2025-2026 ENSO

[MJO812]

https://pix11.com/weather/rare-november-polar-event-brewing-high-above-the-northern-hemisphere/?fbclid=IwdGRjcAOB35RleHRuA2FlbQIxMQBzcnRjBmFwcF9pZAwzNTA2ODU1MzE3MjgAAR4RFB3Tl9cViuycaQaRBQzZsCvGJYeM6M5ZuXzB6yEtRYk1PnPyT-QB3PjoOg_aem_WzC8-WC72b5jdiqjbQ8nOw

[Terpeast]

1 hour ago, George001 said:

You know your shit and bring a lot to the table in terms of ENSO discussions but dude….. watch it. I don’t like that you are post limited because you actually know what you are talking about, but maybe if you actually tried not being a raging d*ckhead for once in your fucking life things would be better for you here. You are 100% right about misinfo/wishcasters like JB. You aren’t going to actually win in your crusade against these people by being insufferable, you need actual people skills. You want to just call me an idiot and ignore this? Fine, go ahead. I can’t stop you from doing that, I said what needed to be said. Now it’s up to you to decide what you want to do.

Thank you for saying the quiet part outloud. I have him on ignore anyways. 

[mitchnick]

2 hours ago, GaWx said:

I just saw it. Right you are and by a good margin!! Mean minimum down to ~0:

And it's still below normal on 12/31.

[so_whats_happening]

2 hours ago, GaWx said:

I just saw it. Right you are and by a good margin!! Mean minimum down to ~0:

This is the wonderful thing of strong blocks and poleward flux. Ill have to take a look back and see what exactly caused the flow to buckle so much over the last 2-3 weeks.

[PhiEaglesfan712]

1 hour ago, SnowGoose69 said:

You’d think getting another mod strong one isn’t too likely.  That would make 3 of the last 4 with only 18-19 not being strong or mod 

4 of the last 5 actually, as 09-10 was another strong el nino (along with 15-16 and 23-24).

Very possible we could have a repeat of 86-89 (remember this came quickly after the 82-83 el nino), with the double el nino in 26-28, then transition to a strong la nina in 28-29. We're overdue for a strong la nina as well. We haven't had one since 10-11, which is the longest stretch without a strong la nina since 55-56 to 73-74. If we don't have a la nina by 28-29, we would have our longest stretch without a strong la nina since 1916-17 to 1955-56.

[Stormchaserchuck1]

ASO ONI was -0.5, meaning we need to make it to DJF -0.5 for an official La Nina.. going to be close. The RONI is definitely in Weak Nina range though. 

[Stormchaserchuck1]

1 hour ago, mitchnick said:

And it's still below normal on 12/31.

Which extends out a -NAO to Jan 20-25 (although not a Strong SSW by late Dec, low correlation in lagged effect). 

[George001]

7 hours ago, GaWx said:

Are you thinking we have a good chance to get a strong+ El Niño per RONI? If so, are you thinking a mainly mild result in the NE US?

I was curious so I looked into it a bit. Following a multi year cold ENSO stretch when it did go warm ENSO, 9/12 times the follow up Nino was a moderate or stronger event. I would bet against a super Nino though, given we just had a +2 ONI peak El Niño 2 years ago. Gun to head, I would bet on our next El Niño being either next year or the year after, and being similar in strength to 02-03 or 09-10. 

[40/70 Benchmark]

23 hours ago, Stormchaserchuck1 said:

I am a little worried about Jan and Feb in the 1989-90 and 2005-06 analogs. I do think there will be more -AO in Jan/Feb so we'll see how that goes. 

Yes, I see a lot of January 2006 like jet extension...it was in my analog list.

[GaWx]

 There are 5 major SSW events on record between Nov 24th and Dec 7th:

-1958
-1965
-1968
-1981
-1987

Here’s the Dec temp. anomaly map: E US mainly 1-2 F BN

 

Here’s the Jan temp. anomaly map: E US mainly 2-4 BN, which incorporates extreme cold in places during 1966 (late), 1982 (mid) and 1988 (early):

 

Here’s the Feb temp. anomaly map: E US NN:

 

 So, the coldest month regarding E US anomalies was Jan and the warmest was Feb. Feb. might have been even warmer (warmer than normal) had 4 of these 5 winters not been during El Niño, which tends to favor cold in the 2nd half of winter vs La Nina’s colder 1st half.

 All of this is telling me that should the late Nov major SSW actually occur, the coldest month could easily be Jan rather than Dec, which makes sense considering an assumed several week lag. But, of course, that would remain to be seen especially considering La Niña often favoring Dec as the coldest anomalywise.
 

https://www.researchgate.net/figure/The-SSW-and-SFW-event-onset-date-year-and-type-identified-in-the-NCEP-NCAR-dataset-The_tbl1_267063738

[Stormchaserchuck1]

Nice post Larry.. Jan Natural Gas is the highest priced contact of the Winter season, implying this is the most -NAO month, but I think the weak-negative ENSO/-QBO might turn us warmer after December, maybe more Pacific-driven warmth. I do see -AO tendency in January this year. Also, Nov 24 - Dec 7 typical lag to -NAO is +35 days, so that is most correlated to -NAO Dec 29 - Jan 12

[so_whats_happening]

This is turning into a nice wave 1 displacement event as we go into the end of the month. Shame we lose the -NAO signal and it is not allowed to grow with depth. Here is the 50mb Euro 240hr forecast for the SPV we did not have the classic approach of a Scandinavian high retrograding into the NAO domain we typically see that helps enhance a wave 2 response so the -NAO is rather shallow in the atmosphere.

Now the question becomes then after this relaxation period in the troposphere do we see a re-emergence of the -NAO as aloft ridging(through the strat) gets pushed over into the NAO domain and we somehow get a connection through the layers? This has been a theme of these events (this one still looks rather mild) over the last 5 or so years. This is not looking like a significant warming event as of now.

It is pretty rare to see something major this early I would look closer to the new year and there after for potential if we can maintain a weakened SPV. Sorry they loaded as 2 pdfs versus visuals.

Heat flux.pdf Zonal wind.pdf

[stadiumwave]

2 hours ago, GaWx said:

 There are 5 major SSW events on record between Nov 24th and Dec 7th:

-1958
-1965
-1968
-1981
-1987

Here’s the Dec temp. anomaly map: E US mainly 1-2 F BN

 

Here’s the Jan temp. anomaly map: E US mainly 2-4 BN, which incorporates extreme cold in places during 1966 (late), 1982 (mid) and 1988 (early):

 

Here’s the Feb temp. anomaly map: E US NN:

 

 So, the coldest month regarding E US anomalies was Jan and the warmest was Feb. Feb. might have been even warmer (warmer than normal) had 4 of these 5 winters not been during El Niño, which tends to favor cold in the 2nd half of winter vs La Nina’s colder 1st half.

 All of this is telling me that should the late Nov major SSW actually occur, the coldest month could easily be Jan rather than Dec, which makes sense considering an assumed several week lag. But, of course, that would remain to be seen especially considering La Niña often favoring Dec as the coldest anomalywise.
 

https://www.researchgate.net/figure/The-SSW-and-SFW-event-onset-date-year-and-type-identified-in-the-NCEP-NCAR-dataset-The_tbl1_267063738

 

Looking at all those years week by week every year was about 4 weeks on average when the full effects of the SSW were felt. Its a good bet the affects of this SSW will be late DEC at the earliest & into JAN.

[Stormchaserchuck1]

I wonder if the Stratosphere warming forecast is going to stay so strong going into the last week of November, with models tonight taking away the -NAO in the long range. 

Here's the 1989/2005-analog pattern with weak-negative ENSO and strong -QBO. This is for Nov 28, based on tonights 0z GEFS

[snowman19]

5 hours ago, stadiumwave said:

 

Looking at all those years week by week every year was about 4 weeks on average when the full effects of the SSW were felt. Its a good bet the affects of this SSW will be late DEC at the earliest & into JAN.

The news is comical right now. The bad, false info about SSWEs they are putting out is astonishing. A real disservice honestly. They don’t even talk about the lag effect and are hyping an ice age coming up the end of this month

[snowman19]

4 hours ago, Stormchaserchuck1 said:

I wonder if the Stratosphere warming forecast is going to stay so strong going into the last week of November, with models tonight taking away the -NAO in the long range. 
Here's the 1989/2005-analog pattern with weak-negative ENSO and strong -QBO. This is for Nov 28, based on tonights 0z GEFS

The 1989 blocking was started by a combination of an early SSWE and a very strong MJO wave that went 7-8-1-2, which lead to the Thanksgiving snowstorm up I-95 and the record cold December…. 
 

[bluewave]

19 hours ago, donsutherland1 said:

Here's the data for December vs. January-April snowfall for New York City for La Niña winters 1979-80 through 2024-2025. 2024-2025 is officially listed as cold neutral. December 2024 had 2.8" of snow.

 

I have been using RONI for La Ninas since they are being defined more these days by how warm the WPAC is vs how cold Niña 3.4 is. So by this newer definition December 2024 was a moderate La Niña.. Plus early snowfall indicator being under or over 4” also works for LGA and EWR.

It has worked for 14 out of the last 15 La Ninas events as defined by RONI since 1995-1996. My guess is that this relationship has become so prominent in the last 30 years due to the more frequent repeating weather patterns as the climate has warmed. 

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

DJF  2025 -1.12 moderate La Nina RONI

 

[GaWx]

1 hour ago, snowman19 said:

The 1989 blocking was started by a combination of an early SSWE and a very strong MJO wave that went 7-8-1-2, which lead to the Thanksgiving snowstorm up I-95 and the record cold December…. 
 

Snowman,

 I don’t see an SSWE at any point in Nov or Dec of 1989. Where are you seeing that?

https://www.researchgate.net/figure/The-SSW-and-SFW-event-onset-date-year-and-type-identified-in-the-NCEP-NCAR-dataset-The_tbl1_267063738

[snowman19]

Snowman,
 I don’t see an SSWE at any point in Nov or Dec of 1989. Where are you seeing that?
https://www.researchgate.net/figure/The-SSW-and-SFW-event-onset-date-year-and-type-identified-in-the-NCEP-NCAR-dataset-The_tbl1_267063738

I took BAMWX’s word for it. Lol I guess they are mistaken?

[40/70 Benchmark]

2 hours ago, snowman19 said:

The news is comical right now. The bad, false info about SSWEs they are putting out is astonishing. A real disservice honestly. They don’t even talk about the lag effect and are hyping an ice age coming up the end of this month

They always get blown out of proportion. Indicative of the decay of society....increased proclivity towards instant gratification and shorter attention spans, decreased tendency towards delayed gratification and the ability to think critically. I would still bet against an actual reversal of the mean zonal wind.

[donsutherland1]

For another illustration of the importance of the PNA for parts of the East, the EPS is forecasting a WPO-/EPO-/AO-/PNA- pattern for the first 10 days of December. Setting aside skill issue at that range, here's how things have fared 1980-2024 when the only difference was a PNA- vs. a PNA+. I used NYC, but the same applies broadly to the Middle Atlantic Region.

[40/70 Benchmark]

1 hour ago, bluewave said:

I have been using RONI for La Ninas since they are being defined more these days by how warm the WPAC is vs how cold Niña 3.4 is. So by this newer definition December 2024 was a moderate La Niña.. Plus early snowfall indicator being under or over 4” also works for LGA and EWR.

It has worked for 14 out of the last 15 La Ninas events as defined by RONI since 1995-1996. My guess is that this relationship has become so prominent in the last 30 years due to the more frequent repeating weather patterns as the climate has warmed. 

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

DJF  2025 -1.12 moderate La Nina RONI

 

Last year was close...I ultimately deemed it moderate after considering MEI and ONI. -1ish can go either way...if the RONI were like -1.3, then I would have called it moderate.

[GaWx]

20 minutes ago, snowman19 said:

I took BAMWX’s word for it. Lol I guess they are mistaken?

 

 

 

 

There are no official Nov or Dec major SSWs based on reversals at 10 mb for any of 1983, 1989, and 2000.

To be fair if you read this closely, BAMwx isn’t explicitly saying that there was an early major SSW in any of those 3 years (if they were they’d be wrong):

A few of these years were absolutely blockbuster in December. Chances to replicate the intensity of cold in years like 2000, 1989 and 1983 are unlikely, but there is strong support notable cold the first half of December setting up.

 That’s not to say that the SPV wasn’t weak. Despite no reversal, 2000 was quite weak mid-Nov through Dec with a low of +4 to +5 m/s in late Nov as per the chart below: (I don’t have these charts for 1983 and 1989….does anyone else have a link to them?):

[donsutherland1]

1 hour ago, bluewave said:

I have been using RONI for La Ninas since they are being defined more these days by how warm the WPAC is vs how cold Niña 3.4 is. So by this newer definition December 2024 was a moderate La Niña.. Plus early snowfall indicator being under or over 4” also works for LGA and EWR.

It has worked for 14 out of the last 15 La Ninas events as defined by RONI since 1995-1996. My guess is that this relationship has become so prominent in the last 30 years due to the more frequent repeating weather patterns as the climate has warmed. 

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

DJF  2025 -1.12 moderate La Nina RONI

 

I agree. Hopefully, CPC will start using RONI as its official measure. In any case, the relationship holds true with ONI or RONI.

[40/70 Benchmark]

14 minutes ago, GaWx said:

There are no official Nov or Dec major SSWs based on reversals at 10 mb for any of 1983, 1989, and 2000.

To be fair if you read this closely, BAMwx isn’t explicitly saying that there was an early major SSW in any of those 3 years (if they were they’d be wrong):

A few of these years were absolutely blockbuster in December. Chances to replicate the intensity of cold in years like 2000, 1989 and 1983 are unlikely, but there is strong support notable cold the first half of December setting up.

 That’s not to say that the SPV wasn’t weak. Despite no reversal, 2000 was quite weak mid-Nov through Dec with a low of +4 to +5 m/s in late Nov as per the chart below: (I don’t have these charts for 1983 and 1989….does anyone else have a link to them?):

Larry, what is the link to get that historical 60* mean zonal wind data?

Thanks.

[EastonSN+]

14 minutes ago, donsutherland1 said:

For another illustration of the importance of the PNA for parts of the East, the EPS is forecasting a WPO-/EPO-/AO-/PNA- pattern for the first 10 days of December. Setting aside skill issue at that range, here's how things have fared 1980-2024 when the only difference was a PNA- vs. a PNA+. I used NYC, but the same applies broadly to the Middle Atlantic Region.

Thanks Don.

The failed blocking episodes prior to last year all included an RNA, which makes the "blocking no longer works" commentary even more perplexing (not from you). Last years blocking failed due suppression of course.

[MJO812]

24 minutes ago, 40/70 Benchmark said:

They always get blown out of proportion. Indicative of the decay of society....increased proclivity towards instant gratification and shorter attention spans, decreased tendency towards delayed gratification and the ability to think critically. I would still bet against an actual reversal of the mean zonal wind.

I have watched so many videos on YouTube stating this is an unusual event unfolding and watch out for major cold and snow in the east coming up.

[GaWx]

7 minutes ago, 40/70 Benchmark said:

Larry, what is the link to get that historical 60* mean zonal wind data?

Thanks.

Ray,

 You have to go to the bottom of this and then choose the winter:

http://arctic.som.ou.edu/tburg/products/realtime/strat/

 Unfortunately, one can go back only to 1990-1 from this source for some reason even though graphs exist back at least to 1958-9.

[40/70 Benchmark]

11 minutes ago, MJO812 said:

I have watched so many videos on YouTube stating this is an unusual event unfolding and watch out for major cold and snow in the east coming up.

The only unusual element is in the event that the zonal wind actually reverses this early, which is still dubious IMHO. This is the latest example of how online forecasting is more geared towards attracting attention and generating revenue, as opposed to adding actual value.

[jm1220]

8 minutes ago, MJO812 said:

I have watched so many videos on YouTube stating this is an unusual event unfolding and watch out for major cold and snow in the east coming up.

How many of them have a link they want you to click so they can get subscriptions? 

Look I don’t doubt there could be a cold/snowy December and many signs are pointing that way, but the “major cold and snow11!111!!” should be met with skepticism.