El Nino 2023-2024

[Stormchaserchuck1]

Fwiw, this is a La Nina-base state (-AAM), going into Nov 6, and the 2nd week of November.

https://ibb.co/yYXvFkF

[Typhoon Tip]

1 hour ago, Stormchaserchuck1 said:

Fwiw, this is a La Nina-base state (-AAM), going into Nov 6, and the 2nd week of November.

https://ibb.co/yYXvFkF

It's crashing ...

[Stormchaserchuck1]

4 minutes ago, Typhoon Tip said:

It's crashing ...

The AAM?

[GaWx]

On 10/20/2023 at 12:57 PM, GaWx said:

 Whereas SST charts near Japan suggest a significant PDO rise has occurred, which I strongly believe, I still would recommend caution before accepting this from WCS as accurate, especially after a rise of 2.3 in just 2.5 weeks. WCS appears to be a private co. as opposed to governmental fwiw.

I use this from NOAA for monthly PDO: 

https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat
 

 Looking at the monthlies, WCS has been much less negative than NOAA:

-Jan is ~-0.75 per WCS graph while NOAA is -1.25

-Feb is ~-0.8 per WCS vs -1.65 per NOAA

-Mar is ~-1.3 per WCS vs -2.45 per NOAA.

-Apr ~-2 WCS vs -3.07 NOAA.

-May/Jun ~-1.5 WCS vs -2.42/-2.53 NOAA.

-Jul ~-1.75 WCS vs -2.52 NOAA

-Aug ~-1.6 WCS vs -2.46 NOAA

-Sep ~-2.25 WCS vs -2.94 NOAA

 So, on average, WCS has been coming in at ~63% of NOAA. But they have been mostly moving in the same direction from month to month. Thus, NOAA has very likely also risen substantially so far this month and thus it wouldn’t shock me if it comes in near -1.5 for Oct vs Sept’s -2.94.

Followup: Let’s say Oct PDO ends up at -1.5, which would mean a rise of 1.44 from Sep and would easily be the third strongest PDO rise in Oct for El Niño since the 1850s. The following five Nino autumns had a PDO rise of 1+ from Sep to Oct along with these E US winters to follow:

1969: 2.02 (weak); cold winter w/PDO +1.07

1880: 1.79 (weak); cool to cold winter w/PDO -0.23

1876: 1.08 (moderate); cool to cold winter w/PDO -0.15

2006: 1.08 (weak); normal winter w/PDO -0.61

1986: 1.03 (moderate); normal E US winter w/PDO +1.55

 So, none of these five were mild. If the winter PDO were to be above -1 and especially above -0.75, I’d think that the PDO wouldn’t likely be a mild influence. The odds of a sub -1 Nino winter PDO are low considering there has been a mere two of the last 50 (4%) at sub -1 (1994-5 and 1951-2).

*Edited for correction to add 1951-2

 

[snowman19]

A powerful STJ is definitely not a La Niña hallmark:

[bluewave]

13 hours ago, snowman19 said:

A powerful STJ is definitely not a La Niña hallmark:
 

It has been a split flow pattern. But the northern branch looks to dominate next weekend with the strong -PNA pattern. So some late season Niña-like 80° heat possible for the Northern Mid-Atlantic. 
 

 

[snowman19]

Massive WWB ongoing, going to trigger another DWKW. The SOI is down to -23
 

[bluewave]

Looks like the CPC is going with the Euro seasonal which has the warm Nino +PNA ridge to the north undercut by the -PDO trough near the southern Rockies. With a +PDO El Niño the trough would be over the Southeast. But it’s pulled west due to the -PDO in the seasonal forecasts. If we see the same error as the seasonal forecasts last winter, then the trough out West will be deeper pumping the ridge more in the East.
You can see the Euro seasonal maintaining the Niña -PDO ridge north of Hawaii. But it also has the Nino +PNA ridge in Canada. Need to lose the -PDO and ridge north of Hawaii for the El Niño to be able to be the main driver.

 

[mitchnick]

21 minutes ago, bluewave said:

Looks like the CPC is going with the Euro seasonal which has the warm Nino +PNA ridge to the north undercut by the -PDO trough near the southern Rockies. With a +PDO El Niño the trough would be over the Southeast. But it’s pulled west due to the -PDO in the seasonal forecasts. If we see the same error as the seasonal forecasts last winter, then the trough out West will be deeper pumping the ridge more in the East.
You can see the Euro seasonal maintaining the Niña -PDO ridge north of Hawaii. But it also has the Nino +PNA ridge in Canada. Need to lose the -PDO and ridge north of Hawaii for the El Niño to be able to be the main driver.

 

Agreed that yhey are likely using the Euro, but I  don't think the Euro Seasonal is quite as bad as you state. It looks like the 3 month mean is skewed due to December. If you look at the monthlies of D-F you can see how the Euro weakens the trough and moves it east and builds a EPP/PNA ridge.

 

[Terpeast]

I’d wait until the next euro run now that the PDO is close to neutral, and the rex block may further cool the ssts north of hawaii. 

The october run is not a bad look though.

And the warmth late october, while I’d have preferred it to happen in november, is not entirely unexpected. The same rex block that should reinforce the pdo rise is the cause behind the upcoming warmth, and it’s only temporary. 

it doesn’t mean that we’re still in a la nina or that a ratter is incoming. 

[bluewave]

13 minutes ago, mitchnick said:

Agreed that yhey are likely using the Euro, but I  don't think the Euro Seasonal is quite as bad as you state. It looks like the 3 month mean is skewed due to December. If you look at the monthlies of D-F you can see how the Euro weakens the trough and moves it east and builds a EPP/PNA ridge.

The main challenge with the Euro seasonal is that it still has a trough near the SW in February. So storms ejecting from the SW could come out too far north without solid blocking on the Atlantic side. But I would still take my chances with that look compared to last winter. While it would be a record 9  warmer winters in a row for the Northeast, the snowfall would probably be better than last winter.

 

 

[mitchnick]

14 minutes ago, bluewave said:

The main challenge with the Euro seasonal is that it still has a trough near the SW in February. So storms ejecting from the SW could come out too far north without solid blocking on the Atlantic side. But I would still take my chances with that look compared to last winter. While it would be a record 9  warmer winters in a row for the Northeast, the snowfall would probably be better than last winter.

 

 

Those Meteo France maps you post look so different than those I  posted off the Euro site. The Euro site look much better. Lol I'll go with them!

[bluewave]

3 minutes ago, mitchnick said:

Those Meteo France maps you post look so different than those I  posted off the Euro site. The Euro site look much better. Lol I'll go with them!

I like the ensemble means better since those tercile maps lack the better definition.

[snowman19]

I really don’t think the -PDO is forcing the pattern even though it’s strongly negative. Maybe when it was record strong positive like back during the 14-15 winter, there was some feedback with those insanely warm ++ GOA and west coast SSTs, but other than that, no. Studies have shown that ENSO forces the PDO, not the other way around.

The 2 main drivers I see this winter will be the El Niño and ++IOD. I think the MJO will largely be a non factor which is typical with strong ENSO events. When there is activity I expect it to be weak and fast moving and not in “La Niña” phases 3-6, so I guess that’s really a plus.

The other secondary factors I see are the Hunga Tonga water vapor…what effects does that ultimately have on the stratosphere?, -QBO, solar (very high solar activity and geomag, approaching a solar max), ++AMO; right now there is no semblance of a “tripole”/New Foundland cold pool in the Atlantic, raging strong STJ, AGW must be factored in too. I can care less what arctic sea ice and Judah’s SAI does as both have proven to be a debacle over the last 15 years, that said, Siberian snowcover development to this point in time has been really horrible, lowest of the last 9 years on his index chart and sea ice is very low, below average…..the people who still follow it, take that for what you will

[griteater]

1 hour ago, bluewave said:

 

Yeah and for January, the Euro had a much better stock El Niño look for the Eastern U.S. in its September release with Aleutian Low / Eastern Trough / Davis Strait Ridging

[Itryatgolf70]

30 minutes ago, griteater said:

Yeah and for January, the Euro had a much better stock El Niño look for the Eastern U.S. in its September release with Aleutian Low / Eastern Trough / Davis Strait Ridging

I believe the November run will be telling for sure. The September outlook actually made more sense, especially if we get continued decrease in pdo and trough north of hawaii to cool waters, because typically niño has Aleutian lows tied into them. 

[Terpeast]

9 minutes ago, Itryatgolf70 said:

I believe the November run will be telling for sure. The September outlook actually made more sense, especially if we get continued decrease in pdo and trough north of hawaii to cool waters, because typically niño has Aleutian lows tied into them. 

Yeah, the oct run of the euro must have been initialized when the pdo was close to -3. Last I checked, we’re within 0.5 of neutral, so I’m curious what the nov run will have to say. Maybe it’ll look more like the sept run, or maybe it’ll stick with the SW trough idea, or come up with something entirely different. 

[raindancewx]

Here is 2002 & 2009 as a composite for October in the US. I'll keep asking this - if the weather never actually matches what those VP maps show for forcing....who cares where the forcing is? We're getting pretty close to winter. Do you really want to ride years as your main analogs that have not worked all Summer? 2009 is pretty warm in November and I think March could be fairly similar, but it's at best a C- type of match.

Oct 25-31 looks fairly cold in the NW and warm in the SE, so we should end up with the pretty traditional October -PDO correlation, where MN to Maine is the warmest spot nationally. The PDO is still going to finish very negative for the month.

Nino 1.2 in October tends to lead changes in the PDO in Nov-Apr. So the PDO should be weakening, but it's not a quick process. It moves in fits and starts. The good news is the -PDO has virtually no correlation to US temps in December. As the warmth of Nino 1.2 moves West, the degradation of the -PDO should slow if anything. I expect it get to 0 to -1 by December and then fluctuate in that band until late winter/March when it may re-strengthen or go weakly positive.

This El Nino is still only "officially" around +1.3C on Tropical Tidbits. Not even sure anymore that we'll top 1.5C for winter. We're hanging out at 28.1-28.2C on the weeklies after reaching 28.3C for a hot minute in September on the weeklies. CPC uses 26.63C as the DJF baseline...and I'm sure it'll be weakening quite quickly by late winter. I think the raw SST number for Nino 3.4 October may come in below September.

 06SEP2023     23.6 2.9     27.0 2.2     28.3 1.6     29.7 1.1
 13SEP2023     23.3 2.6     27.1 2.2     28.3 1.6     29.8 1.1
 20SEP2023     23.5 2.8     27.0 2.1     28.3 1.7     29.9 1.2
 27SEP2023     23.5 2.8     27.0 2.0     28.1 1.5     29.8 1.1
 04OCT2023     23.4 2.6     26.8 1.9     28.2 1.5     29.8 1.2
 11OCT2023     23.2 2.3     27.1 2.1     28.2 1.5     30.0 1.3

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

[bluewave]

1 hour ago, griteater said:

Yeah and for January, the Euro had a much better stock El Niño look for the Eastern U.S. in its September release with Aleutian Low / Eastern Trough / Davis Strait Ridging

That’s why I am not a big fan of the Aleutian ridge north or northwest of Hawaii. This persistent pattern for much of the last 8 winters tends to lower heights over the Western US and pumps the ridge in the Northeast. While the Euro seasonal raises the PNA in Canada, it still has the trough axis tucked underneath in the SW. The one hope is that we can cash in during any +PNA -AO intervals for a better snowfall outcome than last winter around NYC. But it would still be a record 9th warmer than average winter in the the Northeast if the trough axis remains near 115 west.
 

[Typhoon Tip]

The PDO is not strongly negative ... In fact, since the leading physical drive for the PDO is SS stressing due to wind anomaly distribution, it's more likely that the 'coupled' PDO/atmospheric aspect is something other than a -PDO considering it's risen some 2 SD or more in the last 20 days.

[snowman19]

Here is 2002 & 2009 as a composite for October in the US. I'll keep asking this - if the weather never actually matches what those VP maps show for forcing....who cares where the forcing is? We're getting pretty close to winter. Do you really want to ride years as your main analogs that have not worked all Summer? 2009 is pretty warm in November and I think March could be fairly similar, but it's at best a C- type of match.


Oct 25-31 looks fairly cold in the NW and warm in the SE, so we should end up with the pretty traditional October -PDO correlation, where MN to Maine is the warmest spot nationally. The PDO is still going to finish very negative for the month.
Nino 1.2 in October tends to lead changes in the PDO in Nov-Apr. So the PDO should be weakening, but it's not a quick process. It moves in fits and starts. The good news is the -PDO has virtually no correlation to US temps in December. As the warmth of Nino 1.2 moves West, the degradation of the -PDO should slow if anything. I expect it get to 0 to -1 by December and then fluctuate in that band until late winter/March when it may re-strengthen or go weakly positive.
This El Nino is still only "officially" around +1.3C on Tropical Tidbits. Not even sure anymore that we'll top 1.5C for winter. We're hanging out at 28.1-28.2C on the weeklies after reaching 28.3C for a hot minute in September on the weeklies. CPC uses 26.63C as the DJF baseline...and I'm sure it'll be weakening quite quickly by late winter. I think the raw SST number for Nino 3.4 October may come in below September.

 06SEP2023     23.6 2.9     27.0 2.2     28.3 1.6     29.7 1.113SEP2023     23.3 2.6     27.1 2.2     28.3 1.6     29.8 1.120SEP2023     23.5 2.8     27.0 2.1     28.3 1.7     29.9 1.227SEP2023     23.5 2.8     27.0 2.0     28.1 1.5     29.8 1.104OCT2023     23.4 2.6     26.8 1.9     28.2 1.5     29.8 1.211OCT2023     23.2 2.3     27.1 2.1     28.2 1.5     30.0 1.3

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

Besides the -QBO, PDO and the fact that there was an El Nino, I never saw ‘09 as a match. This El Nino is not only stronger, it developed as a pure east-based/EP event. ‘09 was a classic, textbook Modoki, start to finish. It was also -IOD, which affects MJO progression, don’t remember what the solar was but I’m pretty sure it wasn’t a solar max year. The AMO wasn’t anywhere near as positive, you had an Atlantic tripole, you didn’t have record amounts of volcanic water vapor in the stratosphere either, AGW wasn’t anywhere near as pronounced as it is now, the STJ is already very strong now, the STJ response is different when there’s a Modoki, you had well above normal Siberian snowcover buildup in October, arctic sea ice was higher, (not that those matter to me, but still)…..

[griteater]

2 hours ago, snowman19 said:

I really don’t think the -PDO is forcing the pattern even though it’s strongly negative. Maybe when it was record strong positive like back during the 14-15 winter, there was some feedback with those insanely warm ++ GOA and west coast SSTs, but other than that, no. Studies have shown that ENSO forces the PDO, not the other way around.

The 2 main drivers I see this winter will be the El Niño and ++IOD. I think the MJO will largely be a non factor which is typical with strong ENSO events. When there is activity I expect it to be weak and fast moving and not in “La Niña” phases 3-6, so I guess that’s really a plus.

The other secondary factors I see are the Hunga Tonga water vapor…what effects does that ultimately have on the stratosphere?, -QBO, solar (very high solar activity and geomag, approaching a solar max), ++AMO; right now there is no semblance of a “tripole”/New Foundland cold pool in the Atlantic, raging strong STJ, AGW must be factored in too. I can care less what arctic sea ice and Judah’s SAI does as both have proven to be a debacle over the last 15 years, that said, Siberian snowcover development to this point in time has been really horrible, lowest of the last 9 years on his index chart and sea ice is very low, below average…..the people who still follow it, take that for what you will

One thing I disagree on is with respect to solar. Yes, the sunspot and solar flux numbers are elevated as we approach solar max for this solar cycle, but the geomag and solar wind numbers are running pretty low right now…and that’s the rationale for descending solar being the worst portion of the solar cycle for -NAO. That is, as the sunspot and solar flux numbers go past peak and decline, that’s when the geomag and solar wind numbers are typically at their highest. We’re probably looking at this winter and next as roughly solar max for sunspots and flux, with 25-26, 26-27, and 27-28 being the winters with max geomag and solar wind numbers (known to favor +NAO) .  On this chart, the blue line at the bottom is solar geomag (Ap)

 

[qg_omega]

5 hours ago, bluewave said:

Looks like the CPC is going with the Euro seasonal which has the warm Nino +PNA ridge to the north undercut by the -PDO trough near the southern Rockies. With a +PDO El Niño the trough would be over the Southeast. But it’s pulled west due to the -PDO in the seasonal forecasts. If we see the same error as the seasonal forecasts last winter, then the trough out West will be deeper pumping the ridge more in the East.
You can see the Euro seasonal maintaining the Niña -PDO ridge north of Hawaii. But it also has the Nino +PNA ridge in Canada. Need to lose the -PDO and ridge north of Hawaii for the El Niño to be able to be the main driver.

 

Classic Nino temp pattern

[Typhoon Tip]

20 hours ago, Stormchaserchuck1 said:

The AAM?

Yeah … I haven’t looked but just sayn’ 

pretty strong negative WPO index appears ready to punch across the north pacific and send the Pacific into the AB circulation mode type. That’s going to lower the global budget by a bit … so I was speaking about going forward

[Terpeast]

Since we're heading into neutral PDO territory, but we still don't expect it to go positive. PDO may bounce in the cold neutral range from here on out. 

So here's what a cold-neutral PDO winter looks like at 500mb. I didn't filter by ENSO or any other tele. All winters between a DJF average of between 0 and -0.5 PDO since 1950. 

- weak signal of an aleutian ridge and some western US troughing, which makes sense
- stronger blocking signal over on the atlantic side, but may be confounded by other contributing factors like qbo, etc

Take it fwiw.

 

 

I've also been playing around with analog winters that followed a strong rise from deeply negative PDO. I used -1.5 as the threshold anytime between April and July preceding the following winter, and selected winters that were neutral PDO on average. 

It is rare for a deeply negative PDO to rise to neutral so quickly within 6-9 months into the following winter.

This has only happened 5 times in the last 70 years. This year may be the 6th. Here's a 500mb composite of winters following a strong and rapid PDO rise out of deeply negative territory:

This time you see an aleutian low N of Hawaii, which had to be the driver of the strong PDO rise, and it seems to have stuck throughout those winters. Also N atlantic blocking seems to be a recurring theme.

Note I changed the contour intervals to get rid of the exaggerated cold bias of older analogs.

[bluewave]

27 minutes ago, qg_omega said:

Classic Nino temp pattern

El Niños are usually cooler in the Southeast than the CPC and Euro seasonal. The colder departures further SW are more related the expectation on the Aleutian ridge north of Hawaii. This tends to promote downstream troughing near the SW instead of SE. Need a stronger Aleutian low north of Hawaii to keep the ridging near the East Coast in check. 
 

[GaWx]

5 hours ago, snowman19 said:

The 2 main drivers I see this winter will be the El Niño and ++IOD. I think the MJO will largely be a non factor which is typical with strong ENSO events. When there is activity I expect it to be weak and fast moving and not in “La Niña” phases 3-6, so I guess that’s really a plus.

 The Oct 2023 MJO averaged out is going to end up weak in magnitude. Because of a partial correlation of Oct magnitude to the subsequent winter magnitude, there’s a better than average chance for a weak MJO averaged out this winter. During the winter periods when weak has dominated for a long enough time, especially near or inside the COD, they have tended to average colder (BN) for much of the E US, especially SE, during El Niños compared to when the MJO has been stronger as I’ve posted about. So, when you say you’re expecting the MJO to be weak, I (as one who’d prefer a BN winter) like what you’re saying.

[GaWx]

3 hours ago, snowman19 said:

Besides the -QBO, PDO and the fact that there was an El Nino, I never saw ‘09 as a match. This El Nino is not only stronger, it developed as a pure east-based/EP event. ‘09 was a classic, textbook Modoki, start to finish. It was also -IOD, which affects MJO progression, don’t remember what the solar was but I’m pretty sure it wasn’t a solar max year. The AMO wasn’t anywhere near as positive, you had an Atlantic tripole, you didn’t have record amounts of volcanic water vapor in the stratosphere either, AGW wasn’t anywhere near as pronounced as it is now, the STJ is already very strong now, the STJ response is different when there’s a Modoki, you had well above normal Siberian snowcover buildup in October, arctic sea ice was higher, (not that those matter to me, but still)…..

1. I have OND of 2009 as neutral IOD (barely positive) and definitely not negative per this:

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/dmi.had.long.data

2. DJF 2009-10 was only one year after the prior deep minimum and thus sunspots were still very low.

[Terpeast]

I found something potentially interesting. 

According to this dataset, the AMO is at its highest ever. 

https://www1.ncdc.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.amo.dat

Latest AMO is well over +1 in the last several months. Latest Sept value is +1.41

If this has any actual bearing on winter, it may favor south/SW shifts to N Atlantic blocking based on a H5 regression vs AMO using 1990-2023 as the base period. Look at the gpm values in the axis... the signal is strong. Very strong.

Any thoughts? Is this important to include in our winter outlooks? Or am I just going down another rabbit hole?

[bluewave]

14 minutes ago, Terpeast said:

I found something potentially interesting. 

According to this dataset, the AMO is at its highest ever. 

https://www1.ncdc.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.amo.dat

Latest AMO is well over +1 in the last several months. Latest Sept value is +1.41

If this has any actual bearing on winter, it may favor south/SW shifts to N Atlantic blocking based on a H5 regression vs AMO using 1990-2023 as the base period. Look at the gpm values in the axis... the signal is strong. Very strong.

Any thoughts? Is this important to include in our winter outlooks? Or am I just going down another rabbit hole?

Yes. The record NATL SSTs are probably the reason for the more south based blocking down to New England in recent years.