donsutherland1

The heat in the West and Southwest are aided by ongoing aridification linked in recent research to the changes in the North Pacific. Summer: Annual:

UHI is effectively addressed in the adjustments. One needs all temperatures to get a good understanding of climate change. https://www.ncei.noaa.gov/pub/data/ushcn/papers/hausfather-etal2013.pdf

Temperatures will top out mainly in the lower 70s tomorrow and Monday. It will then turn noticeably warmer on Tuesday before another cool front crosses the region on Wednesday. Highs on Tuesday will likely reach the lower 80s with some middle 80s in the warmer spots. The advancing front could trigger some showers or thundershowers. Some additional rain is possible Thursday into Saturday as a low moves along the frontal boundary. Ensemble support for a significant rainfall is low. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was -0.5°C for the week centered around September 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was -2.85 today. The preliminary Arctic Oscillation (AO) was -0.403 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 58% probability that New York City will have a cooler than normal September (1991-2020 normal). September will likely finish with a mean temperature near 68.9° (0.3° below normal). Supplemental Information: The projected mean would be 0.9° above the 1981-2010 normal monthly value.

That's now a fairly common outcome. The combination of site changes in Central Park (overgrowth of trees), increasing urbanization in the vicinity of the LGA/JFK sites (growing heat island, especially at LGA), and more frequent abnormally warm SSTAs off JFK have contributed. The latter two factors are more prominent during the winter months e.g., last winter was a prominent example where JFK had a warm seasonal temperature anomaly while Central Park had a cold one relative to the 1991-2020 baseline. Summer 2025 provides a strong example of the impact of Central Park's trees where Central Park could not reach 100° during the region's hottest June air mass on record.

Below is an illustration of how Social Media's climate change denial scammers mislead when it comes to U.S. temperatures. Notice several things: 1) The 11-year moving average stops short of the chart's end to make things look even cooler than they are 2) The chart is based on maximum temperatures, only. Climate is based on the entire set of temperatures, not just maximum temperatures. Hence, it is good and customary practice to assess climate change based on mean, not maximum temperatures. 3) The chart relies on raw data, only. Doing so is unreliable due to a range of issues, including but not limited to, new stations, eliminated stations, station moves, time of observation, etc. Now to the actual facts: 1) Summers are generally warmer than they were during the Dust Bowl Era on an 11-year moving average (the average used above) and they are warming (trend line): 2) In terms of maximum temperatures, summers are nearing the drought-inflated maximum values achieved during the Dust Bowl Era on an 11-year basis: Note: All data in my charts is official NOAA data.

If it holds, both JFK Airport and Newark will have had identical high and low temperatures today (86°-66°). The last time that happened was July 31. Fun fact: The record is 3 consecutive days (February 7-9, 2004).

Snow seasons were longer in the past in the colder climate. The numbers were not wildly different, though. Below are the numbers for Central Park:

Newark had the warmest temperature last November (83°).

Probably. However, one can't completely rule out a later such temperature, even as it doesn't show up on any of the guidance right now. Just over 1-in-6 years in JFK's period of record saw 86° or above temperatures on September 20th or later. The most recent was 2019 with the epic 95° high on October 2. The last week of the month has some potential with the forecast drop in the PNA, though an even sharper drop would increase prospects.

Today was an unseasonably warm late September day. Preliminary highs included: Bridgeport: 84° Islip: 85° (tied record from 1983) New Haven: 84° New York Cty-Central Park: 84° New York City-JFK Airport: 86° New York City-LaGuardia Airport: 83° Newark: 86° Philadelphia: 84° Westhampton: 83° (tied record set in 1967 and tied in 2024) White Plains: 83° Cooler air will return overnight for the weekend. Temperatures will top out mainly in the lower 70s tomorrow through Monday. It will then turn warmer on Tuesday before another cool front crosses the region on Wednesday. The advancing front could trigger some showers or thundershowers. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was -0.5°C for the week centered around September 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was -4.34 today. The preliminary Arctic Oscillation (AO) was -0.972 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 57% probability that New York City will have a cooler than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.0° (0.2° below normal). Supplemental Information: The projected mean would be 1.0° above the 1981-2010 normal monthly value.

86 (record was 90 in 1983).

Westhampton has reached 83°. That ties the daily record for September 19th that was set in 1967 and tied in 1983. Records go back to 1951.

At Central Park, the temperature has reached 83° so far after yesterday's 83°. Through September 23, New York City has seen at least one-in-five years reach 80° or above on each date in the second half of September. The frequency of such warmth decreases afterward. Even during the shorter 2000-present timeframe, there has been a drop in the frequency of such warmth after September 23: At Newark, the temperature has reached 86° so far after yesterday's 87°. Newark takes a step down in the frequency of 80° or above warmth after September 23 and again after September 26. Since 2000, the frequency of such warmth has increased on all but September 17 (likely to have more to do with sample size issues rather than a genuine cooling). Note: All charts include September 16-18, 2025 data.

Tomorrow will be partly cloudy and unseasonably warm. Temperatures will top out in the lower 80s. The warmer spots could see some middle and perhaps upper 80s. Cooler air will return for the weekend with another warmup possible starting early next week. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was -0.5°C for the week centered around September 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +4.40 today. The preliminary Arctic Oscillation (AO) was -0.972 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 54% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.3° (0.1° above normal). Supplemental Information: The projected mean would be 1.3° above the 1981-2010 normal monthly value.

I meant for this to be in the banter thread, but the point is that one has to use established definitions consistently for clear communication. Otherwise, confusion can erode preparedness and public safety.

Perhaps because his tropical forecast is in bad shape due to a quiet hurricane season so far, Joe Bastardi is now insisting that meteorologists embrace his private fiction of what constitutes a tropical cyclone. As noted previously, the system had fronts. It was a nor'easter. It was not a tropical cyclone. It should not have been classified as a tropical cyclone any more than a winter nor'easter should be classified as a tropical storm or hurricane.

The overall dry September is consistent with the exceptionally dry end to August that had occurred. Indeed, the monthly CFSv2 initially called for a wet September before finally reverting to a dry September. Despite early rainfall during the month, highlighted by an unusually wet week following such a dry end to August, monthly rainfall is now below normal in New York City. Central Park: September 1-18: 2.30" 1991-2020 Average: 2.52" The guidance shows little or no rainfall for at least the next seven days. Statistically, the odds would somewhat favor a rebound in rainfall during October. Since 2000, 64% of drier than normal Septembers were followed by somewhat wetter to wetter than normal Octobers. However, with quasi-resonant amplification driven by changes in the Arctic producing "stuck patterns" that lead to longer-duration patterns, a dry October is possible. Indeed, during the last 10 years, dry Septembers were somewhat more likely (56%) to be followed by a drier than normal October. The most recent such case was October 2024. At present, the CFSv2 is showing drier than normal conditions in the Northeast. The ECMWF weeklies also begin October with near normal to possibly drier than normal conditions. October 2005 saw greatly elevated rainfall due to tropical moisture. Moisture from Subtropical Depression 22 dumped 4.49" of rain during October 7-8. Another system moving along a stalled frontal boundary brought 8.64" of rain during October 11-14. Nassau and Suffolk County saw the heaviest amounts with Lynbrook picking up 14.82", Riverhead receiving 14.26", and Wading River seeing 14.52". Moisture from Extratropical Wilma enhanced rainfall from a developing system along a frontal boundary that saw 2.36" rain fall during October 24-26. The emerging 500 mb pattern could provide insight as one draws closer to October. Very dry Octobers (<1.00" monthly rainfall) 1990-2024: Very wet Octobers (7.00" or more) 1990-2024: The September 18, 2025 0z EPS at 240 hours and 360 hours leans toward a dry start: 240 Hours: 360 Hours:

The system responsible for today's showers and periods of rain will slowly move away from the region tonight and tomorrow. As a result, clouds will break tomorrow morning and a partly to mostly sunny afternoon will follow. Temperatures will return to the upper 70s tomorrow and then rise further into the lower 80s on Friday. The warmer spots could see some middle 80s on Friday. Cooler air will return for the weekend with another warmup possible starting early next week. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was -0.5°C for the week centered around September 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°C and the ENSO Region 3.4 anomaly has averaged -0.37°C. La Niña conditions will likely develop during mid- or late-autumn. The SOI was +4.93 today. The preliminary Arctic Oscillation (AO) was -1.179 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 51% probability that New York City will have a cooler than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.1° (0.1° below normal). Supplemental Information: The projected mean would be 1.1° above the 1981-2010 normal monthly value.

For New York City, the connection isn't as strong. Since 2000, a wet fall is more likely to be followed by a wet winter. Dry falls were only slightly more likely to be followed by wet winters (using the 1991-2020 baselines) for New York City (Central Park). Drier than Normal Falls: 54.5% were followed by above-normal winter precipitation (Last: Fall 2024/Winter 2024-2025) 45.5% were followed by below-normal winter precipitation (Last: Fall 2017/Winter 2017-2018) Wetter than Normal Falls: 61.5% were followed by above-normal winter precipitation (Last: Fall 2023/Winter 2023-2024) 38.5% were followed by below-normal winter precipitation (Last: Fall 2022/Winter 2022-2023)

Picard, My data comes mainly from: https://xmacis.rcc-acis.org/ I periodically use teleconnections data: https://ftp.cpc.ncep.noaa.gov/cwlinks/ and Climate Data: https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/ Most of this data can readily be downloaded or converted into .CSV and .XLSX files

He's done invaluable work. I share your sentiments.

If one is looking for an idea of the warmest potential for any winter (month, season, or year) in the current climate regime (defined as the most recent 30 periods e.g. winters), one can come up with confidence intervals from a linear regression equation. A 1-in-1,000 year probability for the current regime would be the 99.9% confidence interval. For NYC, that value for a winter mean temperature is currently 44.8° (record is 41.6°, in 2001-02). The coefficient of determination for NYC is 0.545. Recently, though, some cities have seen months or even seasons breach this threshold e.g., July 2023 in Phoenix.

It seems quite bizarre, especially with the embedded simulated radar image from a snowstorm that almost certainly won't be equaled during any of our lifetimes in the Deep South.

Latest HREF:

Joe Bastardi is arguing that the current nor'easter that has dumped more than 3" of rain at Norfolk over the past two days with gusts of 50 mph should be counted as a tropical cyclone: The flaw in his reasoning is that the system has fronts. Thus, it is not a tropical cyclone.