas and possibly Bermuda will need to closely monitor the developing tropical cyclone. There remains a degree of uncertainty.

Yes. That’s what the NWS reported.

153rd with a standard deviation of 9.16 degrees. Here's a comparison of 1983 with 2023 (which still ranks second through yesterday):

It was. Islip also tied its daily record of 85° from 1970.

Rainfall amounts in the New York City area were generally less than the 0.50"-1.50" forecast amounts. There was a stripe of heavier rainfall in parts of Connecticut. Storm total amounts included: Hartford: 1.72" Islip: 0.30" New Haven: 1.34" New York City-Central Park: 0.35" New York City-JFK Airport: 1.38" New York City-LaGuardia Airport: 0.33" Newark: 0.17" Storrs: 2.76" White Plains: 0.47" As a result, New York City is on track to finish with rainfall that is below the 4.31" monthly normal value for September. Almost as if to add insult to injury to the dry New York City area, in the past hour, Phoenix has picked up 1.09" of rain, along with winds gusting to 56 mph. The 1.11" so far today is its biggest rainstorm since October 13, 2018. Above normal temperatures will continue through the remainder of September. Another round of showers is possible Saturday night into Sunday. A significant rainfall is unlikely. The guidance and historical experience following a second half September mean temperature of 70° or above suggest that October will be warmer than normal in the New York City area. The two most recent Octobers with a cooler than normal first half like 2025 and a second half with a mean temperature of 70° or above were: 2017 (October mean temperature: 64.1° and October 2019: October mean temperature 59.9°). The extent of ridging to the north and interaction between the Humberto and Invest. 94 could ultimately determine whether Invest. 94 poses an eventual threat to a portion of the Southeast or stays out to sea. The potential Fujiwhara interaction would be unusual for the Atlantic basin. Typically, if the stronger system is to the right or east of the weaker one (possibly Invest. 94 as per most of the guidance at present), the stronger system will tend to deflect the weaker one northward and eastward sooner than might otherwise be the case. If both systems are of similar strength, they can rotate counterclockwise around a midpoint roughly between the centers of the two storms as they move along the steering flow. Two plausible scenarios are landfall along the South Carolina coast or a sharp turn out to sea after an approach toward the coastline. For now, tropics bear watching for the Southeast. The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was -0.4°C for the week centered around September 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.03°C and the ENSO Region 3.4 anomaly has averaged -0.38°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +9.81 today. The preliminary Arctic Oscillation (AO) was +1.341 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 86% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.1° (0.9° above normal). Supplemental Information: The projected mean would be 2.1° above the 1981-2010 normal monthly value.

Newark has reached 86°. That's the fourth time it has reached 86° or above during the second half of September. The last time there were at least four such days during the second half of September was 2019 when there were five such days.

Westhampton reached 81° this afternoon. That broke the daily record of 80° from 1961.

The consistency has been remarkable. Smallest Mean Temperature Standard Deviation for September (through September 25th for 2025) for Central Park: 1. 1968 3.43° 2. 2025 3.75° (10th smallest difference between the mean temperatures for the first and second halves of September) 3. 1870 3.81° (6th smallest difference between the mean temperatures for the first and second halves of September) 4. 2024 3.94° 5. 1908 4.08°

Newark has reached 80 for the fourth consecutive day. The last time that happened after September 20th was October 1-4, 2023.

And the fact check on the political report aimed at reversing the EPA's endangerment finding. https://interactive.carbonbrief.org/doe-factcheck/images/Carbonbrief-DOE-factcheck.pdf

September 16-30, 2025 is well on track to record a mean temperature of 70.0° or above at Central Park. It would become the 12th such case since regular recordkeeping began in 1869. This warmth during the second half of September has often coincided with warmer than normal Octobers, both against the historic baseline and the 1991-2020 baseline. It has also typically been followed by warmer winters, particularly against the historic baseline. However, three of the four winters that followed such second half of September warmth since 2000 topped the 1991-2020 winter baseline. The coefficient of determination between the September 16-30 mean temperature and October and winter mean temperatures is exceptionally low (< 0.04), suggesting no predictive power when it comes to forecasting October and winter values. However, an alternative measure (ROC AUC) for addressing whether October and winter would be warmer/colder than specified values given a September 16-30 mean temperature shows stronger relationships, particularly for October. In general, ROC AUC is for problems where one wants a yes/no outcome and a probability (e.g., will winter be warmer than 36.2°?). ROC AUC Scores: October Outcome: Mean > 57.2°: 0.729 (moderately-strong) Mean > 57.9°: 0.714 (moderate) Mean of 60.0° or above: 0.625 Favored Range: 59.0°-60.0° December-February Outcome: Mean > 32.6°: 0.650 Mean > 36.2°: 0.667 Mean of 40.0° or above: 0.450 Favored Range: 37.5°-39.5° Note: 0.50 is no better than a random guess (no skill). Values < 0.50 include inverse outcomes at increasing skill for lower values. The latest CFSv2 shows a warmer than normal winter for the New York City area: Key Limitations: 1. Sample size is small 2. Mean anomalies do not exclude variability 3. Skill is modest (statistical and model) 4. Outcomes shown do not assess snowfall prospects, but all 11 prior cases saw 20" or more seasonal snowfall.

The landscape was comprised of savannas, wetlands, and woodlands. Tundra and Taiga were greatly reduced. Greenland's ice sheet was much smaller. The fauna of the period included both familiar and extinct animals. Early ancestors of modern elephants, giraffes, antelopes, along saber-toothed cats and short-faced hyenas were present. Giant ground sloths, camels, and early horses were present in North America Megalodon sharks rule the seas. Whales were evolving into today's forms. Early hominins emerged in Africa. Yes, at the current level of consumption, humanity is on an unsustainable path. The concept of "Earth Overshoot Day" captures a current reality where humanity is consuming more resources each year than what the world can provide. Add pollution (unrestrained greenhouse gas-led geoengineering, plastics/microplastics, a range of chemicals and derivatives) into the mix and that further illustrates unsustainability.

Newark reached 81° today. That was its fifth high of 80° or above during the second half of September and is the most such days since there were seven during September 16-30, 2021.

Additional rain is likely tonight into tomorrow. A storm total 0.50"-1.50" rainfall covering late yesterday through tomorrow is likely in New York City and nearby suburbs. Some locations could see higher amounts in excess of 2.00". The potential for an area of 1.00"-3.00" rainfall exists for parts of Connecticut, Massachusetts, and a secton of southeastern New York State well north and west of New York City. Above normal temperatures will continue through at least the coming weekend. Another round of showers is possible Saturday night into Sunday. In addition, Humberto has developed in the central Atlantic and a second tropical cyclone could develop in the western Atlantic in coming days. The extent of ridging to the north and interaction between the two systems could ultimately determine whether one of these systems poses an eventual threat to a portion of the Southeast or stays out to sea. The potential Fujiwhara interaction would be unusual for the Atlantic basin. Typically, if the stronger system is to the right or east of the weaker one (possibly Invest. 94 as per most of the guidance at present), the stronger system will tend to deflect the weaker one northward and eastward sooner than might otherwise be the case. If both systems are of similar strength, they can rotate counterclockwise around a midpoint roughly between the centers of the two storms as they move along the steering flow. For now, tropics bear watching. The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was -0.4°C for the week centered around September 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.03°C and the ENSO Region 3.4 anomaly has averaged -0.38°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +1.43 today. The preliminary Arctic Oscillation (AO) was +1.113 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 82% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.0° (0.8° above normal). Supplemental Information: The projected mean would be 2.0° above the 1981-2010 normal monthly value.

By “unmanageable,” I mean a future marked by significant disruption (economic dislocation, migration, and irreversible environmental/biodiversity loss). These changes will not unfold overnight, but they are already being set in motion. Even a one-meter rise in global sea level, plausible by 2100 and very likely to continue beyond, would reclaim entire neighborhoods of many major coastal cities. Even at one-meter, tens of millions of people would be displaced from major coastal cities. See: https://pmc.ncbi.nlm.nih.gov/articles/PMC8208600/ We don’t have to rely solely on climate models to understand where things are headed under current policy. Paleoclimate evidence is unambiguous. During the mid-Pliocene, when atmospheric CO2 concentrations hovered around 350–450 ppm (levels we have already reached) global temperatures were roughly 3 °C (5.4 °F) warmer than today, and sea level stood at least 10 meters higher than at present. See: https://sciences.ucf.edu/biology/d4lab/wp-content/uploads/sites/23/2018/08/Science-2015-Dutton-.pdf The climate system responds slowly but inexorably to sustained forcing. Ice sheets have not yet equilibrated to today’s CO2 levels, but over centuries to millennia continued melt is inevitable. Research indicates potential hysteresis once a critical threshold is crossed. Under hysteresis, cooling back to current temperatures will not fully restore lost ice. Some modeling places the Greenland Ice Sheet’s critical threshold at roughly 1.7 °C–2.3 °C above pre-industrial temperatures, a range that will likely be surpassed later this century. Warming also amplifies extremes rather than simply shifting the average. Climate change does not “cause” every drought, heatwave, or flood, but it makes them more frequent and more severe, a conclusion supported by a rapidly expanding body of attribution science. See: https://www.worldweatherattribution.org/ Being honest about these well-documented risks is not scaremongering. Communicating evidence-based threats, whether to coastal cities, food and water security, or human health, is a fundamental responsibility of scientists, leaders, and citizens. Describing dangers that the data clearly support is not “spreading fear.” It is providing the information societies need to plan and adapt. That some shrink from the task e.g., as one witnessed at the UN General Assembly, is not an act of courageous leadership. It is an abdication of leadership responsibility and a demonstration of leadership failure. It is a profound display of disregard for the wellbeing of future generations who will have to live with the consequences of bad choices made by those who will evade those very consequences by their having departed the scene well before the tragic returns on their bad policy investments are realized. Given this evidence, the burden of proof no longer lies with scientists who have documented human-induced climate change and its risks. It lies with those who advocate inaction, who must explain how a 3 °C or warmer world relative to pre-industrial temperatures, which is likely by 2100 on the current path, could remain “manageable” despite escalating threats to food and water systems, ongoing ocean acidification, intensifying extreme weather, and one-meter sea-level rise (with more to come beyond 2100). It is their burden to prove at a high confidence level that the laws of physics somehow don't apply in the case of greenhouse gases. Finally, claims that models are unreliable are belied by their track record. Climate models have consistently captured the long-term warming trend with striking accuracy despite the climate system’s complexity. See: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL085378

As much of the scientific community sees it, the speech openly mocked the First Law of Thermodynamics, the quantum mechanics of molecular absorption, and the established concepts of radiative forcing and planetary energy balance. Trump dismissed these fundamental laws of physics, and the principles derived from them, as a “scam,” a “hoax,” and “the greatest con job ever perpetrated on the world.” History will record this repudiation of evidence as among humanity's worst policy excesses. They will mark this speech as an iconic moment where comfort in falsehood outweighed the responsibility to truth and raw ignorance uprooted scientific understanding. They will see this moment as a vivid symptom of a Great Denial: a period when humanity still had real power to avert a return to mid-Pliocene or worse conditions yet chose to perpetuate the profitability of industries responsible and policy paralysis instead. They will place such rhetoric alongside the campaigns that once denied the link between tobacco and lung cancer or between CFCs and ozone depletion, citing it as evidence that many, including those in positions of authority, preferred tribal loyalty and ideology over science, evidence, and truth. Future generations condemned to endure the realities of a mid-Pliocene climate will condemn those who consigned them to an unmanageable world. No political gimmick will change the physics. There are no instant, magical methods to draw down the accumulated greenhouse gases, reverse the radiative forcing, or reglaciate the ice sheets that have already disappeared, much less the much greater damage that will occur in decades and centuries ahead.

I don't expect that outcome either.

With regard to the EPO, I suspect the current issue is less one about whether it can go positive or negative, but the issue of decreasing variability. In other words, there is greater stickiness for either a positive regime or negative regime during winter and that tendency has increased in recent years. More broadly, this tendency would be consistent with the growing evidence that "stuck patterns" are growing more frequent. And if one looks more closely, the stuck patterns seem to be starting to break in favor of EPO+ values. Here are ratios of the percentage of postive and negative days in January-February vs. percentage of positive and negative days in December. These are currently modest trends.

Convection during neutral ENSO events is more evenly spread out; during La Niña it's farther west (often but not always in the vicinity of the Maritime Continent); during El Niño, it's located in the cental/eastern Pacific. Depending on how the atmosphere and ocean couple, these differences matter. MJO phases in the Maritime Continent often favor warmth in eastern North America. ENSO, of course, is but one variable that shapes seasonal outcomes. Other variables can outweigh it.

2.30”.

Some have speculated toward that end. One article: https://www.space.com/space-exploration/james-webb-space-telescope/is-our-universe-trapped-inside-a-black-hole-this-james-webb-space-telescope-discovery-might-blow-your-mind

Best guess: Probably not this century. This does not apply over geological time frames e.g., long after the human greenhouse gas-emitting supervolcano (hopefully by choice, not circumstances beyond human control e.g., exhaustion of fossil fuel reserves) has gone dormant and CO2 levels drop from the human-induced peak that still lies ahead.

The same physics is involved (conservation of angular momentum) in a rotating system be they celestial bodies or tropical cyclones.

Parts of the region again reached 80° today before clouds moved in. Central Park (80°), Islip, and Newark (81°) all reached at least 80°. A low pressure system will move along a nearly stationary front tomorrow. As a result, rain will develop tonight and continue into Friday. A general 0.50"-1.50" rainfall is likely during this period in New York City and nearby suburbs. Some locations could see higher amounts in excess of 2.00". The potential for an area of 1.00"-3.00" rainfall exists for parts of Connecticut and Massachusetts. Above normal temperatures will continue through at least the coming weekend. In addition, one or two tropical cyclones could develop in the western Atlantic in coming days. The extent of ridging to the north and interaction with a potential second system could ultimately determine whether one of these systems poses an eventual threat to a portion of the Southeast or stays out to sea. The potential Fujiwhara interaction would be unusual for the Atlantic basin. Typically, if the stronger system is to the right or east of the weaker one (possibly Invest. 94 as per most of the guidance at present), the stronger system will tend to deflect the weaker one northward and eastward sooner than might otherwise be the case. If both systems are of similar strength, they can rotate counterclockwise around a midpoint roughly between the centers of the two storms as they move along the steering flow. Then, there's low but not zero probability of a subsequent shift in the steering currents that could turn the storm back toward the coast as depicted on the 9/24 12z ECMWF. For now, the potential development and evolution of pair of tropical cyclones bears watching. The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was -0.4°C for the week centered around September 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.03°C and the ENSO Region 3.4 anomaly has averaged -0.38°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +2.62 today. The preliminary Arctic Oscillation (AO) was +0.889 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 75% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.8° (0.6° above normal). Supplemental Information: The projected mean would be 1.8° above the 1981-2010 normal monthly value.