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6 hours ago, bluewave said:

November continues to be one of the few months of the year that is able to reliably produce colder departures at times. 

The monthly temperature increases from 81-10 to 91-20 have been more pronounced during certain months. Newark and Islip are compared below. The +1.0 or warmer months for either station were bolded. 

 

……….EWR…..ISP

Dec…+1.5….+1.5

Jan….+1.2…+1.3

Feb….+0.5….+0.5

 

Mar….+0.4….+0.6

Apr….+0.5…..+0.6

May...+0.6….+0.9

 

Jun….+0.3….+0.6

Jul…..+1.4…..+1.1

Aug...+0.6….+0.9

 

Sep….+1.0….+1.3

Oct…..+0.9..+1.4

Nov….+0.2..+0.5

Interesting how it's more noticeable warming in the fall and early winter, yet spring hasn't shown the same increase.  Seems like it stays warmer longer, but takes awhile to break out of our chilly springs.

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5 hours ago, Dark Star said:

I wonder if there are graphs or charts showing the world wide temperature effects based on volcanic actiivty over the last 200 years?

A very basic method of looking at this would be to go here:

https://en.m.wikipedia.org/wiki/List_of_volcanic_eruptions_1500–2000

And cross reference with high resolution temperature data / plots. Focus on VEI 5 and up events, or tightly clustered series of eruptions that make this list. Volcanic aerosols (sulfur, ash) “decay” out of the stratosphere in 1-3 years, the atmospheric loading of larger events could take a bit longer. And periods like the LIA were though to have had additional self-reinforcing mechanisms that protracted cooling episodes beyond the usual 1-3 years (I’ve heard things like sharp cooling of the North Atlantic SST’s helped to reinforce and extend volcanic cooling episodes, as one example)  

This is a super complex subject and I haven’t the time at the moment to dive deeper, but not all large explosive events impart a detectable climate impact commensurate to the size of the event, or even at all in some instances. Novarupta and Krakatoa were similarly sized and were 3x+ larger than Pinatubo but aren’t commonly believed to have caused a major climate impact. Krakatau especially still did, and I believe both were sandwhiched inside cold decades (from memory), but Pinatubo’s climate forcing was more pronounced AFAIK. 

And again this is getting into territory where you guys are better equipped than I to discuss / debate, but I believe ENSO at the time of the eruption or immediately after can also have an impact on how significant the volcanic forcing is. Especially regionally. I believe Pinatubo’s impact was muted in the northeast US due to ENSO, despite having a very significant global downward surface temp forcing. 

Very complex subject with a ton of info, data, and theorizing to dive into. To me, it’s one of the most fascinating subjects out there (surprise! :P). 

Volcanism drives climate to an extent that most people are simply unaware of, especially as you go back into geologic time and focus on abrupt “state” changes to paleoclimate. Look at the largest eruptions of all (flood basalts that last millenia), and also the Wilson cycle of sea floor spreading - how CO2 is naturally sequestered out of and also expelled into the atmosphere in varying proportions, which in turn forces the planet into and out of both broader hothouse and icehouse regimes. Check out this excellent article which touches on this:

https://www.volcanocafe.org/white-christmas/

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A moderating trend will commence tomorrow. Showers could affect the region late in the day or Saturday.

The ENSO Region 1+2 anomaly was +2.0°C and the Region 3.4 anomaly was +2.1°C for the week centered around November 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.22°C and the ENSO Region 3.4 anomaly has averaged +1.80°C. A basinwide El Niño event is ongoing. El Niño conditions will likely continue to strengthen into the early winter.  

Should the ENSO Region 1+2 and 3.4 anomalies remain at or above +1.00°C in December, which is likely, and should the PDO remain negative, there is a single past case (1950-2022) with similar ENSO/PDO conditions: December 1972.

The SOI was -0.89 today.

The preliminary Arctic Oscillation (AO) was -2.468 today.

On November 27 the MJO was in Phase 3 at an amplitude of 0.555 (RMM). The November 26-adjusted amplitude was 0.824 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.4° (1.5° below normal). That would be New York City's coldest November since November 2019.

 

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20 hours ago, wdrag said:

Please correct me if I'm wrong: NYC-CP and PHL have climate summary for yesterday as Trace snow... but I. must have missed this in the obs... no SB/SE, and I see the CF6 monthly summary that shows the dailies in PHL has no T pcpn and no T snow. Still waiting for NYC.  Not sure if controversy is looming on such a minor event but I might have missed something.  It's possible le local observers that supplement the snowfall data had an override.  

Unofficially, in my mind, it would seem both cities had brief Trace flurries but I might have missed something at the ASOS. If you find it, just let us know.  Thanks.

More on possible first measurable in the Dec thread.

I did not see any start or end times for snow at KNYC either and concur that Parks Dept or other officials responsible for snow measuring observed it.  Same for KPHL except being an augmented site they had a few VCSH and VIRGA remarks.

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RECORD WATCH: Calendar year snowfall to date. Current annual record [full 12 months] shown below each table.

NYC [Tied least of 155 years]

image.png.364dd224f1f9f5aa116aa50155ac8a10.png

Full year record is 3.4" set in 1913.

JFK [3rd least of 67 years]

image.png.ce3867e5093a0dd0d7f341b90572f424.png

Full year record is 2.1" set in 1973.

LGA [3rd least of 84 years]

image.png.6396a5f88e717efa79a1e38cea066152.png

Full year record is 4.1" set in 1973.

EWR [2nd least of 123 years]

image.png.092b5c8dfad680b0e3f32a46da5a1eb2.png

Full year record is 4.0" set in 1973.

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22 hours ago, JerseyWx said:

Interesting how it's more noticeable warming in the fall and early winter, yet spring hasn't shown the same increase.  Seems like it stays warmer longer, but takes awhile to break out of our chilly springs.

I think it's mostly mean reversion. Some of the months showing less warming tendencies in recent years [March, April, November] have historically warmed the most.

At NYC, March has warmed at an average of 4.8F/century; April, 4.0F/century; and November, 3.7F/century. By contrast, the annual mean has risen only 2.8F/century. These months are actually among the months which show the most warming since the late 19th century.

Note that, while the values presented above may be affected by UHI, the findings are robust in that I've seen the same pattern at many locations - with early spring and November being among the times of the year that have warmed the most since the 19th/early 20th century.

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November finished with a mean temperature of 46.7° (1.2° below normal) in New York City. November 2023 was the coldest such month in November since 2021.

Tomorrow will be another mild day. Showers could affect the region late in the day or on Saturday.

The ENSO Region 1+2 anomaly was +2.0°C and the Region 3.4 anomaly was +2.1°C for the week centered around November 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.22°C and the ENSO Region 3.4 anomaly has averaged +1.80°C. A basinwide El Niño event is ongoing. El Niño conditions will likely continue to strengthen into the early winter.  

Should the ENSO Region 1+2 and 3.4 anomalies remain at or above +1.00°C in December, which is likely, and should the PDO remain negative, there is a single past case (1950-2022) with similar ENSO/PDO conditions: December 1972.

The SOI was +6.30 today.

The preliminary Arctic Oscillation (AO) was -3.350 today. Only four prior November cases (1950-2022) saw the AO fall to -3.000 or below during the last week of November: 1985, 2002, 2010, and 2018.

On November 28 the MJO was in Phase 3 at an amplitude of 0.457 (RMM). The November 27-adjusted amplitude was 0.555 (RMM).

 

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6 hours ago, donsutherland1 said:

November finished with a mean temperature of 46.7° (1.2° below normal) in New York City. November 2023 was the coldest such month in November since 2021.

Tomorrow will be another mild day. Showers could affect the region late in the day or on Saturday.

The ENSO Region 1+2 anomaly was +2.0°C and the Region 3.4 anomaly was +2.1°C for the week centered around November 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.22°C and the ENSO Region 3.4 anomaly has averaged +1.80°C. A basinwide El Niño event is ongoing. El Niño conditions will likely continue to strengthen into the early winter.  

Should the ENSO Region 1+2 and 3.4 anomalies remain at or above +1.00°C in December, which is likely, and should the PDO remain negative, there is a single past case (1950-2022) with similar ENSO/PDO conditions: December 1972.

The SOI was +6.30 today.

The preliminary Arctic Oscillation (AO) was -3.350 today. Only four prior November cases (1950-2022) saw the AO fall to -3.000 or below during the last week of November: 1985, 2002, 2010, and 2018.

On November 28 the MJO was in Phase 3 at an amplitude of 0.457 (RMM). The November 27-adjusted amplitude was 0.555 (RMM).

 

Looks like @qg_omegawas only a bit off.

On 11/9/2023 at 6:48 AM, qg_omega said:

Based on sensitivity analysis applied to the latest guidance, there is an implied 52% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 47.8° (0.2° below normal).

Time will tell but I have a hard time seeing how November doesn’t finish at least 1 degree above normal if not more

 

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On 11/30/2023 at 12:35 AM, STORMANLI said:

I did not see any start or end times for snow at KNYC either and concur that Parks Dept or other officials responsible for snow measuring observed it.  Same for KPHL except being an augmented site they had a few VCSH and VIRGA remarks.

Agreed... actually glad the Conservancy stepped up.No oe wanted to make a big deal about it...but you have to start somewhere.  

Monitoring next Tue-Wed for first CP measurable. Long ways to go... pretty sharp short waves carving out the trot along the northeast USA coast. 

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On 10/24/2023 at 7:19 PM, wdrag said:

Hopes for the first measurable snow of the 23-24 cool season for at least interior sections, and when will the first freeze occur at the various climate sites?  

Added the CPC October 19th November Outlook (click for clarity), to be verified on December 1, as we will do the same for October on November 1.  Reliability for the 4 week period with 6 week notice is challenging. Let's see what happens with these monthly outlooks.  

Screen Shot 2023-10-24 at 7.00.42 PM.png

First Trace of snow and first freeze occurred NYC-CP. 

Here is the basic TT/QPF evaluation for Nov excepting missing Nov 1 Pacific Northwest coast. You be the judge on the monthly outlook verification. (not stellar on both Temp and QPF). 

Screen Shot 2023-12-02 at 8.06.20 PM.png

Screen Shot 2023-12-02 at 8.06.49 PM.png

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