2024-2025 La Nina

[mitchnick]

21 minutes ago, snowman19 said:

Amazing how fast the subsurface warmed and went to a purely CP signature. There’s actually +5 anomalies just below the eastern ENSO regions now….

I think you're looking at last year's map.

[snowman19]

6 minutes ago, mitchnick said:

I think you're looking at last year's map.

Oh jeez you’re right. Must be a glitch this morning, the bottom one is up to date. Still a very CP signature 

[bluewave]

Seems like the -PDO background 500mb and Pacific Jet pattern is continuing to be more impressive than the La Niña with a 600dm ridge east of Japan and 6 sigma jet max north of the Aleutians.
 

[40/70 Benchmark]

On 9/28/2024 at 8:12 AM, PhiEaglesfan712 said:

07-08 is probably the top analog right now. That year, we had just the 2 big storms (Dean and Felix) like we do this year (Beryl and Helene). Also, the la nina development took off right about this time in 2007, and though we will likely not reach the ONI strength of that year, the MEI/RONI are a near perfect match. Not to mention, 07-08 was a central based, modoki la nina. Only thing really going against it was that 07-08 was near a solar minimum, while we are currently near a solar maximum.

22-23 was a dissipating la nina, which is opposite of what we have this year.

2007 is a good analog save for the solar, as you said....but you can probably find faults with most of the ideal solar analogs, as well.

I expect the RONI to end up a bit weaker than 2007.

[jm1220]

45 minutes ago, bluewave said:

Seems like the -PDO background 500mb and Pacific Jet pattern is continuing to be more impressive than the La Niña with a 600dm ridge east of Japan and 6 sigma jet max north of the Aleutians.
 

And another huge ridge building right where we don’t want it. Sigh 

[mitchnick]

1 minute ago, jm1220 said:

And another huge ridge building right where we don’t want it. Sigh 

Don't think we should take too much away for winter from progged weather on 10/3.

[snowman19]

1 hour ago, 40/70 Benchmark said:

2007 is a good analog save for the solar, as you said....but you can probably find faults with most of the ideal solar analogs, as well.

I expect the RONI to end up a bit weaker than 2007.

2007 is way better than some of the other ones floating around social media (83-84, 95-96, 10-11, 13-14, 17-18, 20-21)

[40/70 Benchmark]

1 hour ago, mitchnick said:

Don't think we should take too much away for winter from progged weather on 10/3.

Well, when its been the most prominent feature for half of a decade, I think its a more viable indicator than the average bear.

[snowman19]

6 minutes ago, 40/70 Benchmark said:

Well, when its been the most prominent feature for half of a decade, I think its a more viable indicator than the average bear.

If @bluewave indicators hold, it definitely doesn’t look promising. Weak CP La Niña and the progged weak MJO 4-6 forcing starting around mid-October…..  

[40/70 Benchmark]

4 minutes ago, snowman19 said:

If @bluewave indicators hold, it definitely doesn’t look promising. Weak CP La Niña and the progged weak MJO 4-6 forcing starting around mid-October…..  

La Nina in and of itself isn't a big issue given in its meager intensity, but the larger issue is that persistent background state.

[40/70 Benchmark]

2 hours ago, bluewave said:

Seems like the -PDO background 500mb and Pacific Jet pattern is continuing to be more impressive than the La Niña with a 600dm ridge east of Japan and 6 sigma jet max north of the Aleutians.
 

 

Just now, 40/70 Benchmark said:

La Nina in and of itself isn't a big issue given in its meager intensity, but the larger issue is that persistent background state.

 

[snowman19]

4 minutes ago, 40/70 Benchmark said:

La Nina in and of itself isn't a big issue given in its meager intensity, but the larger issue is that persistent background state.

Correct. Weak Niña aside, @bluewave  found a pretty strong correlation to weak MJO forcing in phases 4-6 in October. As of now, that is what the models are showing happening. Of course, that can change though

[Terpeast]

Worth noting most models take the MJO into 4-6 for October, but differ in strength.

GFS ens goes record strong especially in the second half of the month, while Euro ens keeps it weak or COD. 

 

[jm1220]

4 minutes ago, Terpeast said:

Worth noting most models take the MJO into 4-6 for October, but differ in strength.

GFS ens goes record strong especially in the second half of the month, while Euro ens keeps it weak or COD. 

 

Maybe the record strong if it happens would be the one decent indicator I see for winter, since Bluewave showed how stronger 4-6 in Oct has preceded the better La Niña winter outcomes further south in the East in the last decade. I see nothing else promising-our ACE card looks like it’ll be a cackling Joker, another huge ridge popping east of Japan where we want something, anything to reduce those boiling SSTs, weak central based Nina, on and on. Maybe we can get something to reduce the massive SE ridge but if the PNA is that badly negative it’ll reinforce the big SE ridge. 

[bluewave]

2 hours ago, jm1220 said:

And another huge ridge building right where we don’t want it. Sigh 

That Aleutian Ridge from east of Japan to south of the Aleutians has been the most dominant 500mb height anomaly in the Northern Hemisphere since January. 
 

[mitchnick]

32 minutes ago, 40/70 Benchmark said:

Well, when its been the most prominent feature for half of a decade, I think its a more viable indicator than the average bear.

I agree of it's prominence thanks to the -PDO, but the degree of the ridge breaks down in a couple of days and much can change during the winter months some 3-6 months later imho.

[Terpeast]

28 minutes ago, jm1220 said:

Maybe the record strong if it happens would be the one decent indicator I see for winter, since Bluewave showed how stronger 4-6 in Oct has preceded the better La Niña winter outcomes further south in the East in the last decade. I see nothing else promising-our ACE card looks like it’ll be a cackling Joker, another huge ridge popping east of Japan where we want something, anything to reduce those boiling SSTs, weak central based Nina, on and on. Maybe we can get something to reduce the massive SE ridge but if the PNA is that badly negative it’ll reinforce the big SE ridge. 

Yeah, we basically have nothing else going for us (anyone south of 40n east of the apps). If the MJO flops this month like the euro is saying, we have a fairly high probability of looking at another stinker of a winter like 2022-23 barring a rogue fluke. 

If the MJO pops OTOH, it’ll be a good test of the relationship that bluewave has sniffed out and hopefully we’ll get at least a few weeks of a decent wintry period. 

[michsnowfreak]

1 hour ago, 40/70 Benchmark said:

Well, when its been the most prominent feature for half of a decade, I think its a more viable indicator than the average bear.

I may be misreading or you may be posting in jest, but the recent years Oct/Nov weather has in no way been an indicator of the coming winter.

[40/70 Benchmark]

40 minutes ago, michsnowfreak said:

I may be misreading or you may be posting in jest, but the recent years Oct/Nov weather has in no way been an indicator of the coming winter.

The point that it hasn't been relegated to October. Its been omnipresent.

[BlizzardWx]

At least in terms of observed weather this fall. It's interesting how dry it's been down here. 8th driest September on record at TUL and looks quite dry into at least mid October. Some areas down here have had more rain than the airport, but it was a dry month for sure. Looking at past years with similar levels of dryness, most of them were ENSO neutral years for whatever that is worth. I am unsure how this comparison would hold up over a broader area. 

[mitchnick]

Updated Cansips is out later today or this evening. Let's see if it gives any support to the Cfs2, which continues to keep MW & East north of Virginia with average temps and precip for Dec-Feb.

[PhiEaglesfan712]

1 hour ago, michsnowfreak said:

I may be misreading or you may be posting in jest, but the recent years Oct/Nov weather has in no way been an indicator of the coming winter.

Oddly enough, since 2009-10, the September temperature has been an indicator of whether the upcoming February will be warmer than average, at least here at PHL.

Sep 2009 - 68.0 Feb 2010 - 31.8
Sep 2010 - 72.9 Feb 2011 - 37.2
Sep 2011 - 71.1 Feb 2012 - 40.9
Sep 2012 - 70.3 Feb 2013 - 35.1
Sep 2013 - 67.9 Feb 2014 - 32.1
Sep 2014 - 70.5 Feb 2015 - 25.8
Sep 2015 - 74.5 Feb 2016 - 38.6
Sep 2016 - 73.5 Feb 2017 - 44.2
Sep 2017 - 71.4 Feb 2018 - 41.9
Sep 2018 - 72.5 Feb 2019 - 37.1
Sep 2019 - 72.5 Feb 2020 - 40.8
Sep 2020 - 69.4 Feb 2021 - 34.2
Sep 2021 - 71.6 Feb 2022 - 39.7
Sep 2022 - 72.1 Feb 2023 - 42.7
Sep 2023 - 71.4 Feb 2024 - 40.1

All the sub-71 Septembers (in bold) have produced a below average February. September 2024 is going to end below 71. If the trend continues, February 2025 temperature is going to be below average at PHL.

[michsnowfreak]

35 minutes ago, PhiEaglesfan712 said:

Oddly enough, since 2009-10, the September temperature has been an indicator of whether the upcoming February will be warmer than average, at least here at PHL.

Sep 2009 - 68.0 Feb 2010 - 31.8
Sep 2010 - 72.9 Feb 2011 - 37.2
Sep 2011 - 71.1 Feb 2012 - 40.9
Sep 2012 - 70.3 Feb 2013 - 35.1
Sep 2013 - 67.9 Feb 2014 - 32.1
Sep 2014 - 70.5 Feb 2015 - 25.8
Sep 2015 - 74.5 Feb 2016 - 38.6
Sep 2016 - 73.5 Feb 2017 - 44.2
Sep 2017 - 71.4 Feb 2018 - 41.9
Sep 2018 - 72.5 Feb 2019 - 37.1
Sep 2019 - 72.5 Feb 2020 - 40.8
Sep 2020 - 69.4 Feb 2021 - 34.2
Sep 2021 - 71.6 Feb 2022 - 39.7
Sep 2022 - 72.1 Feb 2023 - 42.7
Sep 2023 - 71.4 Feb 2024 - 40.1

All the sub-71 Septembers (in bold) have produced a below average February. September 2024 is going to end below 71. If the trend continues, February 2025 temperature is going to be below average at PHL.

Very interesting. I wonder if it's a fluke though? I'd have to look into my data further.

[Terpeast]

1 hour ago, PhiEaglesfan712 said:

Oddly enough, since 2009-10, the September temperature has been an indicator of whether the upcoming February will be warmer than average, at least here at PHL.

Sep 2009 - 68.0 Feb 2010 - 31.8
Sep 2010 - 72.9 Feb 2011 - 37.2
Sep 2011 - 71.1 Feb 2012 - 40.9
Sep 2012 - 70.3 Feb 2013 - 35.1
Sep 2013 - 67.9 Feb 2014 - 32.1
Sep 2014 - 70.5 Feb 2015 - 25.8
Sep 2015 - 74.5 Feb 2016 - 38.6
Sep 2016 - 73.5 Feb 2017 - 44.2
Sep 2017 - 71.4 Feb 2018 - 41.9
Sep 2018 - 72.5 Feb 2019 - 37.1
Sep 2019 - 72.5 Feb 2020 - 40.8
Sep 2020 - 69.4 Feb 2021 - 34.2
Sep 2021 - 71.6 Feb 2022 - 39.7
Sep 2022 - 72.1 Feb 2023 - 42.7
Sep 2023 - 71.4 Feb 2024 - 40.1

All the sub-71 Septembers (in bold) have produced a below average February. September 2024 is going to end below 71. If the trend continues, February 2025 temperature is going to be below average at PHL.

Notice it happened more frequently before the monster -pdo/-enso background state after 2015. Since that year, it only happened once. So i’m not sure if this pattern will hold this time. If it does, I think its random chance, like flipping a coin and getting tails 5x in a row and then getting heads on the 6th try. 

But if we DO get a cold February, I’m willing to eat my words and concede that you’re onto something. 

[brooklynwx99]

2020-21 and 2010-11 are pretty good analogs... you don't have to think the winter will be as cold/snowy as those years for them to be viable

they both match up well with ONI, they both have a more hybrid/basin-wide orientation rather than a EP or Modoki event, the PDO was negative (strongly so in 2010-11), and the QBO is a good match as well. solar isn't a good match, but it's not an end-all-be-all for analogs. I feel like it gets overstated a bit, if anything

they have enough similarities to what we'll be seeing for them to be included. those years get evened out when you have winters like 1999-00 and 2022-23 being weighed heavily

[BlizzardWx]

One thing I've had on my mind lately is that it would do all of us well to get the bigger picture of "analogs" and not get bogged down in extraneous details. I think seasonal forecasting skill would increase if we could do more to tie the specific anomalous features of a year to the type and magnitude of forcing they will produce. As a hypothetical example, "If la nina focuses at 150W it would favor a standing ridge at x longitude. But because of the west Pacific Warm pool it may be shifted further west...etc" That at least ties real features to real background forcing, which IMO is all we can really do at a seasonal level. I think if we can consider each individual feature, like throwing pebbles in a pond and seeing where the waves go or intersect, we might get a better idea of how things will constructively or destructively interfere, which forcing will dominate if they are competing, and so on. In borderline snow climates all we can really do is try to figure out if the background state will be reasonably supportive for winter weather or not. 

 

And to be clear, I do see some of you doing what I am saying we should do. I think my broader point is that it's very unlikely you will ever have a truly good analog year, and so although analogs can be useful with context, I think we'd be better off looking at specific pieces of analog years instead of the years as a whole. Anyway, that's my opinion. If I am wrong, that's ok too

 

[Terpeast]

7 minutes ago, BlizzardWx said:

One thing I've had on my mind lately is that it would do all of us well to get the bigger picture of "analogs" and not get bogged down in extraneous details. I think seasonal forecasting skill would increase if we could do more to tie the specific anomalous features of a year to the type and magnitude of forcing they will produce. As a hypothetical example, "If la nina focuses at 150W it would favor a standing ridge at x latitude. But because of the west Pacific Warm pool it may be shifted further west...etc" That at least ties real features to real background forcing, which IMO is all we can really do at a seasonal level. I think if we can consider each individual feature, like throwing pebbles in a pond and seeing where the waves go or intersect, we might get a better idea of how things will constructively or destructively interfere, which forcing will dominate if they are competing, and so on. In borderline snow climates all we can really do is try to figure out if the background state will be reasonably supportive for winter weather or not. 

 

And to be clear, I do see some of you doing what I am saying we should do. I think my broader point is that it's very unlikely you will ever have a truly good analog year, and so although analogs can be useful with context, I think we'd be better off looking at specific pieces of analog years instead of the years as a whole. Anyway, that's my opinion. If I am wrong, that's ok too

 

Agreed. I’m actually experimenting with AI and machine learning to enable this sort of pattern recognition and use that to predict where the main features are going to be on a seasonal time scale.

[BlizzardWx]

2 minutes ago, Terpeast said:

Agreed. I’m actually experimenting with AI and machine learning to enable this sort of pattern recognition and use that to predict where the main features are going to be on a seasonal time scale.

This is excellent news! I really think we as a community will be able to produce significantly better outlooks in the future if we do a better job controlling the noise in analogs. I'm looking forward to seeing what you come up with. 

[GaWx]

1 hour ago, brooklynwx99 said:

2020-21 and 2010-11 are pretty good analogs... you don't have to think the winter will be as cold/snowy as those years for them to be viable

they both match up well with ONI, they both have a more hybrid/basin-wide orientation rather than a EP or Modoki event, the PDO was negative (strongly so in 2010-11), and the QBO is a good match as well. solar isn't a good match, but it's not an end-all-be-all for analogs. I feel like it gets overstated a bit, if anything

they have enough similarities to what we'll be seeing for them to be included. those years get evened out when you have winters like 1999-00 and 2022-23 being weighed heavily

Close Niña orientation and QBO notwithstanding:

1. Dec of 2010 barely missed having the strongest Dec -NAO since 1950 with only 1963 and 2009 slightly stronger. In contrast and though it of course is possible, there’s currently no indication that Dec of 2024 will have a -NAO (sub -0.25) at all. This shows the opposite, a very strong +NAO fwiw:

 

2. With the exact opposite SSN vs 2010, this strong +NAO prog for Dec is very believable.

[brooklynwx99]

22 minutes ago, GaWx said:

Close Niña orientation and QBO notwithstanding:

1. Dec of 2010 barely missed having the strongest Dec -NAO since 1950 with only 1963 and 2009 slightly stronger. In contrast and though it of course is possible, there’s currently no indication that Dec of 2024 will have a -NAO (sub -0.25) at all. This shows the opposite, a very strong +NAO fwiw:

 

2. With the exact opposite SSN vs 2010, this strong +NAO prog for Dec is very believable.

yes, I do not think that there will be -NAO blocking of that magnitude. out of the snowy winter scenarios, 2013-14 with poleward AK ridging makes more sense than 2010-11