September 2021

[doncat]

ASTRO summer here came in at 13th warmest past 44 years...Rain of 30.27" beats out 2011 to become wettest.

[donsutherland1]

Under mostly sunny skies, temperatures rose into the middle and upper 70s. A few locations reached 80°. Newark reached 80° for the 108th time this year, which ties 1959 for the 8th most such days. The record is 118 days, which was set in 2015.

Tomorrow will turn mostly cloudy. It will be unseasonably warm. Temperatures will likely top out in the upper 70s and lower 80s.

The potential exists for a moderate to perhaps significant rainfall from tomorrow night through Friday. A widespread 0.50"-1.50" rainfall with locally higher amounts is possible.

The MJO has 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. 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".

Despite the guidance of a few days ago and a likely cold shot to end the month, 2021 is still 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. Considering that the close of September is still more than 10 days out, the guidance can still reverse. 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.

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 +13.02 today.

The preliminary Arctic Oscillation (AO) figure was -0.046 today.

On September 19 the MJO was in Phase 3 at an amplitude of 1.344 (RMM). The September 18-adjusted amplitude was 1.466 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 77% 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).

 

[CIK62]

I don't want to brag, but I am getting a little shower right now  9:15PM

[LibertyBell]

3 hours ago, bluewave said:

The potential for a few more 80° degree days showing up over the next week.

KEWR   GFSX MOS GUIDANCE   9/21/2021  1200 UTC                       
 FHR  24  36| 48  60| 72  84| 96 108|120 132|144 156|168 180|192      
      WED 22| THU 23| FRI 24| SAT 25| SUN 26| MON 27| TUE 28|WED CLIMO
 N/X  67  81| 69  76| 61  75| 59  74| 59  81| 59  77| 59  75| 61 54 72

It's interesting what our summers are turning into, consistently warm to very warm, but very little in the way of extreme heat and particularly extreme heat that lasts a long time.  All of our long 7+ day heatwaves are from over a decade ago.

[LibertyBell]

2 hours ago, bluewave said:

Islip made it to 78° today. So this was the 21st day in September to reach 75° or warmer. It’s only 4 days behind the September all-time record.
 

 

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	Number of Days Max Temperature >= 75	Missing Count
1	2005	25	0
2	2015	24	0
-	1980	24	0
3	2019	23	0
-	1998	23	0
4	2017	22	0
-	2007	22	0
5	2020	21	0
-	1968	21	0
	2021	21	9

1983 isn't on this list?  That had 5x 90+ days in September at JFK

 

[MJO812]

Might be time to track Sam

[psv88]

Helluva way to run a cooldown

[Rtd208]

...Parts of the northern Mid Atlantic...
   Although there remains substantive spread within/among the various
   model output, 30-50+ kt southerly flow in the 850-700 mb layer may
   linger into the day Thursday across much of the northern Mid
   Atlantic region, generally coincident with the corridor of
   seasonably moist boundary-layer air.  Although lower/mid
   tropospheric lapse rates are forecast to remain weak, weak to
   moderate CAPE may still develop and contribute to scattered
   thunderstorm activity with daytime heating.  In the presence of
   moderate to strong shear in the lower to mid-levels, the environment
   may become conducive to organizing lines or clusters with the
   potential to produce locally damaging wind gusts.  Latest guidance
   appears increasingly suggestive that hodographs could become
   characterized by substantial clockwise-curvature in low levels,
   particularly across parts of eastern Pennsylvania and New Jersey
   into south central and southeastern New York state, which may
   support a risk for a couple of tornadoes.

[donsutherland1]

Morning thoughts…

Today will be mostly cloudy and 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: 81°

Philadelphia: 82°

Normals:

New York City: 30-Year: 73.9°; 15-Year: 75.0°

Newark: 30-Year: 75.5°; 15-Year: 76.7°

Philadelphia: 30-Year: 76.7°; 15-Year: 77.7°

A moderate to perhaps significant rainfall is possible tonight through Friday. A general 0.50”-1.50” rainfall with locally higher amounts appears likely.

[Rjay]

12 hours ago, nycwinter said:

newark temps are inaccurate  been that way all summer..

How so?

[gmendevils8204]

9 hours ago, CIK62 said:

I don't want to brag, but I am getting a little shower right now  9:15PM

Must have been the same piece of moisture I got. Went out to my car around 10:30 and the ground was unexpectedly wet.

[CIK62]

The next 8 days are averaging 72degs.(66/79), or +6.

Month to date is  71.8[+0.9].         Could be 71.9[+2.2] by the 30th.

Reached 79* here yesterday.

72*(97%RH) here at 6am, overcast, scuzzy.        75* at Noon.     76* at 1pm.       78* at 3pm.        Reached 79* at 5pm.

Today 76-80,se. wind, m. cloudy.

[donsutherland1]

New York City's Central Park is on track to record a low temperature of 70° or above today. The mean last date such a temperature has increased 4 days from September 10 (1951-80) to September 14 (1991-20). The interval from the first and last dates has also widened 9 days to 104 days during that time. Most of that widening has occurred during the most recent 30-year period (104 days vs. 96 days for 1981-2010). Overall, September has been warming to the extent that it is now more an extension of summer than gateway into autumn.

[SnoSki14]

1 hour ago, bluewave said:

This is such a warm pattern, that even a late September cold front won’t have much cold air behind it. 
 

 

The acceleration in warming over just the last few years has been astounding and terrifying.

And the funny thing is that we're probably one of the coolest spot in the country relatively speaking outside parts of the Pacific NW. 

[wdrag]

No thread yet on a 3+" event for a portion of the subforum and spotty SVR.  Right now, I think it's marginal  but if we happen to get a meso low on the cold front Thursday night over NJ, then i think we'll have some non-routine heavier rains (3") and spotty damaging wind events.

[MJO812]

Happy Autumn 

[forkyfork]

sept so far at ewr: 73.8

august 1967: 73.4

[nycwinter]

2 hours ago, bluewave said:

This is such a warm pattern, that even a late September cold front won’t have much cold air behind it. 
 

 

normal high in nyc for the  last day in september i think is 73 it is not suppose to be cold dude..

[nycwinter]

3 hours ago, Rjay said:

How so?

the asphalt at the airport makes the temps hotter then they would be anywhere else.. the offilcal temp should not be taken at the airport but somewhere else in the city..

[uncle W]

my pool is still open...a nice three day warmth spell would be nice before it closes Oct 10th...

1967 was cool in Sept...much cooler than this year...

IPS-1BD83742-5475-4643-81C9-ACA5CC93FE4D.pdf (noaa.gov)

[FPizz]

20 minutes ago, nycwinter said:

the asphalt at the airport makes the temps hotter then they would be anywhere else.. the offilcal temp should not be taken at the airport but somewhere else in the city..

It is all asphalt practically.  

[donsutherland1]

Newark has reached 80 degrees for the 109th day this year.

[psv88]

52 minutes ago, nycwinter said:

the asphalt at the airport makes the temps hotter then they would be anywhere else.. the offilcal temp should not be taken at the airport but somewhere else in the city..

You realize most of the metro area is also asphalt right? When people walk on a sidewalk, etc, they are over asphalt. So it is more representative than a lush garden in the middle of manhattan

[dieselbug]

48 minutes ago, nycwinter said:

the asphalt at the airport makes the temps hotter then they would be anywhere else.. the offilcal temp should not be taken at the airport but somewhere else in the city..

Most weather sensors in big cities are at the major airports. Based on your reply, all temperatures taken from airports are invalid because they will be "too warm"??

As many here pointed out, the location of the sensor at KEWR is sandwiched on a strip of land with a runway on one side and a canal on the other side. Perfect location? No, but it could be worse!

If the "official" Newark temperature was taken from downtown Newark (more asphalt), the air temperature in my opinion, could be even warmer than it's location at the airport. 

[Santa Claus]

8 hours ago, Rtd208 said:

...Parts of the northern Mid Atlantic...
   Although there remains substantive spread within/among the various
   model output, 30-50+ kt southerly flow in the 850-700 mb layer may
   linger into the day Thursday across much of the northern Mid
   Atlantic region, generally coincident with the corridor of
   seasonably moist boundary-layer air.  Although lower/mid
   tropospheric lapse rates are forecast to remain weak, weak to
   moderate CAPE may still develop and contribute to scattered
   thunderstorm activity with daytime heating.  In the presence of
   moderate to strong shear in the lower to mid-levels, the environment
   may become conducive to organizing lines or clusters with the
   potential to produce locally damaging wind gusts.  Latest guidance
   appears increasingly suggestive that hodographs could become
   characterized by substantial clockwise-curvature in low levels,
   particularly across parts of eastern Pennsylvania and New Jersey
   into south central and southeastern New York state, which may
   support a risk for a couple of tornadoes.

northeast is the new tornado alley confirmed

[Rjay]

I give up

[Santa Claus]

Just now, Rjay said:

I give up

on what

[bluewave]

Continuation of our new subtropical climate theme. The dew point at JFK reached 70° again today. This was the 64th day so far this year. All the top years for 70° or higher dew points have occurred since 2016.

https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=161&network=NY_ASOS&zstation=JFK&var=max_dwpf&dir=aoa&thres=70&month=all&year=2021&dpi=100&_fmt=js

#1…..89 days….2018

#2….77 days…..2019

#3….68 days…..2016

#4….64 days…..2021…2020
 

 

[Brian5671]

78/73 here

[forkyfork]

6 minutes ago, bluewave said:

Continuation of our new subtropical climate theme. The dew point at JFK reached 70° again today. This was the 64th day so far this year. All the highest number of days in a year have occurred since 2016.

https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=161&network=NY_ASOS&zstation=JFK&var=max_dwpf&dir=aoa&thres=70&month=all&year=2021&dpi=100&_fmt=js

#1…..89 days….2018

#2….77 days…..2019

#3….68 days…..2016

#4….64 days…..2021…2020
 

 

the super nino reset our climate