September 2021

[bluewave]

1 hour ago, qg_omega said:

Think low was 48

Yeah, the low was 48° at HPN. The first 40s and 30s have been getting later faster than the first freeze. My guess is that this is due to the September and October warming faster than November. So the first freeze date is closer to the colder weather arriving in November during recent years. Then as the warming has picked up in December, the first low below 20° since 2010  got pushed back by 12 days compared to the 1952-1980 climate normals period. 

HPN average first 40s 2010-2020…..9-20……1952-1980…..9-9

………………………….30s  2010-2020….10-17…….1952-1980…..10-06

………………………….32   2010-2020….10-30…….1952-1980…..10-26

………………………….10s  2010-2020    12-17……..1952-1980…..12-05

[SnoSki14]

55 minutes ago, bluewave said:

Yeah, the low was 48° at HPN. The first 40s and 30s have been getting later faster than the first freeze. My guess is that this is due to the September and October warming faster than November. So the first freeze date is closer to the colder weather arriving in November during recent years. Then as the warming has picked up in December, the first low below 20° since 2010  got pushed back by 12 days compared to the 1952-1980 climate normals period. 

HPN average first 40s 2010-2020…..9-20……1952-1980…..9-9

………………………….30s  2010-2020….10-17…….1952-1980…..10-06

………………………….32   2010-2020….10-30…….1952-1980…..10-26

………………………….10s  2010-2020    12-17……..1952-1980…..12-05

That's how you get these powerful 15-20F freezes that kill everything in one swoop.

[lee59]

1 hour ago, Intensewind002 said:

In Lindenhurst, It seems I’ll finish the month with exactly 5.6” of rain. Low was 53 last night, the coldest of the month so far. We hit 39 for the low here in Albany by comparison

Yea Long Island missed out on some of the heavy rain but still got plenty. I had about 8.5 inches in July, 7 inches in August and 7.5 this month.

[bluewave]

1 hour ago, SnoSki14 said:

That's how you get these powerful 15-20F freezes that kill everything in one swoop.

Yeah, the November 2019 record early hard freeze following the October record warmth was a recent example of this. The record low 20s in November following the record mid 90s in October just flattened the late blooming fall plants. So November has been our month that we can still get record cold. Areas to our north that used to get late September freezes like Albany had them pushed back to mid-Ocrober. Since NYC has had the average first freeze November for a long time, the freeze date change isn’t as dramatic.

First freeze dates

Albany…1951-1980….9-29…..2010-2020….10-16

NYC…….1951-1980….11-11…..2010-2020….11-18

[lee59]

Brookhaven Labs on Long Island already down to 54 degrees, 61 here.

[donsutherland1]

Tonight will provide a genuine autumn preview. Temperatures will likely fall into the lower 50s in New York City, Newark, and perhaps Philadelphia. Outside the cities, temperatures could fall well into the 40s. Westhampton could see the mercury dip below 40°. Afterward, it will be variably cloudy with the mercury rising into the middle and upper 60s in much of the region. Newark's record-breaking 122-day streak with maximum temperatures of 70° or above will be severely challenged. Most of the modeling shows a high of 68°-70° there.

2021 is virtually certain to become the 6th out of the last 7 years during which September has had a mean temperature of 70° or above in New York City. Prior to 2000, New York City saw such warmth on average once every five years. In short, September has become more an extension of summer than a gateway to autumn in the New York City area.

Friday will be another relatively cool day. But warmer temperatures will return and the chance of precipitation will increase as the calendar presses deeper into the first week of October.

There is strong consensus on the long-range guidance that October will be an unseasonably warm month. The first half could feature much above normal readings in the Northern Plains into Central Canada. Overall, the Middle Atlantic and southern New England areas appear to be in line with a warmer to much warmer than normal October (a general 2°-4° above normal).

Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27".

Following very wet July-September periods, winter precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.05°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail through September. Afterward, La Niña conditions could begin to develop during October.

The SOI was +30.49 today.

The preliminary Arctic Oscillation (AO) figure was -1.308 today.

On September 27 the MJO was in Phase 4 at an amplitude of 1.346 (RMM). The September 26-adjusted amplitude was 1.087 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.3° (1.1° above normal).

 

[LibertyBell]

7 hours ago, lee59 said:

Brookhaven Labs on Long Island already down to 54 degrees, 61 here.

it's going to be in the 30s tomorrow night on Long Island, too bad it's going to be October 1 not September 30

 

[donsutherland1]

Morning thoughts…

Today will start off with overcast skies in parts of the region. Those clouds will yield to sunshine. Elsewhere, it will be partly sunny and unseasonably cool. High temperatures will likely reach the middle and upper 60s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 65°

Newark: 70°

Philadelphia: 70°

Normals:

New York City: 30-Year: 70.6°; 15-Year: 71.9°

Newark: 30-Year: 72.2°; 15-Year: 73.7°

Philadelphia: 30-Year: 73.5°; 15-Year: 74.7°

Dry but cool weather will continue through tomorrow.

[lee59]

3 hours ago, LibertyBell said:

it's going to be in the 30s tomorrow night on Long Island, too bad it's going to be October 1 not September 30

 

Yea, projected lows last night were higher than expected thanks to overcast skies. 

[CIK62]

The last day of September is averaging 64degs.(59/69), or -1.

Month to date is  70.7[+1.3].      September should end at 70.1[+0.9]

60*(58%RH) here at 6am.     59* at 7am.          Still 59* at 9am.        62* at Noon.        65* at 2pm.     Reached 67* at 4pm.     62* at 9pm.

Today: 65-70, nw. wind, p. cloudy.

Coming rain reduced on GFS and T's way up.      Week 1 Oct.   68[60/77], +4.   EURO still has days of rain.

[bluewave]

The lack of any real cold air for September shows up with monthly minimum temperatures in the top 3 warmest. New records were set at EWR, BDR, and ISP. This reflects how fast the September temperatures have been rising. 

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Lowest Min Temperature	Missing Count
1	2021	54	1
2	2015	52	0
3	2018	51	0
4	2017	49	0
-	2011	49	0
-	2004	49	0
-	2002	49	0

 

 

Time Series Summary for WESTCHESTER CO AP, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2018	51	0
2	2021	48	1
-	2008	48	0
-	2002	48	0
-	1999	48	2
-	1968	48	0

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2021	55	1
2	2015	54	0
3	2018	53	0
-	2002	53	0
-	1994	53	0

 

Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	1910	57	0
2	2015	56	0
-	1921	56	0
3	2021	54	1
-	2018	54	0
-	2017	54	0
-	2016	54	0
-	2010	54	0
-	2002	54	0
-	1982	54	0
-	1960	54	0
-	1891	54	0

 

Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2010	59	0
2	2018	57	0
-	2016	57	0
3	2021	56	1
-	2015	56	0
-	2012	56	0
-	2002	56	0

 

Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2015	56	0
2	2021	54	1
-	2018	54	0
-	2017	54	0
-	2002	54	0
-	1994	54	0
-	1968	54	0

 

Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2021	52	1
-	2018	52	0
2	2017	50	0
-	2015	50	0
-	2002	50	0
-	1977	50	0

[LoboLeader1]

52 here this AM

[SACRUS]

Down to 51 last night.  Much less clouds than i was expecting.  Cooler train 36 more hours before we warm up this weekend.  We will push 80 in the warmer spots Sat, if enough sun on Sunday (10/3) it will be low 80s (EWR record is 85).  More clouds and Mon (10/4) as upper low pushes west and hung up flow overall.  Should see more persistent onshore to more humid S/SE flow by the middle/end of next week Thu (10/7) - Sat (10/9). Beyond there ridge builds into the east and warmer mid month.  Not sure we see more 80s in the period 10/10 - 10/20 in the  warm spots but chances may be increasing.

[psv88]

No lows in the 40s this month

[LibertyBell]

3 hours ago, bluewave said:

The lack of any real cold air for September shows up with monthly minimum temperatures in the top 3 warmest. New records were set at EWR, BDR, and ISP. This reflects how fast the September temperatures have been rising. 

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Lowest Min Temperature	Missing Count
1	2021	54	1
2	2015	52	0
3	2018	51	0
4	2017	49	0
-	2011	49	0
-	2004	49	0
-	2002	49	0

 

 

Time Series Summary for WESTCHESTER CO AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Lowest Min Temperature	Missing Count
1	2018	51	0
2	2021	48	1
-	2008	48	0
-	2002	48	0
-	1999	48	2
-	1968	48	0

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2021	55	1
2	2015	54	0
3	2018	53	0
-	2002	53	0
-	1994	53	0

 

Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	1910	57	0
2	2015	56	0
-	1921	56	0
3	2021	54	1
-	2018	54	0
-	2017	54	0
-	2016	54	0
-	2010	54	0
-	2002	54	0
-	1982	54	0
-	1960	54	0
-	1891	54	0

 

Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2010	59	0
2	2018	57	0
-	2016	57	0
3	2021	56	1
-	2015	56	0
-	2012	56	0
-	2002	56	0

 

Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Sep
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Rank	Year	Lowest Min Temperature	Missing Count
1	2015	56	0
2	2021	54	1
-	2018	54	0
-	2017	54	0
-	2002	54	0
-	1994	54	0
-	1968	54	0

 

Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Lowest Min Temperature	Missing Count
1	2021	52	1
-	2018	52	0
2	2017	50	0
-	2015	50	0
-	2002	50	0
-	1977	50	0

Just glad that the yucky 70 dew point crap is gone.  I think most would be happy with temps in the 70s during the day with 50s at night for the next 4-5 weeks and most of all low humidity (dew points 50s or lower.)

I dont really like cold weather in October or November, I like a slow transition.

[SACRUS]

So far EWR only up to 69 so the 70(+) streak is in jeopardy.  Mostly cloudy now too.

 

http://synoptic.envsci.rutgers.edu/site/imgs/vis_nj_anim.gif

[lee59]

Most of the area easily staying below  70 today.

[Stormlover74]

2 hours ago, SACRUS said:

So far EWR only up to 69 so the 70(+) streak is in jeopardy.  Mostly cloudy now too.

 

http://synoptic.envsci.rutgers.edu/site/imgs/vis_nj_anim.gif

Made it to 70

[donsutherland1]

The streak goes on... At 4 pm. Newark had a temperature of 70 degrees. The record streak of 70-degree high temperatures is now 123 days.

[lee59]

It may never end at Newark. 

[psv88]

Made it to 65 here, really feels like fall today.

[lee59]

5 minutes ago, psv88 said:

Made it to 65 here, really feels like fall today.

Yea, made it to 66 here. Most current temperatures in the area are in the low to mid 60s. 

[lee59]

When I checked the Newark readings at 4, it showed 70 degrees and the wind NW at 76mph. Now the temperature at Newark is 67 degrees. So I am wondering if the 70 degree reading was incorrect. It certainly seemed like an outlier temperature reading as I checked numerous local stations in the area at 4PM and the highest I could find was Caldwell NJ at 67.

[SnoSki14]

1 hour ago, lee59 said:

It may never end at Newark. 

It won't if it hit 70F today. Next 10-14 days look very mild. The only way it stays below 70F is if enough clouds/rain keep temperatures down.

[lee59]

If the clouds dissipate tonight, it will be the best chance for scattered frost in some of those northern valley areas, such as in the Catskills. 

[lee59]

I looked up Newark on Wunderground and it says high temperature 70 but it also says maximum wind speed 76mph.

[donsutherland1]

At 2:51 pm, the temperature reached a daily high of 70° at Newark. That extended Newark's record streak with high temperatures of 70° or above to 123 consecutive days.

New York City is finishing September with a mean temperature of 70.3° (1.1° above normal). As of 7 pm, that figure is 70.4°, but it is likely to fall to 70.3° as the mercury dips below 58° late this evening. 2021 is the 6th out of the last 7 years during which September has had a mean temperature of 70° or above in New York City. Prior to 2000, New York City saw such warmth on average once every five years.

What will likely turn out to be a warm October will start off on a cool note. Temperatures will rebound into the upper 60s and lower 70s during the afternoon. Warmer temperatures will return this weekend. Next week, the chance of precipitation will increase.

There is strong consensus on the long-range guidance that October will be an unseasonably warm month. The first half could feature much above normal readings in the Northern Plains into Central Canada. Bismarck could have one of its 5 warmest opening weeks in October on record. Overall, the Middle Atlantic and southern New England areas appear to be in line with a warmer to much warmer than normal October (a general 2°-4° above normal).

Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27".

Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.05°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail through September. Afterward, La Niña conditions could begin to develop during October.

The SOI was +18.25 today.

The preliminary Arctic Oscillation (AO) figure was -1.441 today.

On September 28 the MJO was in Phase 4 at an amplitude of 1.420 (RMM). The September 27-adjusted amplitude was 1.349 (RMM).

 

[bluewave]

Another top warmest September across the area.

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	1961	74.5	0
2	2005	73.5	0
3	2015	73.4	0
4	2021	72.5	0
5	2016	71.8	0
-	1971	71.8	0
6	2010	71.6	0
7	1959	71.5	0
8	2018	71.4	0
9	2011	71.2	0
10	1973	71.0	0
-	1931	71.0	0

 

Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2005	74.9	0
2	2015	74.1	0
3	2016	73.8	0
4	1961	73.6	0
5	2007	73.0	0
6	2018	72.8	0
7	2021	72.7	0
8	2010	72.5	0
-	1959	72.5	0
9	2019	72.1	0
10	1998	71.6	0

 

Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2015	73.0	0
-	1961	73.0	0
2	2005	72.1	0
3	1971	71.8	0
4	1959	71.3	0
5	2016	71.1	0
6	1983	71.0	0
7	2021	70.7	0
-	2018	70.7	0
8	2017	70.6	0
9	2010	70.5	0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2015	70.9	0
2	2005	70.2	0
3	2018	69.8	0
4	2021	69.6	0
-	1980	69.6	0
5	2017	69.0	0
-	2011	69.0	0
6	2016	68.9	0
7	1998	68.6	0
8	2010	68.3	0
9	1983	68.1	0
-	1971	68.1	0
10	2008	67.7	0

 

Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2015	71.1	0
2	2016	70.6	0
3	1961	70.5	0
4	2011	70.1	0
5	2021	69.8	0
-	2005	69.8	0
6	2018	69.5	0
7	1959	69.4	0
8	2010	69.3	0
9	2017	69.1	0
10	1971	69.0	0

[wdrag]

Sept worked out warmer and wetter than normal but no real HEAT to speak of. Onward.