2024-2025 La Nina

[snowman19]

54 minutes ago, GaWx said:

 More specifically, I found that all -NAO winters since 1979-80 (only six of them/I define -NAO winters as sub -0.25 since I consider -0.25 to +0.25 neutral NAO) have all occurred when sunspots averaged sub 35. Also, with there having been only 6 of the last 45 winters with a -NAO (only 13%)(1984-5, 1986-7, 1995-6, 2009-10, 2010-1, 2020-1), the frequency has been way lower than that of the prior 25 year period. 
 

*Edited for correction of typo

Monthly NAO since 1950:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table
 

Monthly sunspots:

https://www.sidc.be/SILSO/DATA/SN_m_tot_V2.0.txt

Good info. This solar setup, along with the possible volcanic stratosphere, +QBO/La Nina (possible Modoki?) is a strong signal for +NAO/+AO with a decreased chance of SSWs. Also, the +AMO is a stronger than normal signal for a juiced up SE ridge IMO

[40/70 Benchmark]

10 hours ago, George001 said:

The PDO is still up in the air, but it will likely be negative as is typical for moderate to strong Nina’s. These are valid points, and I agree that it looks ugly right now. Some of the latest guidance is trending more towards a moderate peak than strong one, but regardless the solar activity is a strong negative factor for east coast snow prospects. I am much more concerned about that than the raw strength. In the extremely snowy strong La Niña event in 2010-2011, the solar activity was very low, opposite of this year. Id keep an eye on the PDO, it is negative but not as strongly negative as it was earlier in the year despite the Nino falling apart. That’s one thing to look for as a possible wildcard that could work in favor of those rooting for snow on the east coast. Ultimately, right now things are pointing in the direction of a +NAO moderate-strong Niña which is bad news for weenies such as myself.

I would expect the PDO to be negative again, but we'll see.

[40/70 Benchmark]

2 hours ago, snowman19 said:

IMO very good evidence for a strong -PDO this coming winter despite what Mr. Bastardi is saying. It’s strengthening right now. Also looks to be a moderate La Niña at the very least, possibly strong, especially if the IOD goes negative this fall

I think there is a much better shot of a more moderate La Nina than a positive PDO.

[Typhoon Tip]

34 minutes ago, snowman19 said:

Good info. This solar setup, along with the possible volcanic stratosphere, +QBO/La Nina (possible Modoki?) is a strong signal for +NAO/+AO with a decreased chance of SSWs. Also, the +AMO is a stronger than normal signal for a juiced up SE ridge IMO

could be a contender winter for Boston's first 0 snower 

heh

[snowman19]

18 minutes ago, Typhoon Tip said:

could be a contender winter for Boston's first 0 snower 

heh

Doubtful lol

[George001]

2 hours ago, snowman19 said:

IMO very good evidence for a strong -PDO this coming winter despite what Mr. Bastardi is saying. It’s strengthening right now. Also looks to be a moderate La Niña at the very least, possibly strong, especially if the IOD goes negative this fall

The -PDO has strengthened quite a bit over the past month, I stand corrected on that. For the strength of the nina, im not really buying some of the weaker guidance. The subsurface is already nearly -1C in May, that’s not something that happens in weak events. I’m still thinking it becomes a strong Niña rather than moderate, but we will see.

[snowman19]

42 minutes ago, 40/70 Benchmark said:

I think there is a much better shot of a more moderate La Nina than a positive PDO.

Over the last decade, factors like the PDO, AMO, ENSO, solar, IOD, volcanic, have been more dependable in winter outlooks than have arctic sea ice or Siberian snowcover, both of which have largely been debacles. Not great, but better than those 2. I suspect it’s largely related to AGW. Basically, there’s no denying anymore that AGW is having a HUGE effect on our climate, really big

[rclab]

1 hour ago, Typhoon Tip said:

could be a contender winter for Boston's first 0 snower 

heh

If that’s the case Tip, then NYC matches and raises Boston for the first cold season without a daily maximum temperature below freezing. Sadly the odds may be in our favor. Stay well, as always ….

[GaWx]

42 minutes ago, George001 said:

The -PDO has strengthened quite a bit over the past month, I stand corrected on that. For the strength of the nina, im not really buying some of the weaker guidance. The subsurface is already nearly -1C in May, that’s not something that happens in weak events. I’m still thinking it becomes a strong Niña rather than moderate, but we will see.

 On a RONI basis, I feel strong (-1.5-) has a very good chance at this still very early juncture. As of FMA, RONI was already down to +0.48 vs ONI of +1.15. That means RONI was a whopping 0.67 lower than ONI, a record negative difference.

[roardog]

I’m not on the east coast, but out here, it feels like a first year Nina performs better than a Nina that lasts multiple years. It feels like the winters get worse as the Nina continues over multiple winters. This isn’t always the case obviously but just a general observation. 

[40/70 Benchmark]

44 minutes ago, snowman19 said:

Over the last decade, factors like the PDO, AMO, ENSO, solar, IOD, volcanic, have been more dependable in winter outlooks than have arctic sea ice or Siberian snowcover, both of which have largely been debacles. Not great, but better than those 2. I suspect it’s largely related to AGW. Basically, there’s no denying anymore that AGW is having a HUGE effect on our climate, really big

Well, I don't think AGW is why Arctic sea ice and SCE are not considered silver bullets of seasonal forecasting. As far as the run of crap winters, AGW has to be a factor, but the weather patterns have also just sucked for NE snow and cold...other parts of the globe and country have done fine. But no question that that the fact that we are seemingly haveing a "warmest winter on record" world wide each year is due to CC.

[FPizz]

14 minutes ago, 40/70 Benchmark said:

Well, I don't think AGW is why Arctic sea ice and SCE are not considered silver bullets of seasonal forecasting. As far as the run of crap winters, AGW has to be a factor, but the weather patterns have also just sucked for NE snow and cold...other parts of the globe and country have done fine. But no question that that the fact that we are seemingly haveing a "warmest winter on record" world wide each year is due to CC.

There has been some bad luck with things lining up in the NE.  Your run of bad winters hasn't been too bad in my location.  The last 8 years I've averaged 27.85" of snow, or about 1' below normal, and that includes 2 seasons with less than 7" total.  Where you are a warm winter is still plenty cold to snow.  

[snowman19]

2 hours ago, roardog said:

I’m not on the east coast, but out here, it feels like a first year Nina performs better than a Nina that lasts multiple years. It feels like the winters get worse as the Nina continues over multiple winters. This isn’t always the case obviously but just a general observation. 

Correct. 1995-96 was, 1998-99 wasn’t. Just looking at those quickly as examples

[snowman19]

3 hours ago, GaWx said:

 On a RONI basis, I feel strong (-1.5-) has a very good chance at this still very early juncture. As of FMA, RONI was already down to +0.48 vs ONI of +1.15. That means RONI was a whopping 0.67 lower than ONI, a record negative difference.

If this La Niña does in fact become strong, the most recent example we have that went from super El Niño right to strong La Niña would be 98-99

[PhiEaglesfan712]

17 minutes ago, snowman19 said:

If this La Niña does in fact become strong, the most recent example we have that went from super El Niño right to strong La Niña would be 98-99

Yes, 1973 and 1998 are the only years that have transitioned from super el nino to strong la nina. Two other years, 1988 and 2010, transitioned from strong el nino to strong la nina (2024 would fit this category, since 2023-24 was a consensus strong el nino, rather than a super el nino).

[Stormchaserchuck1]

The La Nina mechanics don't really matter so much what we came out of, or how long it's been in a state. The one factor that may be, is that the globe is typically warmed up by El Nino's and cooled by La Nina's. That could take a year or couple of years after the fact to neutralize. 

I found that a year after Global precipitable water was high (Sept 2023 - March 2024 was #1 on record by 120%) the globe maintains a warm temperature effect.. 

[snowman19]

Not surprising, but the new Copernicus model runs have started to back off the +IOD. It did not fit anyway, +IOD/Nina’s are extremely rare. The models have it going neutral into fall now. My guess is that the IOD flips negative this fall into winter, which would fit typical Niña climo

[40/70 Benchmark]

22 hours ago, snowman19 said:

If this La Niña does in fact become strong, the most recent example we have that went from super El Niño right to strong La Niña would be 98-99

That analog has been my early favorite.

It will be nice to have a fall where I am not bickering with you every day

[raindancewx]

The past winter had a) El Nino conditions b) Russia seeing colder than usual conditions c) extreme warmth over Canada. If you look for a similar trifecta and roll it forward, the matches are pretty interesting,

The only similar El Nino to La Nina transition with the same global pattern in winter is 1997-98. You can make a weak case for 2009-10 but the warmth/cold are in the wrong spots. 1986-87, 2002-03 are kind of similar but avoid going to a La Nina and 1952-53, 1979-80 (if you count them as El Ninos are OK matches too if you warm them up a degree or two globally.

Here is 1997-98 (x4), with 2009-10, warmed up one degree (F). You can see the warmth shows up at about the same magnitude in a lot of the right places, since it never left Russia (southeastern Europe, west Africa, eastern Canada etc - all similar warmth to 2023-24.

We'll see how it goes, but a strong subtropical high in southern Asia with a strong jet running West to East, with any cold diffusing into Northern Europe seems to be the look.

Probably a fairly cold winter for the Northwest US / Northwest Canada, which we already seem to be seeing anyway. As the El Nino fades away the cold that has been getting trapped in the Great Basin will shift to the Northwest more consistently, and the pattern for May will become the occasional dump of Arctic air into the West.

All that being said, if the Atlantic gets hyperactive, I would expect all of the major features shown above by North America to be displaced  by 2-4 'hours' clockwise, that seems to be the main effect of the hyperactivity. If the purple blob is at 1 o-clock and not 11, then presumably the heights end up over TX and the SW, not the NE.

[PhiEaglesfan712]

 

16 minutes ago, raindancewx said:

The only similar El Nino to La Nina transition with the same global pattern in winter is 1997-98. You can make a weak case for 2002-03, 2009-10 but the warmth/cold are in the wrong spots. 1986-87 and 1952-53, 1979-80 (if you count them as El Ninos are OK matches too if you warm them up a degree or two globally.

1986-87 - This one continued into a strong el nino in 1987-88. Transition year was 1988, and 1988-89 was a historically strong la nina. I'd definitely keep 1988 as a top analog year for 2024. (The only difference is that the el nino peaked earlier in the season, but everything else from 1988 lines up with 2024.)

1952-53 - This one was a disjointed el nino over 3 years (1951-54). 1951-52 was a moderate el nino, while 1952-53 and 1953-54 were weak el ninos. Transition year was 1954, and 1955-56 was the strong la nina year, following a weak la nina in 1954-55. This isn't a good analog.

1979-80 - This one was a weak el nino, but there is no la nina anywhere to be found... Again, no analog here.

[40/70 Benchmark]

Just pick another death-knell for the northeast and play it safe-

[40/70 Benchmark]

Honestly, though.....A near record ACE seems to be the only way out of another torpedo DM period, and even then....maybe just servicable. 1998 was pretty active in terms of ACE and it still sucked. I imagine the ceiling could be something like a 2007-2008 outcome, where there is an ample reservoir of cold over eastern Canada via an elongated PV, but there is a sharp gradient due to a se ridge adjoining.

[raindancewx]

This is the closest I've come so far to re-creating what the Canadian has for the winter. It's too cold in the Atlantic, but I'd give it a B+/A- as a match globally. It's not a particularly interesting winter, but it does seem to have some resemblance to how the Spring has gone. The La Nina will be coldest to the east though Sept/Oct before rapidly moving West if this is the right idea.

[40/70 Benchmark]

25 minutes ago, raindancewx said:

This is the closest I've come so far to re-creating what the Canadian has for the winter. It's too cold in the Atlantic, but I'd give it a B+/A- as a match globally. It's not a particularly interesting winter, but it does seem to have some resemblance to how the Spring has gone. The La Nina will be coldest to the east though Sept/Oct before rapidly moving West if this is the right idea.

Reminds me of 2022-2023.

[jm1220]

32 minutes ago, 40/70 Benchmark said:

Honestly, though.....A near record ACE seems to be the only way out of another torpedo DM period, and even then....maybe just servicable. 1998 was pretty active in terms of ACE and it still sucked. I imagine the ceiling could be something like  a 2007-2008 outcome, where there is an ample reservoir of cold over eastern Canada via an elongated PV, but there is a sharp gradient due to a se ridge adjoining.

07-08 was garbage here with endless SWFEs that were awesome for I-90 and sleet to rain here. If that’s the “ceiling” even with the high ACE it’ll be the earliest slam the blinds shut in history. This official Nina or Nina background state with the boiling W PAC that fuels the PAC jet on steroids has to end before us south of I-90 have a shot at a good winter again. This state that started up in 18-19, other than the 20-21 rabbit out of a hat good winter makes that clear as day to me. 

[GaWx]

 Some models have warmed on this month’s runs while some others have cooled. The May UKMET for Aug/Sep rose substantially from April’s ~-1.35 to -1.00 for Nino 3.4. The implied RONI would be a good bit cooler. UKMET and JMA did very well last year. Regardless, several models had either a significant jump or drop this month, telling me there’s still a long ways to go before ONI/RONI can be accurately predicted.

[snowman19]

18 hours ago, PhiEaglesfan712 said:

 

1986-87 - This one continued into a strong el nino in 1987-88. Transition year was 1988, and 1988-89 was a historically strong la nina. I'd definitely keep 1988 as a top analog year for 2024. (The only difference is that the el nino peaked earlier in the season, but everything else from 1988 lines up with 2024.)

1952-53 - This one was a disjointed el nino over 3 years (1951-54). 1951-52 was a moderate el nino, while 1952-53 and 1953-54 were weak el ninos. Transition year was 1954, and 1955-56 was the strong la nina year, following a weak la nina in 1954-55. This isn't a good analog.

1979-80 - This one was a weak el nino, but there is no la nina anywhere to be found... Again, no analog here.

Given the already relentless background Niña state in the PAC (strong -PDO), and I strongly suspect a -IOD develops this fall into winter, if this Niña reaches 88-89 or 73-74 strength, this winter will definitely be in very, very serious trouble IMO. The 88-89 winter was wall to wall ++AO/++NAO

[snowman19]

17 hours ago, raindancewx said:

This is the closest I've come so far to re-creating what the Canadian has for the winter. It's too cold in the Atlantic, but I'd give it a B+/A- as a match globally. It's not a particularly interesting winter, but it does seem to have some resemblance to how the Spring has gone. The La Nina will be coldest to the east though Sept/Oct before rapidly moving West if this is the right idea.

A few models are now showing a rapid transition to a “Modoki” Niña configuration by winter

[40/70 Benchmark]

18 minutes ago, snowman19 said:

A few models are now showing a rapid transition to a “Modoki” Niña configuration by winter

Makes sense to me. How do you feel about 2007 as an analog? Obviously I don't expect quite that much snow in NNE, but I could see that type of pattern qualitatively speaking. QBO will be a poor match, but that wasn't a blocky season, anyway. I think we all agree there shouldn't be much blocking next season.

[40/70 Benchmark]

19 hours ago, raindancewx said:

The past winter had a) El Nino conditions b) Russia seeing colder than usual conditions c) extreme warmth over Canada. If you look for a similar trifecta and roll it forward, the matches are pretty interesting,

The only similar El Nino to La Nina transition with the same global pattern in winter is 1997-98. You can make a weak case for 2009-10 but the warmth/cold are in the wrong spots. 1986-87, 2002-03 are kind of similar but avoid going to a La Nina and 1952-53, 1979-80 (if you count them as El Ninos are OK matches too if you warm them up a degree or two globally.

Here is 1997-98 (x4), with 2009-10, warmed up one degree (F). You can see the warmth shows up at about the same magnitude in a lot of the right places, since it never left Russia (southeastern Europe, west Africa, eastern Canada etc - all similar warmth to 2023-24.

We'll see how it goes, but a strong subtropical high in southern Asia with a strong jet running West to East, with any cold diffusing into Northern Europe seems to be the look.

Probably a fairly cold winter for the Northwest US / Northwest Canada, which we already seem to be seeing anyway. As the El Nino fades away the cold that has been getting trapped in the Great Basin will shift to the Northwest more consistently, and the pattern for May will become the occasional dump of Arctic air into the West.

All that being said, if the Atlantic gets hyperactive, I would expect all of the major features shown above by North America to be displaced  by 2-4 'hours' clockwise, that seems to be the main effect of the hyperactivity. If the purple blob is at 1 o-clock and not 11, then presumably the heights end up over TX and the SW, not the NE.

Why do you feel that is the case? Strength/positioning of the subtropical ridge?