December 2025 OBS and Discussion

[Roger Smith]

Two Decembers that flipped very greatly from cold first half (+2-4 days) to mild second half would be 1875 and 1895. The means changed as follows: 

1895 ___ mean 1-17 30.7 ___ mean 18-31 47.7 ___ overall 38.4

1875 ___ mean 1-20 29.1 ___ mean 19-31 41.3 ___ overall 33.4

The largest upward shifts in recent Decembers are

2003 ___ mean 1-21 34.5 ___ mean 22-31 44.2 ___ overall 37.6

2005 ___ mean 1-22 32.0 ___ mean 23-31 43.2 ___ overall  35.3

The most prolific change was in Dec 1895 and most of the rest of the winter (Jan-Mar 1896) turned quite cold again. Winter 1875-76 remained mild well into Feb 1876, March was cold. 

[sussexcountyobs]

Partly cloudy. Occasional light flurries. 21.6

[eduggs]

Yet another snowy evening out there. Everything's dusted up pretty good - maybe 1/4". From radar I suspect parts of western or northern Morris county have accumulated 1/2" - 1" this evening. These minor events help soothe the snowstorm deprivation angst. 

[eduggs]

For the past few days, meso models and even globals advertised a finger-like lake effect snow band getting into NNJ this evening. And it has verified as advertised. Count me as impressed.

[Stormlover74]

Ewr has fallen below freezing meaning each of the first 11 days of the month will have had lows below 32. The streak should go through at least day 17 before the moderation begins. Looking at other cold Decembers in the past 25 years I can't find another year that matched that feat

[weathermedic]

Band of snow headed to parts of the city 

[Nibor]

Currently in that narrow band. 

 

Jersey City Heights 10 PM

[qg_omega]

Impressive snow band!

[MJO812]

Special weather statement for tonight for nyc

[Nibor]

 

Right before a lull. New round about to come through.

[eduggs]

The junction of I-287 and I-80 looks like it got into that band pretty good. I bet it dropped a quick 1/2" plus in that area.

[jm1220]

Looks like it extends to the south shore of Nassau. Long Beach/5 Towns probably snowing in that band. 

[Nibor]

Visibility down to less than 1/4 a mile here. Great dendrite growth. 

[Bxstormwatcher360]

That band just keeps going. 

[psv88]

If the GFS is correct this is just about all the snow the city sees this year 

[eduggs]

If the GFS is right, some spots might get more snow from tonight's lake effect bands than from the Sat. night event.

[Krs4Lfe]

5 minutes ago, psv88 said:

If the GFS is correct this is just about all the snow the city sees this year 

It’s truly crazy. I can’t think of any other way to describe it. Thinking we might very likely be shut out of snow here this month. That is likely a terrible sign for the rest of the winter. It was actually cold enough to snow this month, it just couldn’t happen though. Always need a bit of luck down here on the coast. But each year that we don’t get a KU, we need more and more luck to get something because of how much the base state has warmed. The 2010s winters feel like ages ago now

[MJO812]

Cmc

[MJO812]

Just now, Krs4Lfe said:

It’s truly crazy. I can’t think of any other way to describe it. Thinking we might very likely be shut out of snow here this month. That is likely a terrible sign for the rest of the winter. It was actually cold enough to snow this month, it just couldn’t happen though. Always need a bit of luck down here on the coast. But each year that we don’t get a KU, we need more and more luck to get something because of how much the base state has warmed. The 2010s winters feel like ages ago now

Even the AI gfs is more robust. Gfs is lost.

[jasperk99]

I’m in Journal Square in Jersey City and the tiny band packed a punch, the squalls were something else!!!


.

[MJO812]

Snowing here

[jasperk99]

Jersey City


.

[sussexcountyobs]

Clear. 17.0

[BxEngine]

7 hours ago, Krs4Lfe said:

It’s truly crazy. I can’t think of any other way to describe it. Thinking we might very likely be shut out of snow here this month. That is likely a terrible sign for the rest of the winter. It was actually cold enough to snow this month, it just couldn’t happen though. Always need a bit of luck down here on the coast. But each year that we don’t get a KU, we need more and more luck to get something because of how much the base state has warmed. The 2010s winters feel like ages ago now

Change the track man. Put that needle in another groove. 

[ForestHillWx]

Another cold morning out this way; 18 currently. With a dusting of snow it looks like early winter. 

[bluewave]

9 hours ago, Stormlover74 said:

Ewr has fallen below freezing meaning each of the first 11 days of the month will have had lows below 32. The streak should go through at least day 17 before the moderation begins. Looking at other cold Decembers in the past 25 years I can't find another year that matched that feat

This is the first time since 1989. But now we are getting the typical moderation which has become a repeating pattern every year as we approach the 17th to 25th period. Dec 1989 stayed cold through the end of the month before its moderation for all of January and February.

Climatological Data for NEWARK LIBERTY INTL AP, NJ - December 1989
Click column heading to sort ascending, click again to sort descending.

Sum	1012	573	-	-	1215	0	0.75	0.5	-
Average	32.6	18.5	25.6	-12.4	-	-	-	-	0.0
Normal	44.8	31.2	38.0	-	837	0	4.14	5.4
1989-12-01	35	22	28.5	-13.5	36	0	0.00	0.0	0
1989-12-02	47	18	32.5	-9.2	32	0	T	T	0
1989-12-03	38	19	28.5	-12.9	36	0	T	T	0
1989-12-04	29	15	22.0	-19.2	43	0	0.00	0.0	0
1989-12-05	32	24	28.0	-12.9	37	0	0.00	0.0	0
1989-12-06	47	27	37.0	-3.6	28	0	0.02	0.0	0
1989-12-07	43	22	32.5	-7.8	32	0	0.00	0.0	0
1989-12-08	26	22	24.0	-16.0	41	0	0.01	0.1	0
1989-12-09	30	18	24.0	-15.7	41	0	0.00	0.0	T
1989-12-10	35	22	28.5	-11.0	36	0	0.00	0.0	0
1989-12-11	40	29	34.5	-4.7	30	0	0.00	0.0	0
1989-12-12	35	30	32.5	-6.4	32	0	T	T	0
1989-12-13	32	22	27.0	-11.6	38	0	T	T	T
1989-12-14	31	15	23.0	-15.4	42	0	0.00	0.0	0
1989-12-15	41	19	30.0	-8.1	35	0	0.10	T	0
1989-12-16	37	19	28.0	-9.9	37	0	T	T	0
1989-12-17	33	17	25.0	-12.6	40	0	0.00	0.0	0
1989-12-18	29	15	22.0	-15.4	43	0	0.00	0.0	0
1989-12-19	27	16	21.5	-15.6	43	0	T	T	0
1989-12-20	33	19	26.0	-10.9	39	0	T	T	T
1989-12-21	23	12	17.5	-19.1	47	0	T	T	T
1989-12-22	20	7	13.5	-22.9	51	0	0.00	0.0	0
1989-12-23	22	7	14.5	-21.7	50	0	0.00	0.0	0
1989-12-24	21	8	14.5	-21.4	50	0	0.00	0.0	0
1989-12-25	26	12	19.0	-16.7	46	0	0.00	0.0	0
1989-12-26	34	13	23.5	-12.0	41	0	T	T	0
1989-12-27	21	8	14.5	-20.8	50	0	T	T	0
1989-12-28	37	19	28.0	-7.1	37	0	T	T	T
1989-12-29	33	23	28.0	-6.9	37	0	0.00	0.0	0
1989-12-30	30	25	27.5	-7.2	37	0	0.14	0.4	T
1989-12-31	45	29	37.0	2.5	28	0	0.48	0.0	T

 

Climatological Data for NEWARK LIBERTY INTL AP, NJ - January 1990
Click column heading to sort ascending, click again to sort descending.

Sum	1478	1027	-	-	756	0	4.72	2.4	-
Average	47.7	33.1	40.4	7.6	-	-	-	-	0.1
Normal	40.0	25.5	32.8	-	1000	0	3.42	9.1
1990-01-01	46	32	39.0	4.7	26	0	0.14	0.0	0
1990-01-02	43	27	35.0	0.9	30	0	0.00	0.0	0
1990-01-03	50	29	39.5	5.6	25	0	0.00	0.0	0
1990-01-04	51	33	42.0	8.3	23	0	T	0.0	0
1990-01-05	49	36	42.5	8.9	22	0	0.00	0.0	0
1990-01-06	47	34	40.5	7.1	24	0	T	T	0
1990-01-07	44	26	35.0	1.7	30	0	0.00	0.0	0
1990-01-08	41	31	36.0	2.9	29	0	1.14	1.4	0
1990-01-09	46	32	39.0	6.0	26	0	0.00	0.0	1
1990-01-10	47	39	43.0	10.1	22	0	0.03	0.0	1
1990-01-11	46	37	41.5	8.7	23	0	0.00	0.0	0
1990-01-12	43	31	37.0	4.3	28	0	T	T	0
1990-01-13	35	25	30.0	-2.6	35	0	T	T	0
1990-01-14	37	22	29.5	-3.0	35	0	0.00	0.0	0
1990-01-15	40	33	36.5	4.1	28	0	0.10	0.2	T
1990-01-16	57	32	44.5	12.1	20	0	0.00	0.0	0
1990-01-17	62	40	51.0	18.7	14	0	0.00	0.0	0
1990-01-18	66	44	55.0	22.7	10	0	T	0.0	0
1990-01-19	44	31	37.5	5.3	27	0	0.00	0.0	0
1990-01-20	36	30	33.0	0.8	32	0	0.46	0.8	0
1990-01-21	38	31	34.5	2.3	30	0	0.30	T	0
1990-01-22	47	30	38.5	6.3	26	0	0.02	T	0
1990-01-23	46	34	40.0	7.8	25	0	0.00	0.0	0
1990-01-24	57	41	49.0	16.8	16	0	T	0.0	0
1990-01-25	55	46	50.5	18.3	14	0	1.12	0.0	0
1990-01-26	58	36	47.0	14.7	18	0	0.20	0.0	0
1990-01-27	46	30	38.0	5.7	27	0	0.00	0.0	0
1990-01-28	58	32	45.0	12.6	20	0	0.00	0.0	0
1990-01-29	44	35	39.5	7.0	25	0	1.07	0.0	0
1990-01-30	46	37	41.5	9.0	23	0	0.14	0.0	0
1990-01-31	53	31	42.0	9.4	23	0	0.00	0.0	0

 

Climatological Data for NEWARK LIBERTY INTL AP, NJ - February 1990
Click column heading to sort ascending, click again to sort descending.

Sum	1382	846	-	-	699	0	1.71	2.8	-
Average	49.4	30.2	39.8	4.7	-	-	-	-	0.1
Normal	43.0	27.2	35.1	-	837	0	2.98	10.1
1990-02-01	54	32	43.0	10.3	22	0	0.00	0.0	0
1990-02-02	53	39	46.0	13.1	19	0	0.06	0.0	0
1990-02-03	40	31	35.5	2.5	29	0	0.10	0.0	0
1990-02-04	40	34	37.0	3.9	28	0	0.29	T	0
1990-02-05	38	22	30.0	-3.3	35	0	0.00	0.0	0
1990-02-06	57	30	43.5	10.1	21	0	0.00	0.0	0
1990-02-07	55	39	47.0	13.4	18	0	T	0.0	0
1990-02-08	57	33	45.0	11.3	20	0	0.00	0.0	0
1990-02-09	63	40	51.5	17.6	13	0	T	0.0	0
1990-02-10	63	35	49.0	14.9	16	0	0.52	0.0	0
1990-02-11	49	31	40.0	5.8	25	0	0.00	0.0	0
1990-02-12	47	32	39.5	5.1	25	0	0.01	0.1	T
1990-02-13	53	29	41.0	6.4	24	0	0.00	0.0	0
1990-02-14	60	41	50.5	15.7	14	0	0.02	0.0	0
1990-02-15	41	35	38.0	3.0	27	0	0.07	0.0	0
1990-02-16	58	37	47.5	12.2	17	0	0.01	0.0	0
1990-02-17	59	24	41.5	6.0	23	0	0.00	0.0	0
1990-02-18	38	20	29.0	-6.7	36	0	0.00	0.0	0
1990-02-19	57	33	45.0	9.1	20	0	0.00	0.0	0
1990-02-20	38	27	32.5	-3.6	32	0	0.00	0.0	0
1990-02-21	50	23	36.5	0.1	28	0	0.00	0.0	0
1990-02-22	63	34	48.5	11.9	16	0	0.13	0.0	0
1990-02-23	66	50	58.0	21.2	7	0	0.22	0.0	0
1990-02-24	50	31	40.5	3.4	24	0	0.15	1.3	0
1990-02-25	33	10	21.5	-15.8	43	0	0.13	1.4	2
1990-02-26	26	8	17.0	-20.6	48	0	0.00	0.0	2
1990-02-27	35	20	27.5	-10.3	37	0	T	T	T
1990-02-28	39	26	32.5	-5.5	32	0	0.00	0.0	T

[NittanyWx]

On 12/10/2025 at 1:56 PM, bluewave said:

 

I understand that the most extreme warming has only occurred over the last 15 to 30 years. So we have a new emergent climate state that is different from the previous colder era. 

We don’t have the luxury anymore of a relatively stable global temperature regime as was the case from 1880 through 1982. So you had a much longer period where there was only a small increase in temperatures. It gave us a 100 years of correlations to work out and use. 

 

 

You're making a lot of assumptions about how I do things and those assumptions are wrong.  I used SAI as an sample of a 'near term' trend with a strong statistical correlation that showed forecastable value off a short sample size and ultimately failed as your sample size got larger.  My correlation work largely ignores what happens before 1991.  The correlation still fails to reach statistical significant when testing between ENSO, the SOI and any number of corresponding variables when you benchmark them to regional snowfall observations.  

 

You're speaking with someone who has done this professionally in the commodities space for 15 years.  My methodologies discount severely anything before 1991 because it is a different climate regime.  This is an industry that benchmarks to the 10 year normal and not 30 -myself included- so I don't need a lecture and explanation about understanding what regime we are in.  This isn't a discussion about that, it's a discussion about overfitting to an arbitrary value.

 

For the record, I also do detrended analysis to find statistical signals around warmer background trends.  I am very cognizant of the CC forcing arguments you've made and how deeply you believe them.   But as we got into an argument last year about Feb, we're getting into an argument here on what constitues actual statistical signal and more importantly *why* you used a threshold value other than fitting it to observational data.

 

You still need to find a robust statistical *and* meteorological reason for 4" of snow meaning something for us to take any real stock in using it as a metric.  I can test it, I can say 'hey, that's kinda interesting' but you're not giving me a real meteorological reason for why 4" is an actual threshold.  

 

[NittanyWx]

1 minute ago, bluewave said:

We are taking about local and not regional snowfall observations. A broad brush approach doesn’t  always work especially with the wide variation between the coastal plain to mountains areas to the north and west. You need to more narrowly focus the data for the sensible weather from EWR to NYC and LGA for which the relationship is valid. 

Those three stations are what I'm testing.  Again, assumption made that is incorrect.  Take an average of those three stations, that's your 'snowfall index'.  Bench that snowfall index to ENSO past 30 years and you get a correlation that fails.

 

So other than arbitrarily fitting it to the data, why does 4" mean something meteorologically?

[NittanyWx]

4 minutes ago, bluewave said:

Then your methodology is off. 

The math does not hold man, I'm literally sitting here doing the testing and its an overfit.  My best guess is found a value you think makes sense based on recent record and picked it because it fit observed data.  All I've asked you, repeatedly I might add, is why 4" means something statistically and meteorologically.  Why did you choose 4"?   

 

ENSO is not and never really has been a great predictor of snowfall here. 

[NittanyWx]

2 minutes ago, bluewave said:

Again. You don’t  know what you are talking about if you continue to make these broad assumptions that don’t match our snowfall patterns. If have seen some of the sloppy work from a number  of the commodity and hedge fund shops which try to pass them off as something meaningful to impress the traders with.

Nice, so now you're calling my work sloppy because you can't find a meteorological reason for why your threshold makes sense other than it 'fits the data'.  You've dodged the question 5 times now.  I know what I am doing and your arrogance is really starting to show here.

 

You haven't seen my work, I can promise you that.  I don't work at a vendor.