2024-2025 La Nina

[Stormchaserchuck1]

On 7/24/2024 at 5:43 PM, bluewave said:

The raw PDO values didn’t work that winter since the actual spatial SST anomaly in 13-14 was one of the strongest composite +PDO patterns on record in terms of the cold pool aspect. Notice the classic +PDO cold pool from Japan to north of Hawaii. The warm blob off the Pacific Northwest associated with the TNH pattern may have been why the raw PDO didn’t match the SST composite. Since the warmest SSTs were just off the coast instead of right along it. So due to the record 13-14 TNH pattern, the typical +PDO trough was centered over the Great Lakes instead of New England. The pattern shifted further east in 14-15 resembling the canonical +PDO. But both seasons shared the record cold patterns downstream of the record NE PAC blocking ridge. So the cold pool near Japan and Hawaii was established a year before the raw +PDO values caught up. Plus there was actually a cold SST pool over the MJO 5 region near the Maritime Continent. So it’s not hard to see why those were such memorable winters. 
 

13-14 +PDO cold pool from Japan to north of Hawaii with record TNH distorting typical NE PAC SST +PDO response

Classic +PDO signature 

The SSTs lagged what was happening atmospherically though. After a Strong High pressure set in, in the Gulf of Alaska, Oct-Dec, SSTs eventually matched suit. They did not look like that when the pattern began in 2013:

-PDO warm pool was far enough south where it really shouldn't have led that -EPO pattern

Like 2002 and many others, the pattern got going real quick in October, but there was a pretty solid -PDO in place before that happened.. 

[PhiEaglesfan712]

4 hours ago, Stormchaserchuck1 said:

Thanks! 

I especially like these examples for the times the N. Pacific H5 pattern most deviated from the surface ENSO state.. For El Nino, 65-66 and 72-73. For La Nina, 95-96 and 00-01

The maps are self-explanatory. And that's 4/4. The correlation isn't always perfect, but when I previously plotted all subsurface data vs surface, I found a stronger N. Pacific 500mb correlation with the subsurface. 

Then of course, this year v before a big -PNA set in Feb 15 - March 31 and carried through the Spring

Making 23-24 the 3rd most deviated situation between El Nino SSTs and the N. Pacific 500mb pattern.. negative subsurface

The subsurface does change a lot, so if there is, say a Moderate Nina in the subsurface now, that doesn't mean it will hold 2-3 months out, or the Winter for that matter. 

Any la nina in the 1950s makes the list. The subsurface was warm throughout the decade, even through a double la nina early in the decade and a triple la nina in the middle.

1949-50

1950-51

1954-55

1955-56 (believe it or not, this was a strong la nina - this probably would be #1 on the list)

1956-57

[snowman19]

The relentless solar onslaught continues, we also have a strengthening geomag storm in progress:
 

[snowman19]

@so_whats_happening Anything new on the MEI updating? Dying to see an update. My guess is that it’s a much different MEI landscape from last year, since everything is coupled much better atmospherically (PDO/PMM) with the developing Niña….

[mitchnick]

2 hours ago, PhiEaglesfan712 said:

Any la nina in the 1950s makes the list. The subsurface was warm throughout the decade, even through a double la nina early in the decade and a triple la nina in the middle.

1949-50

1950-51

1954-55

1955-56 (believe it or not, this was a strong la nina - this probably would be #1 on the list)

1956-57

Honestly, that makes me question the accuracy of those maps.

[brooklynwx99]

2 hours ago, snowman19 said:

@so_whats_happening Anything new on the MEI updating? Dying to see an update. My guess is that it’s a much different MEI landscape from last year, since everything is coupled much better atmospherically (PDO/PMM) with the developing Niña….

RONI for AMJ is -0.2 while the ONI is +0.4, so you can probably lop off half a degree from the ONI going forward. tough to explicitly forecast that, though, as conditions can change as the year goes on

[snowman19]

31 minutes ago, brooklynwx99 said:

RONI for AMJ is -0.2 while the ONI is +0.4, so you can probably lop off half a degree from the ONI going forward. tough to explicitly forecast that, though, as conditions can change as the year goes on

I saw in your post from yesterday, you had 1983 as an analog, which was volcanic. I guess you’re assuming a volcanic stratosphere (El Chichon, 1982)? Given the cumulative VEI 5 eruptions we had back in April? 
@brooklynwx99  Edit: 1983-84

[brooklynwx99]

2 minutes ago, snowman19 said:

I saw in your post from yesterday, you had 82-83 as an analog, which was volcanic. I guess you’re assuming a volcanic stratosphere (El Chichon, 1982)? Given the cumulative VEI 5 eruptions we had back in April? 

i had 1983-84, not 1982-83... it's pretty low on the list regardless. might not even include it once we get into the fall. only really matches ENSO and not much else, but again, just wanted to cast a wide net and narrow down

[brooklynwx99]

I usually don't include volcanic activity in analogs. should I? maybe, but there's already a lot to juggle. credit to those that do it, though

[snowman19]

14 minutes ago, brooklynwx99 said:

I usually don't include volcanic activity in analogs. should I? maybe, but there's already a lot to juggle. credit to those that do it, though

I know 83-84 was considered a volcanic winter because of El Cichon 1982, which was a tropical volcano that pumped sulfate aerosols into the stratosphere. If you have a true volcanic stratosphere, then yes, it should be considered IMO. I believe that El Cichon was a strong VEI 5 eruption that reached the stratosphere back then. This year is a question mark, we obviously don’t have a Pinatubo stratosphere, as that was utterly massive, but will the cumulative VEI 5 eruption we had do anything stratospherically? I don’t know

El Cichon history: https://en.m.wikipedia.org/wiki/El_Chichón

[snowman19]

Just looked further at 1983, the period from 1982-1983 was extremely volcanic. 1983 alone had 58 different volcanic eruptions. No surprise that 83-84 is listed as a volcanic winter

Source: https://volcano.si.edu/faq/index.cfm?question=eruptionsbyyear&checkyear=1983

 

[Stormchaserchuck1]

10 hours ago, PhiEaglesfan712 said:

Any la nina in the 1950s makes the list. The subsurface was warm throughout the decade, even through a double la nina early in the decade and a triple la nina in the middle.

1949-50

1950-51

1954-55

1955-56 (believe it or not, this was a strong la nina - this probably would be #1 on the list)

1956-57

Yeah, it certainly didn't work in those years.. they were very -PNA Winters

It didn't work in 96-97.. we had a Strong Kelvin wave hit in the Winter, that preceded the 1997 Super El Nino.. That was more of a Neutral Winter. 

 

But back I think in 2008, I constructed a custom index going back to 1948, using the ftp custom input on CDC maps, and found it did historically test back better than ENSO measurement, like Nino 3.4 SST and OLR, 850mb winds, 200mb winds.. etc. And since 2008, it has worked at like +200% lol. 

I can't make custom indexes anymore on the CDC daily and monthly composites, but if I could you would see the overall +correlation..  the PDO beats out Nino 3.4 in correlation composites with the N. Pacific pattern, but the subsurface beats out the PDO.. 

[thunderbolt]

https://x.com/paulroundy1/status/1816913123502358642?s=46&t=9oYN55kJQkQ18l6qbtT9mw

[so_whats_happening]

9 hours ago, snowman19 said:

@so_whats_happening Anything new on the MEI updating? Dying to see an update. My guess is that it’s a much different MEI landscape from last year, since everything is coupled much better atmospherically (PDO/PMM) with the developing Niña….

Nah they seem to not have an alternative for the OLR data they used for MEI. NOAA has been having some pretty bad outages over the past couple of weeks so this is probably not on the top of their list, unfortunately.

RONI may be reasonable thing to use for Fall and Winter at this point.

[so_whats_happening]

8 minutes ago, thunderbolt said:

https://x.com/paulroundy1/status/1816913123502358642?s=46&t=9oYN55kJQkQ18l6qbtT9mw

Yea not some typical Nina like response. Has happened off an on over the past couple months with minor WWB events and models seemed to have forecasted the Easterlies a bit to strong at times.

[so_whats_happening]

The last typhoon in the WPAC actually had a pretty significant cooling of waters around the Philippines and Taiwan. 

[roardog]

20 minutes ago, thunderbolt said:

https://x.com/paulroundy1/status/1816913123502358642?s=46&t=9oYN55kJQkQ18l6qbtT9mw

Paul did a great job last year forecasting the strong Nino even when things looked questionable. Maybe he’s on to something. 

[snowman19]

21 minutes ago, so_whats_happening said:

Nah they seem to not have an alternative to for the OLR data they used for MEI. NOAA has been having some pretty bad outages over the past couple of weeks so this is probably not on the top of their list, unfortunately.

RONI may be reasonable thing to use for Fall and Winter at this point.

That write up Ben did a few days ago on the RONI was good. I agree that it would be the go to metric to use for this event given all the warm around. It looks like the MEI is dead in the water so to speak for now

[Stormchaserchuck1]

39 minutes ago, so_whats_happening said:

The last typhoon in the WPAC actually had a pretty significant cooling of waters around the Philippines and Taiwan. 

Those warm pools at 40-45N, off of New Foundland and south of the Aleutian islands really are something.. approaching +10F readings. I think that's the range where it starts having more of an impact on the atmosphere. Or at least it would take a lot of "work" to change.

[Stormchaserchuck1]

These August maps verifying would make it the warmest Dec - Aug on record for the CONUS by a little bit of a margin.. 

Just so you know they aren't general global warming maps, look over Alaska.. the CPC is predicting once again a pretty strong +EPO

The roll forwards, going back to 1948, are ugly, and has a pretty strong correlation signal for every month but December going into March 2025.. not because warm begets warm, but because historically the dominating patterns have remained consistent. 

[bluewave]

The Maritime Continent forcing is even stronger than usual for a developing La Niña in July due to the stronger WPAC warm pool. It may be why the Atlantic hurricane activity has been quieter than expected since Beryl. The 500 mb pattern has also been similar to a very strong La Niña response across the CONUS with the classic Niña ridge axis near New England and the PAC NW. But the strength of the ridges are more exaggerated than we typically see with La Ninas. This has also been the case with the La Ninas in recent summers. So another case of the WPAC warm pool leading the actual La Niña ONI SST readings. 

 

[thunderbolt]

https://x.com/wxpatel/status/1816981513420124267?s=46&t=9oYN55kJQkQ18l6qbtT9mw

[so_whats_happening]

56 minutes ago, bluewave said:

The Maritime Continent forcing is even stronger than usual for a developing La Niña in July due to the stronger WPAC warm pool. It may be why the Atlantic hurricane activity has been quieter than expected since Beryl. The 500 mb pattern has also been similar to a very strong La Niña response across the CONUS with the classic Niña ridge axis near New England and the PAC NW. But the strength of the ridges are more exaggerated than we typically see with La Ninas. This has also been the case with the La Ninas in recent summers. So another case of the WPAC warm pool leading the actual La Niña ONI SST readings. 

 

So we saw a very similar VP map to this year back in 1999, 2017, and 2018. Im sure if I ran through the years we could probably find fairly similar looks. 1999 in a second year Nina we didn't have the equatorial warm pool but we did see the warmth SE of Japan giving the PDO -2.34 in July. 2017 had a developing Nina but was rather weak overall PDO was actually positive neutral during this time and didnt have the huge Japan warmth (was more displaced to Korea and mainland China. We did have the equatorial warm pool east of New Guinea. 2018 was actually a weak Nino but managed to have a fairly similar VP response had the warmth SE of Japan in a fairly similar spot to 1999. Also having the warm pool east of New Guinea. However during the developing 2020 Nina event we managed to have a more typical response in July as shown by your maps above. PDO state was negative but weakening and the waters around Japan were not quite as warm. The waters in the IO near Africa were more anomalously warm then near New Guinea maybe that helped in shifting the VP state for 2020? 

Ill make another post what I have SSTA wise for the beginning of July for these years, except 2020 which I only have until end of May. If you happen to have a better SSTA reanalysis I would love a link.

[so_whats_happening]

[mitchnick]

6 hours ago, thunderbolt said:

https://x.com/paulroundy1/status/1816913123502358642?s=46&t=9oYN55kJQkQ18l6qbtT9mw

At least we know why the Snowman19/Roundy love affair ended. 

(Just bustin' on ya' Snowman)

[bluewave]

9 hours ago, so_whats_happening said:

So we saw a very similar VP map to this year back in 1999, 2017, and 2018. Im sure if I ran through the years we could probably find fairly similar looks. 1999 in a second year Nina we didn't have the equatorial warm pool but we did see the warmth SE of Japan giving the PDO -2.34 in July. 2017 had a developing Nina but was rather weak overall PDO was actually positive neutral during this time and didnt have the huge Japan warmth (

My guess is the reason that the 2022 hurricane season wasn’t as active as forecast was due to the stronger Maritime Continent forcing leading to more subsidence over the Western Atlantic in August and September. 2017 didn’t have this issue so it was much more active. This is probably why the Atlantic has been so quiet in recent weeks. So we’ll probably need to see a decrease in Maritime Continent forcing next few weeks for the Atlantic to become active. The developing La Niña and record SSTs would suggest a much above average Atlantic hurricane season. But the final piece of the equation would be more favorable forcing. Plenty of time for things to shift allowing the more active forecasts to verify since it’s still very early.

 

[snowman19]

[PhiEaglesfan712]

1 hour ago, bluewave said:

My guess is the reason that the 2022 hurricane season wasn’t as active as forecast was due to the stronger Maritime Continent forcing leading to more subsidence over the Western Atlantic in August and September. 2017 didn’t have this issue so it was much more active. This is probably why the Atlantic has been so quiet in recent weeks. So we’ll probably need to see a decrease in Maritime Continent forcing next few weeks for the Atlantic to become active. The developing La Niña and record SSTs would suggest a much above average Atlantic hurricane season. But the final piece of the equation would be more favorable forcing. Plenty of time for things to shift allowing the more active forecasts to verify since it’s still very early.

 

What about 2007? Did we also have the strong Maritime Continent that year? That year was less active in the Atlantic outside of Dean and Felix, and the Pacific had a very quiet year. Pretty similar to what we have so far this year.

[snowman19]

10 hours ago, mitchnick said:

At least we know why the Snowman19/Roundy love affair ended. 

(Just bustin' on ya' Snowman)

I’m still confident that we see a La Niña. If we end up cool-neutral however, it may be a case of “be careful what you wish for”. We are and have been in a default extratropical strong La Niña state for years, even last year with the Nino, we were in a La Niña extratropical state with La Niña MJO forcing (4-6). So, that said, if there is in fact a cool-neutral ENSO, then 2001-2002 becomes an analog IMO….cool-neutral/lack of a distinct ENSO signal, -PDO, -PMM, QBO turning positive, -IOD, +AMO (although not nearly as strong) and record high solar flux 

[mitchnick]

1 hour ago, snowman19 said:

I’m still confident that we see a La Niña. If we end up cool-neutral however, it may be a case of “be careful what you wish for”. We are and have been in a default extratropical strong La Niña state for years, even last year with the Nino, we were in a La Niña extratropical state with La Niña MJO forcing (4-6). So, that said, if there is in fact a cool-neutral ENSO, then 2001-2002 becomes an analog IMO….cool-neutral/lack of a distinct ENSO signal, -PDO, -PMM, QBO turning positive, -IOD, +AMO (although not nearly as strong) and record high solar flux 

I was all for a super Niña this year originally advertised by the Cansips with the hope of breaking the warmth in the western Pacific, but it's not to be and the writing is on the wall for a big fail on any modeling that suggested a moderate or strong Niña. 

That said, I have noticed that there have been a good deal of easterly wind anomalies over the past week or 2 and currently progged along and WEST of the Dateline. I wonder if that might cause a dent in the warmth out there. Don't know, but if the progs are right, I'm interested in seeing what happens. It wouldn't do anything for any areas except for "maybe" Enso 4.