2026-2027 Record-breaking El Nino

[raindancewx]

Maybe I'm wrong - we could end with the wettest month since 1892 here. The land has already rapidly greened up from all the rain. Very pretty. I have mosquito bites all over my back just above my butt from walking, as well as on my arms. Not great.

Conceptually, the winter now has the following setup: Very hot Jun-July (poor for snow), hot for Aug (neutral), wet (good for snow), El Nino (good for snow), duration (>3 yrs since last big season), El Nino + good monsoon (good for snow). September will finish near average for highs with all the rain induced cold days.

Polo is supposed to die right over El Paso, which is amazing spot for a low for most of New Mexico.

[40/70 Benchmark]

Lots to unpack in this final El Niño update before the main Outlook in about 6 weeks time, but this weekend's major east coast storm may be a sign of what is to come. Here is one excerpt to provide a bit of a sneak-preview:

A diligent forecaster that has engaged in an exhaustive analysis of the data will be acutely aware of the fact that the pattern across the hemisphere has grown much more representative of a healthy El Nino during the month of August. A forecaster of this ilk would position oneself to also be aware of a potential mid-season shift westward in the orientation of an El Nino that absolutely presents as east-based in the mean; not to mention a winter season that was exceptionally mild overall in the midst of a rapidly warming climate, yet managed to facilitate shorter-term unions between the arctic branch and the most impressive subtropical jet ever observed to author one of the more scintillating chapters in meteorological lore-

 

 

https://easternmassweather.blogspot.com/2026/09/record-el-nino-poised-to-trigger.html

[Jebman]

40/70 REALLY gets deep into the analysis on his blog!

[Jebman]

5 hours ago, raindancewx said:

Maybe I'm wrong - we could end with the wettest month since 1892 here. The land has already rapidly greened up from all the rain. Very pretty. I have mosquito bites all over my back just above my butt from walking, as well as on my arms. Not great.

Conceptually, the winter now has the following setup: Very hot Jun-July (poor for snow), hot for Aug (neutral), wet (good for snow), El Nino (good for snow), duration (>3 yrs since last big season), El Nino + good monsoon (good for snow). September will finish near average for highs with all the rain induced cold days.

Polo is supposed to die right over El Paso, which is amazing spot for a low for most of New Mexico.

Congrats on getting Polo's rain! Hey could you send a little of that rain down to south central Texas please?

[40/70 Benchmark]

On 9/23/2026 at 10:02 PM, Stormchaserchuck1 said:

This may not be the classic El Nino pattern for October, but it is +AAM in the northern latitudes

AAM cycles usually reverse every 40-45 days so I'd expect something non-El Nino like in mid November

Good....not bad timing for a deviation from warm ENSO climo, especially a record one.

[40/70 Benchmark]

6 hours ago, Terpeast said:

Yeah, most of the tropical convection is very east based with the MC completely shut down (finally, after 10 years). Interestingly there is some remaining convection right around the dateline or just to the east of it. If I loop the forecast forward, that piece stays there. I think it may actually help us a bit this winter if it keeps going. If not, and it stays this east based, that won’t be good news for our cold/snow chances.

 

100% dead-on. ...I just hit on all of that in he piece I just published...competing convective forcing nodes....one in the central Pacific in association with the western warm pool that was dislodged eastward, and one with the El Niño....we are now rooting for the same warm pool that we have spent the better part of a decade cursing out.

[Stormchaserchuck1]

6 hours ago, 40/70 Benchmark said:

Lots to unpack in this final El Niño update before the main Outlook in about 6 weeks time, but this weekend's major east coast storm may be a sign of what is to come. Here is one excerpt to provide a bit of a sneak-preview:

A diligent forecaster that has engaged in an exhaustive analysis of the data will be acutely aware of the fact that the pattern across the hemisphere has grown much more representative of a healthy El Nino during the month of August. A forecaster of this ilk would position oneself to also be aware of a potential mid-season shift westward in the orientation of an El Nino that absolutely presents as east-based in the mean; not to mention a winter season that was exceptionally mild overall in the midst of a rapidly warming climate, yet managed to facilitate shorter-term unions between the arctic branch and the most impressive subtropical jet ever observed to author one of the more scintillating chapters in meteorological lore-

 

 

https://easternmassweather.blogspot.com/2026/09/record-el-nino-poised-to-trigger.html

Hopefully this can make it to the threads most liked post, instead of all that drama stuff

[Stormchaserchuck1]

Monster N. Pacific low finally.. -250dm. You never get -250dm on the D10 ensemble mean unless it's a special circumstance. 

https://ibb.co/6RK3BJMZ

[40/70 Benchmark]

1 hour ago, Stormchaserchuck1 said:

Monster N. Pacific low finally.. -250dm. You never get -250dm on the D10 ensemble mean unless it's a special circumstance. 

https://ibb.co/6RK3BJMZ

Yea, MC is going down...pretty clear.

[EasternLI]

Ok here we go, this is great to see. We've been waiting for the recurving typhoons to show up and now it sure seems like they very well could be. We had that one occur what about a week ago now albeit not very impressive at all. My read on that one was I took it as a baby step. Now we have another one slated to do so. Typhoon Surigae.

 

 

Beyond this one. It looks like chances are pretty good for another one to follow in about another week's time. As most models as of this morning give that impression. Sending these into the north pacific adds the fuel to help fire an Aleutian low. Wouldn't you know it, we're seeing a semblance of one on ensembles now. I don't think these things are unrelated and it will be really interesting to follow this. Feels right on time during October too.

 

[LakePaste25]

3 hours ago, 40/70 Benchmark said:

Yea, MC is going down...pretty clear.

Everything is playing out like I envisioned with this record breaking event. We will be relying on that convection moving west after December. Hopefully we can squeeze in a lake effect event in November. 

 

[GaWx]

32 minutes ago, EasternLI said:

Ok here we go, this is great to see. We've been waiting for the recurving typhoons to show up and now it sure seems like they very well could be. We had that one occur what about a week ago now albeit not very impressive at all. My read on that one was I took it as a baby step. Now we have another one slated to do so. Typhoon Surigae.

 

 

Beyond this one. It looks like chances are pretty good for another one to follow in about another week's time. As most models as of this morning give that impression. Sending these into the north pacific adds the fuel to help fire an Aleutian low. Wouldn't you know it, we're seeing a semblance of one on ensembles now. I don't think these things are unrelated and it will be really interesting to follow this. Feels right on time during October too.

 

Oct 5-11 has been similarly cool/warm in the E/W 1/2 of the U.S. for 4 runs:

[bluewave]

13 hours ago, 40/70 Benchmark said:

but this weekend's major east coast storm may be a sign of what is to come.

This may be the first time so early in the season that a low during and El Niño year backed all the way into the Jersey Shore from the east.

The perfect storm back in October 1991 looped offshore but didn’t make it all the way back to the coast. The January 1992 storm backed in off the ocean into the Delmarva. But the Christmas 1994 subtropical low did make it all the way back to the coast from the east.

These patterns are mostly a result of very strong 500 mb ridging north of the Great Lakes and into the Canadian Maritimes  preventing the storms from escaping to the east of Cape Cod like we usually see with coastal low tracks. 

This month the record ridge over the south was able to build north of the Great Lakes resulting in the capture of the east coast storm. 

Now the recurving typhoons are giving us a strong +WPO +EPO pattern in early October which we typically see during La Niña patterns this time of year. But this is only a snapshot of early October and could shift again mid to late month. 

[GaWx]

 Since May 23rd, I count only 5 days in either the MC or the IO and that rarity in those regions looks to continue at least through Oct 11th. That would most likely mean as of Oct 11th only 5 of the prior 142 days (3.5%) in MC/IO, easily a record low % for that long of a period since records started 6/1/1974:

 

[GaWx]

 The big ups and downs of the WCS daily PDO continue with nearly a 1.00 drop the last 10 days to -1.43:

[bluewave]

Yeah, this was the strongest east based forcing summer pattern on record. So the IO and Maritime Continent had more sinking air than 1997 and 2015. But since the ridging was so strong leading to warmer SSTs from Japan to south of the Aleutians, we got the more Niña-like summer -PDO pattern. This enhanced mid-latitude ridging extended across the CONUS to Europe going against the previous cooler summers during developing El Niño summers. 
 

 

[Stormchaserchuck1]

Let's talk about the odds for a warm December for the CONUS

Strongest east-based El Nino on record

+QBO

-PDO
Chance of beating the 91-20 average warm nationwide is probably 75-80% just generally

What's the odds, 90%

Some La Nina/-QBO's had huge Aleutian blocks, which flexed the SE ridge.. Im thinking that's how it could bust cold, Pacific driven not NAO

[Stormchaserchuck1]

13 minutes ago, bluewave said:

Yeah, this was the strongest east based forcing summer pattern on record. So the IO and Maritime Continent had more sinking air than 1997 and 2015. But since the ridging was so strong leading to warmer SSTs from Japan to south of the Aleutians, we got the more Niña-like summer -PDO pattern. This enhanced mid-latitude ridging extended across the CONUS to Europe going against the previous cooler summers during developing El Niño summers. 
 

 

El Nino's are warmer Summers in Europe

[40/70 Benchmark]

Man, Cosgrove sounds aggressive....have 2014 a shoutout.

[bluewave]

21 minutes ago, Stormchaserchuck1 said:

El Nino's are warmer Summers in Europe

This was the reverse of the typical El Niño summer in Europe since the warmest anomalies were over Western Europe instead of Eastern Europe and Scandinavia.

 

 

[Stormchaserchuck1]

Hmm.. looks closer than not to me

[bluewave]

4 minutes ago, Stormchaserchuck1 said:

Hmm.. looks closer than not to me

Not really when you consider the strongest El summer composite of 2023, 2015, 1997, 1982, and 1972 was cool in France which experienced the historic heat and drought this summer.

[Stormchaserchuck1]

I guess minus La Nina's skews it warmer. US Temp pattern was definitely a bust but I don't see why the northern latitudes should correlate so much in the Summer. The CPC didn't have any below normal anywhere on their lead Summer forecast.

[LakePaste25]

I mostly didn’t pay too much attention to summer NH coupling for a reason and focused on SH cool season coupling. 

[bluewave]

7 minutes ago, Stormchaserchuck1 said:

I guess minus La Nina's skews it warmer. US Temp pattern was definitely a bust but I don't see why the northern latitudes should correlate so much in the Summer. The CPC didn't have any below normal anywhere on their Summer forecast.

The JMA summer El Niño composites are cooler for France than the NOAA charts.

[so_whats_happening]

On 9/22/2026 at 3:33 PM, so_whats_happening said:

I forgot to show the  back half of 1997

 

We look to be roughly a month and a half apart from how 1997 transpired but we have a pretty weak cold pool comparatively, so this will be interesting to see how this event ends. Makes we wonder if we do actually go to a solid La Nina or more so a weak warm to neutral ENSO state. 

Nice to finally see the recurve happening more frequently and maybe just maybe the northern hemisphere pattern changing.

[bluewave]

17 minutes ago, so_whats_happening said:

We look to be roughly a month and a half apart from how 1997 transpired but we have a pretty weak cold pool comparatively, so this will be interesting to see how this event ends. Makes we wonder if we do actually go to a solid La Nina or more so a weak warm to neutral ENSO state. 

Nice to finally see the recurve happening more frequently and maybe just maybe the northern hemisphere pattern changing.

I think that’s why the long range models continue the WWBs and the extreme east based nature of this event right into next June. 

 

[mitchnick]

4 hours ago, GaWx said:

Oct 5-11 has been similarly cool/warm in the E/W 1/2 of the U.S. for 4 runs:

I was surprised to see as well how much the Conus, especially east of the Rockies, stays at or BN for weeks after that week. And the AN is not excessive.

https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202609260000&projection=opencharts_north_america&valid_time=202610050000

[Maestrobjwa]

1 hour ago, bluewave said:

I think that’s why the long range models continue the WWBs and the extreme east based nature of this event right into next June. 

 

Next June? Dang does that usually happen? Thought there was mention of a rebound nina 

[mitchnick]

20 minutes ago, Maestrobjwa said:

Next June? Dang does that usually happen? Thought there was mention of a rebound nina 

Keep in mind that if you're more interested in winter weather, a snapshot of June's Enso is generally irrelevant.