2024-2025 La Nina

[BarryStantonGBP]

2 minutes ago, mitchnick said:

https://sealevel.jpl.nasa.gov/data/el-nino-la-nina-watch-and-pdo/pacific-decadal-oscillation-pdo/

That is, for hurricane season.

[George001]

6 hours ago, PhiEaglesfan712 said:

I disagree. I see the first third of December being cool, and I think there's a chance of a snow event on Dec 4 or 5. The second third looks warm, and I think it will be back to cool again the final third. (I go to the Eagles game on Dec. 29. I don't think this one will be a torch like the first week of January 2023.)

January is likely to be very warm. As I've said all along, the winter comes down to February. I think that final month of winter looks the most promising, but it's way too early to tell.

March is a winter month 

[George001]

4 hours ago, bluewave said:

I know we are just talking about model snapshots at 360 which are tough to extrapolate from for more than a few days if that pattern actually verifies. So these are all just hypotheticals. But if we do get a trough near Japan in conjunction with a ridge axis near the Aleutians, then we would need a strong -AO block to anchor the trough in the East for more than just a few days. Would also need the MJO to peak in 2-3-4 and then weaken in 4-7 to allow a La Niña +PNA mismatch pattern for December. It’s really tough to get the specific December pattern based of of mid-November model forecasts. This is the time of year there can be a ton of model flux so we are probably better off just waiting two weeks until things come into better focus. 

My issue with the relying on a mismatch pattern inside a large scale unfavorable base state is it doesn’t last. Best case scenario is a 2020-2021 or 2021-2022 winter (depending on where you live), both of which had longer unfavorable periods than favorable ones. 20-21/21-22 just doesn’t move the needle. Both winters finished well AN temp wise and had limited snowpack retention. Ultimately the only real hope for a real old school New England winter (like 13-14/10-11/08-09) is a large scale change in the base state. I realize that’s fairly unlikely, but are there any cold ENSO winters you can think of that had this happen mid winter? Only one I can think of is 12-13, which torched both Dec and Jan and then was a cold and snowy Feb-Mar. I guess 14-15 but the background state was favorable going in, this is a completely different situation so I don’t see that as a possible analog even for best case scenario.

[George001]

14-15 was pretty much the exact opposite situation. Despite ultimately being a cold and snowy winter, we had a torch December and the first half of Jan was warm too. Then we had a frigid rest of winter (2.5 months of BN temps, 1.5 months of AN). So really the torch Dec-first half of Jan was the mismatch within a large scale favorable base state (weak modoki Nino, raging +PDO). 

[GaWx]

3 hours ago, BarryStantonGBP said:

What would CP Nino mean for the atlantic come September?

 In general terms El Niño is correlated with less ACE than non-Nino. But if it’s weak, there’s typically less of a reduction. Furthermore, this is only a tendency. For example, look at 2023 for a major exception due to record high Atlantic SSTs.

[BarryStantonGBP]

1 minute ago, GaWx said:

 In general terms El Niño is correlated with less ACE than non-Nino. But if it’s weak, there’s typically less of a reduction. Furthermore, this is only a tendency. For example, look at 2023 for a major exception due to record high Atlantic SSTs.

Could it be like 2004

[GaWx]

8 minutes ago, BarryStantonGBP said:

Could it be like 2004

Yes, 2004 and 1969 were both weak El Niño with active Atlantic hurricane seasons.

[BarryStantonGBP]

43 minutes ago, GaWx said:

Yes, 2004 and 1969 were both weak El Niño with active Atlantic hurricane seasons.

What's the most likely analog?

[GaWx]

41 minutes ago, BarryStantonGBP said:

What's the most likely analog?

I don’t know. It’s way too early for any forecaster to even try to determine that.

[40/70 Benchmark]

12 hours ago, michsnowfreak said:

I disagree on January. I'm really liking January here, and while it will probably be somewhat milder than normal on the east coast it's probably your best winter month this season. I think @40/70 Benchmarkalso thinks Jan will be be your best month. A few months ago I thought Dec might be great and Jan would suck (going by some previous nina years) but I've completely flipped recently. Dec looks to have it's chances but should be the least favorable of the 3 winter months. Cfs and some other models have been steadfast on western Canada just loaded with cold by January. 

I do, but like I said to him the other day, there could be some roll over...so I won't be shocked to see a nice stretch in early February. 

[mitchnick]

All the ensembles remain on the cold side in the east, with Gefs and Eps being the coldest of the 3 at the end their runs.

[bluewave]

17 hours ago, George001 said:

My issue with the relying on a mismatch pattern inside a large scale unfavorable base state is it doesn’t last. Best case scenario is a 2020-2021 or 2021-2022 winter (depending on where you live), both of which had longer unfavorable periods than favorable ones. 20-21/21-22 just doesn’t move the needle. Both winters finished well AN temp wise and had limited snowpack retention. Ultimately the only real hope for a real old school New England winter (like 13-14/10-11/08-09) is a large scale change in the base state. I realize that’s fairly unlikely, but are there any cold ENSO winters you can think of that had this happen mid winter? Only one I can think of is 12-13, which torched both Dec and Jan and then was a cold and snowy Feb-Mar. I guess 14-15 but the background state was favorable going in, this is a completely different situation so I don’t see that as a possible analog even for best case scenario.

You are correct that the +PNA La Niña mismatch patterns didn’t produce extended cold in 17-18 and 20-21. But the snows those two seasons were the best relative to the last 9 winters. We got a one month mismatch in January 22 that made that winter more productive for snowfall than 22-23 and 23-24. But it was one brief month of colder temperatures in a sea of warm. So even getting a winter like 20-21 or 17-18 requires a snowy start to December and a strong +PNA -AO which goes against the La Niña and -PDO background. These mismatch patterns weren’t forecast in advance by the seasonal models so they really only became known by the first week of December. So this is why the pattern and forecasts during the first week of December will be make or break for the whole flavor of the winter forecast. But even then a brief January mismatch like 22 really would become evident in the modeling and forecast until around New Year’s Day. This is why we need to wait until the early December pattern and forecast conformation before forming any firm views about what to expect this winter.

[PhiEaglesfan712]

11 hours ago, BarryStantonGBP said:

What's the most likely analog?

It's too early to tell, but 2013-14 is in the early lead for best analog 2025-26. I think 2025 will be a generally rising PDO year, and the extended ENSO neutral phase will continue in 2025-26. (+PDO will come in 2026, and a strong el nino will come right after.)

[GaWx]

 What’s the deal with the latest CFS forecasted record rate of cooling from Nov to Dec in Nino 3.4?

 The latest CFS mean is forecasting a record shattering cooling of 1.0 to -1.2:

 Compare the CFS to these latest runs for Nov to Dec:

-BoM: no cooling/remain at -0.2

-Euro: 0.25 cooling to -0.5

-JMA: 0.3 cooling to -0.6

-MeteoFrance: 0.2 cooling to -0.45

-UKMET: 0.2 cooling to -0.8

 So, CFS’ cooling of 1.0 from Nov to Dec compares to a range of only 0.0 to 0.3 for the latest run of the other five models.

 The record ONI based cooling from Nov to Dec back to 1950 is only 0.45 (1951) followed by 0.41 (1954) and 0.40 (2008 and 2012)! The record warming from Nov to Dec is only 0.43 (1991).

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/detrend.nino34.ascii.txt

 

[mitchnick]

16 minutes ago, GaWx said:

 What’s the deal with the latest CFS forecasted record rate of cooling from Nov to Dec in Nino 3.4?

 The latest CFS mean is forecasting a record shattering cooling of 1.0 to -1.2:

 Compare the CFS to these latest runs for Nov to Dec:

-BoM: no cooling/remain at -0.2

-Euro: 0.25 cooling to -0.5

-JMA: 0.3 cooling to -0.6

-MeteoFrance: 0.2 cooling to -0.45

-UKMET: 0.2 cooling to -0.8

 So, CFS’ cooling of 1.0 from Nov to Dec compares to a range of only 0.0 to 0.3 for the latest run of the other five models.

 The record ONI based cooling from Nov to Dec back to 1950 is only 0.45 (1951) followed by 0.41 (1954) and 0.40 (2008 and 2012)! The record warming from Nov to Dec is only 0.43 (1991).

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/detrend.nino34.ascii.txt

 

It's been forecasting this trade burst (below) for a while. In fact, I posted this prog and the Gfs prog a few days ago in this thread. It's either off its rocker or finally decided to pay attention to It's own forecast.  Lol

[GaWx]

21 minutes ago, mitchnick said:

It's been forecasting this trade burst (below) for a while. In fact, I posted this prog and the Gfs prog a few days ago in this thread. It's either off its rocker or finally decided to pay attention to It's own forecast.  Lol

 So based on my prior post: IF the CFS cooling in Nino 3.4 from Nov to Dec were to somehow verify closely, it would more than double the old record cooling from Nov to Dec back to 1950 and more than triple the strongest forecasted cooling of any other model (JMA’s 0.3)! For some reason I feel CFS will bust very badly  but we’ll see.

 In light of this likely upcoming huge bust in Nino 3.4, how much weight should be put on the CFS current winter forecast for the E US?

[mitchnick]

3 minutes ago, GaWx said:

 So based on my prior post: IF the CFS cooling in Nino 3.4 from Nov to Dec were to somehow verify closely, it would more than double the old record cooling from Nov to Dec back to 1950 and more than triple the strongest forecasted cooling of any other model (JMA’s 0.3)! For some reason I feel CFS will bust very badly  but we’ll see.

 In light of this likely upcoming huge bust in Nino 3.4, how much weight should be put on the CFS current winter forecast for the E US?

If it's cold...a lot. If it's warm...we toss. 

Those are my only 2 rules for seasonal forecasts.  Lol

Honestly, it's a little hard to take a sudden, radical change by any mr/lr model, let alone the Cfs2. Jmho

 

[bluewave]

We should get a decent EWB leading to some degree of Nino 3.4 cooling since even the EPS is correcting stronger with the MJO over the next week to 10 days. 
 

New run stronger MJO in IO than forecast 

Old run

 

[GaWx]

For the period Sept 1st through Nov 14th back to 1948, 2024 is tied with 2021 for the fewest -EPO (sub -50) days with just 3:

Lowest # of sub -50 EPO days 9/1-11/14 back to 1948 (7 or fewer):
2024: 3

2021: 3

2011: 4

1994: 4

1958: 4

1948: 4

1968: 5

 
I didn’t see any notable correlation to # of sub -50 days one way or the other in the subsequent respective winters, however.

 

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

[BarryStantonGBP]

3 hours ago, PhiEaglesfan712 said:

It's too early to tell, but 2013-14 is in the early lead for best analog 2025-26. I think 2025 will be a generally rising PDO year, and the extended ENSO neutral phase will continue in 2025-26. (+PDO will come in 2026, and a strong el nino will come right after.)

So an inactive hurricane season on the way since you said 2013-14

[michsnowfreak]

4 hours ago, mitchnick said:

If it's cold...a lot. If it's warm...we toss. 

Those are my only 2 rules for seasonal forecasts.  Lol

Honestly, it's a little hard to take a sudden, radical change by any mr/lr model, let alone the Cfs2. Jmho

 

Ive noticed with some on here, warm solutions on longterm guidance (even 384 hr op maps) are gospel and cold solutions should be discounted for their unreliability.

Looking at todays 12z ensembles, nothing screams "RECORD warm start to December" like an ensemble mean of solidly colder than avg 850s to start December. 

[snowman19]

3 hours ago, bluewave said:

We should get a decent EWB leading to some degree of Nino 3.4 cooling since even the EPS is correcting stronger with the MJO over the next week to 10 days. 
 

New run stronger MJO in IO than forecast 

Old run

 

If that’s where the MJO forcing/wave is indeed going to be and going to be that strong, then expect the long range models for early December to change in the next several days. And either Joe Bastardi’s new favorite model (the CFS) is going to score a big coup with the projected huge EWB and rapid Nina strengthening it has for December or it’s totally out to lunch 

[mitchnick]

1 hour ago, snowman19 said:

If that’s where the MJO forcing/wave is indeed going to be and going to be that strong, then expect the long range models for early December to change in the next several days. And either Joe Bastardi’s new favorite model (the CFS) is going to score a big coup with the projected huge EWB and rapid Nina strengthening it has for December or it’s totally out to lunch 

All 3 ensembles at 12z just got even colder for the first 3 or 4 days of December. 

One thing to consider is the Gefs has really sped up the wave and it's no where near as strong as the Cfs with the wave. In fact, none of the models are. My thinking is maybe the speed of the relatively weak wave depicted on the Gefs won't allow for the warming of an otherwise slower, stronger wave, which is why all ensembles have remained on the colder side come December. Idk, just wondering. We'll see.

[GaWx]

1 hour ago, michsnowfreak said:

Ive noticed with some on here, warm solutions on longterm guidance (even 384 hr op maps) are gospel and cold solutions should be discounted for their unreliability.

Looking at todays 12z ensembles, nothing screams "RECORD warm start to December" like an ensemble mean of solidly colder than avg 850s to start December. 

1. Neither should be considered anywhere near gospel out at hour 360 of even the ensemble means as they are typically of pretty low confidence though they’re much better than their respective operationals.

2. Due to cold bias of ensemble means that has existed for years, especially that far out, quite possibly due to the very warm W Pacific, warm solutions have a somewhat better chance to verify closely than cold solutions.

3. As I assume you and many of the members know, cold bias doesn’t at all mean always too cold or anywhere near always. Sometimes they can be either too warm or about right. But overall, too cold is typically more common than too warm (definition of cold bias).

4. Be that as it may, I’ve also noticed the model trend for the start of Dec has turned colder. But again, it remains to be seen whether or not these colder solutions will actually verify closely. Keep in mind that much earlier in the forecast period (11/23-7) that the EPS warmed considerably from an avg of +0.5 AN HDD per US pop weights to 2.5 HDD BN.

[brooklynwx99]

7 minutes ago, mitchnick said:

All 3 ensembles at 12z just got even colder for the first 3 or 4 days of December. 

One thing to consider is the Gefs has really sped up the wave and it's no where near as strong as the Cfs with the wave. In fact, none of the models are. My thinking is maybe the speed of the relatively weak wave depicted on the Gefs won't allow for the warming of an otherwise slower, stronger wave, which is why all ensembles have remained on the colder side come December. Idk, just wondering. We'll see.

the MJO also isn't a silver bullet. it often correlates to the broader pattern but there are times where it doesn't have much of an impact

I do anticipate the models to get a bit warmer for early Dec, though it doesn't have to happen