2025-2026 ENSO

[GaWx]

 Natural gas is down still another 3% today making it a total of a whopping 29% just since the high of Dec 4th!

[leo2000]

Those Euro weeklies are horrendously warm!

 

[michsnowfreak]

After the holiday mild period, will be interesting to see if Jan-Feb takes on a classic nina like roller coaster pattern. With plenty of cold in Canada and plenty of warmth to the south, that may just be in the offing as we head deeper into winter. 

[snowman19]

1 hour ago, leo2000 said:

Those Euro weeklies are horrendously warm!

 

At least you said it. I saw them but wasn’t going to mention it. Didn’t want to start anything. But since you brought it up, verbatim, they look like January, 1990. No exaggeration, they are extremely ugly

[SnowGoose69]

Just now, snowman19 said:

At least you said it. I saw them but wasn’t going to mention it. Didn’t want to start anything. But since you brought it up, verbatim, they look like January, 1990

Chances are those will be wrong.  The evolution looks more like an El Nino than anything else as late January looks like the transition you'd often see begin to happen in that type of winter.  I highly doubt we have a cold +PNA February 

[EastonSN+]

22 minutes ago, snowman19 said:

At least you said it. I saw them but wasn’t going to mention it. Didn’t want to start anything. But since you brought it up, verbatim, they look like January, 1990. No exaggeration, they are extremely ugly

IF IF it happened that way, at least this December was better snowfall wise than 1989 lol. That year had a heartbreaking snow to rain storm in the middle of one of the coldest Decembers in history. 1989/1990 was probably the most disappointing in my lifetime.

[michsnowfreak]

32 minutes ago, snowman19 said:

At least you said it. I saw them but wasn’t going to mention it. Didn’t want to start anything. But since you brought it up, verbatim, they look like January, 1990. No exaggeration, they are extremely ugly

They do not look like January 1990 verbatim. January 1990 was much warmer in the Northeast and midwest than today's run of the euro weeklies is for January 2026. You are essentially doing the same thing you constantly criticize JB for doing. You are taking a mild look and throwing out eye catching warm years past, despite the fact they dont match.

[EasternLI]

Personally, I'm thinking this 8-10 day range here is pretty meaningful. Does Santa deliver a true Scandinavian block or not. Some of these half attempts probably don't work well for us. This is from the 12z eps cluster analysis. 5 of them for this period today. Todays Euro OP says no, and is grouped with cluster 2. Cluster 1 on the eps, populated with a greater number of members says yes. I flipped this for easier viewing of our side of the world. So clusters 1-5 is left to right. Days 8-10 are bottom to top. If we do happen to see an amplified block like the 1st cluster is displaying then you'd probably see a pretty big wave 2 shot that goes up into the strat along with it. If that does not happen, then you won't see that. Probably not a retrograde to a true -NAO block either I would assume. You can see it expressed in the EPS strat mean during this timeframe too. Which is most likely reflecting that potential feature in the members. One way or another, we want to see that block happen. Incidentally, there are factors which support the block to indeed happen based on reasons laid out in this thread already. We wait and see if one does actually materialize but it does appear as a favored outcome in this 12z eps run as well.

[qg_omega]

18 hours ago, GaWx said:

 Well, as of Dec 13th, the MJO still hasn’t returned to phase 8! It was in 8 only Dec 3rd-7th. Dec 8th-13th have all been in very weak (essentially neutral) phases 5-7. I still think it has a good chance to get back into 8 very soon, but we’ll see:

We went from historic phase 8 length to 4 days of verification 

[MJO812]

3 hours ago, leo2000 said:

Those Euro weeklies are horrendously warm!

 

Wait until today for another solution 

Gefs is pulling back on the warmth again. Continue to watch the Christmas timeframe for a storm in the northeast.

[MJO812]

Steve D thinks the same like others about  moving forward.  

[George001]

1 hour ago, qg_omega said:

We went from historic phase 8 length to 4 days of verification 

I know we don’t always see eye to eye, but this is a good observation and explains why we are seeing a relaxation period instead of a wall to wall cold December. It was initially expected to spend the entire month in phase 8, but things changed. It’s important to update and adjust our expectations accordingly with new information. 

[EasternLI]

This run is vastly different from all the previous gefs runs along the eastern seaboard.

[George001]

23 minutes ago, MJO812 said:

Wait until today for another solution 

Gefs is pulling back on the warmth again. Continue to watch the Christmas timeframe for a storm in the northeast.

I agree with pumping the breaks on the warmth. However, as someone who pounded the table for a big January I am keeping an open mind to the idea it may not be as frigid as I expected. I do still think it will be a big month for northern areas. We will know more after the Christmas timeframe.

[donsutherland1]

I have no big changes from yesterday. Going forward, the WPO- is likely to become less negative and the EPO could go negative for a time, which would blunt the full effects of warming across the northern tier of the U.S. and especially Canada. The PNA will remain persistently negative.

The changes favor a Southeast ridge, strong trough in the Pacific Northwest, and a weakening trough over the Northeast and eastern Canada. Thus, the southern tier of the U.S. and perhaps most of the CONUS could see a warmer than normal December 20-31 period overall. The warmup could take time to develop in New England and the upper Midwest. Canada should remain broadly colder than normal for the period overall. 

There's a chance that the warmth could finally overspread the Northeast as December concludes and January starts. Should an EPO+/AO+ pattern develop, that would increase prospects for warmth in the Northeast. The EPS favors a near neutral AO while the GEFS favors a negative one.

[40/70 Benchmark]

4 hours ago, 40/70 Benchmark said:

Pattern update.

https://easternmassweather.blogspot.com/2025/12/mid-month-warm-up-arrives-on-schedule.html

 

[40/70 Benchmark]

47 minutes ago, George001 said:

I agree with pumping the breaks on the warmth. However, as someone who pounded the table for a big January I am keeping an open mind to the idea it may not be as frigid as I expected. I do still think it will be a big month for northern areas. We will know more after the Christmas timeframe.

Doubtful....at least in the mean.

[Krs4Lfe]

Ski resorts will get a big one in the northwest. Blizzard warnings posted for the cascades which isn’t typical over there, even in the winter. Looks like a North Dakota and north Minnesota blizzard as well. Lots of high winds with this Incoming storm, entire intermountain west will see 60+, with mountain ranges seeing up to 90. Could be quite the power outage event over there over next 24-36 hours. Northwest coast has been pounded with rain past week and it’ll only be heavier this week as well. 

[40/70 Benchmark]

4 hours ago, EastonSN+ said:

IF IF it happened that way, at least this December was better snowfall wise than 1989 lol. That year had a heartbreaking snow to rain storm in the middle of one of the coldest Decembers in history. 1989/1990 was probably the most disappointing in my lifetime.

Not here it wasn't. 

[40/70 Benchmark]

2 hours ago, George001 said:

I know we don’t always see eye to eye, but this is a good observation and explains why we are seeing a relaxation period instead of a wall to wall cold December. It was initially expected to spend the entire month in phase 8, but things changed. It’s important to update and adjust our expectations accordingly with new information. 

....or call BS on it beforehand via own obervations.

[raindancewx]

I'm running +7 or +8 month to date here, while Boston is running -7 to -8 month to date...but we've still had more snow than Boston even with less precipitation and a warmer base climate.

Really is a pretty weird pattern this month - everything is a bit off from normal flow and progression.

[PhiEaglesfan712]

5 hours ago, EastonSN+ said:

IF IF it happened that way, at least this December was better snowfall wise than 1989 lol. That year had a heartbreaking snow to rain storm in the middle of one of the coldest Decembers in history. 1989/1990 was probably the most disappointing in my lifetime.

2000-01 was the most disappointing in my lifetime. I know this one technically ended with above average snowfall, but the epic snow bust in early March left a very sour taste. Oh what could have been if the forecast had even come close to verifying.

[GaWx]

 Today’s GEFS is progging ~-1.7 PNA for Dec as a whole. That would be ~5th strongest -PNA since 1950. But what were similarly strong -PNA Dec followed by in Jan since 1984-5 during -ENSO?

1984-5: from -1.6 to +1.6

2008-9: from -1.4 to +0.6

2010-1: from -1.8 to +1.3

2021-2: from -2.6 to +1.0

 All 4 of these Januaries were cold in the E US.

[Daniel Boone]

18 minutes ago, GaWx said:

 Today’s GEFS is progging ~-1.7 PNA for Dec as a whole. That would be ~5th strongest -PNA since 1950. But what were similarly strong -PNA Dec followed by in Jan since 1984-5 during -ENSO?

1984-5: from -1.6 to +1.6

2008-9: from -1.4 to +0.6

2010-1: from -1.8 to +1.3

2021-2: from -2.6 to +1.0

 All 4 of these Januaries were cold in the E US.

Everyone of them went to a +PNA. Wow .

[Daniel Boone]

2 hours ago, 40/70 Benchmark said:

Not here it wasn't. 

Not here either. December '89 was colder and snowier.

[Stormchaserchuck1]

1 hour ago, GaWx said:

 Today’s GEFS is progging ~-1.7 PNA for Dec as a whole. That would be ~5th strongest -PNA since 1950. But what were similarly strong -PNA Dec followed by in Jan since 1984-5 during -ENSO?

1984-5: from -1.6 to +1.6

2008-9: from -1.4 to +0.6

2010-1: from -1.8 to +1.3

2021-2: from -2.6 to +1.0

 All 4 of these Januaries were cold in the E US.

I don't really get this "negative ENSO turned -PNA to +PNA" since 1980 thing. 

1. Why does it only start in the 1980s? Data was not unreliable before then, so it's not like you're starting from a blank point. I think a lack of examples increases the odds of random. If it didn't work before 1980, that's telling, not an ignored difference.

2. That's not what Negative ENSO does. Negative ENSO does not support a +PNA in January. The Hadley cell is extended in the N. Pacific in La Nina more often than not, and that supports -PNA. 

Since we are having such a strong -PNA December, here is a fun roll forward. This is what 500mb January looks like after -PNA Dec.. this is a total composite of 73 years, both - and + signs considered, going back to 1948:

That's an Aleutian ridge in the mean for January. But the ridge is a little further NE, which makes January a cold month for a lot of the US. 

The reason why it will sometimes switch is the MJO runs if 45-day cycles and Kelvin and Rossby waves sometimes run in 45-60 day cycles. We don't have a strong phase of those things now -- it will be interesting to see if we do go more +PNA after the 1st week of January. I think you are discovering a high mathematical random skew. 

[GaWx]

23 minutes ago, Stormchaserchuck1 said:

I don't really get this "negative ENSO turned -PNA to +PNA" since 1980 thing. 

1. Why does it only start in the 1980s? Data was not unreliable before then, so it's not like you're starting from a blank point. I think a lack of examples increases the odds of random. If it didn't work before 1980, that's telling, not an ignored difference.

2. That's not what Negative ENSO does. Negative ENSO does not support a +PNA in January. The Hadley cell is extended in the N. Pacific in La Nina more often than not, and that supports -PNA. 

Since we are having such a strong -PNA December, here is a fun roll forward. This is what 500mb January looks like after -PNA Dec.. this is a total composite of 73 years, both - and + signs considered, going back to 1948:

That's an Aleutian ridge in the mean for January. But the ridge is a little further NE, which makes January a cold month for a lot of the US. 

The reason why it will sometimes switch is the MJO runs if 45-day cycles and Kelvin and Rossby waves sometimes run in 45-60 day cycles. We don't have a strong phase of those things now -- it will be interesting to see if we do go more +PNA after the 1st week of January. I think you are discovering a high mathematical random skew. 

Hey Chuck,

 Here’s a post I made on Friday going all of the way back to 1950 that shows that for some reason (possibly randomness) the sharpest rises from a sub -1 PNA Dec to Jan have occurred since 1984-5 (CC related?):

 

“This implies the realistic chance for a sub -1 Dec PNA. Whereas that’s bad news for those wanting E US cold in the 2nd half of Dec in the MidAtlantic/OH Valley south, it isn’t necessarily bad news for January prospects. That’s because in the vast majority of cases for -ENSO, the PNA in January rose sharply from Dec:

 

PNA Dec/Jan for -ENSO for strongly -PNA in Dec

- 1955-6: -2.1/-1.3 (rose 0.8)

- 1961-2: -1.2/-0.1 (rose 1.1)

- 1964-5: -1.7/-0.2 (rose 1.5)

- 1971-2: -1.5/-1.4 (rose 0.1)

- 1984-5: -1.6/+1.6 (rose 3.2)

- 1996-7: -1.2/+0.6 (rose 1.8)

- 2008-9: -1.4/+0.6 (rose 2.0)

- 2010-1: -1.8/+1.3 (rose 3.1)

- 2012-3: -1.0/+0.6 (rose 1.6)

- 2013-4: -0.9/+1.0 (rose 1.9)

- 2021-2: -2.6/+1.0 (rose 3.6)

So, average PNA rise Dec to Jan for these was a whopping 1.9!

[Stormchaserchuck1]

6 minutes ago, GaWx said:

Hey Chuck,

 Here’s a post I made on Friday going all of the way back to 1950 that shows that for some reason (possibly randomness) the sharpest rises from a sub -1 PNA Dec to Jan have occurred since 1984-5 (CC related?):

 

“This implies the realistic chance for a sub -1 Dec PNA. Whereas that’s bad news for those wanting E US cold in the 2nd half of Dec in the MidAtlantic/OH Valley south, it isn’t necessarily bad news for January prospects. That’s because in the vast majority of cases for -ENSO, the PNA in January rose sharply from Dec:

 

PNA Dec/Jan for -ENSO for strongly -PNA in Dec

- 1955-6: -2.1/-1.3 (rose 0.8)

- 1961-2: -1.2/-0.1 (rose 1.1)

- 1964-5: -1.7/-0.2 (rose 1.5)

- 1971-2: -1.5/-1.4 (rose 0.1)

- 1984-5: -1.6/+1.6 (rose 3.2)

- 1996-7: -1.2/+0.6 (rose 1.8)

- 2008-9: -1.4/+0.6 (rose 2.0)

- 2010-1: -1.8/+1.3 (rose 3.1)

- 2012-3: -1.0/+0.6 (rose 1.6)

- 2013-4: -0.9/+1.0 (rose 1.9)

- 2021-2: -1.6/+1.0 (rose 2.6)

So, average PNA rise Dec to Jan for these was a whopping 1.8!”

Hey Larry, 

All of your examples 1950-1980 were -PNA January. Then you have only 7 examples after 1980.. now 7/7 is a strong point, I agree, but it might be in the field of random if you consider what ENSO is/does. A good test would be the opposite: What did January do in +ENSO after a +PNA December? What there a difference 1950-1980 and after 1980 (I haven't run the data, but will say probably not - just guessing). My map in the last post includes that, so since it rolls forward to a pretty strong N. Pacific ridge in January, I'm thinking it probably doesn't check out the other way around: (does +PNA Dec lead to -PNA Jan in +ENSO?).

[GaWx]

7 minutes ago, Stormchaserchuck1 said:

Hey Larry, 

All of your examples 1950-1980 were -PNA January. Then you have only 7 examples after 1980.. now 7/7 is a strong point, I agree, but it might be in the field of random if you consider what ENSO is/does. A good test would be the opposite: What did January do in +ENSO after a +PNA December? What there a difference 1950-1980 and after 1980 (I haven't run the data, but will say probably not - just guessing). My map in the last post includes that, so since it rolls forward to a pretty strong N. Pacific ridge in January, I'm thinking it probably doesn't check out the other way around: (does +PNA Dec lead to -PNA Jan in +ENSO?).

Chuck,

 Let’s see. I’m looking now at +ENSO 1+ PNA Decembers to Januaries: there were 8 cases:

- 1953-4 +1.3 to -1.1: drop of 2.4

- 1963-4 +1.8 to +0.2: drop of 1.6

- 1969-70 +1.8 to +0.6: drop of 1.2

- 1986-7 +1.4 to +1.0: drop of 0.4

- 1997-8 +1.2 to +0.7: drop of 0.5

- 2002-3 +1.6 to +1.3: drop of 0.3

- 2006-7 +1.9 to +0.7: drop of 1.2

- 2023-4 +1.2 to +0.5: drop of 0.7

 

- avg drop 1.0

- avg drop much higher for 1st 3 cases (1.7) vs last 5 (0.6)

———— 
Your thoughts?

[Stormchaserchuck1]

16 minutes ago, GaWx said:

Chuck,

 Let’s see. I’m looking now at +ENSO 1+ PNA Decembers to Januaries: there were 8 cases:

- 1953-4 +1.3 to -1.1: drop of 2.4

- 1963-4 +1.8 to +0.2: drop of 1.6

- 1969-70 +1.8 to +0.6: drop of 1.2

- 1986-7 +1.4 to +1.0: drop of 0.4

- 1997-8 +1.2 to +0.7: drop of 0.5

- 2002-3 +1.6 to +1.3: drop of 0.3

- 2006-7 +1.9 to +0.7: drop of 1.2

- 2023-4 +1.2 to +0.5: drop of 0.7

 

- avg drop 1.0

- avg drop much higher for 1st 3 cases (1.7) vs last 5 (0.6)

———— 
Your thoughts?

Yeah, it neutralizes. If you start from the most extreme point, it should come toward evening out. Still, ENSO is a powerful factor so I would have thought the +PNA January's would be more extreme. 6/7 were +PNA January's though, and since 1980, 5/5 were +PNA January's. It neutralizes the other side/point. Still, a net neutral signal in January-ENSO is something. Will be interesting to watch and see how this January evolves, I do know that Natural Gas led these Euro weeklies and all this warm stuff for Jan by some time! I'm going to say that they are probably too warm, but we'll see.