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16 minutes ago, bluewave said:

I know we talk a lot about El Niño and La Nina. But there seems to be another factor that has been influencing the pattern of our monthly departures. A monthly departure pattern that has been regularly repeating since 2010. We are all familiar with how warm September and a October has been over this period. But this turn to cooler has been a regular feature in November. Notice how closely this November has matched the 2010-2020 composite. 

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64C21285-8A4C-4E92-81A2-E30AD0B73DCE.png.cf92523d388786b8396e1f63b55f7cc8.png

 

March is the other cooler month and if November played out that way this year I wouldn't be surprised to see another cold March. 

Also think Jan & especially Feb torches unless there's massive blocking. Also hoping we see a 2017-2018 winter play out.

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24 minutes ago, SnoSki14 said:

March is the other cooler month and if November played out that way this year I wouldn't be surprised to see another cold March. 

Also think Jan & especially Feb torches unless there's massive blocking. Also hoping we see a 2017-2018 winter play out.

This fall so far is much more Pacific dominant than 2017 was. We had the record early November Arctic outbreak that year. This year is all Pacific and continental air masses with no Arctic cold.

 

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Morning thoughts…

Sunshine will give way to increasing clouds this afternoon. It will be noticeably milder. High temperatures will likely reach the lower and middle 50s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 53°

Newark: 56°

Philadelphia: 55°

Normals:

New York City: 30-Year: 50.7°; 15-Year: 50.9°

Newark: 30-Year: 51.4°; 15-Year: 51.8°

Philadelphia: 30-Year: 52.4°; 15-Year: 52.7°

After some overnight showers, it will turn colder again. There remains a possibility that parts of the region could see a light snowfall Sunday night into Monday.

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3 minutes ago, uncle W said:

its been cold without arctic air...

It’s been colder compared to September and October, but there has been no record cold Arctic air like we got in 2017. That early November Arctic outbreak signaled the very cold end of  December and early January before the record warmth arrived. If you want Arctic cold, then you generally need a -EPO. This fall the +EPO has been running the table.

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3 hours ago, jfklganyc said:

Another odd night of temps

37-39-30F at 630am

That is twice this week with the up and down temps.

Anyone know what is causing this?

Happy Thanksgiving

 

The other night was multiple wind direction changes.  With very warm water off the coast we saw some crazy temp jumps when winds switched around to the south.   Last night clouds moved in so temps rose.  Then the clouds moved out and temps dropped, before the clouds came back around daybreak.   

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2 hours ago, bluewave said:

I know we talk a lot about El Niño and La Nina. But there seems to be another factor that has been influencing the pattern of our monthly departures. A monthly departure pattern that has been regularly repeating since 2010. We are all familiar with how warm September and a October has been over this period. But this turn to cooler has been a regular feature in November. Notice how closely this November has matched the 2010-2020 composite. 

It's also interesting that we have been running opposite of last year now 4 months in a row, both at 500mb and on the surface. The correlation is >75% each of the 4 months so it's a pretty good anomaly. 

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1 hour ago, Rjay said:

The other night was multiple wind direction changes.  With very warm water off the coast we saw some crazy temp jumps when winds switched around to the south.   Last night clouds moved in so temps rose.  Then the clouds moved out and temps dropped, before the clouds came back around daybreak.   

Looks like temps dropped 3-5 degrees overnight when the wind went calm. Radiational cooling FTW. 

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The GFS,  'AssWipe' of a model it is, has changed again!!!!        Dec. 01-10 now 39/54 = 46 or as much as +6 on an Old Style Almanac for NYC.      The 7" on the 6th. is now 10" on the 11th.  

No graphic this time.  

 

Mind your Turkey instead.      Happy Holiday 

 

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9 hours ago, SnoSki14 said:

March is the other cooler month and if November played out that way this year I wouldn't be surprised to see another cold March. 

Also think Jan & especially Feb torches unless there's massive blocking. Also hoping we see a 2017-2018 winter play out.

I don’t know about January and February but November and March seem to move in tandem lately. 

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After today's brief shot of warmer air, much colder air is again poised to move into the region. Tomorrow will see temperatures hold steady or fall from the 40s during the afternoon and evening hours. An unseasonably cold weekend will follow. There is a small chance that a weak system could bring a period of light snow or flurries to parts of the region late Sunday into Monday.

First measurable snowfall statistics for select cities:

Allentown: Normal: December 6; 2020-21: December 9
Bridgeport: Normal: December 3; 2020-21: December 16
Islip: Normal: December 10; 2020-21: December 16
New York City: Normal: December 13; 2020-21: December 16
Newark: Normal: December 9; 2020-21: December 9
Philadelphia: Normal: December 19; 2020-21: December 16

The temperature anomaly for November 20-30 is on course to average below normal due to the development of AO blocking. The recent guidance has been correcting colder in response to this blocking. The Arctic Oscillation fell below -1.000 on November 23. Such strong blocking typically favors a period of colder than normal weather (November 20-30, 1991-2020 period):

Boston: Normal: 42.2°; AO cases: 38.4°
New York City: Normal: 45.5°; AO cases: 41.7°
Philadelphia: Normal: 45.4°; AO cases: 41.7°

The duration of the blocking remains uncertain. Should blocking dissipate, warmer conditions could develop near the start of December. Both the CFSv2 and EPS weeklies favor a return of warmer air at some point during the first week of December.

Fall 2021 is well on course to being 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". Fall rainfall through November 25 4 pm is 16.28".

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 -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter.

The SOI was +24.68 today.

The preliminary Arctic Oscillation (AO) figure was -1.222 today.

On November 23 the MJO was in Phase 4 at an amplitude of 0.931 (RMM). The November 22-adjusted amplitude was 0.733 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

 

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The last 5 days of November are averaging  40degs.(35/44), or -3.

Month to date is  47.9[-0.9].      November should end at  46.5[-1.5].

Reached 59 here yesterday.

Today: Little T change early, 45-47, falling late, drizzle till Noon, wind w., some clearing and 33 tomorrow AM.

Models are back to the 60's(Assassinations, Government Cover-Ups, Un-popular wars, drugs, crime....etc.)lol again.

The first 12 days of December are showing up as  41/54 = 47 or +7.        Car   2015DEC   Where R U?

46*(85%RH) here at 6am.{was 50* at Midnight}   47* at Noon.     42* at 3pm.     41* at 5pm.       38* at 8pm.

 

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Looks like the delayed leaf drop keeping the NYC ASOS in deep shade has allowed it to have a colder departure this month so far of the major ASOS sites. The other stations are -0.2 to +0.9.  While the departures will decline with colder temperatures to close out the month, NYC will be artificially low.

EWR…+0.9

NYC….-0.9

LGA…..+0.7

JFK….+0.2

ISP…..-0.2

 

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1 minute ago, bluewave said:

Looks like the delayed leaf drop keeping the NYC ASOS in deep shade has allowed it to have the only real cold departure this month so far of the major ASOS sites. The other stations are -0.2 to +0.9.  While the departures will decline with colder temperatures to close out the month, NYC will be artificially low.

EWR…+0.9

NYC….-0.9

LGA…..+0.7

JFK….+0.2

ISP…..-0.2

 

I know that site is a joke with  vegetation but I’ve found IMBY that nighttime lows are sometimes a bit warmer this time of year until all the leaves are down as they act as a bit of an insulator.  Daytime is a different story. 

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30 minutes ago, IrishRob17 said:

I know that site is a joke with  vegetation but I’ve found IMBY that nighttime lows are sometimes a bit warmer this time of year until all the leaves are down as they act as a bit of an insulator.  Daytime is a different story. 

With the unusually calm winds this month, it almost looks like all the foliage near the sensor is creating a very localized radiational cooling effect. We can see how much cooler the highs are than the other stations that are in open sunlight. But the cold departure  is much lower than any of the other urban sites.

EWR…max….+2.4….min….-0.5

NYC…max….-0.1…..min…..-1.8

LGA….max…..+1.1….min….+0.3

JFK….max…..+1.6….min….-1.2

ISP…..max…..+1.9…..min….-2.2

 

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5 minutes ago, bluewave said:

With the unusually calm winds this month, it almost looks like all the foliage near the sensor is creating a very localized radiational cooling effect. We can see how much cooler the highs are than the other stations that are in open sunlight. But the cold departure  is much lower than any of the other urban sites.

EWR…max….+2.4….min….-0.5

NYC…max….-0.1…..min…..-1.8

LGA….max…..+1.1….min….+0.3

JFK….max…..+1.6….min….-1.2

ISP…..max…..+1.9…..min….-2.2

Maybe just representative of Central Park

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Morning thoughts…

Light rain will move out of the region and the clouds could break late in the day. High temperatures will likely reach the middle and upper 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 46°

Newark: 49°

Philadelphia: 49°

Normals:

New York City: 30-Year: 50.4°; 15-Year: 50.6°

Newark: 30-Year: 51.0°; 15-Year: 51.4°

Philadelphia: 30-Year: 52.0°; 15-Year: 52.4°

A cold weekend lies ahead. There remains a possibility that parts of the region could see a light snowfall Sunday night into Monday. The areas with the highest chance of measurable snow are to the north and west of Newark, New York City, and Bridgeport.

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9 minutes ago, qg_omega said:

Maybe just representative of Central Park

Urban environments can cool at night with enough of a tree canopy when it’s very dry like November has been in NYC with only 1.00”.

https://www.sciencedirect.com/science/article/abs/pii/S1618866716303776

Highlights

 

Urban trees are incorporated into an advanced single-layer urban canopy model.

Shading effect of trees is enabled by a Monte Carlo ray-tracing algorithm.

The fully-integrated WRF-urban modeling system with trees was applied to simulate.

Urban hydroclimate in an arid city.

The cooling effect of urban shade trees is found to be more prominent in nighttime.

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1 hour ago, bluewave said:

Urban environments can cool at night with enough of a tree canopy when it’s very dry like November has been in NYC with only 1.00”.

https://www.sciencedirect.com/science/article/abs/pii/S1618866716303776

Highlights

 

Urban trees are incorporated into an advanced single-layer urban canopy model.

Shading effect of trees is enabled by a Monte Carlo ray-tracing algorithm.

The fully-integrated WRF-urban modeling system with trees was applied to simulate.

Urban hydroclimate in an arid city.

The cooling effect of urban shade trees is found to be more prominent in nighttime.

Good morning BW. I cannot remember where I saw it, perhaps from Liberty. It was a proposal to build residential skyscrapers as living self sustained tiered parks. The entire structure was covered in magnificent carbon eating flora. I could go for that building code change. One can wish/dream. As always …

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2 hours ago, bluewave said:

Looks like the delayed leaf drop keeping the NYC ASOS in deep shade has allowed it to have a colder departure this month so far of the major ASOS sites. The other stations are -0.2 to +0.9.  While the departures will decline with colder temperatures to close out the month, NYC will be artificially low.

EWR…+0.9

NYC….-0.9

LGA…..+0.7

JFK….+0.2

ISP…..-0.2

 

Stop it! :) This is getting ridiculous with the leaves.

This wasnt a warm month and CPK was one of the last to record a freezing temperature in the region. It a postage stamp of grass in a sea of cement…totally insulated from elements by a wall of tall buildings on all sides

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25 minutes ago, jfklganyc said:

Stop it! :) This is getting ridiculous with the leaves.

This wasnt a warm month and CPK was one of the last to record a freezing temperature in the region. It a postage stamp of grass in a sea of cement…totally insulated from elements by a wall of tall buildings on all sides

Good morning and thank you jfk you’ve confirmed, for me,  that my postage stamp and CPK are close relatives. As always …

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3 hours ago, jfklganyc said:

Stop it! :) This is getting ridiculous with the leaves.

This wasnt a warm month and CPK was one of the last to record a freezing temperature in the region. It a postage stamp of grass in a sea of cement…totally insulated from elements by a wall of tall buildings on all sides

That’s not what the raw data says. The minimums and maximum departures have been running lower than the surrounding ASOS sites. NYC has also been running colder than many of the micronet sites. The first freeze in NYC was much closer to the recent average date than areas away from the heat Island. POU had one of their latest first freezes on record. While NYC wasn’t even close to its latest first freeze. 
 

NYC had the lowest temperature on the coldest morning this week for surrounding urban sites

11-24 low temperatures 

EWR…32

NYC…30

LGA….33

Corona….32

Queensbridge….32

East 40th Manhattan….33

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