2025-2026 ENSO

[40/70 Benchmark]

6 hours ago, 40/70 Benchmark said:

SON is -.85

 

1 hour ago, BlizzardWx said:

That's fair. I think the tri-monthly is around -0.9 eyeballing it. 

Close..

[vegan_edible]

1 hour ago, MJO812 said:

You just love being wrong.  Its amazing. 

dont even stress it. bro doesnt have the computational output to look at an ensemble rather an op model

[GaWx]

 Today’s Euro Weeklies for the 4 weeks Dec 22nd through Jan 18th continue to look bad (mild) especially in the SE and MidAtlantic. There’s no way to sugarcoat it. The hope is that they’re just pain wrong. But that’s just a hope:

12/22-28:

12/29-1/4:

1/5-11

1/12-18:

[PhiEaglesfan712]

The MEI finally updated. Here are the values for the past several months:

MJ 2025: -1.2

JJ 2025: -1.2

JA 2025: -0.9

AS 2025: -1.1

SO 2025: -1.2

ON 2025: -1.1

[Krs4Lfe]

Things are looking rather ugly later in the month. Looks like we lose the cold real quickly around the 20th or so. If we’re going to see snow for rest of month it should be in that period. La Ninas are notorious for torches in January and February. Not seeing any signs of anything different this time around. I could even seen a December 2022 repeat. Great pattern but 0 snow. The worst of the worst 

[MJO812]

8 minutes ago, Krs4Lfe said:

Things are looking rather ugly later in the month. Looks like we lose the cold real quickly around the 20th or so. If we’re going to see snow for rest of month it should be in that period. La Ninas are notorious for torches in January and February. Not seeing any signs of anything different this time around. I could even seen a December 2022 repeat. Great pattern but 0 snow. The worst of the worst 

I will be saving this post

[stadiumwave]

25 minutes ago, Krs4Lfe said:

Things are looking rather ugly later in the month. Looks like we lose the cold real quickly around the 20th or so. If we’re going to see snow for rest of month it should be in that period. La Ninas are notorious for torches in January and February. Not seeing any signs of anything different this time around. I could even seen a December 2022 repeat. Great pattern but 0 snow. The worst of the worst 

 

Agree on the end of month, but disagree on JAN. The best analogs have JAN as the coldest month. So, I think based on the law of averages, we have a decent shot of seeing at least a period of winter in JAN. 

[anthonymm]

1 hour ago, Krs4Lfe said:

Things are looking rather ugly later in the month. Looks like we lose the cold real quickly around the 20th or so. If we’re going to see snow for rest of month it should be in that period. La Ninas are notorious for torches in January and February. Not seeing any signs of anything different this time around. I could even seen a December 2022 repeat. Great pattern but 0 snow. The worst of the worst 

Yup I believe i pointed out 22-23 was a great analog

[Krs4Lfe]

6 minutes ago, anthonymm said:

Yup I believe i pointed out 22-23 was a great analog

Yeah once we ended up getting 0” that month after a great pattern, and January was warm and a shutout; I knew we were in for one of the least snow winters ever. 

[anthonymm]

1 minute ago, Krs4Lfe said:

Yeah once we ended up getting 0” that month after a great pattern, and January was warm and a shutout; I knew we were in for one of the least snow winters ever. 

Thats how nina decembers go. Getting 0" is a la nina december is a great way to ensure getting a historically least snowy winter. This winter could be over by about the 15th if we dont have anything credible to track unfortunately

[MJO812]

5 minutes ago, anthonymm said:

Thats how nina decembers go. Getting 0" is a la nina december is a great way to ensure getting a historically least snowy winter. This winter could be over by about the 15th if we dont have anything credible to track unfortunately

Why do you keep doing this to yourself? 

[bncho]

 

10 minutes ago, anthonymm said:

Thats how nina decembers go. Getting 0" is a la nina december is a great way to ensure getting a historically least snowy winter. This winter could be over by about the 15th if we dont have anything credible to track unfortunately

It's only December 9th and you're calling winter over already? lmao

[PhiEaglesfan712]

1 hour ago, stadiumwave said:

 

Agree on the end of month, but disagree on JAN. The best analogs have JAN as the coldest month. So, I think based on the law of averages, we have a decent shot of seeing at least a period of winter in JAN. 

This only works if December torches, like in 2015, 2021, or 2023.

A cold December, like this one, makes it more likely, based on the law of averages, a torch will happen in January. The period of winter might already be happening.

[MJO812]

1 minute ago, PhiEaglesfan712 said:

This only works if December torches, like in 2015, 2021, or 2023.

A cold December, like this one, makes it more likely, based on the law of averages, a torch will happen in January. The period of winter might already be happening.

There are other factors like the weakening La nina , MJO , etc.

[Cobalt]

2 minutes ago, PhiEaglesfan712 said:

This only works if December torches, like in 2015, 2021, or 2023.

A cold December, like this one, makes it more likely, based on the law of averages, a torch will happen in January. The period of winter might already be happening.

Sounds like a bit of gambler's fallacy also. 

[Krs4Lfe]

11 minutes ago, PhiEaglesfan712 said:

This only works if December torches, like in 2015, 2021, or 2023.

A cold December, like this one, makes it more likely, based on the law of averages, a torch will happen in January. The period of winter might already be happening.

I think it would be a lot better if we saw *something* here this month. Ideally, if NYC saw 4”+ we would Be in ok shape because 4” is the magic number. That being said, lots of signs for a warm up after rhe 20th

[EasternLI]

12z EPS mean at hour 360:

 

At face value, this looks like quite a huge ridge for the east is inevitable. Potentially a protracted one at that. Looks can be deceiving. Such as the cases when ensembles show epic patterns that fail to come to fruition. There's actually a lot going on under the hood in the model run when you take a little deeper look into it. Ensemble means will just blend everything together and give you whatever that looks like. As it stands right now, based off of this run, at this hour of the run. That likely doesn't verify verbatim. You're seeing a smoothed out mean of different solutions. Take for instance the cluster analysis from the same run at the same time. 3 clusters for that period today. Not what you would expect to see given the above image. Especially seeing the left one as the leading cluster, encompassing the greatest amount of individual members. This is all subject to change of course based on future runs. I'm simply suggesting to stay open minded.

 

Also interesting to note from this run of the EPS is the situation with the MJO. Personally, I'm of the firm belief that any legitimate Phase 8 attempt has not occured. For reasons mentioned earlier in this thread. Regardless of what the RMM plots are showing/telling everyone. The signal was pushed there via the strong (aided by events in the stratosphere) kelvin wave but abandoned just as it got there while the kelvin wave had continued on. That kelvin wave went on to amplify the MC forcing in the near term which has been discussed and we will likely see ramifications from. Meanwhile, keep in mind this is/has been the slow moving variety of MJO. Kelvin waves move much faster and they are the high frequency component Paul Roundy makes references of from time to time.

 

So on this 12z run today, there are finally some surprising hints of perhaps attaining an actual period of phase 8 forcing from this MJO event. As the kelvin wave moves on from the MC region and picks up the underlying original MJO signal that was previously abandoned in phase 8. Then re-amplifying that signal and potentially in the legitimate way this time. See the following velocity potential forecast from this run. Where I have circled is the key timeframe as to whether or not that happens. As myself and others here believe, we need this suppressed phase to take over the MC completely in addition to the western hemisphere enhanced phase in order to properly accomplish that. Looking over the individual members VP forecasts, there are finally a good cluster of members doing exactly what is needed. In the timeframe that is circled. Hence the look on this mean today. Will be interesting to follow future runs in light of this considering individual members were quite literally all over the place in previous runs. There's a group of them that are on board with this idea today though.

[Benjamn3]

4 minutes ago, EasternLI said:

12z EPS mean at hour 360:

 

At face value, this looks like quite a huge ridge for the east is inevitable. Potentially a protracted one at that. Looks can be deceiving. Such as the cases when ensembles show epic patterns that fail to come to fruition. There's actually a lot going on under the hood in the model run when you take a little deeper look into it. Ensemble means will just blend everything together and give you whatever that looks like. As it stands right now, based off of this run, at this hour of the run. That likely doesn't verify verbatim. You're seeing a smoothed out mean of different solutions. Take for instance the cluster analysis from the same run at the same time. 3 clusters for that period today. Not what you would expect to see given the above image. Especially seeing the left one as the leading cluster, encompassing the greatest amount of individual members. This is all subject to change of course based on future runs. I'm simply suggesting to stay open minded.

 

Also interesting to note from this run of the EPS is the situation with the MJO. Personally, I'm of the firm belief that any legitimate Phase 8 attempt has not occured. For reasons mentioned earlier in this thread. Regardless of what the RMM plots are showing/telling everyone. The signal was pushed there via the strong (aided by events in the stratosphere) kelvin wave but abandoned just as it got there while the kelvin wave had continued on. That kelvin wave went on to amplify the MC forcing in the near term which has been discussed and we will likely see ramifications from. Meanwhile, keep in mind this is/has been the slow moving variety of MJO. Kelvin waves move much faster and they are the high frequency component Paul Roundy makes references of from time to time.

 

So on this 12z run today, there are finally some surprising hints of perhaps attaining an actual period of phase 8 forcing from this MJO event. As the kelvin wave moves on from the MC region and picks up the underlying original MJO signal that was previously abandoned in phase 8. Then re-amplifying that signal and potentially in the legitimate way this time. See the following velocity potential forecast from this run. Where I have circled is the key timeframe as to whether or not that happens. As myself and others here believe, we need this suppressed phase to take over the MC completely in addition to the western hemisphere enhanced phase in order to properly accomplish that. Looking over the individual members VP forecasts, there are finally a good cluster of members doing exactly what is needed. In the timeframe that is circled. Hence the look on this mean today. Will be interesting to follow future runs in light of this considering individual members were quite literally all over the place in previous runs. There's a group of them that are on board with this idea today though.

“We can hold our gates. 
We can win. “

[George001]

11 hours ago, PhiEaglesfan712 said:

Pretty much all the metrics are screaming at me "warm January and February". I mean, we got a deep -IOD. The last 2 times we had that, January and February literally torched.

89-90 is once in a lifetime, though. We had the coldest December, than turned into spring in January, and winter never really returned.

PHL temperatures (Dec 1989-Mar 1990):

Dec 89: 25.5

Jan 90: 40.3

Feb 90: 41.2

Mar 90: 46.1

A 15-degree increase in between December and January is absurd. That's something you see in between spring months (and sometimes, you don't even get a monthly swing that big).

The Decembers in 95, 00, 05, and 10 all ended up in the 31-34.5 range (and this December may end up not even being that cold), so the turnaround won't be as dramatic.

I don’t agree. Yes, the deep -IOD is a warm signal but it has weakened significantly since earlier in the fall, and the other factors are more tilted towards cold than say 89-90. 89-90 was a strong La Niña, this is a weak La Niña. Also, the PDO has risen a lot in recent weeks to weakly negative rather than strongly negative. I will concede that Feb has warmer risks, but think we are getting slammed in Jan. Maybe 1 warm week, but I think we go BN temp with well AN snow in the east, especially for northern areas. It will be interesting to see how things play out.

[George001]

3 hours ago, MJO812 said:

I will be saving this post

Yep. He’s not wrong that a snowless December in La Niña bodes poorly for the rest of winter, but a lot can happen in 3 weeks.

[raindancewx]

My assumption for winter was 2025-26 as primarily a blend of 2013-14 and 2024-25. The weighting will vary between the two by month, but December now looks pretty warm West (like 2024) and pretty cold East (like 2013). Will be curious on the exact splits, as that's likely the correct weighting going forward and the pattern should weaken and then change by month end.

Southwest US warmest Novembers on record tend to follow the same pattern here. For New Mexico the warmth slowly diminishes in intensity after an early-mid Nov heat burst in the valleys (5,000 ft+) to 75F or so, until you eventually arrive at a seasonal or cool month in the late winter-spring transition.

Our warmest Novembers here are 2017, 1995, 1949, 2021, 1999, 2020, 1954, 2007, 2012, 1965.

17-18 was never really cold, but it did go from no rain/snow for 96 days and warm, to a wet/cooler period mid-Feb to mid-Mar. Similar for 1995-96, 2021-22, 1999-00, 2020-21. 1949-50 was cold in Dec, same for 1954-55.  07-08 was cold Dec-Jan. 2012-13 was cold Jan-Feb - 1965-66 too. Since we didn't get the cold Dec here, almost all other periods following a super warm Nov are either very cold Jan-Feb, or Feb-Mar...so Feb is the signal.

[qg_omega]

5 hours ago, vegan_edible said:

dont even stress it. bro doesnt have the computational output to look at an ensemble rather an op model

[raindancewx]

Nov/Feb/Mar

[PhiEaglesfan712]

9 hours ago, George001 said:

I don’t agree. Yes, the deep -IOD is a warm signal but it has weakened significantly since earlier in the fall, and the other factors are more tilted towards cold than say 89-90. 89-90 was a strong La Niña, this is a weak La Niña. Also, the PDO has risen a lot in recent weeks to weakly negative rather than strongly negative. I will concede that Feb has warmer risks, but think we are getting slammed in Jan. Maybe 1 warm week, but I think we go BN temp with well AN snow in the east, especially for northern areas. It will be interesting to see how things play out.

88-89 was the strong la nina. 89-90 was a dissipating weaker la nina/cold neutral, and was firmly ENSO neutral by the time the winter was over.

The IOD was still at -1.4 on November 24, pretty much comparable to 2016 and 2022, both of which were low snow winters at PHL, and torched in January and February. The mid-March snowstorm in 2017 kept that year from being another below 10 inch snowfall season at PHL, and we all know the disaster that 2022-23 was.

Cold and low snow Decembers are the worst combination. They almost always produce torch Januarys and Februarys. Come to think of it, I can't remember a time when a cold and low snow December produced a great rest of the winter.

[bluewave]

On 12/8/2025 at 4:03 PM, LakePaste25 said:

Models have been placing the block too far west, which impacts how much it bleeds into the EPO domain. Take the 11th-14 for example. A week ago, the EPS had a positive EPO for this time period. Now, it has a deeply negative EPO.

 

This is similar to what happened last year at this time with the models. Last December started with the extended guidance locking in the -EPO for the whole month. But as we approached the December 10th, the models caught onto how much stronger the Pacific Jet would be and the warmer +EPO pattern.

Now the Pacific Jet is forecast to be much stronger mid-December than was indicated last week. Notice how much deeper the +EPO vortex is forecast to be now even with a near record -WPO 500 mb block.

In the old days we would usually have the Pacific Jet weaken and we get more of a -WPO -EPO block. So we are on track for our annual warm up from December 17th to 25th. The +EPO is now forecast to becomes more dominant for our sensible weather than the -WPO as the Pacific Jet overpowers the pattern again.

New run

Old run

[MJO812]

JB agress with Paul Roundy in regards to a milder break ahead . He does say right back to cold after that .

[snowman19]

11 hours ago, George001 said:

I don’t agree. Yes, the deep -IOD is a warm signal but it has weakened significantly since earlier in the fall, and the other factors are more tilted towards cold than say 89-90. 89-90 was a strong La Niña, this is a weak La Niña. Also, the PDO has risen a lot in recent weeks to weakly negative rather than strongly negative. I will concede that Feb has warmer risks, but think we are getting slammed in Jan. Maybe 1 warm week, but I think we go BN temp with well AN snow in the east, especially for northern areas. It will be interesting to see how things play out.

Every single IOD event (negative or positive) in history has weakened in December. It peaks in October/November then weakens in December. This is perfectly normal climo, no matter how strong the event peaks, every one of them has done this

[brooklynwx99]

not surprising that we're seeing a warmer interlude with some -VP contaminating things in the IO and western MC. this quickly changes back to strong WHEM forcing in late Dec, likely signaling a flip back to a more favorable pattern after Christmas and into the New Year

[snowman19]

37 minutes ago, bluewave said:

This is similar to what happened last year at this time with the models. Last December started with the extended guidance locking in the -EPO for the whole month. But as we approached the December 10th, the models caught onto how much stronger the Pacific Jet would be and the warmer +EPO pattern.

Now the Pacific Jet is forecast to be much stronger mid-December than was indicated last week. Notice how much deeper the +EPO vortex is forecast to be now even with a near record -WPO 500 mb block.

In the old days we would usually have the Pacific Jet weaken and we get more of a -WPO -EPO block. So we are on track for our annual warm up from December 17th to 25th. The +EPO is now forecast to becomes more dominant for our sensible weather than the -WPO as the Pacific Jet overpowers the pattern again.

New run

Old run

There is still a standing wave at the MC (phases 4-6) until that changes, this is going to keep happening 

[MJO812]

Just now, snowman19 said:

There is still a standing wave at the MC (phases 4-6) until that changes, this is going to keep happening 

That's why we will warm up a bit.