2024-2025 La Nina

[40/70 Benchmark]

@Stormchaserchuck1Here in excerpt from my ENSO discussion within the Outlook publication last fall....worked out very well for the most part...was on the weaker end of my expectation envelop and it didn't end up obtaining official designation, as suggested, but I am in agreement that it acted as a borderline weak/moderate event.

The primary ENSO analog of 2008 was very predicative in terms of the late developing nature, progression westward, and even the ultimate intensity per RONI and MEI.

 

ENSO 2024-2025

Primary ENSO Analogs: 2021-2022, 2020-2021, 2011-2012, 2008-2009

Intensity & Structure Discussion

The October update of ENSO guidance from the International Research Institute reflected a significant reduction in the forecasted peak intensity of La Niña with a -.6 NDJ peak. 

 

 

 

While this is in better agreement with the -.4 DJF peak suggested by statistical guidance, the remaining difference still implies uncertainty with respect to whether an official La Niña will be declared. This is especially true given the paltry ASO ONI of -0.2 in conjunction with the fact that the weekly reading in region 3.4 was down from -0.5 on 10/23 to -0.2 as of 10/31. The reason for this is attributable to the behavior of the subsurface in conjunction with the zonal wind pattern during latter portion of the month of October.

The trend in the subsurface since mid October has been for the cold pool to shift east and even intensify.

 

 

 

However, during this same period of time, the trade winds have also shifted to the east and completely abated and even reversed to westerlies over region 3.4 

 

 

This has triggered a warming over region 3.4 with a burst of cooling over the eastern flank of ENSO. Note the sea surface temperature anomaly profile as of September 17th with the max anomalies focused in region 3.4

 

As compared to the max anomalies having relocated to region 3 on November 4th.

 

 

 

These changes have cooled the eastern flank of region 1.2 from -0.1C on October 16th to -0.5 on October 30, while both region 4 and 3.4 warmed from 0.1 to 0.2 and from -0.3 to -0.2, respectively. Although the trade winds are anticipated to re establish over the western flank in region 4, the forecast moving forward is precarious. There is uncertainty as to whether or not the occasional flirtation of the eastern extent of the trades with the western periphery of region 3.4 will be able to colocate with the western periphery of the subsurface cold pool to foster the development of an official La Niña event per ONI. The dynamical guidance suite, as stated, remains at odds with the statistical guidance. The former, albeit weaker, insists on the development of La Niña, and the latter has been steadfast on the ENSO neutral scenario.

 

 

This recent trend for the trade winds to be relegated to the east is already reversing, as they have to die died off and redevelop over region 4, which has halted cooling for the entire eastern half and likely even induce some warmer fluctuations. In fact, as of the November 6ht update, the region 1.2 has already warmed back up to -0.2 from -0.5 on the 30th and region 3.4 is back down to -0.3. Despite this, the notable absence of a subsurface cold pool beneath region 4 will prevent this event from becoming a full-fledged Modoki event, and it should instead remain central-based in nature. 

 

 

Guidance affirms this central based assessment, but like most hybrid events, there will be variation and mixed elements of each.

 

 

The convective forcing that has been redolent of the mixed type La Nina pattern should remain as such in the aggregate seasonal mean, however, expect it to assume that of a Modoki during warmer times, and that of an east-based event during the anticipated period of deviation. 

 

 

Note the positive precipitation anomaly beneath this area of maximum convective forcing  on model guidance.

 

The El Nino Modoki Index (EMI) forecast for the Japanese Meteorological Society confirms.

EMI analogs include  2008, 2010, 2011, 2020 and 2021 and the EMI forecast is between -.5 and -.7

Overall, while it may still appear somewhat muddled as to whether or not La Nina will officially come to fruition due to its recent stagnation coupled with the discrepancy between statistical and dynamical guidance, analog data offers support to scenario depicted by dynamical intensity guidance.

 

Analog Data Confirms that Official La Nina Designation is Likely

Eastern Mass Weather has identified five ONI analogs, three of which peaked as cool ENSO neutral and two with a weak La Niña designation. The three ENSO cool neutral seasons are as follows:

 

1996: -0.4 ASO ONI, -0.5 peak ONI, 10/30 3.4 weekly reading of -0.1, 12/25 weekly peak of -0.8

 

2001: -0.2 ASO ONI, -0.3 peak ONI, 10/30 3.4 weekly reading of -0.5, 11/21 weekly peak of -0.7

 

2013: -0.3 ASO ONI, -0.5 peak ONI, 10/30 3.4 weekly reading of -0.1, 2/5 weekly peak of -1.3

 

And the two weak La Niña analogs:

 

2005: -0.1 ASO ONI, -0.9 peak ONI, 11/2 3.4 weekly reading of -0.4, 11/18 weekly peak of -1.1

 

2008: -0.2 ASO ONI, -0.8 peak ONI, 10/29 3.4 weekly reading of -0.1, 12/22 weekly peak of -1.0

 

Here is the subsurface and zonal wind juxtaposition for later October-early November 2024 for comparison with the rest of the dataset, as measured against the appropriate climate period.

 

2024:

 

 

Weak La Niña members:

 

2005:

 

 

2008:

 

 

Cool ENSO Neutral Members:

 

The glaring discrepancy between the ENSO neutral portion of the dataset and 2024 is that the sample from 1996 is completed devoid of any trades and has a very weak subsurface cold pool.

 

1996:

 

 

The years 2001 and 2013 have neither a cold pool nor any semblance of trade winds, which is why neither of these years featured the development of an official La Niña per ONI.

2001:

 

 

2013:

 

 

The recent descent of the Indian Ocean Dipole (IDO) into negative territory represents a nod towards the La Niña analogs is thus also supportive of a marginal cool ENSO event crossing the threshold into official La Niña designation as an added measure of confidence.

 

 

 

 

Given the congruence of 2024 with the weak La Niña composite of 2005 and 2008 in conjunction with continued support from the dynamical ENSO guidance, one last concerted cooling of region 3.4 between mid November and mid December should be sufficient to ultimately achieve a weak La Niña designation, with a peak DJF ONI of between -0.6 and -0.8. This range is slightly more aggressive than suggested by the current consensus of guidance out of deference to the ongoing severe cold phase of the Pacific and its tendency to constructively interfere with and reinforce episodes of cool ENSO. This is reflected well by the Multi ENSO Variate Index (MEI) and Relative Ocean Nino Index (RONI).

Relative Ocean Nino & Multivariate ENSO Index Expected to be Indicative of Moderate La Niña Peak

In addition to the absolute intensity analogs (peak ONI) of 2005 and 2008, the strong 1973 La Nina event will be considered as a relative ENSO analog, due to the fact that it may inform the degree of additional development from this point forward considering that this year also featured a robust El Nino transitioning into a La Nina during a deeply negative PDO regime. This is precisely when the RONI is more critical than the ONI for assessing the overall intensity of ENSO. The reason why that is the case is because the RONI attempts to remove the trend due to global warming in an effort to produce a measure that is of more direct relevance to changes in tropical convection driven by SST anomalies, rather than the general warming around the globe. This in conjunction with a lack of appreciation for the Maritime forces competing with ENSO were the primary sources of confusion with respect to the inaccurate diagnosis of last season's El Niño. When used in conjunction with the MEI, which combines both oceanic and atmospheric variables into a single index as an overall assessment of ENSO, a more accurate measure of the true strength of the interface between land and sea that is represented by ENSO can be made. The ASO RONI values for the aforementioned three seasons and the subsequent peaks are as follows:

 

1973: -.1.54 ASO RONI and -1.95 peak.

2005: -.02 ASO RONI and -.93 peak.

2008: -.27 ASO RONI and -.89 peak.

 

 

What is apparent when examining the data is that the residual, baseline cool ENSO influence that is being reflected by the RONI is enhancing the current La Nina, as opposed to when it was competing and in conflict with El Niño last year. These analogs support a peak RONI range of -1.2 to -1.4, which is of course a significant, moderate cool ENSO event. An analysis of the ground truth can be completed for the atmosphere to confirm what an exhaustive analysis of the data has suggested.

The evolution of the Walker Cycle dictates that it is the upwelling of cooler subsurface waters via the enhancement of easterly trade winds that drives the development of La Niña, as touched upon previously. This is evident by the robust trade winds that are evident when viewing a composite of strong La Niña events.

 

The contrast between this composite and that of weak La Niña events is clear.

 

When viewing the May-August zonal wind anomalies for 2024, it is obvious that the meager strength of the trades winds thus far in the mean spanning the last several months has inhibited the development of La Niña. This corresponds with the earlier analysis citing the collapse of the trades in conjunction with some nuances concerning the subsurface cold pool as the reason for the recent stall in the development of La Niña.  

However, there are a multitude of indicators that are suggestive of a cool ENSO event that is appreciably better coupled with the atmosphere than the meager ONI value would imply.

 

 

 

This configuration is clearly more representative of the a stronger La Niña, such as the 1973-1974 event, rather than the weaker 2005 analog.

 

 

This represents a splendid illustration of why having the North Pacific in phase with La Niña, as it is now during the current deeply -PDO, results in a RONI that is stronger than the ONI and very likely a cool ENSO event that is well coupled with the atmosphere. Last season, this was not the case with El Niño, as it usually is not when the PDO is so deeply negative. Having climate change enhance the West Pacific warm pool that is a staple of an already record powerful Pacific cold phase only accentuates this phenomenon further. This is clearly evinced when comparing October composites of Pacific pressure anomalies during weak and strong La Niña events to October 2024.

Normally in a healthy La Niña event, the abundance of convection fostered by warmer waters over the western Pacific MC result in low pressure anomalies, which result in sinking air across the eastern portion of the basin and higher pressure. 

 

 

Note how diffuse this dipole is in the weak la Nina May-October composite.

 

 

The dipole is comparatively much more pronounced in the strong La Niña composite.

 

However, its even more well defined in 2024, despite the paltry ONI reflection to date.

 

 

Prior to this recent intensification of the pressure dipole, its initial slow response over the summer was at least partially attributable to the influence of the Southern Oscillation Index, which had been lethargic to respond to the burgeoning cool ENSO event given the magnitude of the strong El Niño event that preceded it. This resulted in a lag due to the extensive recovery necessary for the atmosphere to switch phases and couple with the ocean. However, during the middle to latter portion of summer, and then again in October, the SOI finally began to elevate and the MEI tumbled more precipitously, which is now fueling a faster intensification of the cool ENSO walker cycle.

 

The notable lack of a Pacific pressure dipole during the early portion of the summer season was also present during the relative ENSO analog season of 1973, which like this event, was transitioning from a strong Pacific cold phase El Niño to La Niña.

 

Now here is the May-August pressure pattern prior to strong La Nina events.

 

 

Note that the pressure dipole during the summer of 2024 was still rather disjointed in comparison to the strong La Niña composite.

 

However, as of the last update for the JA bi-monthly period, the MEI had already descended to -0.7.

 

 

The MEI calculation has unfortunately not been updated since last summer due to the immense flooding in the aftermath of Hurricane Helene, however, it is safe to expect given the above data and recent trends that a peak MEI value between -1 to -1.2 is to be expected. 

[PhiEaglesfan712]

With April over, PHL officially finishes the 2024-25 season with 8.1 inches of snow. This is the 7th time in 9 seasons (dating back to 2016-17) that PHL has finished below average in snowfall. 2017-18 was the only season in that timespan that finished slightly above average in snowfall (and that was due to a record snowfall in March), while 2020-21 finished near average in snowfall.

[40/70 Benchmark]

8 hours ago, PhiEaglesfan712 said:

With April over, PHL officially finishes the 2024-25 season with 8.1 inches of snow. This is the 7th time in 9 seasons (dating back to 2016-17) that PHL has finished below average in snowfall. 2017-18 was the only season in that timespan that finished slightly above average in snowfall (and that was due to a record snowfall in March), while 2020-21 finished near average in snowfall.

2017-2018 was my last above average snowfall season due to a record March. 7 conecutive stinkers since.

[Jebman]

7 hours ago, 40/70 Benchmark said:

2017-2018 was my last above average snowfall season due to a record March. 7 conecutive stinkers since.

I fervently hope you guys get happily buried ALIVE in powder snow soon!

[Stormchaserchuck1]

7 hours ago, 40/70 Benchmark said:

2017-2018 was my last above average snowfall season due to a record March. 7 conecutive stinkers since.

My last biggest storm was 5.5" on Nov 15, 2018. Can you believe that. 

I also think every year has been below average since 15-16. 

There was a some major warming happening though around the perimeters in 14-15 and 15-16.. Dec 15 was record warm. 14-15 was record warm in the West. And last Winter had the opposite: some cold around the perimeters. Hopefully we are changing into a better pattern for the next few Winters. 

[FPizz]

17 hours ago, 40/70 Benchmark said:

2017-2018 was my last above average snowfall season due to a record March. 7 conecutive stinkers since.

17-18 and 20-21 were well above average here (I'm pretty much dead center between Philly and NYC).  Again, some of these things are location dependent and picking a big city like many do isn't necessarily accurate.  Last year (23-24) I was exactly average due to one sneaky storm that dropped a foot in a small swath.  But the same can be said for other winters when a nor'easter gets Long Island/NYC putting them above average snow and gives me an inch since I am 10 miles too west.  We are running 3" below average here for the past 8 years, but some area's are much lower, some are higher.  

[michsnowfreak]

On 5/1/2025 at 6:35 AM, PhiEaglesfan712 said:

With April over, PHL officially finishes the 2024-25 season with 8.1 inches of snow. This is the 7th time in 9 seasons (dating back to 2016-17) that PHL has finished below average in snowfall. 2017-18 was the only season in that timespan that finished slightly above average in snowfall (and that was due to a record snowfall in March), while 2020-21 finished near average in snowfall.

 

17 hours ago, 40/70 Benchmark said:

2017-2018 was my last above average snowfall season due to a record March. 7 conecutive stinkers since.

The 28.7" at Detroit was over a foot below avg, though Jan & Feb were 2 solid months of excellent conditions for all outdoor things winter (with off and on spurts Nov/Dec), so those who dont just go by numbers would call it a solid winter. The last 10 years, since 2015-16, have seen 2 above avg snow seasons, 2 avg snow seasons, and 6 below avg snow seasons, although with the lowest being 23.5" in '23-24, none have been record low.

 

However, the 10-year avg of 39.1" is only 2" below the longterm avg and 6" below the 1991-2020 avg. The 20-year avg of 46.2" is still 5" above the longterm avg and 1" above 1991-20 avg, and the rolling 30-year avg (1996-2025) is 43.7", which is still approx 1.5" above the longterm avg. So all in all, its purely been a regression to the mean and im looking forward to seeing what the next few winters brings.

[bluewave]

1 hour ago, FPizz said:

17-18 and 20-21 were well above average here (I'm pretty much dead center between Philly and NYC).  Again, some of these things are location dependent and picking a big city like many do isn't necessarily accurate.  Last year (23-24) I was exactly average due to one sneaky storm that dropped a foot in a small swath.  But the same can be said for other winters when a nor'easter gets Long Island/NYC putting them above average snow and gives me an inch since I am 10 miles too west.  We are running 3" below average here for the past 8 years, but some area's are much lower, some are higher.  

This doesn’t have anything to do with whether you are taking the measurements in a big city of the surrounding areas. It’s is a region-wide phenomenon including all the locations within the general I-95 corridor. 

First, we don’t have a continuous snowfall record for your individual location spanning more than 60 years. So you are just guessing when it comes to how your recent snowfall compares against historical averages.

Second, the stations around your region are in a similar boat as the other bigger city stations that have a longer period of record. So this snow drought is very extensive and isn’t just located in the big cities. Since you can see how close Philly to Trenton and New Brunswick have been. 

Everyone is near the record 7 season snowfall lows. But we have warmed so much, that a big rebound in the coming years like which followed past snow droughts isn’t as likely. So we are seeing what a decline in snowfall looks like in real time as a warmer climate and storm track will result in less snow. So while it’s within the range of possibilities that we could see a bit of a bounce off these lows in coming seasons, my guess is that 18-19 will mark the shift to a longer term decline which will become obvious when we look back in time 10 to 20 years into the future. 

Recent 7 year snowfall through 2025 compared to past lowest 7 year stretches. Past snow droughts were the result of too dry and not too warm. This is an important distinction to now as we are experiencing too much warmth for snow. Since in the old days there was always enough cold once the snow droughts ended due to dry conditions ended. Like we saw in the earky 1930s with record cold and snow in 33-34. Also from the late 1950s into early 1960s with the very snowy and cold conditions following those 7 year snowfall through droughts. 

New Brunswick……2025…..15.9”…….1956……13.8”………1932…..13.8”

Trenton…..2025…..14.1”…….1933…..14.2” 

Philly………2025…..10.5”……1932…..12.3”

[michsnowfreak]

1 hour ago, bluewave said:

This doesn’t have anything to do with whether you are taking the measurements in a big city of the surrounding areas. It’s is a region-wide phenomenon including all the locations within the general I-95 corridor. 

First, we don’t have a continuous snowfall record for your individual location spanning more than 60 years. So you are just guessing when it comes to how your recent snowfall compares against historical averages.

Second, the stations around your region are in a similar boat as the other bigger city stations that have a longer period of record. So this snow drought is very extensive and isn’t just located in the big cities. Since you can see how close Philly to Trenton and New Brunswick have been. 

Everyone is near the record 7 season snowfall lows. But we have warmed so much, that a big rebound in the coming years like which followed past snow droughts isn’t as likely. So we are seeing what a decline in snowfall looks like in real time as a warmer climate and storm track will result in less snow. So while it’s within the range of possibilities that we could see a bit of a bounce off these lows in coming seasons, my guess is that 18-19 will mark the shift to a longer term decline which will become obvious when we look back in time 10 to 20 years into the future. 

Recent 7 year snowfall through 2025 compared to past lowest 7 year stretches. Past snow droughts were the result of too dry and not too warm. This is an important distinction to now as we are experiencing too much warmth for snow. Since in the old days there was always enough cold once the snow droughts ended due to dry conditions ended. Like we saw in the earky 1930s with record cold and snow in 33-34. Also from the late 1950s into early 1960s with the very snowy and cold conditions following those 7 year snowfall through droughts. 

New Brunswick……2025…..15.9”…….1956……13.8”………1932…..13.8”

Trenton…..2025…..14.1”…….1933…..14.2” 

Philly………2025…..10.5”……1932…..12.3”

It is an absolute guess as to whether or not your region will get another very snowy period. ESPECIALLY with the feast/famine nature of your climo. You JUST had the snowiest time on record a short decade ago. You think there wasnt warming in place already when that snowy spell occurred? I remember back in the late '90s when global warming was a hot media topic and we had a string of mild winters, we heard that "by 2020 this will happen and that will happen and it wont snow" blah blah blah and we proceeded to see the 2000s and 2010s produce multiple severe winters. And whats more, these predictions for a future of radically different weather than was seen in the past are nothing new. Its been going on for centuries, and it never materializes. 

[FPizz]

7 minutes ago, michsnowfreak said:

It is an absolute guess as to whether or not your region will get another very snowy period. ESPECIALLY with the feast/famine nature of your climo. You JUST had the snowiest time on record a short decade ago. You think there wasnt warming in place already when that snowy spell occurred? I remember back in the late '90s when global warming was a hot media topic and we had a string of mild winters, we heard that "by 2020 this will happen and that will happen and it wont snow" blah blah blah and we proceeded to see the 2000s and 2010s produce multiple severe winters. And whats more, these predictions for a future of radically different weather than was seen in the past are nothing new. Its been going on for centuries, and it never materializes. 

It's becoming sad, as he obviously is a good poster, but his head has become so clouded now is downright laughable.  Talk about letting your bias get in way, lol.  You are 100% right, we went through a stage where we averaged a good 7" or so more than normal for 20 years.  Now since 2016 it is a below average stretch and the new norm.  So delusional.  

[michsnowfreak]

23 minutes ago, FPizz said:

It's becoming sad, as he obviously is a good poster, but his head has become so clouded now is downright laughable.  Talk about letting your bias get in way, lol.  You are 100% right, we went through a stage where we averaged a good 7" or so more than normal for 20 years.  Now since 2016 it is a below average stretch and the new norm.  So delusional.  

I agree 100%. From everything I read he is a great poster and a very smart guy, but absolutely lets his bias get in the way. As I posted a few posts up, our snowfall is just slightly below avg the past decade despite multiple warm winters, and our 20 year avg and 30 year avg are STILL slightly above longterm avg. The area also saw some 10-15" MORE snow in 2019-20 & 2022-23 than we did in '24-25, and those were winters 5-6° warmer than 2024-25 (but '24-25 saw more days with snow on the ground - THAT is the bigger connection to temps). Plus we aren't a feast or famine climate like yours. It's not always about temps. Climate, pattern, and storm tracks play a big role. A pattern conducive to noreasters will quickly shoot up snow totals on the east coast, regardless of winters final mean temp.

[TheClimateChanger]

3 hours ago, bluewave said:

This doesn’t have anything to do with whether you are taking the measurements in a big city of the surrounding areas. It’s is a region-wide phenomenon including all the locations within the general I-95 corridor. 

First, we don’t have a continuous snowfall record for your individual location spanning more than 60 years. So you are just guessing when it comes to how your recent snowfall compares against historical averages.

Second, the stations around your region are in a similar boat as the other bigger city stations that have a longer period of record. So this snow drought is very extensive and isn’t just located in the big cities. Since you can see how close Philly to Trenton and New Brunswick have been. 

Everyone is near the record 7 season snowfall lows. But we have warmed so much, that a big rebound in the coming years like which followed past snow droughts isn’t as likely. So we are seeing what a decline in snowfall looks like in real time as a warmer climate and storm track will result in less snow. So while it’s within the range of possibilities that we could see a bit of a bounce off these lows in coming seasons, my guess is that 18-19 will mark the shift to a longer term decline which will become obvious when we look back in time 10 to 20 years into the future. 

Recent 7 year snowfall through 2025 compared to past lowest 7 year stretches. Past snow droughts were the result of too dry and not too warm. This is an important distinction to now as we are experiencing too much warmth for snow. Since in the old days there was always enough cold once the snow droughts ended due to dry conditions ended. Like we saw in the earky 1930s with record cold and snow in 33-34. Also from the late 1950s into early 1960s with the very snowy and cold conditions following those 7 year snowfall through droughts. 

New Brunswick……2025…..15.9”…….1956……13.8”………1932…..13.8”

Trenton…..2025…..14.1”…….1933…..14.2” 

Philly………2025…..10.5”……1932…..12.3”

I think some people are missing out on how much warming has occurred globally since the 1990s. Just look at the UAH temperature data [which uses a 1991-2020 baseline] and the 1990s look as warm globally as the 1800s used to look in the 1980s & 1990s, which to me suggests as much warming occurred in the last 25 years as had occurred in the preceding 100+ years.

[George001]

10 hours ago, FPizz said:

It's becoming sad, as he obviously is a good poster, but his head has become so clouded now is downright laughable.  Talk about letting your bias get in way, lol.  You are 100% right, we went through a stage where we averaged a good 7" or so more than normal for 20 years.  Now since 2016 it is a below average stretch and the new norm.  So delusional.  

The sample size isn’t large enough to know for sure one way or another, but given that AGW is accelerating rather than just steadily increasing, it’s worth keeping an open mind about his ideas. The snow decline is already happening in some southern areas, and it started before 2016. It’s a logical assumption to make that with additional warming since then, some areas farther north reached a tipping point. There isn’t anything wrong with discussing ideas about what the future holds and trying to figure out what is going on. There is no malicious agenda pushing going on here. If Bluewave is right he’s right, if he’s wrong he’s wrong. Maybe he’s right about some things, wrong about others (I would bet on this one). We all have our biases, but Bluewave is a fairly objective poster.

[bluewave]

20 hours ago, michsnowfreak said:

It is an absolute guess as to whether or not your region will get another very snowy period. ESPECIALLY with the feast/famine nature of your climo. You JUST had the snowiest time on record a short decade ago. You think there wasnt warming in place already when that snowy spell occurred? I remember back in the late '90s when global warming was a hot media topic and we had a string of mild winters, we heard that "by 2020 this will happen and that will happen and it wont snow" blah blah blah and we proceeded to see the 2000s and 2010s produce multiple severe winters. And whats more, these predictions for a future of radically different weather than was seen in the past are nothing new. Its been going on for centuries, and it never materializes. 

My call that the snowfall peaked in 17-18 from Philly to Boston and we were at the beginning of a snowfall decline is based on 60 years of snowfall data. I first raised this possibility back around the 2020 winter after only 2 years. I can remember getting plenty of pushback when I raised this possibility just after 2 seasons. But it’s a bit like that old game show Name That Tune. I only needed a few notes to recognize the pattern.

In the following years we got more data to confirm my idea. When there was a much colder climate from the early 1960s to the early 1990s, there wasn’t an all or nothing snowfall pattern. Most of the seasons were in a narrow range focused near the long term average  mid-range. There were few seasons with very high or very low snowfall.

This all began to change in 93-94 as nearly all our snowfall seasons were well below or well below with almost none in the mid range which was a staple of our colder climate. We were cold enough back then to have a bunch of small to moderate events in a season without a KU NESIS storm to reach average. In contrast, none of the seasons since 93-94 reached average or above without some NESIS event contributing to a the seasonal snowfall total. So as we warmed our snowfall became all or nothing.

The record 2010s featured mostly all or well above normal seasons. This period indeed was warming while the heavy snowfall was occurring. But even in the warmer winters the snowstorm tracks were still cold. As the Northern Stream of the Pacific Jet was weaker and didn’t disrupt benchmark storm track formations. These days the winter storm tracks have significantly warmed with the storm tracks shifting through the Great Lakes. This lead to an average temperature of 41° degrees this past winter in the I-95 corridor in the days the precipitation over .25 fell.  so it negated the overall 34.8° colder average.

The dominant storm tracks since the increase of the Northern Stream of the Pacific Jet speeds in 18-19 have been Great Lakes cutter, I-95 , I-78, I-80, and I-84 huggers, and suppressed Southern Stream storms. This makes it very difficult to get to average to above average snowfall. This is why the last 7 years have seen snowfal amounts near all-time lows for a 7 year interval. 

So we had to rely completely on one type of storm track to reach average to above average snowfall over the past 30 years. But having to rely exclusively on the benchmark storm track in a warming climate has pitfalls. Before 93-94 we would regularly have snowy seasons with hugger and weaker coastal storm tracks since it was still cold enough with those tracks to reach average. These days this type of storm tracks has become much warmer with mostly rain. There was a wider number of ways to get to average when it was colder. The 2010s featured a record number of benchmark storm tracks. This level of benchmark snowstorms was somewhere in the range of a 50 to perhaps 100 year event. So it’s unlikely that amount of benchmark tracks will repeat anytime soon.

So we are left with a few scenarios going forward over the next 7 seasons and beyond. One is just a continuation of the last 7 years with well below average snowfall continuing. Another possibility is that we could see a bit of an uptick in benchmark tracks and some improvement over the past 7 seasons. Though any increase would probably come in well below the 2010s levels. My guess is that this would be transient before a lower snowfall regime returns in the 2030s and beyond. The obvious caveat would be some time of super volcanic or cosmic event which would completely shift the climate in a sudden and dramatic way. Absent something like this, increasing emissions will continue to reduce our snowfall over time. 

[michsnowfreak]

On 5/3/2025 at 7:13 AM, bluewave said:

My call that the snowfall peaked in 17-18 from Philly to Boston and we were at the beginning of a snowfall decline is based on 60 years of snowfall data. I first raised this possibility back around the 2020 winter after only 2 years. I can remember getting plenty of pushback when I raised this possibility just after 2 seasons. But it’s a bit like that old game show Name That Tune. I only needed a few notes to recognize the pattern.

In the following years we got more data to confirm my idea. When there was a much colder climate from the early 1960s to the early 1990s, there wasn’t an all or nothing snowfall pattern. Most of the seasons were in a narrow range focused near the long term average  mid-range. There were few seasons with very high or very low snowfall.

This all began to change in 93-94 as nearly all our snowfall seasons were well below or well below with almost none in the mid range which was a staple of our colder climate. We were cold enough back then to have a bunch of small to moderate events in a season without a KU NESIS storm to reach average. In contrast, none of the seasons since 93-94 reached average or above without some NESIS event contributing to a the seasonal snowfall total. So as we warmed our snowfall became all or nothing.

The record 2010s featured mostly all or well above normal seasons. This period indeed was warming while the heavy snowfall was occurring. But even in the warmer winters the snowstorm tracks were still cold. As the Northern Stream of the Pacific Jet was weaker and didn’t disrupt benchmark storm track formations. These days the winter storm tracks have significantly warmed with the storm tracks shifting through the Great Lakes. This lead to an average temperature of 41° degrees this past winter in the I-95 corridor in the days the precipitation over .25 fell.  so it negated the overall 34.8° colder average.

The dominant storm tracks since the increase of the Northern Stream of the Pacific Jet speeds in 18-19 have been Great Lakes cutter, I-95 , I-78, I-80, and I-84 huggers, and suppressed Southern Stream storms. This makes it very difficult to get to average to above average snowfall. This is why the last 7 years have seen snowfal amounts near all-time lows for a 7 year interval. 

So we had to rely completely on one type of storm track to reach average to above average snowfall over the past 30 years. But having to rely exclusively on the benchmark storm track in a warming climate has pitfalls. Before 93-94 we would regularly have snowy seasons with hugger and weaker coastal storm tracks since it was still cold enough with those tracks to reach average. These days this type of storm tracks has become much warmer with mostly rain. There was a wider number of ways to get to average when it was colder. The 2010s featured a record number of benchmark storm tracks. This level of benchmark snowstorms was somewhere in the range of a 50 to perhaps 100 year event. So it’s unlikely that amount of benchmark tracks will repeat anytime soon.

So we are left with a few scenarios going forward over the next 7 seasons and beyond. One is just a continuation of the last 7 years with well below average snowfall continuing. Another possibility is that we could see a bit of an uptick in benchmark tracks and some improvement over the past 7 seasons. Though any increase would probably come in well below the 2010s levels. My guess is that this would be transient before a lower snowfall regime returns in the 2030s and beyond. The obvious caveat would be some time of super volcanic or cosmic event which would completely shift the climate in a sudden and dramatic way. Absent something like this, increasing emissions will continue to reduce our snowfall over time. 

I'm definitely not an expert in your climate. It's actually confusing to me. It's simultaneously too snowy and not snowy enough for an outsider to understand, if that makes sense. I don't see nyc as having a true wintry climate, but I also don't see them as being a 1-snow-a-year climate like the south.

It's interesting to note that if you compare the 1875-1900 period to the 2000-2025 period, east coast cities are generally 3.5-5° warmer in 2000-25 than 1875-1900, while lower Great Lakes cities are generally 0.5-2° warmer. Clearly winter has warmed more on the east coast. That's likely a contributing factor to the feast/famine snowfall and why many of your largest snowstorms have occurred this century.

While I'm no fan of warmer winters, I've noticed a trend locally that's encouraging- more dynamic snowstorms during warmer winters than there used to be. Always prefer colder winters, but it would be nice to have that in the back pocket. But I REALLY hesitate to place any bets on future decades, and that's what my main disagreement with you is. You may be wrong you may be right....but we won't know for a long while.

[chubbs]

11 hours ago, michsnowfreak said:

I'm definitely not an expert in your climate. It's actually confusing to me. It's simultaneously too snowy and not snowy enough for an outsider to understand, if that makes sense. I don't see nyc as having a true wintry climate, but I also don't see them as being a 1-snow-a-year climate like the south.

It's interesting to note that if you compare the 1875-1900 period to the 2000-2025 period, east coast cities are generally 3.5-5° warmer in 2000-25 than 1875-1900, while lower Great Lakes cities are generally 0.5-2° warmer. Clearly winter has warmed more on the east coast. That's likely a contributing factor to the feast/famine snowfall and why many of your largest snowstorms have occurred this century.

While I'm no fan of warmer winters, I've noticed a trend locally that's encouraging- more dynamic snowstorms during warmer winters than there used to be. Always prefer colder winters, but it would be nice to have that in the back pocket. But I REALLY hesitate to place any bets on future decades, and that's what my main disagreement with you is. You may be wrong you may be right....but we won't know for a long while.

We've discussed the problem with comparing city and airport obs in Detroit and Chicago before. Need to maintain consistency or remove station changes  to isolate the long-term climate trend. Winter warming has been uniform across the eastern US. If anything warming increases slightly from south to north. The fastest warming is in the upper midwest and northern New England. The warming map is confirmed by long-term data from Ann Arbor and lake freeze data from Mendota Lake in Madison Wisconsin. 

[40/70 Benchmark]

On 5/1/2025 at 11:08 PM, Stormchaserchuck1 said:

My last biggest storm was 5.5" on Nov 15, 2018. Can you believe that. 

I also think every year has been below average since 15-16. 

There was a some major warming happening though around the perimeters in 14-15 and 15-16.. Dec 15 was record warm. 14-15 was record warm in the West. And last Winter had the opposite: some cold around the perimeters. Hopefully we are changing into a better pattern for the next few Winters. 

Yes, that is my hope....something has to give...this goes on any longer and it will begin to lend more credence to some of Chris' theories.

[40/70 Benchmark]

1 hour ago, chubbs said:

We've discussed the problem with comparing city and airport obs in Detroit and Chicago before. Need to maintain consistency or remove station changes  to isolate the long-term climate trend. Winter warming has been uniform across the eastern US. If anything warming increases slightly from south to north. The fastest warming is in the upper midwest and northern New England. The warming map is confirmed by long-term data from Ann Arbor and lake freeze data from Mendota Lake in Madison Wisconsin. 

Now examine snowfall since 1970....the lagest surplus is in the NE coast, thus some of this is due to natural variability and regression. Not all of it.

[40/70 Benchmark]

On 5/2/2025 at 9:57 PM, George001 said:

The sample size isn’t large enough to know for sure one way or another, but given that AGW is accelerating rather than just steadily increasing, it’s worth keeping an open mind about his ideas. The snow decline is already happening in some southern areas, and it started before 2016. It’s a logical assumption to make that with additional warming since then, some areas farther north reached a tipping point. There isn’t anything wrong with discussing ideas about what the future holds and trying to figure out what is going on. There is no malicious agenda pushing going on here. If Bluewave is right he’s right, if he’s wrong he’s wrong. Maybe he’s right about some things, wrong about others (I would bet on this one). We all have our biases, but Bluewave is a fairly objective poster.

I agree that there is no malicious agenda pushing...I don't think anyone has ever implied that there were malicious intentions by anyone on this forum. But I do think that a lot of folks already have their mind made up one way or another.

[michsnowfreak]

4 hours ago, chubbs said:

We've discussed the problem with comparing city and airport obs in Detroit and Chicago before. Need to maintain consistency or remove station changes  to isolate the long-term climate trend. Winter warming has been uniform across the eastern US. If anything warming increases slightly from south to north. The fastest warming is in the upper midwest and northern New England. The warming map is confirmed by long-term data from Ann Arbor and lake freeze data from Mendota Lake in Madison Wisconsin. 

Chicago (and Cleveland) lakeshore would have more of a difference year-round than Detroit. Its my understanding the entire reason the NWS (or formerly Weather Bureau) moved stations is for more uniformity due to increasing influences at a station site. DTW airport absolutely has seen increasing UHI since the 1980s due to so much expanding concrete. They were a radiational cooling magnet in the 1960s-70s and that changed drastically starting in the 1990s. Detroit city airport is no longer a first-order station, but it does have a thermometer so to compare, the first 20 years DTW became the official site, DTW averaged 1.7F cooler than DET. The last 20 years DTW has averaged just 0.3F cooler.

Regardless of the site locations, we dont know all the warming influences (or lackthereof) at any given time. There is no way a big city full of dirt roads in the 1870s would have the same temperature readings as that same spot would have as a concrete jungle in the 2020s. 

That chart, "since 1970". THAT has also been discussed multiple times now. This unusual starting date is used frequently, and it is soley to make warming look as extreme as possible. Starting a chart in 1970 ahead of the coldest winters on record will give you the biggest regression line. And as we move farther away from 1970, why cling onto using that starting point? Its now 55 years, so far more than the 30-year periods commonly used, that you wonder why not go longterm? Its because to do that, youd have to include the much milder winters of the 1930s-1950s which would really tone down that regression line. So youd have to go back to 1870 to make it a bit better. You will never, EVER see a regression line chart start in 1930. And whats funny is that that would make a lot more sense than 1970 as we are nearing the 100-year mark. Yes Ann Arbor winters have warmed 3.9F since 1970....and theyve warmed 1.4F since 1930. 

Regardless of the amount of warming or any discussion on temps, site changes, etc...the lower Great Lakes are not seeing any notable adjustments to their snowfall or snowcover climo other than normal decade to decade noise, although erring on the side of INCREASING somewhat rather than decreasing. So this brings me back to my original point, how is it that suddenly NYC is seeing this erratic rubber band from snowiest decade on record to a snow drought from which they supposedly may never recover?

[LibertyBell]

On 5/2/2025 at 1:34 PM, TheClimateChanger said:

I think some people are missing out on how much warming has occurred globally since the 1990s. Just look at the UAH temperature data [which uses a 1991-2020 baseline] and the 1990s look as warm globally as the 1800s used to look in the 1980s & 1990s, which to me suggests as much warming occurred in the last 25 years as had occurred in the preceding 100+ years.

It's interesting how much the ocean has sucked up the heat which has stopped the increase of 90 and 100 degree heat which peaked in the 1990s (with another peak from 2010-13).  The earth is trying to balance out humankind's excess by dumping the heat into the ocean, let's see how long that lasts.

[LibertyBell]

17 hours ago, michsnowfreak said:

I'm definitely not an expert in your climate. It's actually confusing to me. It's simultaneously too snowy and not snowy enough for an outsider to understand, if that makes sense. I don't see nyc as having a true wintry climate, but I also don't see them as being a 1-snow-a-year climate like the south.

It's interesting to note that if you compare the 1875-1900 period to the 2000-2025 period, east coast cities are generally 3.5-5° warmer in 2000-25 than 1875-1900, while lower Great Lakes cities are generally 0.5-2° warmer. Clearly winter has warmed more on the east coast. That's likely a contributing factor to the feast/famine snowfall and why many of your largest snowstorms have occurred this century.

While I'm no fan of warmer winters, I've noticed a trend locally that's encouraging- more dynamic snowstorms during warmer winters than there used to be. Always prefer colder winters, but it would be nice to have that in the back pocket. But I REALLY hesitate to place any bets on future decades, and that's what my main disagreement with you is. You may be wrong you may be right....but we won't know for a long while.

the reason coastal areas have warmed more is because the oceans are heatsinks.

We're very lucky the oceans are there to do that, otherwise the entire planet would have become like Venus already.  It might yet one day anyway when the oceans become so warm they are completely saturated with heat.

[chubbs]

7 hours ago, 40/70 Benchmark said:

Now examine snowfall since 1970....the lagest surplus is in the NE coast, thus some of this is due to natural variability and regression. Not all of it.

Yes the NE coast and parts of the upper midwest have had increased snow since 1970. That's consistent with the paper I posted upthread (relinked below and added a second). As expected the snowfall signal is emerging much slower than the temperature signal due to offsetting precipitation and temperature effects and natural variability. 

https://journals.ametsoc.org/view/journals/clim/26/20/jcli-d-12-00832.1.xml

https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2018GL079820

 

 

 

[TheClimateChanger]

 

4 hours ago, LibertyBell said:

It's interesting how much the ocean has sucked up the heat which has stopped the increase of 90 and 100 degree heat which peaked in the 1990s (with another peak from 2010-13).  The earth is trying to balance out humankind's excess by dumping the heat into the ocean, let's see how long that lasts.

 

Not sure I buy that. It looks like a 5-period moving average is near the maximum for 90-degree days at both LGA and EWR, with the LOESS curve predicting the highest value of 90+ days in the POR at both sites. Looks like we are on the precipice of a big upswing in heat. Even a small additional increase in 90+ days would likely push your area outside of historic norms.

Also, as I have noted numerous times, the heat spike from 1986-1995 very likely an artifact of the data collection due to the defective HO-83 sensors in use during that brief era. The increase in 90+ days matches up temporally with the proliferation of HO-83 units. After installation of ASOS, the 90+ days rapidly drop back to pre-1986 levels, from which they have since steadily climbed.

The impact of the HO-83 cannot be dismissed a small bias. It was a substantial bias, the magnitude of which varied by site. At Lincoln, Nebraska, it averaged nearly 2F warmer than the ASOS, although at times, it could be as much as 7F warmer.

See: Central Region Technical Attachment 93-07, Comparison of ASOS and HO83 Temperatures at Lincoln, Nebraska from November 1991 through October 1992, George H. Grosshans, NWS Lincoln (1993).

[PhiEaglesfan712]

10 minutes ago, TheClimateChanger said:

Not sure I buy that. It looks like a 5-period moving average is near the maximum for 90-degree days at both LGA and EWR, with the LOESS curve predicting the highest value of 90+ days in the POR at both sites. Looks like we are on the precipice of a big upswing in heat. Even a small additional increase in 90+ days would likely push your area outside of historic norms.

I really hope not. We're already getting lows in the 80s here in PHL. I can't imagine living through lows of 90 and highs near 110.

[chubbs]

6 hours ago, michsnowfreak said:

Chicago (and Cleveland) lakeshore would have more of a difference year-round than Detroit. Its my understanding the entire reason the NWS (or formerly Weather Bureau) moved stations is for more uniformity due to increasing influences at a station site. DTW airport absolutely has seen increasing UHI since the 1980s due to so much expanding concrete. They were a radiational cooling magnet in the 1960s-70s and that changed drastically starting in the 1990s. Detroit city airport is no longer a first-order station, but it does have a thermometer so to compare, the first 20 years DTW became the official site, DTW averaged 1.7F cooler than DET. The last 20 years DTW has averaged just 0.3F cooler.

Regardless of the site locations, we dont know all the warming influences (or lackthereof) at any given time. There is no way a big city full of dirt roads in the 1870s would have the same temperature readings as that same spot would have as a concrete jungle in the 2020s. 

That chart, "since 1970". THAT has also been discussed multiple times now. This unusual starting date is used frequently, and it is soley to make warming look as extreme as possible. Starting a chart in 1970 ahead of the coldest winters on record will give you the biggest regression line. And as we move farther away from 1970, why cling onto using that starting point? Its now 55 years, so far more than the 30-year periods commonly used, that you wonder why not go longterm? Its because to do that, youd have to include the much milder winters of the 1930s-1950s which would really tone down that regression line. So youd have to go back to 1870 to make it a bit better. You will never, EVER see a regression line chart start in 1930. And whats funny is that that would make a lot more sense than 1970 as we are nearing the 100-year mark. Yes Ann Arbor winters have warmed 3.9F since 1970....and theyve warmed 1.4F since 1930. 

Regardless of the amount of warming or any discussion on temps, site changes, etc...the lower Great Lakes are not seeing any notable adjustments to their snowfall or snowcover climo other than normal decade to decade noise, although erring on the side of INCREASING somewhat rather than decreasing. So this brings me back to my original point, how is it that suddenly NYC is seeing this erratic rubber band from snowiest decade on record to a snow drought from which they supposedly may never recover?

Long-term temperature trends in the US are very well determined. There are thousands of stations and well proven methods for detecting non-weather-related station changes, heat islands, etc. 1970 was the only start date I had. Yes, warming would be a little less starting from 1950; but, warming would be even larger starting in 1900. Doubt the starting date would have much impact on the relative stance of the midwest,  which is the point I was addressing.

[LibertyBell]

1 hour ago, TheClimateChanger said:

 

 

Not sure I buy that. It looks like a 5-period moving average is near the maximum for 90-degree days at both LGA and EWR, with the LOESS curve predicting the highest value of 90+ days in the POR at both sites. Looks like we are on the precipice of a big upswing in heat. Even a small additional increase in 90+ days would likely push your area outside of historic norms.

Also, as I have noted numerous times, the heat spike from 1986-1995 very likely an artifact of the data collection due to the defective HO-83 sensors in use during that brief era. The increase in 90+ days matches up temporally with the proliferation of HO-83 units. After installation of ASOS, the 90+ days rapidly drop back to pre-1986 levels, from which they have since steadily climbed.

The impact of the HO-83 cannot be dismissed a small bias. It was a substantial bias, the magnitude of which varied by site. At Lincoln, Nebraska, it averaged nearly 2F warmer than the ASOS, although at times, it could be as much as 7F warmer.

See: Central Region Technical Attachment 93-07, Comparison of ASOS and HO83 Temperatures at Lincoln, Nebraska from November 1991 through October 1992, George H. Grosshans, NWS Lincoln (1993).

it goes beyond that, look into the gap in 100 degree highs at JFK, it's been increasing, currently we have set the new record for the longest gap in 100 degree days in station history.  Ever since 1966 the gap has been growing larger.

The oceans do absorb the heat but hopefully that is about to come to an end and JFK will once again get 100 degree days with a shorter gap like we used to before.

The other sign is the complete absence of 7+ day heatwaves since 2002.  These were more common in the 70s, 80s and 90s but we haven't had a 7+ day heatwave in NYC since 2002 (when we had two) and 1999 (when we also had two).

[LibertyBell]

33 minutes ago, PhiEaglesfan712 said:

I really hope not. We're already getting lows in the 80s here in PHL. I can't imagine living through lows of 90 and highs near 110.

I went less humidity but more heat.

[michsnowfreak]

4 hours ago, LibertyBell said:

it goes beyond that, look into the gap in 100 degree highs at JFK, it's been increasing, currently we have set the new record for the longest gap in 100 degree days in station history.  Ever since 1966 the gap has been growing larger.

The oceans do absorb the heat but hopefully that is about to come to an end and JFK will once again get 100 degree days with a shorter gap like we used to before.

The other sign is the complete absence of 7+ day heatwaves since 2002.  These were more common in the 70s, 80s and 90s but we haven't had a 7+ day heatwave in NYC since 2002 (when we had two) and 1999 (when we also had two).

Extreme heat is definitely nothing here like it used to be. More days in the 80s and warmer summer nights increase summer mean temps. So I have a hard time seeing any wild uptick In 90s here either.

[Stormchaserchuck1]

37 minutes ago, michsnowfreak said:

Extreme heat is definitely nothing here like it used to be. More days in the 80s and warmer summer nights increase summer mean temps. So I have a hard time seeing any wild uptick In 90s here either.

I'm surprised that you didn't jump on that 1970-now warming image, since the 1970s were one of the coldest decades