September 2025 OBS-Discussion centered NYC subforum

[Stormlover74]

Gfs is coming in wetter for mid to late week but the heaviest is still to our west

[LibertyBell]

6 hours ago, bluewave said:

I had 1.78 spread out over 3 days. My wettest single day was only .76. The last 1.02” in a day was way back on May 5th. 3-23-24 was my last 2.92” in one day. 

This was my 5th driest summer at only 4.99”. It was also my 4th warmest summer here. So all the vegetation and grass was on the brown side. 

But July 99 back on the South Shore of LI still holds the record for the brownest vegetation that I have seen. Nearly all the lawns and the parkways were completely brown.

Time Series Summary for NEW HAVEN TWEED AP, CT - Jun through Aug
Click column heading to sort ascending, click again to sort descending.

1	2000	3.02	65
2	1966	4.15	0
3	2022	4.29	0
4	2017	4.76	3
5	2025	4.99	0
6	1957	5.26	0
7	2016	5.28	0
8	1949	5.83	0
9	1965	5.93	0
10	2014	6.23	2

 

1999 and 2002 were two of my favorite summers, I don't mind yellow or brown grass, it feels nice and crunchy

How does this summer compare for dryness to 2010 where you are Chris??

 

[LibertyBell]

6 hours ago, bluewave said:

I had 1.78 spread out over 3 days. My wettest single day was only .76. The last 1.02” in a day was way back on May 5th. 3-23-24 was my last 2.92” in one day. 

This was my 5th driest summer at only 4.99”. It was also my 4th warmest summer here. So all the vegetation and grass was on the brown side. 

But July 99 back on the South Shore of LI still holds the record for the brownest vegetation that I have seen. Nearly all the lawns and the parkways were completely brown.

Time Series Summary for NEW HAVEN TWEED AP, CT - Jun through Aug
Click column heading to sort ascending, click again to sort descending.

1	2000	3.02	65
2	1966	4.15	0
3	2022	4.29	0
4	2017	4.76	3
5	2025	4.99	0
6	1957	5.26	0
7	2016	5.28	0
8	1949	5.83	0
9	1965	5.93	0
10	2014	6.23	2

 

wild I don't remember 2000 being so dry (or hot for that matter)

 

[Stormlover74]

2 minutes ago, LibertyBell said:

wild I don't remember 2000 being so dry (or hot for that matter)

 

2000 was a cool summer

[Sundog]

What a day today!

 

[LibertyBell]

16 minutes ago, Sundog said:

What a day today!

 

Too cloudy, yesterday was much better.

[bluewave]

51 minutes ago, LibertyBell said:

1999 and 2002 were two of my favorite summers, I don't mind yellow or brown grass, it feels nice and crunchy

How does this summer compare for dryness to 2010 where you are Chris??

 

This summer was much drier in New England than 2010 was leading to the record low streamflows that some areas are experiencing.

 

 

[Sundog]

14 minutes ago, LibertyBell said:

Too cloudy, yesterday was much better.

Great for walking and being outside. And I prefer the cooler temps. 

[LibertyBell]

1 minute ago, Sundog said:

Great for walking and being outside. And I prefer the cooler temps. 

But yesterday was cool too, under 80 is good, below 70 not so much.  Today is at or above 70 so it's okay but not as pristine as yesterday was.

[LibertyBell]

12 minutes ago, bluewave said:

This summer was drier in New England than 2010 was leading to the record low streamflows we are currently experiencing.

 

 

Are we more sensitive to drought now than we were in the 1980s? I feel like the kind of rainfall we are experiencing right now is similar to what we had back then but it's being taken more seriously now?

 

[bluewave]

3 hours ago, anthonymm said:

High dews too. Somehow I dont think this summer will truly end until mid October.

We’ll see if a piece of the over the top warm up in Canada near the end of September can build down into the Northeast in October.
 

[TheClimateChanger]

1 hour ago, LibertyBell said:

wild I don't remember 2000 being so dry (or hot for that matter)

 

There is over two months of data missing from that summer (65 days), so that amount shown is based on less than a month.

[donsutherland1]

1 hour ago, LibertyBell said:

Are we more sensitive to drought now than we were in the 1980s? I feel like the kind of rainfall we are experiencing right now is similar to what we had back then but it's being taken more seriously now?

 

Lack of precipitation is one variable. Temperature is another. At higher temperatures, more soil moisture is lost to evaporation. Here's a comparison of September 1984-August 1985 vs. September 2024-August 2025 for the Northeast Region:

1984-1985:

Temperature: 49th warmest (2.0°F cooler than 2024-2025)

Precipitation: 35.23" (6th driest)

Palmer Z-Index: -0.90 (13th driest)

2024-2025:

Temperature: 13th warmest (2.0°F warmer than 1984-1985)

Precipitation: 37.97" (23rd driest)

Palmer Z-Index: -1.12 (7th driest)

Numerous locations in New England with 0 days of missing data have seen < 35.00" precipitation over the 12-month period. Three such locations have seen < 30.00" precipitation.

Bridgeport (27.62"), Islip, JFK Airport, LaGuardia Airport, Newark, and White Plains have all seen <35.00" of rain during the same period.

[donsutherland1]

Through the first three weeks of September, JFK Airport, LaGuardia Airport, and Central Park have all recorded a monthly high temperature of 86°. The last time all three sites had the same monthly high temperature was August 2024 when the peak temperature was 95°. The last time all three sites had the same highest temperature in September was 2011 when the highest temperature was also 86°. There is a single case where all three sites recorded identical highest and lowest monthly temperatures: November 1957 with a monthly high of 66° and a monthly low of 28°.

Back to the present, temperatures will top out mainly in the lower and middle 70s tomorrow. 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.

Additional rain is possible Thursday into Saturday as a series of low pressure systems move along the frontal boundary. 

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 +0.12 today. 

The preliminary Arctic Oscillation (AO) was +0.667 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.