2024-2025 La Nina

[Daniel Boone]

1 hour ago, GaWx said:

Don/others,

 Compare this to WxBell’s 10 day avg for DJF (see image below)(apples to apples): WxBell is significantly too cold in the E 2/3 of the US! In the NE for example, WxBell averages ~-1C/-1.8F vs CPC’s ~+0.75C/+1.35F. So, WB is ~3F too cold! Another ex: Atlanta is ~2F too cold on WB. This is further proof that WB CFS maps tend to be significantly too cold in the E US.

 In addition note once again on the WB CFS map that everpresent cold spot in S Lake Michigan and warm spot just 250 miles N in N Lake Michigan/N Michigan:

 

**Edit: Also, WB’s climo base is 1981-2010, which would make their maps even warmer than going against 1991-2020. In other words, if WB were to change the climo to 1991-2020, their maps would be even colder. So, WxBell may actually even be further off vs CPC than what I stated above!

Conspiracy Theory Larry ??

[Daniel Boone]

5 hours ago, donsutherland1 said:

The recent runs of the CFSv2 have grown warmer for December 2024-February 2025. It is uncertain whether this is a temporary development or the evolution of what will become a warmer winter forecast.

From 10/1-10:

From 10/11-20:

Adjusting to the probable likely outcome.

[GaWx]

1 hour ago, Daniel Boone said:

Conspiracy Theory Larry ??

 I’m currently leaning against it being intentional as my nature is to give the benefit of the doubt initially. It is hard for me to believe they’d do this on purpose when it is so easy for anyone to compare to other sources of CFS output. So, I’m still thinking unintentionally badly flawed company algorithms. But the longer this goes on without fixing it, the more I start to wonder somewhat since colder E US sells in winter. And shouldn’t they have at least noticed that cold spot in S Lake Michigan and warm spot in N Lake Michigan that almost always show up by now?

 Is it possible they (including JB) still have no idea that their CFS maps differ so much? I say it’s possible because they may never look at other CFS output. But what about those everpresent cold/warm spots? If they really still don’t know now and they later figure it out, would they then be honest and fix the algos or ditch their versions?

[mitchnick]

19 minutes ago, GaWx said:

 I’m currently leaning against it being intentional as my nature is to give the benefit of the doubt initially. It is hard for me to believe they’d do this on purpose when it is so easy for anyone to compare to other sources of CFS output. So, I’m still thinking unintentionally badly flawed company algorithms. But the longer this goes on without fixing it, the more I start to wonder somewhat since colder E US sells in winter. And shouldn’t they have at least noticed that cold spot in S Lake Michigan and warm spot in N Lake Michigan that almost always show up by now?

 Is it possible they (including JB) still have no idea that their CFS maps differ so much? I say it’s possible because they may never look at other CFS output. But what about those everpresent cold/warm spots? If they really still don’t know now and they later figure it out, would they then be honest and fix the algos or ditch their versions?

I believe it was @brooklynwx99 that posted WB is the Control run of the Cfs2. I believe what you posted is the Control run because it has the "(C)" after the words "CFS Monthly" top, left.

I could be wrong, of course. Lol

[GaWx]

33 minutes ago, mitchnick said:

I believe it was @brooklynwx99 that posted WB is the Control run of the Cfs2. I believe what you posted is the Control run because it has the "(C)" after the words "CFS Monthly" top, left.

I could be wrong, of course. Lol

1. Brooklyn was also warning me and others about comparing single runs vs multi runs. The only WB CFS maps that go out through Feb (all of DJF) are control runs. Also, when JB shows winter CFS, they are always control runs.

2. The only multi run CFS maps WB has are control runs.

3. The WB CFS mean of 10 days of runs I showed earlier was a mean of control runs. That’s all they have for DJF.

4. Check this out: mean of 30 days of control runs for DJF: look how cold it is! 30 days! This is absurd! Their CFS mean is about always too cold in the E US along with having the Lake Michigan nonsense.

[Terpeast]

23 minutes ago, mitchnick said:

I believe it was @brooklynwx99 that posted WB is the Control run of the Cfs2. I believe what you posted is the Control run because it has the "(C)" after the words "CFS Monthly" top, left.

I could be wrong, of course. Lol

Even when looking at the control run, it still doesn't look right. I think it's something that's gone a bit haywire. As far as whether or not it's intentional, I'm not going there. I'll just use other maps.

[MJO812]

https://x.com/webberweather/status/1848506703542948155?t=yKnUAfpu7hvNuFwibnBbjA&s=19

[snowman19]

Westerly anomalies behind a fast moving MJO wave is not going to result in a full scale shift of the Indo-Pacific warm pool. You would need STRONG, sustained, honest to goodness WWBs (i.e. El Niño) to do that. We are obviously not getting an El Niño this winter or even a warm-La Nada. All that’s going to happen (and is being shown) is transient, temporary westerly anomalies behind MJO wave convection, not true WWBs. This is not even going to be close to a true trade wind reversal/WWB event, like not even in the ballpark. Webb clearly eludes to this if you read the entirety of his tweet. Once the MJO goes back to the eastern IO and Maritime Continent, phases 4-6, which is what the models are showing, EWBs and cooling is going to start anew. The MEI, RONI, PDO, IOD, PMM and SOI are all deep into La Niña mode. All one has to do is look at the global long wave circulation and OLR over the last several months till now to see that the atmosphere is very clearly into a La Niña state. And the subsurface under region 3.4 is still cold

[40/70 Benchmark]

1 hour ago, snowman19 said:

Westerly anomalies behind a fast moving MJO wave is not going to result in a full scale shift of the Indo-Pacific warm pool. You would STRONG, sustained, honest to goodness WWBs (i.e. El Niño) to do that. We are obviously not getting an El Niño this winter or even a warm-La Nada. All that’s going to happen (and is being shown) is transient, temporary westerly anomalies behind MJO wave convection, not true WWBs. This is not even going to be close to a true trade wind reversal/WWB event, like not even in the ballpark. Webb clearly eludes to this if you read the entirety of his tweet. Once the MJO goes back to the eastern IO and Maritime Continent, phases 4-6, which is what the models are showing, EWBs and cooling is going to start anew. The MEI, RONI, PDO, IOD, PMM and SOI are all deep into La Niña mode. All one has to do is look at the global long wave circulation and OLR over the last several months till now to see that the atmosphere is very clearly into a La Niña state. And the subsurface under region 3.4 is still cold

La Nina should be peaking on the weeklies here within the next few weeks, regardless...probably at about 1.1 or 1.2. 

I think bursts like this could potentially start a longer term shift, which is long overdue, however, it won't matter for this season. I agree with you there.

[bluewave]

The big modeling story this month is how much stronger the +EPO was than originally forecast by the Euro back in September. We may need to monitor this for the winter forecast since it could have a warmer influence than the Euro winter forecast is indicating. This is not something winter fans would like to see since we really haven’t had a +EPO dominant La Niña since 11-12, 99-00, and 98-99.

Euro forecast for October

 

Much stronger +EPO than forecast 

 

[snowman19]

9 minutes ago, bluewave said:

The big modeling story this month is how much stronger the +EPO was than originally forecast by the Euro back in September. We may need to monitor this for the winter forecast since it could have a warmer influence than the Euro winter forecast is indicating. This is not something winter fans would like to see since we really haven’t had a +EPO dominant La Niña since 11-12, 99-00, and 98-99.

Euro forecast for October

 

Much stronger +EPO than forecast 

 

The Euro suite has been underestimating +EPO’s and showing huge -EPO ridges over AK that never actually happen for several years now. The beat goes on

[jm1220]

3 minutes ago, snowman19 said:

The Euro suite has been underestimating +EPO’s and showing huge -EPO ridges over AK that never actually happen for several years now. The beat goes on

When Alaska’s colder than average, the East roasts. That’s a pretty good rule to follow. 

[40/70 Benchmark]

30 minutes ago, bluewave said:

The big modeling story this month is how much stronger the +EPO was than originally forecast by the Euro back in September. We may need to monitor this for the winter forecast since it could have a warmer influence than the Euro winter forecast is indicating. This is not something winter fans would like to see since we really haven’t had a +EPO dominant La Niña since 11-12, 99-00, and 98-99.

Euro forecast for October

 

Much stronger +EPO than forecast 

 

1999-2000 is one of the better analogs. I think this pattern would have been warmer relative to normal for the northeast during the winter due to wavelengths.
 

Thankfully, October doesn't have much of a coorelation to winter.

[GaWx]

20 minutes ago, bluewave said:

The big modeling story this month is how much stronger the +EPO was than originally forecast by the Euro back in September. We may need to monitor this for the winter forecast since it could have a warmer influence than the Euro winter forecast is indicating. This is not something winter fans would like to see since we really haven’t had a +EPO dominant La Niña since 11-12, 99-00, and 98-99.

Euro forecast for October

 

Much stronger +EPO than forecast 

 

However, Sep-Nov of 2021 had a solid +EPO similar to Sep-Oct of 2024 and the winter of 21-2 ended up with a neutral EPO fwiw.

[GaWx]

1 hour ago, bluewave said:

The big modeling story this month is how much stronger the +EPO was than originally forecast by the Euro back in September. We may need to monitor this for the winter forecast since it could have a warmer influence than the Euro winter forecast is indicating. This is not something winter fans would like to see since we really haven’t had a +EPO dominant La Niña since 11-12, 99-00, and 98-99.

Euro forecast for October

 

Much stronger +EPO than forecast 

 

What about 2020-1? It was an +EPO dominant La Niña: it had 47 +EPO, 32 neutral EPO, and only 11 -EPO days. DJF had an avg daily EPO way up at +60, a solid +EPO avg for a 90 day period:

https://downloads.psl.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt

Edit: Also, what about 2007-8? It was also +EPO dominant. It had this breakdown for # of days: 50 +EPO, 21 neutral, and 20 -EPO. It also averaged ~+60 over the 91 days.

 Edit: I consider a -50 to +50 individual day to be neutral EPO.

[PhiEaglesfan712]

2 minutes ago, 40/70 Benchmark said:

1999-2000 is one of the better analogs. I think this pattern would have been warmer relative to normal for the northeast during the winter due to wavelengths.
 

Thankfully, October doens't have much of a coorelation to winter.

1998-99 is a much better analog than 1999-2000. 1998 is a near perfect MEI/RONI match, a strong el nino -> la nina transition, a dry fall for most of the Eastern US (which led to a drought winter), and near identical Atlantic hurricane season activity.

1999-2000, much like 2011-12, was one of the wettest falls on record, which is clearly not what we have here.

[40/70 Benchmark]

21 minutes ago, PhiEaglesfan712 said:

1998-99 is a much better analog than 1999-2000. 1998 is a near perfect MEI/RONI match, a strong el nino -> la nina transition, a dry fall for most of the Eastern US (which led to a drought winter), and near identical Atlantic hurricane season activity.

1999-2000, much like 2011-12, was one of the wettest falls on record, which is clearly not what we have here.

Yea, we have been though this. You do you...1999 is a much better fit from a polar perspective. Different analogs have different stengths and weaknesses.

[40/70 Benchmark]

The largest weakness I see with certain seasonal forecasters time and time again is this "all or nothing" black vs white thought process. I can't emphsize enough how important nuanced thinking is.

[bluewave]

41 minutes ago, 40/70 Benchmark said:

1999-2000 is one of the better analogs. I think this pattern would have been warmer relative to normal for the northeast during the winter due to wavelengths.
 

Thankfully, October doesn't have much of a coorelation to winter.

Sometimes the location of the NE PAC vortex in a La Niña locks in early like in 16-17. Notice how the trough set up near the PAC NW in October 2016 and didn’t move in the winter means. Way too early to know if the vortex stays closer to Alaska like we saw this October. But even if a fraction more of a vortex verifies this winter near Alaska than the current forecasts have it could present warmer risks to the winter forecast than the models are currently showing. 
 

 

 

[40/70 Benchmark]

1 minute ago, bluewave said:

Sometimes the location of the NE PAC vortex in a La Niña locks in early like in 16-17. Notice how the trough set up near the PAC NW in October 2016 and didn’t move in the winter means. Way too early to know if the vortex stays closer to Alaska like we saw this October. But even if a fraction more of a vortex verifies this winter near Alaska than the current forecasts have it could present warmer risks to the winter forecast than the models are currently showing. 
 

 

 

Sure, and sometimes it doesn't, which is probably why October isn't highly correlated to winter. BTW, I would gladly take a repeat of 2016, anyway....esstentially normal snowfall around here.

[40/70 Benchmark]

No question its going to be warm....the issue is whether or not it will be prohibitively warm again.

[jm1220]

23 minutes ago, 40/70 Benchmark said:

Sure, and sometimes it doesn't, which is probably why October isn't highly correlated to winter. BTW, I would gladly take a repeat of 2016, anyway....esstentially normal snowfall around here.

16-17 wasn’t bad here, was best NYC on NE which is typical for these fast flow Nina years. Late Jan and Feb had same good snow events. The 3-14-17 event going 75 miles further SE would’ve made it a great season vs not bad. 

[40/70 Benchmark]

3 minutes ago, jm1220 said:

16-17 wasn’t bad here, was best NYC on NE which is typical for these fast flow Nina years. Late Jan and Feb had same good snow events. 

Yea, I think a season like that is the ceiling....decent snowfall with low retention.

[PhiEaglesfan712]

I get the feeling November-February 2024-25 is going to mimic October-January 2021-22. November and January are going to be absolute torch months, while December and February are going to be near (and possibly even slightly cooler than) normal. That +10 January is going to skew the temperature departure of this winter into a +3 or +4, when the rest of the winter was otherwise near normal.

[40/70 Benchmark]

1 minute ago, PhiEaglesfan712 said:

I get the feeling November-February 2024-25 is going to mimic October-January 2021-22. November and January are going to be absolute torch months, while December and February are going to be near (and possibly even slightly cooler than) normal. That +10 January is going to skew the temperature departure of this winter into a +3 or +4, when the rest of the winter was otherwise near normal.

I agree, just still grappling with the timing a bit....

[Terpeast]

3 minutes ago, PhiEaglesfan712 said:

I get the feeling November-February 2024-25 is going to mimic October-January 2021-22. November and January are going to be absolute torch months, while December and February are going to be near (and possibly even slightly cooler than) normal. That +10 January is going to skew the temperature departure of this winter into a +3 or +4, when the rest of the winter was otherwise near normal.

Reasonable, my timing is a bit different from yours, but overall agreed

[Eduardo]

13 hours ago, MJO812 said:

https://x.com/webberweather/status/1848506703542948155?t=yKnUAfpu7hvNuFwibnBbjA&s=19

I mean, even if that were to happen (and that’s a big if), wouldn’t it be too little too late?

[40/70 Benchmark]

On 10/21/2024 at 9:39 AM, PhiEaglesfan712 said:

What makes this winter tough to predict is the disjointedness of the ONI, RONI, and MEI. We've never had a scenario before where the ONI is somewhere near ENSO neutral, the MEI is a strong la nina, and the RONI is somewhere in the middle. The best we can do is probably find years where 2 of the 3 measures are somewhat similar:

1998-99: MEI & RONI

2007-08: MEI & RONI

2016-17: ONI & RONI 

2020-21: MEI & RONI

What really complicates matters is undersanding WHY the metrics are disjointed and how that will manifest itself into the hemispheric manifold on a seasonal scale. The latter is where I failed last season. The lower =colder rationalization is a reductive and archic way of conceptualizing it (not directed at you...theoretical).

[snowman19]

28 minutes ago, jm1220 said:

16-17 wasn’t bad here, was best NYC on NE which is typical for these fast flow Nina years. Late Jan and Feb had same good snow events. The 3-14-17 event going 75 miles further SE would’ve made it a great season vs not bad. 

IMO 16-17 was helped by a neutral/slight positive PDO

[40/70 Benchmark]

33 minutes ago, snowman19 said:

IMO 16-17 was helped by a neutral/slight positive PDO

Yep. Great point...an identical regime this season would evolve even more unfavorably for NE winter enthusiasts if the polar domain also behvaves similarly. However, it was very hostile that year and I suspect we will have a bit more of a blocking signature in the mean this year.