December 2023

[Stormlover74]

38 minutes ago, the_other_guy said:

A lot of people here are jumping the gun, not only on the winter but on this month.

21 days left, and it looks slightly above average. It doesn’t look like a torch. Everything is in play when you see a bunch of 40s in the day over a 2 to 3 week period

We need to see a few below average days in the mix to have any hope to pull off a snow event. Dec 90 for example got cold right before Christmas and we ended up with a solid snow on the 27th which melted 2 days later. We just lucked out and timed it perfectly 

 

1990 (Friday)

Today's 7.2" snowfall (which began late last night) was the first snowfall of the winter, the largest accumulation in nearly four years (since January 1987), and the biggest December snowfall since 1960. Snow ended shortly before 11 AM.   

[bluewave]

2 hours ago, the_other_guy said:

Bam. I think this is really important because a lot of the 30 year averages are smoothing Just how bad it has become in the last 15 years.

 

They also put out a separate 15 year climate normals but it’s not as widely used as the 30 years. The main challenge of using climate normals in a rapidly warming climate is that it masks the warming. With the new 39.1 average December temperature in NYC, they only need a +3.4 departure to enter the top 10 warmest of December average temperatures. And we hear the sentiment on here that a +3.4 really isn’t anything out of the ordinary since it’s much lower than the +13.3° and 50° December 2015. Plus we have had something like 20-30 top 10 warmest months of the year depending on the local station used to only one top 10 coldest since 2015. 

 

Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2015	50.8	0
2	2001	44.1	0
3	2021	43.8	0
4	1984	43.7	0
5	2006	43.6	0
6	2011	43.3	0
7	1998	43.1	0
8	1982	42.7	0
9	1990	42.6	0
10	1891	42.5	0

[winterwx21]

On 12/8/2023 at 7:37 AM, Allsnow said:

Anywho…close the shade for a while on cold/snow in our location. Hopefully Sunday is interesting with the wind. Looks like another sloppy jets game 

This rainy weather really helped the Jets today. As you said frustrating year with your Jets, but both Wilsons played great today. 

[Brian5671]

38 minutes ago, the_other_guy said:

A lot of people here are jumping the gun, not only on the winter but on this month.

21 days left, and it looks slightly above average. It doesn’t look like a torch. Everything is in play when you see a bunch of 40s in the day over a 2 to 3 week period

You may see that warm as we get closer. Snow covrr is minimal, and warmups tend to overprform I’d bet we see 50’s galore Xmas week

[bluewave]

3 minutes ago, Brian5671 said:

You may see that warm as we get closer. Snow covrr is minimal, and warmups tend to overprform I’d bet we see 50’s galore Xmas week

Yeah, but some on here won’t consider 50s that big a deal in later December since it’s much cooler than the low 70s reached in 2015 and +33 departure. 
 

[Rjay]

On 11/30/2023 at 6:20 PM, MJO812 said:

How do you know that all the cold will be on the other side ? Crystal Ball?

[40/70 Benchmark]

6 hours ago, donsutherland1 said:

1997-98 is one example where Phase 8 was very warm in the East. I still don't think that Winter 2023-24 will be 1997-98 2.0. I do think that the long-range guidance has two big issues: sticks with continuity through weeks 5-6 too often or rushes pattern changes. I think this time around, we're facing the latter scenario.

It increasingly appears that a transition is more likely to occur during the first week of January than last week of December. The Pacific jet streak that is forecast to develop is consistent with what has happened in past moderate or strong El Niño events and the MJO's passage through Phases 5-7 at a high amplitude.

Things still working in our favor for improvement:

1. Weakening stratospheric polar vortex (favors Atlantic blocking, which has often been the case following the development of strong blocking during the last week of November--basically suggests a tendency toward what has occurred in the past). A major stratospheric warming event would be helpful for the second half of winter, but that's still a less than 50% probability. Model skill is very low beyond a week or so on these events.

2. There remains a hint that a "Greenland High" pattern could try to develop in early January. That pattern would favor troughing across the CONUS, including the East.

The 12/9 ECMWF weeklies continued to show improvement for the first week of January.

Potential issues:

1. The Greenland High pattern never fully develops

2. The stratospheric polar vortex begins to recover after weakening into early January (the latest forecast has pulled back somewhat on the magnitude of weakening)

3. Adverse impacts of multiple ongoing marine heatwaves (highest degree of uncertainty)

The 12/9 CFSv2 weeklies have shifted to show a continuation of the warmth during the first week of January

Even as there are some risks, I believe January will see some opportunities. I don't see any extreme cold shots through the end of December. I also don't buy into the "Snowmaggedon" pattern one Twitter/X account has suggested.

As usual, an oasis of objectivity in a sea of impulsive knee-jerk overreaction. It goes both ways...there was a great deal of premature football spiking from winter enthusiasts at the onset of December.

I agree with all of this, though still do favor an eventual SSW....not that it is the end all, be all...but it is what it is.

[Jersey Andrew]

6 hours ago, donsutherland1 said:

The final chart following last season for NYC's warmest and least snowy winters. The score is the combined standard deviation from the historic DJF temperature and seasonal snowfall means.

What is amazing to me is ‘73 was as bad a winter for snow in NYC and DC for that matter but was a full five degrees cooler than last year. That has to be climate change Don.

[bluewave]

26 minutes ago, Jersey Andrew said:

What is amazing to me is ‘73 was as bad a winter for snow in NYC and DC for that matter but was a full five degrees cooler than last year. That has to be climate change Don.

It was the cold in February which allowed the Southeast to cash in. 
 

https://www.weather.gov/ilm/Feb1973Snow

One of the greatest snowstorms in Southeastern United States history occurred February 9-11, 1973.  This storm dropped one to two feet of snow across a region that typically sees only an inch or two of snow per year.  New all-time snowfall records were established in a number of locations including Rimini, SC with 24 inches; 18 inches in Darlington, SC; and 16.5 inches in Macon, GA.  Snowfall in Wilmington, NC reached 12.5 inches with 7.1 inches recorded in Charleston, SC, both setting all-time records which were broken just 16 years later during the Christmas snowstorm of 1989.  Measurable snow fell along the Gulf Coast from Texas to Florida and flurries were reported as far south as Lisbon and Clermont, Florida just outside of Orlando.

[michsnowfreak]

2 hours ago, bluewave said:

I scanned it very quickly and didn’t realize the data was missing. So  the most recent decade at BTV is +5.9 warmer than than their earliest 30 year December average. It would probably be closer to +6.7 warmer if they had a complete record that started around 1870 like the NYC comparison which was in a colder era than the earliest available.

 

Hard to tell. Locally, the 1870s were cold, but the 1880s had a few incredibly warm winters and several warm Decembers...so adding 1880s to the mix would warm an avg, not cool it (for Detroit).

 

Picking data-sets can be called cherry picking, but it can also be a great way to see what the trends are. And right now, clearly the recent trend is that Decembers have gotten suckier but Februarys have gotten wintrier. In the past 100 years, there has been ZERO change in the Jan-Feb avg temp in Detroit, so the slight winter warming is entirely December. Again, this is for Detroit. But super easy to plug in ANY city provided they have no missing data. I know you didnt do the Burlington thing on purpose, but its one thing to be mindful of when checking data with a city we arent as familiar with (ive done it myself).

POR (1874-2022)
Dec warmed 2.1F, gotten 0.19” wetter & 0.7” snowier
Jan warmed 0.4F, gotten 0.12” drier & 2.1” snowier
Feb warmed 2.9F, gotten 0.36” drier & 2.8” snowier

100 years (1923-2022)
Dec warmed 2.6F, gotten 0.25” wetter & 2.5” snowier
Jan COOLED 0.5F, gotten 0.13” drier & 5.4” snowier
Feb warmed 0.5F, gotten 0.21” wetter, & 7.3” snowier

50 years (1973-2022)
Dec warmed 5.9F, gotten 0.40” drier, 6.5” less snowy
Jan warmed 4.0F, gotten 0.17” wetter, 1.8” snowier
Feb warmed 2.7F, gotten 0.64” wetter, 10.5” snowier!

30 years (1993-2022)
Dec warmed 3.4F, gotten 0.70” wetter, 0.2” snowier
Jan warmed 0.6F, gotten 0.73” drier, 2.2” less snowy
Feb COOLED 1.0F, gotten 0.51” wetter, 12.6” snowier!
 

[bluewave]

42 minutes ago, michsnowfreak said:

Hard to tell. Locally, the 1870s were cold, but the 1880s had a few incredibly warm winters and several warm Decembers...so adding 1880s to the mix would warm an avg, not cool it (for Detroit).

December during the 1870s and 1880s in NYC were very cold. The 1890s were significantly warmer. I started the groupings on the 1s since that is the first year for each new climate normals period. So December temperatures in NYC since 2011 have been similar to Novembers in the 1870s.

NYC Dec Avg Temperature 

1871-1880…31.9°

1881-1890…33.8°

1891-1900…36.1°

1901-1910…34.1°

1911-1920…34.8°

1921-1930…35.2°

1931-1940°…36.2°

1941-1950°…35.0°

1951-1960°….36.4°

1961-1970°….35.1°

1971-1980°….37.1°

1981-1990….37.5°

1991-2000…38.3°

2001-2010….37.9°

2011-2020….40.6°
 

 

Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Nov	Season
Mean	41.4	41.4
1880	38.9	38.9
1879	42.9	42.9
1878	44.1	44.1
1877	44.2	44.2
1876	45.1	45.1
1875	38.9	38.9
1874	42.8	42.8
1873	37.2	37.2
1872	41.4	41.4
1871	38.8	38.8

 

Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.6	40.6
2020	39.2	39.2
2019	38.3	38.3
2018	40.1	40.1
2017	35.0	35.0
2016	38.3	38.3
2015	50.8	50.8
2014	40.5	40.5
2013	38.5	38.5
2012	41.5	41.5
2011	43.3	43.3

[donsutherland1]

A significant rainfall is likely tonight into tomorrow. A general 1.50"-2.50" rainfall with locally higher amounts is likely in the New York City area.

Parts of Connecticut could see 3.00"-5.00" of precipitation. Already, Bridgeport has seen 1.55" through 6 pm. That breaks the daily record of 0.87" from 1994 (an El Niño December).

Strong southeasterly winds will gust past 40 mph. Coastal flooding and beach erosion are likely. The strong winds could bring down limbs and even some trees. Thunderstorms are possible as the cold front pushes across the region late tonight or early tomorrow. The rain will likely end as a period of wet snow or flurries north and west of New York City. New York City could see some snowflakes, as well.

A cooler period will follow the storm. However, temperatures could again rise to above and perhaps much above normal levels as the winter solstice approaches. No Arctic air appears likely through the remainder of December. However, a transition to a colder pattern could commence during the first week of January.

The ENSO Region 1+2 anomaly was +2.1°C and the Region 3.4 anomaly was +2.0°C for the week centered around November 29. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.18°C and the ENSO Region 3.4 anomaly has averaged +1.87°C. A basinwide El Niño event is ongoing. El Niño conditions will likely continue to strengthen somewhat further this month.  

The SOI was -10.07 today.

The preliminary Arctic Oscillation (AO) was -1.294 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January.

On December 8 the MJO was in Phase 5 at an amplitude of 1.766 (RMM). The December 7-adjusted amplitude was 1.732 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 71% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 41.0° (1.9° above normal).

 

[North and West]

Was just thinking about this… we’re forecasted to have a warm Christmas, and we’re all annoyed about it and feel like we’re going on No Snow Part II.




Last year, we had a frigid Christmas… and it still didn’t snow for many the remainder of the season.

Maybe it’ll work out. Granted, do I have any idea of which I am speaking of? I do not. Just mentioning how things sometimes have a funny way of working themselves out.


.

[40/70 Benchmark]

7 hours ago, bluewave said:

All that -AO did was trap mild Pacific air underneath.

I think the NAO also prevented a full on torch in the NE, too...not that it mattered, aside from ski areas.

[40/70 Benchmark]

53 minutes ago, donsutherland1 said:

A significant rainfall is likely tonight into tomorrow. A general 1.50"-2.50" rainfall with locally higher amounts is likely in the New York City area.

Parts of Connecticut could see 3.00"-5.00" of precipitation. Already, Bridgeport has seen 1.55" through 6 pm. That breaks the daily record of 0.87" from 1994 (an El Niño December).

Strong southeasterly winds will gust past 40 mph. Coastal flooding and beach erosion are likely. The strong winds could bring down limbs and even some trees. Thunderstorms are possible as the cold front pushes across the region late tonight or early tomorrow. The rain will likely end as a period of wet snow or flurries north and west of New York City. New York City could see some snowflakes, as well.

A cooler period will follow the storm. However, temperatures could again rise to above and perhaps much above normal levels as the winter solstice approaches. No Arctic air appears likely through the remainder of December. However, a transition to a colder pattern could commence during the first week of January.

The ENSO Region 1+2 anomaly was +2.1°C and the Region 3.4 anomaly was +2.0°C for the week centered around November 29. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.18°C and the ENSO Region 3.4 anomaly has averaged +1.87°C. A basinwide El Niño event is ongoing. El Niño conditions will likely continue to strengthen somewhat further this month.  

The SOI was -10.07 today.

The preliminary Arctic Oscillation (AO) was -1.294 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January.

On December 8 the MJO was in Phase 5 at an amplitude of 1.766 (RMM). The December 7-adjusted amplitude was 1.732 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 71% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 41.0° (1.9° above normal).

 

I  had +1 to +3 this month, so 1.9 would work.

[donsutherland1]

3 minutes ago, 40/70 Benchmark said:

I  had +1 to +3 this month, so 1.9 would work.

You did a terrific job. 

[40/70 Benchmark]

12 minutes ago, donsutherland1 said:

You did a terrific job. 

Too bad we may lose the holiday period, but climo is an uphill battle for the atlantic CP at that point, anyway.

[qg_omega]

16 minutes ago, 40/70 Benchmark said:

I  had +1 to +3 this month, so 1.9 would work.

Yup, I’ll take the over on +3 despite the next week of weather.  Torch will trend very impressive to end the month, warmest of the month despite temps over 60 today

[Roger Smith]

Not many U.S. stations go back into 1840s and 1850s, Toronto does, and you notice right away that winters in the 1840s were generally milder than in any decade until perhaps the 1930s, also snowfall tends to peak for Toronto around 1870. Winters were generally quite severe until the 1920s when a more modern trend began. I would not expect to find any location with similar temperatures in 1870s to 1890s as in recent times, it was generally quite a cold period, 1875, 1883 and 1888 are probably the three coldest years on record in any locations that observed back then. 1904 was also a very cold year. 

Personally while I acknowledge the science behind climate change I think we just happened to peak in fossil fuel output at the worst possible time when natural variability was swinging towards its own peak. If we weren't here, a lot of these trends would still be in evidence. We are just making things a bit worse. Perhaps we will catch a break and run into a cooling trend on the natural variability side. Some thought it would happen with the solar downturn (which seems to be over already) but strong El Nino events like 2015-16 overwhelmed that possibility. 

It will snow again, I don't believe the shift is that great, one encouraging sign, I just updated a data base for arctic Canada and winter 2022-23 was colder than almost all winters since 1970 and fairly similar to averages before 1970. This current winter is not as cold so far in the arctic regions.  

[the_other_guy]

30 minutes ago, qg_omega said:

Yup, I’ll take the over on +3 despite the next week of weather.  Torch will trend very impressive to end the month, warmest of the month despite temps over 60 today

You always skew too warm. MJO skews to cold. If you go over, Ill take the under.

Stick around enough, and you get the biases in everyones calls

[40/70 Benchmark]

31 minutes ago, qg_omega said:

Yup, I’ll take the over on +3 despite the next week of weather.  Torch will trend very impressive to end the month, warmest of the month despite temps over 60 today

We'll see.

[Rjay]

I'm on board with >+3 departures.  

[michsnowfreak]

48 minutes ago, Roger Smith said:

Not many U.S. stations go back into 1840s and 1850s, Toronto does, and you notice right away that winters in the 1840s were generally milder than in any decade until perhaps the 1930s, also snowfall tends to peak for Toronto around 1870. Winters were generally quite severe until the 1920s when a more modern trend began. I would not expect to find any location with similar temperatures in 1870s to 1890s as in recent times, it was generally quite a cold period, 1875, 1883 and 1888 are probably the three coldest years on record in any locations that observed back then. 1904 was also a very cold year. 

Personally while I acknowledge the science behind climate change I think we just happened to peak in fossil fuel output at the worst possible time when natural variability was swinging towards its own peak. If we weren't here, a lot of these trends would still be in evidence. We are just making things a bit worse. Perhaps we will catch a break and run into a cooling trend on the natural variability side. Some thought it would happen with the solar downturn (which seems to be over already) but strong El Nino events like 2015-16 overwhelmed that possibility. 

It will snow again, I don't believe the shift is that great, one encouraging sign, I just updated a data base for arctic Canada and winter 2022-23 was colder than almost all winters since 1970 and fairly similar to averages before 1970. This current winter is not as cold so far in the arctic regions.  

I have a book on weather in my area from.the 1830s to 1880s. Much like now they vary year to year, but indeed there were some very warm 1840s winters documented. 

[SnoSki14]

December 2015 really did seem like a tipping point. 

The temperature acceleration since then has been nothing short of extraordinary. 

Anyone still denying the warming trend is a complete imbecile. 

[Brian5671]

1 hour ago, Rjay said:

I'm on board with >+3 departures.  

Same here the warm ups usually over perform 

[Jersey Andrew]

2 hours ago, Roger Smith said:

Not many U.S. stations go back into 1840s and 1850s, Toronto does, and you notice right away that winters in the 1840s were generally milder than in any decade until perhaps the 1930s, also snowfall tends to peak for Toronto around 1870. Winters were generally quite severe until the 1920s when a more modern trend began. I would not expect to find any location with similar temperatures in 1870s to 1890s as in recent times, it was generally quite a cold period, 1875, 1883 and 1888 are probably the three coldest years on record in any locations that observed back then. 1904 was also a very cold year. 

Personally while I acknowledge the science behind climate change I think we just happened to peak in fossil fuel output at the worst possible time when natural variability was swinging towards its own peak. If we weren't here, a lot of these trends would still be in evidence. We are just making things a bit worse. Perhaps we will catch a break and run into a cooling trend on the natural variability side. Some thought it would happen with the solar downturn (which seems to be over already) but strong El Nino events like 2015-16 overwhelmed that possibility. 

It will snow again, I don't believe the shift is that great, one encouraging sign, I just updated a data base for arctic Canada and winter 2022-23 was colder than almost all winters since 1970 and fairly similar to averages before 1970. This current winter is not as cold so far in the arctic regions.  

Thanks for sharing some optimism Roger. Toronto can still get mighty cold in the winter as I experienced on some February trips up there for Super Bowl parties. Subzero lows and single digit highs reminded me of time spent in Chicago. The thing that surprised me though was the lack of massive snowstorms in Toronto’s history. No 20+ inch snows on record whereas NYC has 8 such storms and DC metro area at least 6.

[JerseyWx]

1 hour ago, SnoSki14 said:

December 2015 really did seem like a tipping point. 

The temperature acceleration since then has been nothing short of extraordinary. 

Anyone still denying the warming trend is a complete imbecile. 

I don't disagree, but I'm not sure that's the problem I'm seeing on this forum, to me it's two things.

1. People expect too much, too soon.  I was just paging through my records and it's not uncommon to get very little snow in December, especially since 2015.  Our prime is always January through the beginning of March.  

2. The cold camp is way too focused on only seeing what they want to see.  Any sort of model run, chart, graph, etc. that shows a hint of warmth is wrong or the poster is just a warm troll, even if they are a credible member.  Yet you could show a 300 hour GFS run that has some sort of cold tucked in there, and boom it's gonna snow in 2 weeks.

[40/70 Benchmark]

2 hours ago, SnoSki14 said:

December 2015 really did seem like a tipping point. 

The temperature acceleration since then has been nothing short of extraordinary. 

Anyone still denying the warming trend is a complete imbecile. 

I don't know of anyone denying climate change.

[Stormlover74]

44 minutes ago, JerseyWx said:

I don't disagree, but I'm not sure that's the problem I'm seeing on this forum, to me it's two things.

1. People expect too much, too soon.  I was just paging through my records and it's not uncommon to get very little snow in December, especially since 2015.  Our prime is always January through the beginning of March.  

2. The cold camp is way too focused on only seeing what they want to see.  Any sort of model run, chart, graph, etc. that shows a hint of warmth is wrong or the poster is just a warm troll, even if they are a credible member.  Yet you could show a 300 hour GFS run that has some sort of cold tucked in there, and boom it's gonna snow in 2 weeks.

Yeah even I hadn't realized that there were no 6" events in December between 1960 and 1990. From 1990 to 2020 we had at least 7 or 8. Still that's less than 1 every 3 years. 

[40/70 Benchmark]

2 hours ago, JerseyWx said:

I don't disagree, but I'm not sure that's the problem I'm seeing on this forum, to me it's two things.

1. People expect too much, too soon.  I was just paging through my records and it's not uncommon to get very little snow in December, especially since 2015.  Our prime is always January through the beginning of March.  

2. The cold camp is way too focused on only seeing what they want to see.  Any sort of model run, chart, graph, etc. that shows a hint of warmth is wrong or the poster is just a warm troll, even if they are a credible member.  Yet you could show a 300 hour GFS run that has some sort of cold tucked in there, and boom it's gonna snow in 2 weeks.

Too be fair, I think #2 goes both ways.....def more posters biased toward cold, though.