September 2021

[LibertyBell]

On 9/25/2021 at 7:15 PM, bluewave said:

It looks like NYC may finally drop below 55° next week. HPN could also see the first 40s of the fall. This would be very late for these temperature benchmarks at both stations. 
 

Latest first day below 55° in NYC

First/Last Summary for NY CITY CENTRAL PARK, NY
Each section contains date and year of occurrence, value on that date.
Click column heading to sort ascending, click again to sort descending.

Year	Last	Value	First	Value	Difference
2015	06-04 (2015)	54	10-02 (2015)	48	119
1910	06-08 (1910)	53	10-02 (1910)	54	115
1921	06-05 (1921)	54	10-01 (1921)	52	117
1908	05-16 (1908)	53	09-30 (1908)	52	136
2005	06-02 (2005)	54	09-29 (2005)	54	118
2003	06-17 (2003)	53	09-29 (2003)	53	103
2002	06-08 (2002)	53	09-29 (2002)	54	112
1968	06-21 (1968)	53	09-29 (1968)	53	99
1930	06-01 (1930)	50	09-29 (1930)	53	119
1970	05-30 (1970)	50	09-27 (1970)	54	119
2016	06-09 (2016)	54	09-25 (2016)	54	107

Latest first 40s at HPN

 

First/Last Summary for WESTCHESTER CO AP, NY
Each section contains date and year of occurrence, value on that date.
Click column heading to sort ascending, click again to sort descending.

Year	Last	Value	First	Value	Difference
2018	06-12 (2018)	49	10-12 (2018)	47	121
2017	06-09 (2017)	47	09-29 (2017)	47	111
2002	06-08 (2002)	48	09-29 (2002)	48	112
1970	05-30 (1970)	44	09-29 (1970)	42	121
1968	05-28 (1968)	46	09-29 (1968)	49	123
2005	05-25 (2005)	46	09-28 (2005)	46	125
2015	06-02 (2015)	48	09-27 (2015)	47	116
1980	06-14 (1980)	47	09-27 (1980)	44	104
2016	05-21 (2016)	48	09-25 (2016)	44	126

this is wonderful fall weather, we've been around 55 for a few days here already and looks like we might get into the upper 40s in a few days later this week

 

[LibertyBell]

On 9/25/2021 at 8:33 PM, CIK62 said:

What is going on here on the EURO?         The area that is hanging back from SAM  'hangs on' for at least 72 hours of 40mph gusts{from N} near here, starting at 168hrs.(not shown)     The GFS and CMC have this is in a minor way only.

 

That is the SON OF SAM !

 

[LibertyBell]

On 9/25/2021 at 8:35 PM, donsutherland1 said:

Tomorrow and Monday will be fair and pleasantly warm days. Afterward, a cold front could bring some showers or thundershowers to the region on Tuesday.

The MJO had recently been locked in Phase 3 at a high amplitude, frequently in excess of 1.500. Only 2006 and 2009 saw the MJO in Phase 3 at an amplitude of 1.500 or above for 2 or more days during September 10-20. Both years saw September end with a cold shot that continued into the first days of October. Both days saw Central Park's temperature fall to 49° on September 30. The guidance has now come into better agreement concerning a cool shot to end the month. Afterward, in the MJO cases, a fairly sharp rebound in temperatures followed. October wound up wetter than normal with 7.07" rainfall in 2006 and 5.58" of rainfall in 2009. Normal rainfall (1991-2020) is 4.38".

2021 remains on course 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.

There is increasing 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.

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".

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.4°C for the week centered around September 15. 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 -0.45°C. Neutral ENSO conditions will likely prevail through September. Afterward, La Niña conditions could begin to develop.

The SOI was -15.92 today.

The preliminary Arctic Oscillation (AO) figure was +0.142 today.

On September 23 the MJO was in Phase 4 at an amplitude of 0.946 (RMM). The September 22-adjusted amplitude was 1.305 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 89% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.4° (1.2° above normal).

 

Don looks like the warmth will continue to be centered in the middle of the country and Canada, not here?  Nice fall weather here.  And I think we can cautiously say that the chances for anything tropical are much less now.  Most storms will either recurve or hit the Gulf.

 

[donsutherland1]

5 hours ago, LibertyBell said:

Don looks like the warmth will continue to be centered in the middle of the country and Canada, not here?  Nice fall weather here.  And I think we can cautiously say that the chances for anything tropical are much less now.  Most storms will either recurve or hit the Gulf.

 

Yes. That’s where the warmest anomalies will be.

[donsutherland1]

Morning thoughts…

Today will be mostly sunny and unseasonably warm. High temperatures will likely reach the upper 70s and lower 80s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 78°

Newark: 83°

Philadelphia: 81°

Normals:

New York City: 30-Year: 71.9°; 15-Year: 73.1°

Newark: 30-Year: 73.4°; 15-Year: 74.9°

Philadelphia: 30-Year: 74.7°; 15-Year: 75.9°

Tomorrow will be another warm day, but a strong cold front will move across the region tomorrow night.

[CIK62]

The last 4 days of September are averaging 67degs.(61/73), or +2.

Month to date is  71.2[+1.2].        September should end at  70.6[+1.4].

Reached 74* here yesterday.

Today:   76-80, w. wind, p. sunny.

62*(63%RH) here at 6am, scattered clouds.        64* at 9am.       69* at Noon.       71* at 1pm.        77* at 3pm.       78* at 4pm.       79* at 4:30pm.      Reached 80* at 5pm.

 

[the_other_guy]

56F this morning. Chilly, but warm wind signals change. 

[bluewave]

Today and possibly tomorrow look like it will be our warmest days for a while as the usual warmer spots reach 80°+. Several locations have had their warmest low max for the month so far. This was the first time that HPN hasn’t had a high below 70° through 9-26.

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	70	0
2	2016-09-26	69	0
-	1968-09-26	69	0
3	2015-09-26	68	0
-	2005-09-26	68	0
-	1961-09-26	68	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	76	0
2	1968-09-26	74	0
3	2005-09-26	72	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	74	0
2	1968-09-26	73	0
3	2015-09-26	72	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	72	0
2	2015-09-26	71	0
-	2005-09-26	71	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	74	0
2	1968-09-26	72	0
3	2016-09-26	71	0
-	2005-09-26	71	0

 

Time Series Summary for Boston Area, MA (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	70	0
2	1957-09-26	68	0
-	1930-09-26	68	0

[forkyfork]

good lapse rates tomorrow

[psv88]

What a day. 78 and sunny. 

[bluewave]

Newark sets the new record of 120 consecutive days reaching 70° or higher. 

 

Number of Consecutive Days Max Temperature >= 70 
for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Dates
Period of record: 1931-01-01 to 2021-09-26
1	120	2021-05-31 through 2021-09-27
2	119	2008-05-23 through 2008-09-18
3	117	1995-05-29 through 1995-09-22
-	117	1994-05-28 through 1994-09-21
4	113	2020-05-25 through 2020-09-14
5	112	2016-06-09 through 2016-09-28
6	110	1966-06-02 through 1966-09-19
7	107	1957-06-09 through 1957-09-23
8	106	2014-05-30 through 2014-09-12
-	106	2010-05-29 through 2010-09-11

[donsutherland1]

Tomorrow will be another warm day, but a cold front will push across the region overnight bringing some showers and perhaps thundershowers to parts of the region. It is almost a coin toss as to whether Central Park will pick up the 0.24" of rain that it needs to reach 10" for September. The 12z EPS had 30/51 (59%) of members with sufficient rainfall. Afterward, the coolest air so far this fall will close out the month.

The MJO had recently been locked in Phase 3 at a high amplitude, frequently in excess of 1.500. Only 2006 and 2009 saw the MJO in Phase 3 at an amplitude of 1.500 or above for 2 or more days during September 10-20. Both years saw September end with a cold shot that continued into the first days of October. Both days saw Central Park's temperature fall to 49° on September 30. The guidance has now come into better agreement concerning a cool shot to end the month. Afterward, in the MJO cases, a fairly sharp rebound in temperatures followed. October wound up wetter than normal with 7.07" rainfall in 2006 and 5.58" of rainfall in 2009. Normal rainfall (1991-2020) is 4.38".

2021 remains on course 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.

There is increasing 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.

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".

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 +24.25 today.

The preliminary Arctic Oscillation (AO) figure was -1.185 today.

On September 25 the MJO was in Phase 5 at an amplitude of 0.815 (RMM). The September 24-adjusted amplitude was 0.715 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 98% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.4° (1.2° above normal).

 

[Rjay]

Gusting over 30mph here

[SACRUS]

9/27

EWR: 83
LGA: 82
PHL: 82
BLM: 80
JF: 80
New Brnswck: 80
ACY: 80
TEB: 79
TTN: 79
NYC: 78
ISP: 76

[psv88]

1 minute ago, SACRUS said:

9/27

EWR: 83
LGA: 82
PHL: 82
BLM: 80
JF: 80
New Brnswck: 80
ACY: 80
TEB: 79
TTN: 79
NYC: 78
ISP: 76

Hit 78 here today. Beautiful

[SACRUS]

3 hours ago, bluewave said:

Newark sets the new record of 120 consecutive days reaching 70° or higher. 

 

Number of Consecutive Days Max Temperature >= 70 
for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Dates
Period of record: 1931-01-01 to 2021-09-26
1	120	2021-05-31 through 2021-09-27
2	119	2008-05-23 through 2008-09-18
3	117	1995-05-29 through 1995-09-22
-	117	1994-05-28 through 1994-09-21
4	113	2020-05-25 through 2020-09-14
5	112	2016-06-09 through 2016-09-28
6	110	1966-06-02 through 1966-09-19
7	107	1957-06-09 through 1957-09-23
8	106	2014-05-30 through 2014-09-12
-	106	2010-05-29 through 2010-09-11

Close call on of all days July 3 with ahigh of 70. Streak looks to break Thursday.  I'll go 68 for a high

[LibertyBell]

16 hours ago, bluewave said:

Today and possibly tomorrow look like it will be our warmest days for a while as the usual warmer spots reach 80°+. Several locations have had their warmest low max for the month so far. This was the first time that HPN hasn’t had a high below 70° through 9-26.

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	70	0
2	2016-09-26	69	0
-	1968-09-26	69	0
3	2015-09-26	68	0
-	2005-09-26	68	0
-	1961-09-26	68	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	76	0
2	1968-09-26	74	0
3	2005-09-26	72	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	74	0
2	1968-09-26	73	0
3	2015-09-26	72	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	72	0
2	2015-09-26	71	0
-	2005-09-26	71	0

 

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

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	74	0
2	1968-09-26	72	0
3	2016-09-26	71	0
-	2005-09-26	71	0

 

Time Series Summary for Boston Area, MA (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Lowest Max Temperature Sep 1 to Sep 26	Missing Count
1	2021-09-26	70	0
2	1957-09-26	68	0
-	1930-09-26	68	0

Has JFK ever had a September where they never had a high below 70?

 

[LibertyBell]

3 hours ago, Rjay said:

Gusting over 30mph here

stupid ragweed !#$^^&

[donsutherland1]

Morning thoughts…

Today will be partly sunny and warm. A strong cold front could trigger some showers and thunderstorms from late afternoon into the night. High temperatures will likely reach the upper 70s and lower 80s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 75°

Newark: 79°

Philadelphia: 80°

Normals:

New York City: 30-Year: 71.5°; 15-Year: 72.8°

Newark: 30-Year: 73.0°; 15-Year: 74.5°

Philadelphia: 30-Year: 74.3°; 15-Year: 75.5°

The remainder of the month will be fair but unseasonably cool.

[donsutherland1]

6 hours ago, LibertyBell said:

Has JFK ever had a September where they never had a high below 70?

 

Yes. In 2015, the lowest daily high temperature was 72.

[CIK62]

The last 3 days of September are averaging 65degs.(58/71), or Normal.

Month to date is  71.2[1.4].       September should end at 70.6[+1.2].

Reached 80 here yesterday.

First two weeks of October look boring w/o spectacular rains, or T's.......50/70 is the range, or +2.

Today:   73-76, w. to n. wind, Rain possible 1pm onward.

66*(80%RH) here at 6am, scattered overcast.     67* at 7am.       69* at 9am.       72* at 11am.       68* at Noon, with rain and a little thunder during the last hour.        Went back up and reached 75* at 4:30pm.

[SACRUS]

 

Down to 57 last night rain and showers into EPA as front is moving through.  Clear and dry out later tonight setting up a step down cooler pattern starting Wed (9/29) and through the coming weekend Sun (10/3).  We have a quick warmup Monday (10/4) and Tuesday (10/5) very outside chance of 80s.  Beyond that more onshore NE flow the middle of next week.  Beyond there ECM has ridging into the east and warmer than normal as round out the end of the  first full  week of Oct into mid month.

[wdrag]

Good Tuesday morning,

 

Wantage NJ rolls of thunder since 650A, and now .06 in a few minutes ..big drops.  Not threading but there could be isolated svr today via hail and marginal wind gusts, mainly afternoon and especially I78 south. 

 

I saw how last Saturdays rain just grazed e LI.  Much less than I what I anticipated would occur with excellent weather prevailing NYC.  

This Wed or Thu might see a sprinkle into NYC? as the cold pool slides south; the EPS ensembles of last week out-performing the GEFS idea of possibly separating streams. My expectation is lots of afternoon cloudiness both days (5000-8000')

Late weekend onward: threat of showery periods ensues as RRQ of the departing Maine trough interacts with central USA eastward moving shortwaves, enhancing WAA possibilities. 

[SACRUS]

Clouds ahead of schedule may throw wrench in the 70 degree high stretch?

 

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

[the_other_guy]

Another warm September morning: 65F

[psv88]

70/63

[psv88]

1 hour ago, SACRUS said:

Clouds ahead of schedule may throw wrench in the 70 degree high stretch?

 

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

Newark already at 70

[bluewave]

This is now the wettest September on record at Newark. Wet September patterns in the past have been much cooler. So this will be the first in the top 5 wettest to average above 70°.

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	Total Precipitation	Avg  Temperature
1	2021	10.32	73.2°
2	1944	10.28	68.2°
3	1999	9.38	69.3°
4	1975	9.00	64.3°
5	1933	8.33	68.0°

[SACRUS]

EWR now to 70 so early clouds didnt prevent the max of atleast 70's streak

[BxEngine]

Line looks like itll get knyc to 10”.