2025 ENSO/Winter Speculation

[cleetussnow]

Hold up.  We cancel winter on a 6 month snow map but we toss 5 day snow maps.

Got it.  

[cleetussnow]

On 9/10/2025 at 4:37 PM, FXWX said:

Once again this is wrong that it implies the SST is driving the bus!

Ok the ssts are like footprints.  Something is making the footprints - ssts depicted aren’t derived in a vacuum.  Unless they are and that’s why seasonal models utterly suck.  

[SnowGoose69]

On 9/11/2025 at 10:18 AM, 40/70 Benchmark said:

I think there can start to be some positive feedback, but it's defintely not the primary catalyst. Agreed.

I think maybe like last year we might have lucked out with the -PDO peaking too early.  Its hard to sustain a -3 or 4 from July-August through an entire winter.  Last year it basically bottomed out in October and then it was -1 during the winter.  Could see the same thing happen again though I'd be wary of it not averaging slightly more negative than last winter.

[40/70 Benchmark]

10 hours ago, SnowGoose69 said:

I think maybe like last year we might have lucked out with the -PDO peaking too early.  Its hard to sustain a -3 or 4 from July-August through an entire winter.  Last year it basically bottomed out in October and then it was -1 during the winter.  Could see the same thing happen again though I'd be wary of it not averaging slightly more negative than last winter.

I think that is a given.

[Snowcrazed71]

So... As we start to see all the " Hype factor " for this upcoming Winter.... A new one just popped up. It's the CFS model and it shows very cold air for December, January, and February for much of the Central and Eastern US. I'm just not sure if that is a reliable model or not ( at least compared to the other Global models ). 

[40/70 Benchmark]

20 hours ago, Snowcrazed71 said:

So... As we start to see all the " Hype factor " for this upcoming Winter.... A new one just popped up. It's the CFS model and it shows very cold air for December, January, and February for much of the Central and Eastern US. I'm just not sure if that is a reliable model or not ( at least compared to the other Global models ). 

I don't think it's means much in the sense that it will nail the forecast per se, as the CFS is really only useful anout a month out; however, it is very notable because the model is usually warm in the winter.

[40/70 Benchmark]

CFS for December:

[40/70 Benchmark]

Not that this is right per se, because it probably isn't....but I'm not sure folks appreciate just how cold this is given the 1984-2009 climo base. If I were planning to copy and paste a composite of the past ten winters as some often muse, this would give me pause.

[40/70 Benchmark]

Looks to be a severe -WPO/EPO.....somewhat +PNA and a modestly -NAO/AO. PNA and especially AO are iffy...

[weathafella]

Looks like the Nina is minoring out.  Also, negative anomalies are no longer east based.  Hard to tell but this appears to be the trend over the past few weeks.  Gun to head I’d hedge normal in temperatures and snow for the winter.  For a lot of sne, that’s going to feel snowy since the past few winters have been paltry snow wise.

[Typhoon Tip]

6 hours ago, 40/70 Benchmark said:

Not that this is right per se, because it probably isn't....but I'm not sure folks appreciate just how cold this is given the 1984-2009 climo base. If I were planning to copy and paste a composite of the past ten winters as some often muse, this would give me pause.

What are we looking at here?  (there's no headers on this image -)

anyway, this also reflects higher latitude blocking. 

[40/70 Benchmark]

4 minutes ago, Typhoon Tip said:

What are we looking at here?  (there's no headers on this image -)

anyway, this also reflects higher latitude blocking. 

Sorry, had to do a screenshot or this site drives me nuts over the size.

CFS 2m temp anomaly forecast for JFM.

[Typhoon Tip]

22 minutes ago, 40/70 Benchmark said:

Sorry, had to do a screenshot or this site drives me nuts over the size.

CFS 2m temp anomaly forecast for JFM.

word.  thanks. 

not really much of a cfs user but ...  I'd have thought that'd be more first half tendency

 

[stadiumwave]

On 9/16/2025 at 11:44 AM, weathafella said:

Looks like the Nina is minoring out.  Also, negative anomalies are no longer east based.  Hard to tell but this appears to be the trend over the past few weeks.  Gun to head I’d hedge normal in temperatures and snow for the winter.  For a lot of sne, that’s going to feel snowy since the past few winters have been paltry snow wise.

Are you sure about that? Looks clearly east.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/wkxzteq.shtml

 

[Typhoon Tip]

ENSO isn't truly neutral ... it's more like quasi negative, fw little iw ... biased in regions < 3.4. 

The problem is, regardless of that, the surrounding atmosphere is so expanded beyond there's no geophysical triggers to force a pattern evolution because of that.  It's like a chick moving around inside an eggshell - the outside world doesn't know that is happening.

That won't ( likely...) characterize the winter ahead, of course.  But for the time being, the intraseasonal variance may see wondering into a quasi positive or negative ( probably favoring the latter this time...), and it won't mean a darn thing to the hemisphere.  Not until the seasonal compression of the hemisphere quickens the geopotential height medium --> increasing basal winds, and that's when the planetary wave tendencies/feedbacks are forced/exposed.  In fact, this may transitively then feedback and force a more coherent tendency with the ENSO, one way or the other ...

Anyway, that's probably ... I dunno, later October+ but more so by Thanks Giggedy.  And that may not really turn out to be the winter hemisphere.  Some > 50% of the time, yes, there is some vestigial usefulness in identifying - usually through - the nonlinear observations of "lurking" tendencies during those early seasonal flavors...  It's your chance to be artful..

The other aspect - as I wonder into a seasonal outlook tendency I did not mean to ... - is that it's been papered by other sources that jet meanders are becoming more common, particularly during the shoulder seasons.  It's why I suspect that we may observe some blocking tendencies in the AO(WPO/EPO/NAO) between the late Oct - Xmas time.. 

But I grow increasingly confident with each passing year that the winter hemisphere might be forever changed - it seems regardless of all leading indicator methods, we seem to wend our way into a version of:  This may obliterate, however ...as the machinery of deep winter takes over with its (probable) repeat performance of > normal gradient everywhere and basal flow velocities hurried along, that disturbs resonance feedbacks and patterns have difficulties establishing...  That means we may have problem locking in either cold or warm, in lieu rapid variance ( relatively...).  10 day winter pops followed by 53 F streaks kind of thing.  That's also sloppy description of the last several winters, frankly, which seem to have become a leitmotif. 

[40/70 Benchmark]

2 hours ago, Typhoon Tip said:

ENSO isn't truly neutral ... it's more like quasi negative, fw little iw ... biased in regions < 3.4. 

The problem is, regardless of that, the surrounding atmosphere is so expanded beyond there's no geophysical triggers to force a pattern evolution because of that.  It's like a chick moving around inside an eggshell - the outside world doesn't know that is happening.

That won't ( likely...) characterize the winter ahead, of course.  But for the time being, the intraseasonal variance may see wondering into a quasi positive or negative ( probably favoring the latter this time...), and it won't mean a darn thing to the hemisphere.  Not until the seasonal compression of the hemisphere quickens the geopotential height medium --> increasing basal winds, and that's when the planetary wave tendencies/feedbacks are forced/exposed.  In fact, this may transitively then feedback and force a more coherent tendency with the ENSO, one way or the other ...

Anyway, that's probably ... I dunno, later October+ but more so by Thanks Giggedy.  And that may not really turn out to be the winter hemisphere.  Some > 50% of the time, yes, there is some vestigial usefulness in identifying - usually through - the nonlinear observations of "lurking" tendencies during those early seasonal flavors...  It's your chance to be artful..

The other aspect - as I wonder into a seasonal outlook tendency I did not mean to ... - is that it's been papered by other sources that jet meanders are becoming more common, particularly during the shoulder seasons.  It's why I suspect that we may observe some blocking tendencies in the AO(WPO/EPO/NAO) between the late Oct - Xmas time.. 

But I grow increasingly confident with each passing year that the winter hemisphere might be forever changed - it seems regardless of all leading indicator methods, we seem to wend our way into a version of:  This may obliterate, however ...as the machinery of deep winter takes over with its (probable) repeat performance of > normal gradient everywhere and basal flow velocities hurried along, that disturbs resonance feedbacks and patterns have difficulties establishing...  That means we may have problem locking in either cold or warm, in lieu rapid variance ( relatively...).  10 day winter pops followed by 53 F streaks kind of thing.  That's also sloppy description of the last several winters, frankly, which seem to have become a leitmotif. 

I think the opposite is true for La Nina....which is what the RONI reflects. The surrounding atmosphere is more of an impediment for the expression of warm ENSO.

[Typhoon Tip]

1 hour ago, 40/70 Benchmark said:

I think the opposite is true for La Nina....which is what the RONI reflects. The surrounding atmosphere is more of an impediment for the expression of warm ENSO.

I'm aware of that but .. I don't believe they have that right.

The ENSO and the La Nina apparent fingerprint is coincidental in that sense - not being forced by the ENSO state/thermal distribution as it terminates into the westerlies.  It just so happens to be that in the absence of either, there is a feeble ONI that encourages upwelling over the eastern Pac but it doesn't really reflect a La Nina. 

Makes it exceedingly difficult to parse the two apart, sure.. because the expanding HC and the break down of that device/organized circulation machinery, lends to a residual SS stressing that orients E --> W

In other words, the correlation is too linear.

[40/70 Benchmark]

37 minutes ago, Typhoon Tip said:

I'm aware of that but .. I don't believe they have that right.

The ENSO and the La Nina apparent fingerprint is coincidental in that sense - not being forced by the ENSO state/thermal distribution as it terminates into the westerlies.  It just so happens to be that in the absence of either, there is a feeble ONI that encourages upwelling over the eastern Pac but it doesn't really reflect a La Nina. 

Makes it exceedingly difficult to parse the two apart, sure.. because the expanding HC and the break down of that device/organized circulation machinery, lends to a residual SS stressing that orients E --> W

In other words, the correlation is too linear.

Yes, right....the western warm pool incites convective action over the MC, which mimics cool ENSO. 

No argument there....all I was saying is that it's easier to get a cool ENSO like expression than it is warm ENSO....but we require a stronger ENSO signal for it to be the primary catalyst these days, yes.