GaWx

15 minutes ago, qg_omega said:

Wow

https://x.com/meteomark/status/2115552472420831557?a=0nstg66dq8DYsk9UZEo&s=46

Why is Mark saying surface impacts are expected to start in mid-Nov? @Stormchaserchuck1said it takes 30-45 days, which wouldn’t be til Dec. Does he need clicks and likes that badly?

Check this colder change from the EWs for week 2 (Nov 9-15):

1. H5 2 runs ago:

Yesterday’s:

Today’s: nice E US trough

2m from 2 days ago:

Yesterday: cooler

Today’s: even cooler

Rainfall:

2 days ago: slightly wet SE

Yesterday’s: a little drier

Today’s: even drier with the colder air

It’s not +3. It’s ~+2.6 per NOAA. Record for any week is +2.9:

https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

 Meanwhile there’s this to look at that shows strong +AAM still S of 30N:

@40/70 Benchmark

More from Webb about the SSW:

 The wave pattern that forces stratospheric warming events varies from case to case. Displacement events (wave 1) require an Aleutian low and a Scandinavian-Kara Sea block, but splits of the polar vortex (wave 2) do not necessarily. 

 This particular stratospheric warming event actually starts out as a split type (wave 2), and then morphs into a wave 1/displacement type event as the Aleutian low becomes established later. The tropospheric trigger for this event is clearly traceable to the Eastern Pacific w/ divergent wind anomalies from active convection propagating poleward into N America and then eastward into the North Atlantic jet stream, eventually forcing the Kara Sea/Scandinavian block that sets this entire stratospheric warming event into motion.

 Also, note that early in the model forecasts, wave 2 amplitude dominates the -NAM/AO changes, wave 1 comes later and is largely confined to the mid-upper stratosphere initially at least.

1 hour ago, Winter Wizard said:

Looks like 1965, 1968, 1987, and 1998 had an additional SSW event later in Winter. Only 1987-88 has the same ENSO/QBO combo.  

-1952-3 only barely missed a 2nd one in Jan with it getting down to +1 fwiw.

-I had thought a +QBO reduced the chance for a mid to late winter major SSW during +1.3+ El Niño. However, upon further review, that may not be true:

Here are the +1.3+ peaking El Niño events with a +QBO and whether or not they had a Jan 15th+ major SSW:

1957-8: yes

1982-3: no

1987-8: yes

1994-5: yes

2015-6: yes

So, that’s 4 of 5 (80%) +QBO +1.3+ Nino with a Jan 15th+ SSW

————————

What about -QBO Nino winters?

1965-6: yes

1986-7: yes

1991-2: no

2009-10: yes

2023-4: yes

So, that’s 4 of 5 (80%) -QBO +1.3+ Nino with a Jan 15th+ SSW.

 So, it’s a statistical tie for Jan 15th+ SSWs chances during +1.3+ El Niño.

1 hour ago, EasternLI said:

El Niño is driving the current situation in the stratosphere... 

 

 

Webb is right. All but 3 of the 12 +1.3+ peaking Ninos had at least one major SSW Jan 15th+:

57-8: Jan 30th

65-6: Feb 24th

72-3: Feb 2nd

82-3: none

86-7: Jan 23rd

87-8: Mar 14th

91-2: none

94-5: Feb 4th

97-8: none

02-3: Jan 17th

09-10: two in Feb

15-16: Mar 5th categorized as an SSW but also by others as a near earliest FSW on record

23-4: mid Jan and early Mar

41 minutes ago, mitchnick said:

Agreed that if it rises fast, it won't be a good thing for a cold or snowy December especially in light of enso climo. But if you go to the link below for that graph, as recently as 10/14 or 10/15, the PV split (I'll call it for ease) wasn't even showing up on that weekly prog, and was very slow thereafter to show the extent of the PV's demise. So I  guess, probably because I've lived in the M. Atlantic snow hole for so many years, I'll not worry about the state of the PV come December or trust the PV forecast at this distance.

https://charts.ecmwf.int/products/extended-zonal-mean-zonal-wind?area=nh&base_time=202610140000

Mitch,

 The modeled 10 mb/60N wind rise after the historic dip is by no means faster than what commonly happens with SSWs, especially early season SSWs.

 Looking at the image below, one can that the plunges downward from SSWs are often followed by pretty sharp rises soon afterward. By that time, the SSW has already done its “damage” so to speak. 
 

 Look at the SSWs in here (circled). I count 8 SSWs prior to Jan 1st: 

1952, 1958, 1965, 1968, 1981, 1984, 1987, and 1998

 Most of these other than 1984 rose fairly steeply within a few weeks, which is what the models are showing for 2026 (assuming they will even be right obviously). Even some of those after Jan 1st rose steeply.

@snowman19@Winter Wizard

41 minutes ago, Typhoon Tip said:

i'm trying to figure out if i need to establish alternate/ancillary sources. This measure, in the off chance that greed and/or corruption and/or the unstoppable epidemic of growing standardizing idiocy, or some combination of all these..., at last succeed in hiding the telecon from general access.

It is getting harder and harder to find what should be free. 

As an aside, humanity really needs a comet named Humility to set it back to something like a realization of how bad their shit stinks and humility.   

LOL... but this is a lot to look for, I know.  hahaha

Seriously, ... I may have to pick a source and I'd like it to be good.

So right now the CPC - the only remaining easy access site - indicates a descending AO modality, ending in a dish-pan negative mode ... -.75 or -1.   However, the CPC assesses the AO based upon the geopotential height anomaly.  This can be misleading at times... because the specific curvature geometry of the isohypses around the stereographic projection of the hemisphere are not always consistent with actual high latitude blocking we'd normally associate with the -AO state. 

Case in point, last night's extended GEFs rendition around the hemisphere.

There is a some semblance, though very modest, of a block in the NE EPO domain N of Alaska there, but that's hardly substantive.  This is more sort suggestive that the AOs negative coming purely from numerical positive N and negative S, but not being representative very well in the orientation of the height gradient/geometry, it is kind of fake - so to speak.  

Other sources/ corroboration might be useful here. 

 John,

 I’m being extra wary of the GEFS AO progs because they’ve been verifying significantly too -AO, especially in week 2:

July 1st-Oct 28th verification: AO +0.6559 per image below

vs mean GEFS progs of (all from image below):

day 7: +0.287 (too -AO most days since Sep 1st)
day 10: +0.0533 (too -AO since Sep 1st by larger amount)
day 14: -0.086 (too -AO since Aug 25th by even larger amount)

39 minutes ago, Winter Wizard said:

Down the line, that seems like a discouraging sign for December. After initial weakening, the PV rapidly rebuilds and that is another piece of evidence pointing toward a very warm December. which is a strong signal in historic analogs. Recall that last year, the disruption occurred in late November and that contributed to a cold start in December with an Arctic spell mid-month. The end of December into early January torched for the majority of the CONUS right as the PV rebuilt. 

I suspect this time, if it even couples to the troposphere, it would only really benefit Europe with cold/snow based on the large scale pattern. 

Maybe it implies potential for disruptions or splitting later in the season, but historically that is less likely with this ENSO/QBO combo. Either way, I think there are bad actors who are clinging onto this as confirmation bias of cold/snow in order to sell subscriptions or get social media views. 

Thanks. I don’t doubt the bad actors!

For me this is introducing more variability for Dec than I had assumed previously. Based on @snowman19posts on +QBO/ENSO analogs as well as my own research to confirm Adam’s mild E US forecast, I had been thinking mild Dec except possibly NN SE, especially deep SE. But with this historically very early SSW coming, I feel that there’s increased uncertainty for Dec.

Per @Stormchaserchuck1the avg lag from an SSW to first getting well down into the troposphere early in the season is 35-40 days if I recall correctly. This would mean ~Dec 9-14 for it to first reach well down. And then it would last for a period of time (most likely 2-3 weeks minimum per history). Thus, this increases the possibility of a cold overall E US Dec, especially mid to late month and especially SE US, vs my prior thinking from very low to a nontrivial chance.

Nino Nov 1-15 avg 10 mb/60N mean zonal wind (m/s)
 

26: projected +2

09: +15

04: +16

58: +17

06: +18

68: +18

77: +19

79: +20

76: +20

14: +21

72: +23

51: +23

87: +24

Avg: +25

94: +26

57: +26

65: +27

63: +27

18: +28

91: +28

69: +29

15: +30

02: +30

86: +30

82: +30

23: +32

53: +32

97: +34

Per Eric Webb: interesting

I have a sneaking suspicion that the extreme eastward shift (& intensity) of this year's El Niño potentially has something to do w/ the unusually early stratospheric warming event that's being forecast.

I also wonder if there's a theoretical point where we shift the Indo-Pacific Warm Pool so far east that we actually don't end up getting a massive torch in December in the SE US & we just haven't observed an El Niño event strong/eastward shifted enough to challenge this idea. 

Perhaps, the trough that's normally buried in the Desert SW in December of a "normal" strong-super Nino bleeds eastward into the SE US instead, mirroring the eastward shift in convection/stronger subtropical jet stream forced by the extreme eastward shift in the mean warm pool. There are certainly some significant unknowns/wild cards on the table w/ this winter despite the normally high predictive power that comes with strong El Niños.

14 minutes ago, OSUmetstud said:

This is not how the real word works though. The anomalous trades are causing the most east-based event on record. Pointing out that these models just have the peak SST anomalies 10, 20, or 30 degrees east of the Nino 3.4 is relevant and different than the whole event being weaker. 

 
Yes, they are by a good margin and that’s important. I’m not disagreeing at all and don’t think anyone is. I’ve pointed out a number of times about 26-7 being the most E based on record. But at the same time, we’re right to also point out that 3.4 is coming in weaker than progged, which is interesting and a fact and makes it even more E based but also means it’s coming in weaker officially. So, in future references to the official strength of the 2026-7 Nino, it appears it will not be as strong in the official table as what the Euro and BoM were predicting.

27 minutes ago, OSUmetstud said:

The overshooting in forecasts is because the SST anomalies are farther east, not because the Nino is weaker. Both BOM and ECMWF SST anomaly forecast has been excellent and if anything undershooting the SSTs in Nino 3. 

Yes and no because the official ENSO strength is determined by Nino 3.4, which is what we’re referring to, rather than other regions. So, in terms of official strength, it technically is coming in weaker than these overshooting models. At the same time, it has become more E based than the models had due to the E regions coming in stronger.

1 hour ago, 40/70 Benchmark said:

Maybe the EURO is doing better than the guidance continuously underestimating El Niño, but it looks like it's been overshooting to me.

 The BoM has been overshooting every near month forecast by a significant margin (0.4+) since April with it averaging 0.5 too high! Oct is joining the club:

 Here was the forecast for Oct as of just 2 weeks ago, which had Oct way up at +3.5:

 Look how far down the Oct 24th MTD is: only +2.8! So, full Oct is likely going to end up at no warmer than +3.0, which would make its Oct forecast verify 0.5+ too warm and thus continue the trend that started with April:

 This tells me that Nov will have a good chance to end up verifying ~0.5 too warm or at ~+3.2 vs its forecast of +3.7. Either Nov or Dec will very likely end up as the peak.

 So, if BoM monthlies were to peak at, say, +3.3, then the NOAA monthlies would likely come in cooler and peak at ~+3.0 and the trimonthlies would likely peak at ~+2.8, which is where I am currently (not much change from before).

22 minutes ago, mitchnick said:

Aren't the + signs supposed to be - signs?

Mitch,

 I just realized I had a typo as I called the winds on those charts “anomalies”. I realize they’re not anomalies and are instead absolutes but for some reason I typed anomalies.  

 Thus, I just corrected the original post. My original thoughts are unchanged. I think my erroneously originally referring to them as anomalies threw you off. So, the +5 and +4 are actual winds rather than being 5 and 4 above normal. Is that what threw you off?

——————

 Aside: Ignore the trolls. Apparently moderation is nonexistent here.

8 minutes ago, mitchnick said:

Aren't the + signs supposed to be - signs?

Mitch,
 Danny Devito says no and I agree with him.  1976 and 2009 had very weak winds but they didn’t go <0. I was looking at El Niño Novs that dipped to +5 or lower. 1968, 1976, and 2009 were the only three to do so per ERA data. A +5 dip is very weak.

 The chart below has 10 mb/60N winds back to 1949. According to it, Nov 2026 is going to per ERA obliterate the old record (all of the way back to at least 1949) earliest SSWe whether it gets down to 0 (major SSW) or stays just above. The earliest SSW on record is 1952’s ~Nov 15th SSW. So, 2026 is headed to possibly beat 1952 by ~11 days!

————————

 Looking at the above chart for only El Niño Novs, the only three that got to +5 or lower per ERA5 in Nov were 1968 (-5 on Nov 27th), 1976 (+4 on ~Nov 15th), and 2009 (+5 on ~Nov 15th). These three had the lowest DJF AO of any winters since at least 1949-50. Thus, these very strong winter -AOs were quite possibly connected to a large extent to the very weak Nov SPV period. Thus, a case could be made for a better than average chance for a strong -AO averaged out in 2026-7 despite the lack of seasonal model support:

1968-9: AO -2.3

1976-7: AO -2.6

2009-10: AO -3.4

@Typhoon Tip
 

*Edited for typo 

17 minutes ago, snowman19 said:

Traditional ONI: almost +3.5C RONI: +2.9C The EURO has been dead balls accurate with this event. The over +4C peak it shows for December is not only believable, it’s very likely. Also, the subsurface warming continues. My final call is a December peak of +4.0C - +4.1C (traditional ONI) and +3.5C - +3.6C (RONI). I think the subsurface peaks next month at +13C

 
 The official NOAA Nino weekly (based on OISSTv2.1) was at +2.5 for the avg of last week and is likely ~+2.6 now. Based on this as well as forecasts, I’m currently thinking their weeklies will likely peak no higher than low +3’s, which means monthlies will likely peak no higher than ~+3.0. That would mean a trimonthly RONI peak probably in the upper +2.0s.

10 minutes ago, bluewave said:

Parts of the CONUS are at +8 to +9 and it’s only October. None of the seasonal models were forecasting this from the September runs. Even the early October runs turned out too cool. 
 

 

But note that the CS3 Oct ‘26 mean for the E coast states has verified quite well based on Oct 1-25.

3 hours ago, EasternLI said:

Overnight 00z EPS jumps to 86% of it's members... Gefs now at 65%.. EPS looks impressive if you loop 10 and especially 50 mb. 

 

 For those who don’t realize how unprecedented in the ERA5 records this is forecasted to be at 10mb, 60N:

The 0Z 10/27/26 EPS mean is forecasted to be 10-14 below the weakest on record (I don’t know how far back though) and 24-29 below the mean per ERA5 data Nov 3rd-10th!

21 minutes ago, Typhoon Tip said:

There is no SSW modeled from what I'm seeing anyway ...

Just pointing that out for the straw man if no one's betting.

John,

 There is a record weak SPV for early Nov being modeled, which would result in anomalies of ~-20 m/s. It may not result in an actual wind reversal (<0 m/s), but, say, a +5 m/s event would still be record shattering.

39 minutes ago, bluewave said:

That’s a near record STJ off the Baja being forecast which will help to amplify the ridge over the Great Lakes and Northeast moving into early November. 
 

 

 With this record breaking and possibly even record shattering weak early Nov SPV very likely, what do you and others think that leads us to for Dec? Previously I was thinking based on @snowman19+QBO/Nino analogs that Dec overall would likely be mild in the E US outside of possibly NN in the SE. But, I noticed that while Nov warmed considerably on the latest 10 day mean CFS (2-3F) since the runs from ~3 weeks ago, it has also cooled considerably (~2F) for Dec since just 10 days ago. I’m wondering if this is related to the 35-40 day @Stormchaserchuck1typical cooling lag for the E US after an SSW this time of year:

CFS 10 day mean from 10 days ago: torchy

Latest CFS 10 day mean for Dec: ~2F colder E US: not torchy

 Today’s IOD release (avg for 10/19-25) came in at +0.69 vs the +0.88 of the prior week:

20260831,20260906,0.24
20260907,20260913,0.63
20260914,20260920,0.68
20260921,20260927,0.75
20260928,20261004,0.59
20261005,20261011,0.88
20261012,20261018,0.88
20261019,20261025,0.69

https://www.bom.gov.au/clim_data/IDCK000072/iod_1.txt?1791781094025

 The NOAA relative weeklies released this morning:

-Nino 3.4 warmed slightly to +2.5. It remains at record levels for the time of year with it way ahead of the 2nd warmest, +2.0 of 2015. The record for any week is +2.9 of 12/29/82.

-Nino 3’s +3.6 is much warmer than the 2nd warmest for the week, +2.9 of 1997 and it also ties the warmest for any week, 12/29/1982.

-Nino 1+2’s +4.4 remains much warmer than its 2nd warmest for the week, +3.6 of 1997. Its warmest for any week is the +4.6 of 1998.

30SEP2026         4.5        3.3        2.3        0.1
 07OCT2026         4.4        3.4        2.4        0.2
 14OCT2026         4.4        3.5        2.4       -0.1
 21OCT2026         4.4        3.6        2.5        0.0

https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

8 hours ago, mitchnick said:

Lowest yet I believe. Maybe @GaWx or @Stormchaserchuck1 will correct me.

Bottom map is 10mb.

Yes, Mitch, the latest EW (10/25) is slightly weaker than the 10/24 run.