donsutherland1

The temperature dipped to 49° at White Plains this morning. Last year's first low in the 40s occurred on September 9. That is the earliest season low in the 40s since 2001 when the temperature fell to 49° on July 3.

FYI, the NWS has added the rainfall amounts that were missing for both August and yesterday for Bridgeport. The region benefits from its high quality and responsive NWS office.

As of 4 pm, Central Park had a high of 68°. Should Central Park have a high of 69° or below, it would be the first time New York City has seen a high in the 60s during the first week of September since September 6, 2019 when the mercury topped out at 67°. Yesterday, Central Park received 1.01" of rain, its first 1.00" or above daily rainfall since July 14. Additional rain fell today. Two-day rainfall amounts across the region included: Islip: 0.77" New Haven: 1.39" New York City-Central Park: 1.64" New York City-JFK Airport: 0.99" New York City-LaGuardia Airport: 1.56" Newark: 0.89" White Plains: 1.56" Temperatures will mainly top out in the 70s during the daytime and fall into the 50s at nighttime in New York City through at least Wednesday. Thursday could be briefly warmer with highs in the upper 70s to perhaps lower 80s. Additional showers or rain is possible on Thursday, as another cold front crosses the region. The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.4°C for the week centered around August 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.33°C and the ENSO Region 3.4 anomaly has averaged -0.32°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +6.95 today. The preliminary Arctic Oscillation (AO) was -0.932 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 59% probability that New York City will have a cooler than normal September (1991-2020 normal). September will likely finish with a mean temperature near 68.2° (1.0° below normal). Supplemental Information: The projected mean would be 0.2° above the 1981-2010 normal monthly value.

Years with one or more 90° temperatures on or after the fall equinox for select New York City Area locations: Bridgeport: 1970 Islip: 1980 New York City-Central Park: 1881, 1895, 1914, 1927, 1933, 1938, 1939, 1941, 1959, 1961, 1970, 1980, 2017, 2019 New York City-JFK Airport: 1970, 1980, 2007, 2017, 2019 New York City-LaGuardia Airport: 1941, 1946, 1970, 1980, 1998, 2007, 2010, 2017, 2019 Newark: 1881, 1895, 1908, 1914, 1938, 1939, 1941, 1949, 1958, 1959, 1961, 1968, 1970, 1980, 1998, 2007, 2010, 2016, 2017, 2019 White Plains: 1970, 2017, 2019

It should also be noted that since 2000, there has been a tendency for Newark's above normal days to be backloaded in September (relative to the 1991-2020 baseline): That doesn't mean that this year will be the case, but the idea that there could be much warmer air in the Plains States/Midwest toward mid-month suggests that it's something to watch for should the guidance continue to show such warmth in the Plains States/Midwest. The Week 3 outlooks on the ECMWF Weeklies and the CFSv2 are warmer than normal in the Northeast:

For the second time in less than a month, Bridgeport is not reporting its precipitation. Yesterday's hourly data: The lowered visibilities are consistent with falling rain: Yesterday's NOWData: In sum,Bridgeport had measurable rainfall yesterday. That data was not recorded. So far, today's rainfall has also not been measured.

What this means is that the social media hurricane hypesters will simply shift the goalposts to a few weeks down the road to maybe late September or October (an art that many have perfected from punting long-range cold/snow calls when they don't verify). I suspect that there will be some activity before the season concludes, so they will also proclaim that they were correct. Also, there's no reason the current season can't end with only a modest uptick in activity. Every season does not end with a spectacular burst of late-season storms. There's a window currently suggested on the MJO guidance for the second half of September (probably after the 20th) into the first week of October. Afterward, things could largely shut down. The forecast lift isn't as great or widespread as one would look for if there were to be a big explosion of tropical cyclone genesis or a large number of hurricanes.

Today saw the temperature top out at 90° at Newark and strong thunderstorms bring drenching rainfall to parts of the region. Newark reached 90° or above in June, July, August, and September for the first time since 2023. 2023 also saw the mercury hit 90° in May, unlike this year. Hourly rainfall amounts included: Central Park: 0.89", LaGuardia Airport: 0.78"; and, White Plains: 0.90". Today is Central Park's wettest day since 2.64" fell on July 14. A cold front crossing the region will bring additional showers and thundershowers tonight. Rain could linger into tomorrow as the front slows. A general 0.50"-1.50" rainfall is likely around the New York City area and its nearby suburbs with localized amounts in excess of 2.00" by the time the rain ends tomorrow. Following the passage of the cold front, highs will reach the upper 60s to lower 70s tomorrow. Afterward, temperatures will mainly top out in the 70s during the daytime and fall into the 50s at nighttime in New York City through at least the middle of next week. Additional showers or rain is possible around midweek. The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.4°C for the week centered around August 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.33°C and the ENSO Region 3.4 anomaly has averaged -0.32°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +17.47 today. The preliminary Arctic Oscillation (AO) was -0.837 today.

0.78" hourly amount at Central Park as of 3:32 pm.

For reference: Highest hourly amount for September 6: 0.96", 2008.

Newark has reached 90° for the 39th time this year. Thunder is also reported.

I suspect that its seeming inability to see cold anomalies except at shorter timescales has a lot to do with the idea that boundary conditions drive seasonal averages. ENSO, PDO are prominent conditions. The oceans overall are warming. Therefore, the model forecasts are tipped toward the warmer idea more broadly than is realistic. Worse, the coefficients of determination for such variables related to boundary conditions and actual seasonal outcomes are very low. These weak relationships reveal that other important factors are involved, including synoptic scale events that cannot be reliably forecast beyond 10-14 days. Some of these additional variables may not yet be known. Synoptic scale events i.e., large snowstorms, Arctic blasts, etc., can have a great influence on the overall seasonal outcomes. Thus, even a warm winter can be much snowier than normal or a cold winter can lack snowfall. On account of these other variables, every La Niña or El Niño event is not alike. The seasonal models are not yet at a stage where they can even begin to consistently resolve the actual events that ultimately produce the seasonal outcome. A similar situation applies to subseasonal forecasting. Not surprisingly, beyond two weeks, model skill on the weekly guidance largely disappears. There also seems to be a larger deal of persistence in the two week or longer forecasts than what actually occurs. AI may improve some of these outcomes. But even then, big challenges could still persist. For example, even as some experiments with random forest models have shown a degree of improved skill in forecasting ENSO, those models are constrained by their knowledge base. Hence, when it comes to forecasting extreme events e.g., super El Niño events, they have great difficulty. Perhaps the combination of AI and quantum computing might produce some significant breakthroughs. But that's still in the future and perhaps a decade or more away, assuming society values science and basic research to make the investments necessary to arrive at that improved state of forecasting. That's an open question in some areas and it will become even more relevant as major states grapple with the costs of aging populations, rising debt relative to GDP, etc., and the trade-offs involved in making budget allocations.

With ECMWF seasonal maps coming out, focus briefly turns to the coming winter. While it is far too soon to expect much skill from the models, recent winter outcomes suggest that New York City is beginning to put distance between the present and a golden snowfall era. The core of winter (December-February) was especially snowy for the most part from Winter 1999-00 through Winter 2017-18. Storms dumped an average of 2.9" per event and there were 30 days with 6" or more snow, including 9 with 10" or more. The December-February periods saw an average of 28.2" of snow. For all other winters, storms averaged 1.9" per event with the December-February period averaging 20.8".

The 0.48" rainfall at Bridgeport today broke the daily record for September 5. The old mark of 0.44" was set in 2012.

Here you go:

It was. Notice how similar the map looks to last September's outlook for the past winter. I suspect that the similarity reveals that the expected ENSO state plays a disproportionate role in the seasonal forecasts.

Overnight, New York City saw its biggest one- and two-day rainfall since August 20 and August 20-21. The guidance has continued to increase rainfall amounts for later Saturday into Sunday with some of the guidance showing the potential for an inch or more of rain in places. As a result, this could be New York City's biggest rainfall since 2.64" fell on July 14. That rainfall was highlighted by an hourly figure of 2.07". September 6 will also be the 17th anniversary of a widespread rainstorm that produced daily record figures across the New York City region and nearby southern New England. Daily records set in 2008 included: Bridgeport: 2.90" Danbury: 5.96" Hartford: 5.22" Islip: 2.29" New Haven: 3.31" New York City-Central Park: 3.26" New York City-JFK Airport: 2.51" New York City-LaGuardia Airport: 3.21" Newark: 3.64" Poughkeepsie: 2.20" Providence: 3.95" Westhampton: 2.32" White Plains: 4.42" In terms of temperatures, tomorrow will be another warm day. Temperatures will top out in the lower and middle 80s before another cooler air mass moves into the region. A few of the warmer spots could top out in the upper 80s. Following the passage of a strong cold front, temperatures will mainly top out in the 70s during the daytime and fall into the 50s at nighttime in New York City through at least the middle of next week. Additional showers or rain is possible around midweek. The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.4°C for the week centered around August 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.33°C and the ENSO Region 3.4 anomaly has averaged -0.32°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +17.71 today. The preliminary Arctic Oscillation (AO) was -0.231 today.

I agree. At some degree of warming or ocean acidification/deoxygenation, the food chain dominoes will begin to fall. The precise levels where this will occur are uncertain. Even if they were well-established, I don't think that knowledge, alone, would galvanize human society. Unfortunately, if past extinction/mass extinction events are representative, once the food chain dominoes begin to fall, it will be too late to mount an effective response.

Yes. At present, for most crops, gains in production outweigh declines in production. I suspect that modern agricultural practices are helping increase yields at present more than anything else. That could begin to change in coming decades assuming that technological advances don't offset adverse impacts from drought/heat/flood events. With regard to the Midwest, I suspect that the widespread use of irrigation has allowed for greater moisture than would otherwise be the case. That has played out in higher humidity, less frequent droughts, and less intense heat than during the Dust Bowl era there. But even those benefits could be temporary at some degree of additional warming.

The issue isn't so much whether climate change is creating such events. The issue is how much more frequent, intense, or worse climate change is making such events. There is a growing body of attribution studies that discuss the linkage. My point is that much larger and more frequent events than what have occurred or are likely to occur in the near-term to drive a fundamental shift in thinking. Even, let's say a $500 billion hurricane or a colossal heatwave that claims ten times the lives of the 2003 European heatwave by themselves won't really change the realities of human psychology that anchor human societal inertia.

Here's how the ECMWF seasonal forecasts changed: August 2025: September 2025: For perspective, here's where things stood last September for Winter 2024-2025, along with the actual outcome:

Good question. I posted the actual data, because even when the data is detrended for the warming, one still finds similar outcomes.

In a welcome respite from the dry conditions, last night's rainfall overperformed the guidance in New York City. The one day rainfall for yesterday of 0.40" was the largest since 0.51" fell on August 20 and the two-day rainfall into this morning of 0.57" was the largest since August 20-21 when 0.78" fell.

At least it's not that dry. Phoenix is currently seeing blowing dust courtesy of an outflow boundary that is moving through:

Rainfall amounts have fizzled as the front moved toward New York City. Some amounts through 8:15 pm include: Newark: 0.02" (light rain) Sussex: 0.33" Trenton: 0.07"