2025-2026 ENSO

[so_whats_happening]

On 8/4/2025 at 4:31 PM, GaWx said:

Check out the recent trend of the reduced difference in RONI and ONI:

RONI-ONI:

MJJ 2024 -0.60

JJA -0.54

JAS -0.52

ASO -0.54

SON -0.55

OND -0.55

NDJ -0.55

DJF -0.53

JFM 2025 -0.51

FMA -0.49

MAM -0.43

AMJ -0.38

MJJ -0.32

To me at least this is telling me we are slowly cooling off the WPAC with no real discernable changes in the central and EPAC with SST. Baby steps.

[so_whats_happening]

Should have saved this until tomorrow but whatever here is all of June/July and the 1st of August. 

[snowman19]

This strongly supports the development of a Niña:

[PhiEaglesfan712]

8 hours ago, so_whats_happening said:

We still keep getting random bouts of a Nino like response even with the -PDO where it is and the weak cool/ neutral SST profile.

It could probably be that Nino 1+2 has been in an el nino state, even after the 2023-24 el nino ended. My guess that will stick at least through the next official el nino. If we get a strong or super el nino in the coming years, Nino 1+2 will really go off the charts (like in 82-83 and 97-98).

[40/70 Benchmark]

11 hours ago, donsutherland1 said:

ECMWF Monthly Anomalies for Select Cities:

Main idea: The best of winter would be December-January in the Great Lakes, Mid-Atlantic, and New England areas, if the guidance is correct. The Southwest would be warm for the fall and winter.

Buffalo and Toronto:

September: +1.3
October: +0.8
November: +1.3
December: +0.4
January: 0.0
February: 1.3

Savannah:

September: +0.8
October: +0.8
November: +0.8
December: +0.4
January: +0.8
February: +1.8

Don, I am thinking December-January and then again in March.

[40/70 Benchmark]

21 hours ago, Stormchaserchuck1 said:

Yeah, in the NAO roll-forward we would have to get -EPO to balance out those US Temps with such a strong +NAO going on. I just think it's cool how they pick their own unique landing place with the northern latitude trough, not in what's occurring or has occurred, but going forward. 

What is your NAO formula at currently?

[Stormchaserchuck1]

38 minutes ago, 40/70 Benchmark said:

What is your NAO formula at currently?

With 61% of the period complete, it's at +0.20 for DJFM NAO. Given the 0.54 sd, which has hit 11-9 since inception in 2005, it has a 50% probability of being in the range -0.34 to +0.74 Winter NAO. 

[snowman19]

Skeptical hippo here that this is going to somehow magically turn into a very active Atlantic hurricane season with high ACE. I’m feeling confident sticking with my guess of below normal

[GaWx]

1 hour ago, snowman19 said:

Skeptical hippo here that this is going to somehow magically turn into a very active Atlantic hurricane season with high ACE. I’m feeling confident sticking with my guess of below normal
 

 

CSU 8/6/25 update: 145 total ACE vs 140 in last month’s forecast, vs 122, which is 1991-2020 average, and vs the new Euro seasonal’s ~155:

FORECAST OF ATLANTIC SEASONAL HURRICANE ACTIVITY AND
LANDFALL STRIKE PROBABILITY FOR 2025 We have maintained our forecast for a slightly above-normal 2025 Atlantic basin hurricane season, although noting lower-than-normal confidence with this outlook. Sea surface temperatures across the eastern and central Atlantic have anomalously warmed over the past few weeks and are now somewhat warmer than normal. Multiple indicators anticipate likely cool ENSO neutral conditions during the peak of the Atlantic hurricane season. Warm sea surface temperatures and ENSO neutral conditions typically provide a more conducive dynamic and thermodynamic environment for hurricane formation and intensification. The primary reason for the uncertainty in the outlook is the high observed Caribbean shear over recent weeks. Typically, high levels of Caribbean shear in June July are associated with less active hurricane seasons. We anticipate a slightly above- average probability for major hurricanes making landfall along the continental United States coastline and in the Caribbean for the remainder of the hurricane season.

[Winter Wizard]

Came across this which I found somewhat interesting...Arctic sea ice is currently matching 2012's pace for record low but in the Beaufort Sea (Alaska) it's actually well above the 2000s and 2010s median. Not sure what, if anything, that means for Winter but may be worth keeping an eye on. 

 

[FPizz]

26 minutes ago, Winter Wizard said:

Came across this which I found somewhat interesting...Arctic sea ice is currently matching 2012's pace for record low but in the Beaufort Sea (Alaska) it's actually well above the 2000s and 2010s median. Not sure what, if anything, that means for Winter but may be worth keeping an eye on. 

 

I know that says August 5th above, but it seems like the chart is from late July?  Bluewave posted this one in the ice thread.  Looks like it slowed down a bit from 2012?

[roardog]

4 hours ago, FPizz said:

I know that says August 5th above, but it seems like the chart is from late July?  Bluewave posted this one in the ice thread.  Looks like it slowed down a bit from 2012?

People forget that 2012 fell off a cliff in August. Prior to that it wasn’t that low relatively speaking. Also when a graph only has this year and 2012 on it, it’s hard to get a visual on how it compares to other years since then.

[Stormchaserchuck1]

Actually us not breaking 2012's record in this time of exponential global warming, for now 13 years.. is just as impressive. 

2021-2024

[Stormchaserchuck1]

Since 2012, this is what the following Winter looks like in years with -SLP May-Aug 60-90N vs +SLP (anomaly map below is showing negative base, with both sides included). This is why I think the Euro seasonal has that pressure map in the Pacific despite -PDO, and why the CPC is going cooler. 

[so_whats_happening]

2 hours ago, Stormchaserchuck1 said:

Actually us not breaking 2012's record in this time of exponential global warming, for now 13 years.. is just as impressive. 

2021-2024

Legitimately if this had not started out as one of the lowest winter time volumes recorded this would have been an amazing retention year. The pattern was damn near perfect to lock in ice and cooler temps. The biggest help has been the lack of Canadian warmth up to the Archipelago. I don't even think the NW passage will open this year given we have about 3-4 weeks left of melt, unless this pattern completely flips on us.

[PhiEaglesfan712]

11 hours ago, snowman19 said:

Skeptical hippo here that this is going to somehow magically turn into a very active Atlantic hurricane season with high ACE. I’m feeling confident sticking with my guess of below normal

Yeah, if it was early June, I would have entertained the thought of an active Atlantic hurricane season. But we're now in early August. If we were going to have an active hurricane season, we would have seen something by now. (Even last year we had Beryl.) Instead, we are at about 2.5 ACE.

Yes, I can see a big storm like Hurricane Andrew hitting at some point in the season, but that will be an outlier on the season, just as Andrew was in 1992 (another year that was very active in the Pacific, not so much in the Atlantic). For the most part, the Pacific is going to be active, and the Atlantic will be rather quiet. We're close to halfway on the hurricane season. The tiger isn't going to change stripes at this point in the season.

155 ACE has very low probability, and would be like if the Rockies made the playoffs this year. 

[GaWx]

9 hours ago, PhiEaglesfan712 said:

Yeah, if it was early June, I would have entertained the thought of an active Atlantic hurricane season. But we're now in early August. If we were going to have an active hurricane season, we would have seen something by now. (Even last year we had Beryl.) Instead, we are at about 2.5 ACE.

Yes, I can see a big storm like Hurricane Andrew hitting at some point in the season, but that will be an outlier on the season, just as Andrew was in 1992 (another year that was very active in the Pacific, not so much in the Atlantic). For the most part, the Pacific is going to be active, and the Atlantic will be rather quiet. We're close to halfway on the hurricane season. The tiger isn't going to change stripes at this point in the season.

155 ACE has very low probability, and would be like if the Rockies made the playoffs this year. 

 2025 ACE, which is now 3.5, has just moved ahead of both 1998 and 1999 as of this date. Neither of those years had another storm til Aug 18/19. And yet they each ended up with ACE of 181 and 176, respectively. I’m not predicting that’s going to happen again. But I am saying that it isn’t a remote possibility that the season end up active (say 140+) just because it was only at 3.5 as of 8/6.

Edit: Fwiw in the spring I predicted a slightly above 1991-2020 avg of 139 for 2025 ACE in the contest, and I wouldn’t change that even if I could.

[snowman19]

Despite the great patterns for retaining arctic sea ice, here we sit with this:
 

 

 

 

 

[bluewave]

July was the strongest Southeast ridge on record for the month from NYC to ATL. This beats the previous record July 500mb heights set back in 1952.

But the difference this time is that we had a +0.74 PNA for July. While July 1952 had a -1.23 PNA. So we continue to see these disconnects between the higher latitudes and mid-latitudes.

This disconnect is why the Euro still has a Southeast ridge into next winter while also having a -EPO and +PNA.  

 

[40/70 Benchmark]

20 hours ago, Stormchaserchuck1 said:

With 61% of the period complete, it's at +0.20 for DJFM NAO. Given the 0.54 sd, which has hit 11-9 since inception in 2005, it has a 50% probability of being in the range -0.34 to +0.74 Winter NAO. 

That is not as strongly positive as I had suspected. I'm doing a lot of seasonal work on the polar domain right now...will be interesting to see if we jive again.

[Stormchaserchuck1]

1 hour ago, bluewave said:

July was the strongest Southeast ridge on record for the month from NYC to ATL. This beats the previous record July 500mb heights set back in 1952.

But the difference this time is that we had a +0.74 PNA for July. While July 1952 had a -1.23 PNA. So we continue to see these disconnects between the higher latitudes and mid-latitudes.

This disconnect is why the Euro still has a Southeast ridge into next winter while also having a -EPO and +PNA.  

Because of shortened wavelengths in the mid Summer, July has a +temp correlation with +PNA from ATL to NYC

[Stormchaserchuck1]

1 hour ago, 40/70 Benchmark said:

That is not as strongly positive as I had suspected. I'm doing a lot of seasonal work on the polar domain right now...will be interesting to see if we jive again.

That lack of ice melt pattern leading to -AO is really neat.. I almost want to think that the cold there in the Summer is artificial because of how it snaps the following Winter. I'm leaning toward something not so +nao and -pna. I might not do a seasonal outlook this year because of how close everything is to "neutral". We'll see. 

[40/70 Benchmark]

22 minutes ago, Stormchaserchuck1 said:

That lack of ice melt pattern leading to -AO is really neat.. I almost want to think that the cold there in the Summer is artificial because of how it snaps the following Winter. I'm leaning toward something not so +nao and -pna. I might not do a seasonal outlook this year because of how close everything is to "neutral". We'll see. 

We don't need indexes in this new, warmer climate. Just stick a thermo in the piss-pool east of Japan and call it a day.

Seriously, though...I do agree that there is a ceiling on our winter potential until that changes.

[Stormchaserchuck1]

34 minutes ago, 40/70 Benchmark said:

We don't need indexes in this new, warmer climate. Just stick a thermo in the piss-pool east of Japan and call it a day.

Seriously, though...I do agree that there is a ceiling on our winter potential until that changes.

24-25 is probably my top analog for 25-26 right now. Since 2014 though, there have been only like 3-4 periods where we had sustained below average for a 2+ month period, like last Winter. So the odds are stacked against it. It's not impossible though. 

[40/70 Benchmark]

5 minutes ago, Stormchaserchuck1 said:

24-25 is probably my top analog for 25-26 right now. Since 2014 though, there have been only like 3-4 periods where we had sustained below average for a 2+ month period, like last Winter. So the odds are stacked against it. It's not impossible though. 

I just hope to god its wetter for the NE or I'll plunge into the Japanese piss-pool.

[Stormchaserchuck1]

This Summer has been significantly cooler in the Southwest, US. Last year Phoenix was breaking records by >+2F, and the roll forward of those very warm analogs had a +PNA in Dec-Jan.. It was a good indicator. But we don't have that this year. 

[GaWx]

 Since Atlantic ACE is considered to be a winter forecast factor:

TSR just updated their forecast from last month….

-ACE increased markedly from 126 to 144. This compares to the CSU’s 145 and the Euro seasonal’s ~155.
-The # of NS/H/MH increased slightly from 15/7/3 to 16/8/3. 
-However, US impacts remained the same at 4 NS/2 H.

https://www.tropicalstormrisk.com/docs/TSRATLForecastAugust2025.pdf

[Stormchaserchuck1]

2 hours ago, bluewave said:

 

Also a strong Gulf of Alaska High pressure has been there June-July

Analogs

US Temp pattern of analogs

[TheClimateChanger]

19 hours ago, Winter Wizard said:

Came across this which I found somewhat interesting...Arctic sea ice is currently matching 2012's pace for record low but in the Beaufort Sea (Alaska) it's actually well above the 2000s and 2010s median. Not sure what, if anything, that means for Winter but may be worth keeping an eye on. 

 

Interesting. Wonder if there is any chance for a late Beaufort melt to gain some ground? Delayed, but not denied, as JB would say.

[TheClimateChanger]

8 minutes ago, Stormchaserchuck1 said:

This Summer has been significantly cooler in the Southwest, US. Last year Phoenix was breaking records by >+2F, and the roll forward of those very warm analogs had a +PNA in Dec-Jan.. It was a good indicator. But we don't have that this year. 

True, but a very impressive heat wave is ongoing now.  Phoenix has set two record highs already this month, including 116F yesterday, which was just 1F shy of the all-time monthly record. The low of 94F this morning was also one shy of the monthly record high minimum. Today is forecast to reach 117F which would match the August monthly record high.