GaWx

4 hours ago, stadiumwave said:

CanSips NOV Update

FEB

Now that the multi-run CFS’ have warmed considerably in the E US for Feb vs how they were a couple of weeks ago, the above Nov Cansips run for Feb is notably colder by ~2F than the latest 3 day CFS for Feb, which is below (even after considering the ~1F colder climo being used by this TT CFS):

 I ended up with 4.3” of rainfall this month, which is slightly above normal. But I’ve gotten none since Oct 11th, which was from a feeder band with thunderstorms that woke me ~7AM from the influence of Isaias’ remnants and which was just ahead of a cold front. I got a total of 1.6” from Isaias Oct 9-11th.

 The wx especially early this week and last week with comfy dewpoints and sunshine was great for outdoor activities. 

 Due to the combo of persistent breezy NE winds most of this week and the full moon early this week, there was coastal flooding near times of high tide Oct 25th-29th despite sunny wx (“King Tides”).

28 minutes ago, Typhoon Tip said:

Not directed at you Don, just in general.. 

I wish the scientific ambit would elect to place a "P" on SSW as a suffix, for/if/when an intrusion of warming into the PV/stratospheric pressure coordinates is proven ( crucially ) to be a downward "P"ropagating event.  

There is a life cycle to the SSW --> -AO, that requires some 20 to 30 days to complete.  Whether this is that, or just an intrusion that quickly disappears ... still remains to be seen. 

This needs to be factored into this "suspected" intrusion event and I'm not reading anywhere, in or outside this social media ... like that is in the gears of reasoning.   

First of all, the AO is progged currently at CPC to go ~ -.75 SD over this next week.   There is no antecedent SSW/propagating downward phenomenon prior to that occurring.  Should this 10 mb warm node and any vortex collapse become resonate ( downward radiating through the vortex) .... your looking at the end of November before any AO mode response - when considering the proven total SSW phenology.   

I just suspect that SSW is being blurred in the proper usage of why Sudden Stratospheric Warming was originally identified.  Since there are intrusion events that don't down well, yeah... technically it's a warming in the stratosphere that is/was rather expedient in how it manifested.   But semantically... and really machine wise, if you want an SSW to correlate to winter at mid latitude, it has to go thru 20+ day downward evolution, then the -AO happens. And I still don't see that very convincingly modeled in the GFS.       

What I do see occurring is both aft of present and continuing in the models, a warmer than normal static 70 to 100 hPa level state.  I'm willing to hunch pretty heavily that it's CC related... This looks more like a pan-dimensional aspect than an intrusion - aside from the fact that it's emerging from the bottom up.  As well, it is/has vastly predated(s) the canonical 'disruption season'.    

 

 Despite the historical earliest SSW and accompanying historically weak early Nov 10 hPa/60N winds, the 60-90N 10 hPa avg temp. is only going to rise ~5C and stay well below the record warmest for early Nov. So, it’s a mixed bag of sorts.

3 hours ago, snowman19 said:

As @40/70 Benchmark and myself suspected, due to the hostile background state, the models are showing a rapid recovery to an above normal/strong SPV by December
 

 

And as unbelievable as it is, this WWB looks like it may actually rival the one back in April. This is certain to cause more warming. I feel very good about my guess of this Nino peaking in December at a traditional ONI of +4C and a RONI around +3.5C. I still think the subsurface reaches a final peak of +13C next month. Also, no surprise that the SOI has gone negative again after a very brief positive run

@donsutherland1

1. Even with this rapid recovery, which is not at all uncommon for an early SSW as climo rises well into Dec, Nov as a whole would still ~tie for the lowest avg 10 hPa/60N wind (back to 1948).

2. I’ve got RONI monthly/trimonthly peaking ~+3.0C/~+2.8C now.

 Whereas the progged drop in the 10 hPa 60N winds is quite impressive, the progged overall temp. rise of the 60-90N region at 10 hPa (~5-6C and only to ~-57C vs early Nov record of -43C and others in Jan/Feb rising 15-20C) is not because it is mainly on the Russian side with less on our side of the pole:

Comparing Oct 1st with Oct 29th, neither 3.4 nor 1+2 have changed much:

But Nino 3 has had a steady rise:

Nino 4 ended up ~same but that’s because after a 1st half drop it had a sharp rise last 5 days:

 After a mild DJ, Cosgrove has a frigid Feb:

With the rapid decline of the El Nino and evidence for high-latitude ridging and cross-polar flow, I went in a colder direction for February to the right of the Continental Divide. The southern branch jet stream looks depressed into the Deep South and up off of the Eastern Seaboard, which would seem to favor more cold air and frozen precipitation. While I do not think that we will have a 2009 or 2015 type outcome, I lean toward a colder look than what official and major vendor sources are showing for February.

43 minutes ago, Cobalt said:

 

Their methodology has a pretty good track record. This does not seem too far fetched

Cosgrove’s just released Nov forecast disagrees just slightly :

 I think that CWG will verify much more closely based on the Euro Weeklies.

Recent 10 day mean CFS runs have warmed for Feb:

10 days ago:

Today:

^The 12Z UKMET has no TC or even any surface low in this area.

45 minutes ago, 40/70 Benchmark said:

Maybe it lingered just long enough at 70mb to help trigger this...who knows....

 I understand that. But why did Paul Roundy, whom many of us including myself greatly respect, today post that the 70 hPa signal is still E when it already switched to W (~+3) in Sept per the first source below? Does he use a source that has different values from these two?

https://www.atmohub.kit.edu/data/qbo.dat

 The above link had it already at ~+3 in Sept. at 70 hPa

and then this has it ~+8 at 70 hPa as of 10/28/26:

——————————

Paul Roundy
@PaulRoundy1
Message Present 70 hPa QBO signal is still easterly. It will likely be changing over the next few
months.

2 hours ago, stadiumwave said:

Great thread on SSW research  & I screenshot Paul's reply in case someone misses it. Found interesting. He links a paper.

https://x.com/Recretos/status/2115980492876984698?a=SxXaM4VN5NxdefH8xsg&s=19

 

It changed in Sept from E (white) to W (gray) at 70 hPa and should by now already be well within the gray (say likely +5+) per this (I’m hoping this updates soon to confirm this):

Edit: confirmed as it went from -10 in Aug to +3 in Sept. at 70 hPa:

https://www.atmohub.kit.edu/data/qbo.dat

Oct should be out in early Nov and will likely be higher than +3.

Cosgrove for NE US: after a mild DJ is going for frigid Feb and cold Mar.

 Thank goodness the models will be coming out an hour earlier starting next week!

1 hour ago, EasternLI said:

Regardless of any consequences, it appears increasingly likely that this is going to occur. GEFS up to 94% now.  EPS still 100% plus seeing the operational EURO continue a trend to prolong it is interesting also. 

 Based on your graph, the 0Z 10/30 Euro is calling for the avg of Nov 1-15 to be ~-1 m/s. That’s ~16 lower than the next lowest for any Nino since 1950 (2009), which was near +15, and ~26 lower than the avg for El Niño since 1950:
 

26: projected -1 per 0Z 10/30 Euro op

09: +15

04: +16

58: +17

06: +18

Avg Nino +25

*Edit: 0Z 10/30 Euro ens mean ~0

On 10/28/2026 at 10:09 PM, vortex95 said:

In the 4 previous very strong El Nino years,

Last TS or HU formation date
1982 - 9/30
1991 - 10/31
1997 - 10/14
2015 - 11/8

So odds would suggest we are done for the season.  Nothing apparent on the models for the next week.
 

14 hours ago, TheDreamTraveler said:

Yeah I'd be shocked if we see anything else form at this point. Isaias was basically our Joaquin of the season too. Very interesting season regardless all things considered. Tons of records broken in the opposite direction for once 

9 hours ago, jconsor said:

This is quite an active look for Nov of a strong El Nino.

 

 Well, well, well, the 0Z UKMET at hour 96 suddenly has a (TS or STS) form off the FL E coast as it does have somewhat of a warm core per 850/700/500 mb temps being warmer near the center than surrounding areas and it has mid-70s dewpoints surrounding the center. It forms just off of SC portion of the FL E coast and then moves mainly NNE to Wilmington, NC:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 96 HOURS
FORECAST POSITION AT T+ 96 : 28.0N 79.6W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 03.11.2026 96 28.0N 79.6W 1007 44
1200UTC 03.11.2026 108 28.3N 78.9W 1004 43
0000UTC 04.11.2026 120 29.0N 78.3W 1003 36
1200UTC 04.11.2026 132 30.7N 79.2W 1001 33
0000UTC 05.11.2026 144 32.1N 78.9W 1001 31
1200UTC 05.11.2026 156 35.1N 77.8W 1001 35
0000UTC 06.11.2026 168 39.5N 76.3W 1000 32

 Today’s 10 day averaged CFS RONI run for Nov has dropped a little to between +2.75 and +2.70. It also suggests that near future 10 day means for Nov will probably drop a little lower since all 8 of the blue lines, the most recent runs, are lower than today’s mean of the 40 lines whereas the red lines are more balanced. It also suggests a similar small drop for Nino 4 and Nino 3 for the same reason. However, unlike the other 3 regions, Nino 1+2’s blue lines are balanced suggesting little near future change upcoming for its Nov forecast mean thus implying probably a slightly even more E based Nino:

37 minutes ago, BlizzardWx said:

Good agreement on that positive PNA to start out November among all modeling systems. (Yeah I know I need to clean this graphic up a bit but I guess it'll get the job done for today)

This is just like the strongly E based 1997 was in the first half of Nov, but is unlike the 9 other strong+ Ninos since 1959, which had either neutral or -PNA then.

36 minutes ago, LakePaste25 said:

PNA probably stays ++ all winter. Remember one of the measuring points lies in the SE US, so the SE trough combined with the GOA low centered just offshore of western Canada will keep it positive. 

Looking at only Ninos of +1.4+ (per RONI), there have been 10 others since 1950 but only one (1997) had a +PNA dominant first half of Nov like GEFS says 2026 is going to have. GEFS is suggesting ~+1.0 (after adjusting downward for bias) for 11/1-15/2026. How does this compare to the other 10 actual 11/1-15?

2023: -0.1

2015: -0.2

2009: -0.3

1997: +1.2

1991: +0.1

1986: -0.9

1982: -0.3

1972: +0.1

1965: -0.5

1957:  0.0

 I wonder if this strong early Nov +PNA in 2026 is largely due to how E based it is being that 1997 was so E based early.
 

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

 Whereas the GEFS -AO looks significantly less impressive than yesterday, the +PNA still looks very impressive for at least the 3rd day in a row:

10/27 run:

10/28 run:

10/29 run: even a bit more impressive 

 Granted, the GEFS has had a +PNA bias averaged out the last 3 months, but the bias has had only ~half the magnitude of its -AO bias, and it has been mainly after day 7. So, perhaps it’s a bit too +PNA late in the run but otherwise likely has the right idea.

 I’ll for now assume it has the right idea for the first half of Nov with a PNA of near or above +1 most of the days. What other Nino first half of Nov had a mainly +PNA that was pretty high?

2014, 2002, 1997, 1987, 1976, 1968, and 1953 with only 1997 being strong+.

11 minutes ago, snowman19 said:

Even if this turns into a true SSWE (major or minor) and a wind reversal, it has to downwell into the bottom of the stratosphere and fully couple with the troposphere, otherwise it’s completely useless.

Eric Webb had this to say:
 

Thanks, Adam. Point taken, which @Typhoon Tipand many of us agree with.

 In case you missed it yesterday, Eric also suspects the occurrence of this very early SSW is connected in some way to the very strong and E based Nino:

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.

The comparison of the following GEFS AO progs fits in well with its strong -AO bias the last couple of months:

10/28/26 GEFS run: look at all of the members plunging to sub -1 and even sub -2 during Nov 2-4 with the mean plunging to -1.5 on Nov 3rd:

10/29/26 GEFS run: what happened to the Nov 2-4 members going below -1? There’s only one left and the mean dips down only to -0.6 instead of -1.5 on Nov 3rd. Also, the medium range mean isn’t as -AO as yesterday:

@Typhoon Tip

29 minutes ago, Typhoon Tip said:

Yeah, that's why I'm careful to describe the downward propagating, crucially ...highly indicative using the temperature monitoring...

I also am just commenting that perhaps delineating whether that specific behavior is occurring or not, is crucial.   Because the correlation to the AO is very tightly correlated to that phenomenon.    That site, and the information, at both ends that I provided, coherently show that.   If you take those down welling examples, and compare them to historical AO records, you'll see the 20 to 30 day lag rather obviously.  If you do the same with those warm nodes that did not apparently propagate, AO responses are variable and very less correlated. 

I'm also - again - not intending to say this November won't observe a downward inertial displacement, from 10 hPa ..thru the lower pressure coordinates and destined to affect the AO...etc... just that I'm not seeing that type of SSW totality at this time. 

The gist:  What we're getting at here is the well-studied form of stratosphere–troposphere coupling.

The current 10 hPa bloop - at least in the GFS suite I provided ...again, I have not seen the Euro and refuse to pay for it hahahaha - does not appear GFS-destined to be a coupled phenomenon.  

It's not likely to be a deterministic value on the AO and subsequent goodies ...etc... if even registerable at all, unless the coupling model takes place.   Critical distinction being ...inertial displacement at 10 hPa only describes the PV's forced horizontal position at that level, not proof that the same displacement is traveling downward... that has to happen or the coupling won't.

Even if this SSW ends up not propagating downward to a significant degree and thus doesn’t lead to strong -AO/-NAO in Dec, just the fact that this very early SSW is occurring may have implications as to the chance of a subsequent major SSW (i.e., a canary in the coal mine) that actually does downwell significantly and thus leads to a strong -AO/-NAO after that as I think @40/70 Benchmarkhas talked about.

47 minutes ago, Typhoon Tip said:

I'm not seeing the complete suite off the Euro cluster ... but, the GEFs I've always used do not indicate an SSW...

There's some wild confusion going on, as some folks among this social media, and outside of it, are seemingly not even aware of their confusion: appears just just wrongly attributable in what is going on....

First of all, warm thermal events pop off in the PV/stratospheric altitudes, all the time.  Seldom are they down propagators after the fact, a key behavioral component in the Sudden Stratospheric Warming defined phenomenon.

The modeling presentation I've found at https://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/   (NCEP/GFS Analyses and Forecasts)  provides a means ( though could be improved ) to deduce if in situ outlooks for warming at those respective levels ( y-axis of the above annotated graph) may be destined to downwell.  Note the unit conversion from MB to hPa (millibars to hectopascals) a conversion they do to be consistent with SI units.

When you see an warm sudden introduction in the 1 thru 10 hPa, then look at the 30 --> 50 --> 70 ...etc, out in time. If the pretty red blob of the polar stereographic thermal anomaly layout are then subsequently introducing the warmth, that is at least a 'reasonable' implication of an actual downward welling behavior.  

If you don't see that... it's probably an event that is like this...

Ie., no propagation.   Having defined/illustrated these different types of stratospheric warm event basics ... just as a knowledge aspect, there does not appear to be a temperature extreme/amplitude dependency in whether an event is a propagator or not.  As this image above demos, I carefully choose; it shows multiple irrelevant perturbed warm introductions. However, the last in the series there, very late in the spring of 2007, vaguely suggests there was a downward mass propagation.  The key take away is the down ward movement of the temperature (warming) anomaly.  We are thus using the temperature fields to infer wave mechanics taking place that will eventually become important in situ to the stratosphere-troposphere coupled model.  There may be amplitude requirement the physical wave mechanics - intuitively that's no brainer.   A weak downward temperature signal ... prooooobably is indicative of a weak collapsing PV ..which then weakly correlates to AO modality.  

Otherwise, no propagation, no crucially defined SSW event.   

Now, if we want to call any warm protuberance that introduces itself at all ... like those spanning that winter of 2007, as a SSW?  we do so at risk of confusing and conflating the two disparate systemically effective events - like what sounds like is happening now...  

I did go over the modeled GFS hPa levels wrt time ... it appears around 240 hours, there is a moderate 10 hPa warm emergence, but subsequent time intervals at successively lower levels do not present any propagating behavior.  That can change - sure.  We're not excluding the possibility that an actual SSW will happen this year in the unusually early November window.   Just not seeing it right now.

Having said all that... look at the 70 and 100 hPas...  There's something else happening, already, ...partly I suspect is contributing to some folks misconception of what's going on.  There is a coherent warm anomaly that is all but statically occurring in those lower stratospheric levels... That is is not SSW, but... I believe it is related to CC invading the fixed hPa aspect of the monitoring system...  speculation -

 

John,

 As long as the 10 hPa/60N mean zonal winds reverse (go to <0) in Nov or winter, that event is defined as a major SSW regardless of the degree of actual strat. warming and degree of propagation down into the troposphere, if at all. If it doesn’t drop to <0, the strat warming event is called a minor SSW.

 Despite the reversal or at least near reversal being progged on models, the degree of actual warming at 10 hPa being progged has been tame compared to many other SSWs. So, that could very well be a factor to consider as regards its potential to later significantly disrupt well down into the troposphere. I wonder if that reduces that potential. Opinions?

Check out this GFS prog, for example. The change in the strat. wind pattern at 60N looks quite impressive, but the degree of strat. warming up there doesn’t as there usually are widespread red colors, including dark red, that abruptly move into the area located within 60-90N but in this case the darker reds largely remain in and near Siberia:

 The Arctic N of 80N 2m anomalies have been back to their typical autumn warmer than 1958-2002 averages after a short dip to just BN at the end of Sept: