GaWx

Would you please post the Euro’s 2 meter temperature forecast for each of D, J, and F? Also, what is the climo base period?

From my standpoint here in the SE for wanting a normal or cooler winter, I’ll take any El Niño influence over none. Just get rid of the dominating SER of the last few winters. Get rid of anything resembling a typical La Nina. Thus a strong El Niño atmospheric influence would be a major improvement for me.

For those not wanting a La Ninalike/SER/MJO 4-5 dominant type of pattern, wouldn’t it actually be good rather than bad news that El Niño will likely have a strong instead of weak atmospheric influence?

Thanks for the link. 1. Excellent point about it miserably failing in its Nov H5 forecast for the prior Nino D, J, and F, 2018-9. And I’m not a big proponent of seasonal forecasts in general due to lack of accuracy. But, will it fail again? At least this time the Nino is much stronger with ASO of 2023 RONI of +1.05 vs only +0.39 for ASO of 2018. 2018-9’s RONI peaked at only +0.76, 0.29 weaker than RONI already is. It is likely headed to near a high end moderate. https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt Also, the ASO of 2023 SOI was -10.4 vs only -4.2 for ASO of 2018: https://data.longpaddock.qld.gov.au/SeasonalClimateOutlook/SouthernOscillationIndex/SOIDataFiles/MonthlySOIPhase1887-1989Base.txt So, does the fact that the 2023-4 El Niño is much stronger than 2018-9 mean much? 2. The good news for folks who don’t want a warm E US winter is that the Nov of 2017 as well as Nov of 2019-22 Euro forecasts all had much higher H5 heights in the E US and the Aleutians in all of the D, J, and F forecasts vs what the Nov of 2023 forecast is for the upcoming D, J, and F. Nov of 2018 is the only Nov forecast back to 2017 even remotely similar to Nov of 2023.

Indeed, it is about the same as last month with an ONI peak near +2.08. But keep in mind that the Euro was much too warm in Oct. So, I don’t buy it peaking that high and remain in the +1.7 to +1.9 range for at least now.

The SE US can average very cold with a “warm” Canada. Actually, that’s typical of a +PNA because the Canadian air is pushed way down into the US, where it can be very cold vs averages even if the originating air is warm to Canadian averages:

The is a learning process at least for me. I realize it wouldn’t be anything near wall to wall in 6 because it never is that way in any phase. But I just hope that should this model happen to be right with the bulge that it wouldn’t mean more of 6/7 than average due to MJO waves being triggered at 6.

The good news from my perspective is that the seasonal models are not dependable because I’d much rather that main bulge be ~30-40 degrees E of where this has it. That is assuming that that main bulge will be the main driver. Would it be?This has the light blues of the bulge from 150E to 170W or centered on 170E. That would favor MJO phase 6 as per the top image below. Phase 6 is the warmest phase for the E US in JFM per the 2nd image below. As one (like most of us) who would like a cool to cold E US winter, I’d prefer it be supportive of phases 8 and 1, which would be supported by enhanced precip a fair bit east of the dateline or near the heart of Nino 3.4 (say, 160W to 140W/centered near 150W) instead of being centered near 170E:

Not what I wanted to see for Dec -AO prospects compared to prior runs but hoping it is just a wobble rather than portending an actual model trend away from the notably weak SPV shown on several runs last week. This one has the ensemble mean’s low at 30-31 m/s (normal for then is 35) vs one run last week being way down at 21 m/s and yesterday’s at 27:

Griteater and some others, largely based on an external study, feel that the chance for a -NAO is enhanced this winter because of it still being during the ascending portion of the sunspot cycle despite approaching maximum. My analysis is based strictly on the last 44 winters since the winter -NAOs became scarce because of a perceived change in influences. The external study was based on going way further back than that and thus includes the prior era when -NAO winters were much more frequent. My analysis of the 6 -NAO winters since 1979-80: 1984-5: (NAO -0.70) (moderate La Niña) headed down in cycle 21 with limited sunspots averaging only 20/month; this was 20 months before the minimum of Sept 1986 1986-7: (NAO -0.30) (moderate El Niño) very early in cycle 22 four months after the Sept 86 minimum with very limited sunspots of only 6/month 1995-6: (NAO -0.62) (moderate La Niña) headed down in cycle 22 with limited sunspots of only 12/month nine months before Sept 1996 minimum 2009-10: (NAO -1.67) (strong El Niño) one year into cycle 24 at 13 months after the Dec 2008 minimum just starting to head upward but with still limited sunspots of only 22/month 2010-11: (NAO -0.68) (strong La Niña) two years into cycle 24 at 25 months after the Dec 2008 minimum headed further up but still low at 33/month 2020-1: (NAO -0.42) (moderate La Niña) early into cycle 25 at 13 months after the Dec of 2019 minimum just starting to head up but still with limited sunspots of only 14/month So, these six were 20 months before min (1984-5), 4 months after min (1986-7), 9 months before min (1995-6), 13 months after min (2009-10) 25 months after min (2010-2), and 13 months after min (2020-1). So, these six averaged only 4 months after min, which isn’t really saying that much about it favoring ascending. To me it says a lot more about favoring being near min than favoring ascending. But that’s just my thinking.

The Oct 2023 PNA came in at +1.20, which is a little higher than the +0.85 to +1.15 range that I had expected. For El Niño winters since 1950, here are the Oct PNAs along with the nature of the subsequent winter’s temperatures in the SE US: 1953: +1.91 warm 2015: +1.78 warm 1979: +1.53 normal 2023: +1.20 ???? 1965: +1.14 cool 1977: +0.98 cold 1986: +0.92 cool 2014: +0.89 cool 1963: +0.69 cold 1976: +0.68 cold 1987: +0.53 cool 2009: +0.43 cold 1969: +0.35 cold 1957: +0.27 cold 1968: +0.26 cool 1951: +0.24 warm 2018: +0.21 warm 1958: +0.16 normal 1994: -0.23 mild 1997: -0.26 mild 2002: -0.65 cool 2006: -0.84 mild 1982: -0.93 normal 2004: -1.39 normal 1972: -1.50 normal 1991: -2.28 warm Like most here, I prefer BN winters. Note that 11 of 12 of the BN SE El Nino winters since 1950 occurred when the preceding Oct PNA was within +0.26 to +1.14. Based on the assumption that this clumping isn’t mainly due to randomness (I don’t think it is), I’m content with the idea that the +1.20 Oct 2023 PNA suggests an enhanced chance of a BN SE winter though I would have preferred that the Oct PNA had come in a little lower (say ~+1.00) to within the clump rather than just above the clump. The +1.20 is still good enough in my mind. Let’s say that the Oct PNA had instead come in, say, either negative, or +1.75+. I definitely wouldn’t have felt it was enhancing BN SE winter chances and probably would have felt it meant the opposite, if anything. PNA monthlies back to 1950: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table

Followup to the above analyzing those QBO analogs and anti-logs: 1. El Niño DJF NAO -QBO Analogs: two had a -NAO (1986-7 and 2009-10) and the other two had a +NAO (1991-2 and 2014-5). This 50% having a -NAO is actually pretty impressive considering that -NAO winters have been pretty rare (only 6 of the last 44 (14%) winters since 1979-80). Moreover, the only two -NAO El Niño winters of the 14 (14%) El Niños since 1979-80 are the QBO analog El Niños of 1986-7 and 2009-10. The other four -NAO winters (1984-5, 1995-6, 2010-1, and 2020-1) weren’t El Niño. -QBO Anti-logs: all five had a +NAO. 2. El Niño DJF AO: -QBO Analogs: two had a -AO (1986-7 and 2009-10) and the other two had a +AO (1991-2 and 2014-5). So, 50% had a -AO vs 36% of all 14 Nino winters since 1979-80 having a -AO. So, that’s fairly close. -QBO Anti-logs: none had a -AO as 4 of the 5 (80%) were neutral and one (1994-5) had a +AO. I consider neutral AO to be between +0.5 and -0.5. Conclusions for this winter’s NAO/AO based on above regarding current QBO in combo with El Niño: - Nothing overly conclusive since sample sizes are small and the analogs were 50-50 on -NAO/-AO. - But -NAO chances this winter considering the current era of difficult to achieve -NAO winters may be enhanced somewhat due to current QBO vs where they’d be with different QBO timing. - -AO chances this winter may be enhanced some due to current QBO. - Both -NAO and -AO chances during El Niño winters would appear to be higher during analog QBO than during anti-log QBO. - I’ve in the past not been one to use the QBO much, if any, in winter predictions due to what I’ve perceived to be too much variability of analogs and the difficulty of having large enough sample sizes with similar QBO timing. After all, this QBO table goes back only to 1979. But, I will say based on this latest analysis that I feel somewhat (but not dramatically) better about the chances of a -NAO and -AO this winter than I felt before I did this. To clarify, that doesn’t mean I’m saying either is likely, especially -NAO, though I will say that -AO winters have been less difficult to attain than -NAO winters since 1979-80. I’ve been really down on the chances of a -NAO this winter (even though I’ve been leaning -NAO for Feb, alone) based on how rare they’ve been since 1979-80 along with this winter’s expected high (>100) sunspot activity. All 6 -NAO winters since 1979-80 had low sunspot activity (all had 33 or less). Maybe the QBO/El Nino combo will trump the sunspots. (Plus I know some others here feel this winter’s still ascending part of the sunspot cycle will actually be helpful for -NAO chances even with it approaching max mainly based on an external study.)

1. El Niño DJF NAO -QBO Analogs: two had a -NAO (1986-7 and 2009-10) and the other two had a +NAO (1991-2 and 2014-5). This 50% having a -NAO is actually pretty impressive considering that -NAO winters have been pretty rare (only 6 of the last 44 (14%) winters since 1979-80). Moreover, the only two -NAO El Niño winters of the 14 (14%) El Niños since 1979-80 are the QBO analog El Niños of 1986-7 and 2009-10. The other four -NAO winters (1984-5, 1995-6, 2010-1, and 2020-1) weren’t El Niño. -QBO Anti-logs: all five had a +NAO. 2. El Niño DJF AO: -QBO Analogs: two had a -AO (1986-7 and 2009-10) and the other two had a +AO (1991-2 and 2014-5). So, 50% had a -AO vs 36% of all 14 Nino winters since 1979-80 having a -AO. -QBO Anti-logs: none had a -AO as 4 of the 5 (80%) were neutral and one (1994-5) had a +AO. I consider neutral AO to be between +0.5 and -0.5. Conclusions for this winter’s NAO/AO based on above regarding current QBO combined with El Niño: - Nothing overly conclusive since sample sizes are small and the analogs were 50-50 on -NAO/-AO. - But -NAO chances this winter considering the current era of difficult to achieve -NAO winters may be enhanced somewhat due to current QBO vs where they’d be with different QBO timing. - -AO chances this winter may be enhanced some due to current QBO. - Both -NAO and -AO chances during El Niño winters would appear to be higher during analog QBO than during anti-log QBO. - I’ve in the past not been one to use the QBO much, if any, in winter predictions due to what I’ve perceived to be too much variability of analogs and the difficulty of having large enough sample sizes with similar QBO timing. After all, this QBO table goes back only to 1979. But, I will say based on this latest analysis that I feel somewhat (but not dramatically) better about the chances of a -NAO and -AO this winter than I felt before I did this. To clarify, that doesn’t mean I’m saying either is likely though I will say that -AO winters have been less difficult to attain than -NAO winters since 1979-80. But I’ve been really down on the chances of a -NAO this winter based on how rare they’ve been since 1979-80 along with this winter’s expected high (>100) sunspot activity. All 6 -NAO winters since 1979-80 had low sunspot activity (all had 33 or less). Maybe the QBO/El Nino combo will trump the sunspots.

The 30 mb QBO (which I know @nrgjeffamong others follows closely) for Oct came in about as expected at -16.98. The closest El Niño summers/autumns to 2023 (analogs) since 1979 in terms of timing of peaks and valleys are 1986, 1991, 2009, and 2014. These had their first -QBO month within two months of the preceding July and had a -QBO throughout winter. 2023’s first -QBO month was July. The furthest El Niños from 2023 (anti-logs) in terms of timing since 1979 are 1982, 1987, 1994, 2015, and 2018. These all had their first -QBO month about a year earlier than the preceding July and had a +QBO throughout winter. https://www.cpc.ncep.noaa.gov/data/indices/qbo.u30.index

The 30 mb QBO for Oct came in about as expected at -16.98. The closest El Niño summers/autumns to 2023 (analogs) since 1979 in terms of timing of peaks and valleys are 1986, 1991, 2009, and 2014. These had their first -QBO month within two months of the preceding July and had a -QBO throughout winter. 2023’s first -QBO month was July. The furthest El Niños from 2023 (anti-logs) in terms of timing since 1979 are 1982, 1987, 1994, 2015, and 2018. These all had their first -QBO month about a year earlier than the preceding July and had a +QBO throughout winter. https://www.cpc.ncep.noaa.gov/data/indices/qbo.u30.index

Although today’s EPS actually shows fewer members with a (impending) major SSW (5% vs 7%), the mean wind dropped back to 27 m/s vs 30 m/s yesterday. Lowest of any run so far is the 21 m/s of 3 days ago. Normal is 35

Probably not changing from EP to CP but changing to EP/CP cross is actually being forecasted.

The unrounded ASO ONI was +1.54, officially making this a strong Nino. Also, for the 3rd trimonth in a row, the RONI was ~0.5 cooler (near/at a record amount cooler). So, that’s a full ONI category weaker! So, odds are imho that the current low end RONI based moderate will not reach strong.

Indeed, the +AAM correlates partially to +ONI/-SOI/Nino. Thus, there’s a partial correlation for AAM at H5 in the E US to a canonical El Niño pattern. So, the current -AAM is more Ninalike than Ninolike. Does anyone have a link to daily AAM?

So, 2023’s Sep MEI was weaker than all 14 Nino’s since 1979 except 1979, 2004, 2009, 2014, and 2018. And with 1979, 2004, 2014, and 2018 all being weak, only 2009 and 2023 stand out as going strongly against the grain of the ONI/MEI correlation. (2009 does finally get above +1 Nov+.) And wasn’t 2009 arguably Modoki? If so, that makes Webb’s comment about an MEI/Modoki correlation even more questionable.

Yeah, Webb implied that and I was just repeating what he said. Looking at the graphs, MEI since 1979 was clearly highest during the three strongest Nino’s based on ONI and thus 2023 is clearly lagging those three. Do you have a link to the monthly tabular MEI values?

Yeah, I‘m just saying that Webb is saying that the atmospheric response has been “pretty strong” despite the weak MEI. As I’ve said, how one classifies the atmospheric response can vary with how one defines what that is. I’ve been saying that the SOI is one way to measure atmospheric response and it averaging -10.4 in ASO is a form of a notable atmospheric response as that is well up into -SOI range for strong El Niños since 1950. But I realize that there are other forms of A.R. like H5 outside of the tropics.

I mistakenly referred to Webb referring to a stubborn -PNA whereas it was actually TheBetterDoge saying that in a reply to Webb.

On rereading the @snowman19post, I now realize that I mistakenly attributed the “stubborn -PNA” reference to Webb when it was actually “TheBetterDoge” who referred to that in a reply to Webb. I’ll correct my earlier post to refer to that person instead. Webb is saying the atmospheric response is actually pretty strong despite the weak MEI because the MEI tends to be stronger only during Modokis and that thus there will still be good warming upcoming even with the MEI still weak.

Why is “TheBetterDoge” talking about a “stubborn” -PNA? Just because 11 of the last 14 days and the last 3 days in a row have had a -PNA? Big deal. A much bigger deal is that for only the second El Niño and 4th year since 1950, 2023 had a +PNA (+0.25+) in all of June-Oct with only 2005, 2009, and 2021 being the others. Furthermore, per GEFS there are no more -PNA days in sight with neutral to positive the next 14++ days. Included in this is a pretty strong+PNA returning midmonth. So, Nov may turn out to be the 6th +PNA month in a row. The only year since 1950 with a +PNA in all of June-Nov is 2021: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table Edited for correction as TheBetterDoge rather than Webb referred to a “stubborn -PNA”.