Winter 2024-25 Discussion/Speculation

[Bob Chill]

52 minutes ago, brooklynwx99 said:

i can definitely see that happening. there are reasons to believe this could actually be a decent to good winter. 2013-14, 2020-21, and 2021-22 are all good analogs

i just don't think anyone has the balls (including myself personally or professionally) to actually pull the trigger. better to go conservative in this -PDO regime and bust low

Considering enso, climo, and recent pac jet history... oh boy is it easy to jump to doomclusions lol. I never really felt that this fall. Just gut stuff but I've watched enough unfold over the last 20 years to trust my intuition algorithm. Now that we're deep into fall, my conscious mind likes what it sees. 

Like I said some weeks back, my gut is yelling that this winter will have its highlights that will put it ahead of the last couple years. Warm periods will almost certainly include some form of an annoying SER. But i really doubt it will be a statue. HL blocking has been flexing on and off quite a bit last few months. No reason to think that goes poof.... yet.... lol

[DarkSharkWX]

3 hours ago, WxUSAF said:

CWG winter forecast is out and it’s shockingly bullish. Near normal temps and median to mean snowfall. 

2013-14, 2012-13, 2005-06, 1961-62 are their top analogs

probably leaning towards +TNH winter instead of canonical Nina bc of the persistent warm pool in the tropical wpac at ~160E

+TNH winters also tend to break the mold of typical Nina winters which are usually frontloaded, and have a colder jan-feb than dec, which is what they went with

[bncho]

3 hours ago, WxUSAF said:

CWG winter forecast is out and it’s shockingly bullish. Near normal temps and median to mean snowfall. 

pray to god lmfao

 

but then again wusa9 is pretty bullish as well 

[40/70 Benchmark]

1 hour ago, DarkSharkWX said:

2013-14, 2012-13, 2005-06, 1961-62 are their top analogs

probably leaning towards +TNH winter instead of canonical Nina bc of the persistent warm pool in the tropical wpac at ~160E

+TNH winters also tend to break the mold of typical Nina winters which are usually frontloaded, and have a colder jan-feb than dec, which is what they went with

Yea, I honed in on that...here is in excerpt from my outook:

Western & Northern Pacific May Be Crucial for Winter 2024-2025

The winter pattern over the northern and western Pacific will play an instrumental role in dictating what type of variation is seen from the predominate MC forcing this winter season, especially since La Nina appears poised to assume a secondary role this year. Meteorologist Eric Webb has posited that an area of anomalously warm SSTs over the tropical Pacific in the vicinity of 150-160 degrees east longitude may be a reasonably skilled indicator with respect to the WPO during the ensuing winter season.

 

 

 The theory essentially is that anomalous sea surface warmth in the vicinity of 150-160 degrees East longitude in the tropical Pacific increases convection and convergence near the surface, which leads to negative outgoing long wave radiation (OLR) anomalies aloft, or divergence and sinking air. If this persists into the winter season, it correlates to the opposite pattern over the higher latitudes in the area of the Bering sea, which means sinking air and ridging at the surface in this area. This would obviously yield a -WPO pattern in the DM seasonal mean.

 

 

 

 

As a point of reference, here is the October SST anomaly profile in this area prior to the strongly negative DM period of 2013-2014.

 

 

And the resultant DM pattern.

 

 

Here is the October 2020 SST pattern preceding the strongly positive 2020-2021 season, which is the most prominent +WPO member of the variation data set.

 

 

Note the pronounced +WPO despite the variation within the PNA and polar domains that allowed for a prolonged early to mid season wintry interlude over the northeast.

 

Here are the October 2017 SST anomalies that preceded the more moderately +WPO winter of 2017-2018.

 

The WPO did not provide a particularly strong signal that season and the warmth over the east was subdued by the EPO/NAO blocking in tandem with +PNA.

 

 

Here is the October SST anomaly pattern that yielded a -WPO/+PNA reprieve from the predominate MC forcing during the 2021-2022 winter season.

 

 

And the resultant pattern that led to a noteworthy wintry interlude mid season in the absence of high latitude blocking over Greenland or the Arctic.

 

 

Here is the SST anomaly pattern from October 2022 that preceded the strongly positive WPO winter of 2022-2023.

 

 

The strong polar blocking in March was insufficient to overcome a hostile Pacific for the east coast, which was largely left unscathed, at least in terms of snowfall, by a stormy beginning and end to the season.

 

 

Finally, here is the SST anomaly chart from October 2024.

 

 

The SST anomaly profile this year most closely resembles that of the severely negative WPO seasons of 2013-2014 and 2021-2022. 

 

 

Considering this composite match, the forecast for the DM mean WPO value is within the range of -.40 to -.70, and given the strong tendency for +EPO among the cool ENSO deviation dataset, the JM EPO is predicted to register anywhere within a range of .30 to .60. This is anticipated as being the primary distinction between the coming season and 2013-2014, which also featured a severely negative JM mean EPO value of -.89, and was thus very cold relative to the modern climate. 

 

 

For the sake of perspective, a comparison between the North Pacific SST anomaly pattern in the Gulf of Alaska during October 2014 and 2011 are provided; each preceding contrasting extreme variations of the seasonal EPO pattern.

 

 

 

Note that while clearly October of 2024 represents a compromise that is as extreme as either depiction, it does more closely resemble the warmer, October 2011 anomaly, suggestive of a more moderately +EPO seasonal mean during the coming winter.

 

 

 

Lending credence to this forecast for a predominately +EPO/-WPO during the coming winter season is the subgroup of older extra Pacific analogs, including 1973, and 1974, which are uncoincidentally from the secondary PDO nadir just prior to the end of the previous Pacific cold phase, as well as 1954, 1955, 1970, 1971, 1999, 2007 and 2010.

 

 

This general idea has support from some seasonal guidance, granted it manifests differently with a more exaggerated southeast ridge during this modern era.

 

 

[DarkSharkWX]

33 minutes ago, 40/70 Benchmark said:

Yea, I honed in on that...here is in excerpt from my outook:

Western & Northern Pacific May Be Crucial for Winter 2024-2025

The winter pattern over the northern and western Pacific will play an instrumental role in dictating what type of variation is seen from the predominate MC forcing this winter season, especially since La Nina appears poised to assume a secondary role this year. Meteorologist Eric Webb has posited that an area of anomalously warm SSTs over the tropical Pacific in the vicinity of 150-160 degrees east longitude may be a reasonably skilled indicator with respect to the WPO during the ensuing winter season.

 

 

 The theory essentially is that anomalous sea surface warmth in the vicinity of 150-160 degrees East longitude in the tropical Pacific increases convection and convergence near the surface, which leads to negative outgoing long wave radiation (OLR) anomalies aloft, or divergence and sinking air. If this persists into the winter season, it correlates to the opposite pattern over the higher latitudes in the area of the Bering sea, which means sinking air and ridging at the surface in this area. This would obviously yield a -WPO pattern in the DM seasonal mean.

 

 

 

 

As a point of reference, here is the October SST anomaly profile in this area prior to the strongly negative DM period of 2013-2014.

 

 

And the resultant DM pattern.

 

 

Here is the October 2020 SST pattern preceding the strongly positive 2020-2021 season, which is the most prominent +WPO member of the variation data set.

 

 

Note the pronounced +WPO despite the variation within the PNA and polar domains that allowed for a prolonged early to mid season wintry interlude over the northeast.

 

Here are the October 2017 SST anomalies that preceded the more moderately +WPO winter of 2017-2018.

 

The WPO did not provide a particularly strong signal that season and the warmth over the east was subdued by the EPO/NAO blocking in tandem with +PNA.

 

 

Here is the October SST anomaly pattern that yielded a -WPO/+PNA reprieve from the predominate MC forcing during the 2021-2022 winter season.

 

 

And the resultant pattern that led to a noteworthy wintry interlude mid season in the absence of high latitude blocking over Greenland or the Arctic.

 

 

Here is the SST anomaly pattern from October 2022 that preceded the strongly positive WPO winter of 2022-2023.

 

 

The strong polar blocking in March was insufficient to overcome a hostile Pacific for the east coast, which was largely left unscathed, at least in terms of snowfall, by a stormy beginning and end to the season.

 

 

Finally, here is the SST anomaly chart from October 2024.

 

 

The SST anomaly profile this year most closely resembles that of the severely negative WPO seasons of 2013-2014 and 2021-2022. 

 

 

Considering this composite match, the forecast for the DM mean WPO value is within the range of -.40 to -.70, and given the strong tendency for +EPO among the cool ENSO deviation dataset, the JM EPO is predicted to register anywhere within a range of .30 to .60. This is anticipated as being the primary distinction between the coming season and 2013-2014, which also featured a severely negative JM mean EPO value of -.89, and was thus very cold relative to the modern climate. 

 

 

 

For the sake of perspective, a comparison between the North Pacific SST anomaly pattern in the Gulf of Alaska during October 2014 and 2011 are provided; each preceding contrasting extreme variations of the seasonal EPO pattern.

 

 

 

Note that while clearly October of 2024 represents a compromise that is as extreme as either depiction, it does more closely resemble the warmer, October 2011 anomaly, suggestive of a more moderately +EPO seasonal mean during the 

 

 

Lending credence to this forecast for a predominately +EPO/-WPO during the coming winter season is the subgroup of older extra Pacific analogs, including 1973, and 1974, which are uncoincidentally from the secondary PDO nadir just prior to the end of the previous Pacific cold phase, as well as 1954, 1955, 1970, 1971, 1999, 2007 and 2010.

 

 

This general idea has support from some seasonal guidance, granted it manifests differently with a more exaggerated southeast ridge during this modern era.

 

 

where do you get that website and the one you used to show the level of the warm pool, psl monthly only lets me put in 20 years

[40/70 Benchmark]

2 minutes ago, DarkSharkWX said:

where do you get that website and the one you used to show the level of the warm pool, psl monthly only lets me put in 20 years

Subsurface: https://www.pmel.noaa.gov/tao/drupal/disdel/

Coralreef: https://www.pmel.noaa.gov/tao/drupal/disdel/

[scope1]

On 11/11/2024 at 6:56 PM, 87storms said:

Kammerer went a little below average, but respectable snow totals for a La Niña.

He hit the nail on the head winter 22-23 he predicted pretty much a shutout and that’s exactly what happened. 

[WEATHER53]

7 hours ago, Bob Chill said:

Considering enso, climo, and recent pac jet history... oh boy is it easy to jump to doomclusions lol. I never really felt that this fall. Just gut stuff but I've watched enough unfold over the last 20 years to trust my intuition algorithm. Now that we're deep into fall, my conscious mind likes what it sees. 

Like I said some weeks back, my gut is yelling that this winter will have its highlights that will put it ahead of the last couple years. Warm periods will almost certainly include some form of an annoying SER. But i really doubt it will be a statue. HL blocking has been flexing on and off quite a bit last few months. No reason to think that goes poof.... yet.... lol

I agree it will be a bit better than last year which was better than year before 

it’s going to be two days normal, 3-4 days above to well above, 2 very cold and quickly back to normal for day 3. 

[brooklynwx99]

 

[Chris78]

15 hours ago, WxUSAF said:

CWG winter forecast is out and it’s shockingly bullish. Near normal temps and median to mean snowfall. 

21 to 42 inches for the far western burbs lol. I'd be tickled with that.

Seems very very bullish.

[Roger Smith]

I posted in NYC discussion that a similar dry spell (to 2024) in Oct-Nov 1924 was followed by a winter where almost all the snow (93%) fell in Jan which had a few severe cold spells (record low Jan 28) and that Feb 1925 was mild. 

Anyway, my winter forecast is along similar lines to discussion above, mixed temperatures, storm track often a bit north of this region, but wit variations so some opportunities for snow. I have predicted 13 to 19 inches at local airports in contest, and 6.5" RIC. 

It may be a gangbusters winter for parts of central plains, midwest, lower lakes and inland n.e., so when that happens this region is not likely to be shut out entirely. 

 

[stormy]

The CPC drops from 71% in September to 57% now regarding a La Nina dominated winter.

[CAPE]

Just a reminder- weak La Ninas historically almost always feature below average snowfall for the MA. Seems a weak event is most likely at this juncture.

[87storms]

On 11/13/2024 at 4:56 PM, scope1 said:

He hit the nail on the head winter 22-23 he predicted pretty much a shutout and that’s exactly what happened. 

Yea, that was a legendary forecast. I have a difficult time envisioning much snowfall this year given the pattern leading in, but it’s also not that difficult to hit average here, so who knows.

[CAPE]

Long term avg snowfall here is 18.5. I never expect that(anymore), although exceeded it in 2022- right around 20". So it is still possible.

10-15" would be a really good outcome for my yard this winter given what we know going in(probably a weak event, solar, QBO) and gleaning some hints from the long range/seasonal guidance. Wildcard imo is a favorable EPO/WPO for an extended period. A little over 10" was it for the super awesome el Nino of last winter lol. Nina winters have generally yielded more snow here since 2015.

[psuhoffman]

I've been super swamped with work and still am, I will try to do a full write up soon...but since I don't have time right now I figured I would at least share my top analogs.  I set up the criteria a while ago and have been updating the data as it comes in month to month.  This is probably the last update so these are it.

Top analogs

1:2012-13   

2:2001-02     

3:2022-23

4:2008-09

5: 2020-21

Adjusted weighted predicted snowfall 

BWI: 5.9"

IAD: 6.9"

DCA: 3.7"

Quick thoughts... I set up the parameters I will use to identify analogs and the methodology to weight snowfall months ahead of time to avoid any bias. After last years utter failure I did revamp my process some and did historical testing to verify the new methodology is sound.  It was better but as is any long range predictive process it's not perfect.  Mainly because using the data available in the fall is not always indicative since things can flip quickly sometimes.  For example:  if the PDO were to start going through a larger scale phase switch in the next month or two it would bring 2014 into play as a possible analog.  I don't see that right now though.   I hope I am as wrong this year as I was last!  

[CAPE]

38 minutes ago, psuhoffman said:

I've been super swamped with work and still am, I will try to do a full write up soon...but since I don't have time right now I figured I would at least share my top analogs.  I set up the criteria a while ago and have been updating the data as it comes in month to month.  This is probably the last update so these are it.

Top analogs

1:2012-13   

2:2001-02     

3:2022-23

4:2008-09

5: 2020-21

Adjusted weighted predicted snowfall 

BWI: 5.9"

IAD: 6.9"

DCA: 3.7"

Quick thoughts... I set up the parameters I will use to identify analogs and the methodology to weight snowfall months ahead of time to avoid any bias. After last years utter failure I did revamp my process some and did historical testing to verify the new methodology is sound.  It was better but as is any long range predictive process it's not perfect.  Mainly because using the data available in the fall is not always indicative since things can flip quickly sometimes.  For example:  if the PDO were to start going through a larger scale phase switch in the next month or two it would bring 2014 into play as a possible analog.  I don't see that right now though.   I hope I am as wrong this year as I was last!  

Hard to argue the predicted snowfall tallies, but the PDO has been hostile for awhile, and we have managed several decent snowfall winters in that timeframe. The bigger issue to me is weak Ninas consistently produce below normal snowfall in our region. I think all of them have for the DC area.

[PrinceFrederickWx]

I just can’t see us ever getting 2013/14 again; I would argue that was far more rare than even 2009/10. 

[Jebman]

1 hour ago, CAPE said:

Hard to argue the predicted snowfall tallies, but the PDO has been hostile for awhile, and we have managed several decent snowfall winters in that timeframe. The bigger issue to me is weak Ninas consistently produce below normal snowfall in our region. I think all of them have for the DC area.

Yeah, I found that one out when I used to live there. 

It is why I have been predicting average snow tallies from my armchair weather weenie service lol.

[bncho]

7 hours ago, stormy said:

The CPC drops from 71% in September to 57% now regarding a La Nina dominated winter.

2024-2025 La Nina ❌
2024-2025 Cold-Neutral✅

[Jebman]

31 minutes ago, PrinceFrederickWx said:

I just can’t see us ever getting 2013/14 again; I would argue that was far more rare than even 2009/10. 

Getting another 2013-14 in the Washington Metro Region would be like winning 3.7 billion in the Mega Millions.

[87storms]

I just can’t see us ever getting 2013/14 again; I would argue that was far more rare than even 2009/10. 

2013-15 was uncommon, that’s for sure.

[psuhoffman]

2 hours ago, CAPE said:

Hard to argue the predicted snowfall tallies, but the PDO has been hostile for awhile, and we have managed several decent snowfall winters in that timeframe. The bigger issue to me is weak Ninas consistently produce below normal snowfall in our region. I think all of them have for the DC area.

2022 but the QBO was opposite that year. Also pattern analysis would indicate we might have got lucky some that year. There was a rather small snow max wrt mean right over some parts of our area.  We totally maxed out potential, ate all the meat off that bone, and it was still below avg across most of the area  

But the strength of the Nina and the QBO make that a bad analog anyways.  2018 was really before the PDO went super negative.  We got a little unlucky that we got 3 relatively meh snowfall years 2017-2019 right before we entered a historically awful PDO cycle that slammed the door on our chances of a big snowfall winter for a while.  The past few examples of similar PDO patterns were bookended by some blockbuster winters.  This time we entered a bad phase already in a snow drought.  That’s some bad luck maybe.  
 

But I could be wrong about how I identified analog years.  

 

[CAPE]

2 hours ago, PrinceFrederickWx said:

I just can’t see us ever getting 2013/14 again; I would argue that was far more rare than even 2009/10. 

Something similar to that pattern is probably our best chance to get enough cold to end up with normal / above normal snow this winter.

[psuhoffman]

23 minutes ago, CAPE said:

Something similar to that pattern is probably our best chance to get enough cold to end up with normal / above normal snow this winter.

I think we do see some periods similar. Some of my analogs features some colder periods. 2009 and 2013. But I doubt it locks in all winter like 2014. Also, most comparable patterns to 2014 don’t go as well to the same extreme. That’s another year where we outperformed the pattern some imo.