GaWx

The Sept 100-180W OHC came in at +1.03, down slightly from last month’s +1.09 and well below the June peak of +1.40. This drop was the last thing I had earlier expected for Sep. (though I realized Sep could easily come in lower once I saw it fall way back) and the clock is ticking. Unless this does something extreme like the sometimes considered analog of 2009, when it suddenly warmed 0.99 from Sep to Nov to 1.75 after having fallen back from an initial high point in June of +1.13 to a temporary low point of only +0.76 (similar to the 2023 pattern); or like 1991, when after sputtering between April’s +0.80 and Sept’s +0.60 it suddenly warmed 0.81 to Oct’s +1.41 and then another 0.30 to Dec’s +1.71; it will not ever get to the high 1 area that I had earlier thought had a good chance to occur: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

Nino 4 at 29.87 is likely the warmest on record for 10/1 at least back to 1982. Also, when comparing to other Nino regions at the same time, it is very impressive! But considering GW, including how much warmer the globe has been this year, is it the most impressive for 4 for 10/1? Compare to 29.0 in 82, 29.1 of 86/87, 29.2 of 91, 29.6 of 15.

The August PDO was way down at -2.47. There have been 15 other sub -2 Aug PDOs since 1854 with only 1876 during El Niño. This is how the E US subsequent winters went including PDO: 1876 (only other Nino): winter cold mainly due to Dec, PDO -0.15 (rose 2.01, the third sharpest rise of the 15 from Aug to DJF), snowy NYC in DJ, major snowstorm Atlanta in D 1881: winter NN NE, warm SE, PDO -1.51 1883: winter cold NE, NN SE but very cold J, PDO -1.80, snowy NYC in D; wintry ATL in J 1892: winter cold, PDO -0.77 (rose 2.08, the 2nd sharpest rise of the 15 from Aug to DJF), heavy SN JF Boston/NYC, one of heaviest SN on record Atlanta in J 1909: winter cold, PDO -1.72, very cold/wintry ATL in D 1916: winter cool NE, NN SE, PDO -1.96, snowy NYC 1920: winter NN, PDO -1.11, heavy SN Boston F 1921: winter cool NE, mild SE, PDO -0.40, Knickerbocker SN NC/Mid Atlantic in J preceded by historic ZR SE coast 1933: winter very cold NE mainly due to Feb, NN SE, PDO -0.32 (rose 2.60, the sharpest rise of the 15 from Aug to DJF), heavy SN DFM NYC/Boston, major SN ATL in F 1950: winter mild NE, NN SE, PDO -1.26, wintry ATL D 1955: winter NN, PDO -2.25, very heavy SN M NYC/Boston 2010: winter cool NE, cold SE, PDO -1.77, very snowy winter Boston/NYC/ATL 2011: winter warm, PDO -1.87 2012: winter mild, PDO -1.28, very heavy SN FM Boston/NYC 2022: winter very warm, PDO -1.70 - 53% of the winters were cool to cold in the NE but only 27% were in the SE. - 27%/33% of winters were mild to warm in the NE/SE, including the last 3 - Active winters NE/SE when PDO rose sharply Monthly PDO back to 1854: https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat **Edited due to typo as it’s Aug to DJF, not Oct to DJF, sharpest rises I’m referring to

Today’s GEFS based PNA is saying a daily peak of +2+ is likely near Oct 10th. The following Octs since 1950 peaked at +2+ with these peak dates and these full Oct PNAs: 1953: 10/6 Nino +1.91 1963: 10/12 Nino +0.69 1965: 10/5 Nino +1.14 1969: 10/8 Nino +0.35 1979: 10/1 Nino +1.53 1980: 10/4 +2.45 1984: 10/8 -0.63 1987: 10/3 Nino +0.53 2003: 10/6 +0.97 2008: 10/3 +0.86 2010: 10/2 +1.80 2011: 10/2 +0.63 2015: 10/10 Nino +1.78 - All 13 peaked within Oct 1-12 just like 2023’s prog. El Niños were the most favored ENSO for these through 1979. - All but one of these Octs had a monthly PNA of +0.53+. Seven of these 13 were within +0.53 to +1.14. All but one of the 13 cool to cold E US El Niño winters since 1950 were preceded by Octobers with a PNA of +0.16 to +1.14 fwiw. So, as one who’d prefer a cool to cold winter, I’ll be hoping for an Oct PNA within that range. - As @George001just reminded me though, the PDO was sub -2 in August, which itself doesn’t bode well if one is hoping for a neutral PDO or +PDO in DJF. More about that in my next post.

The colder map’s 8 cases include 7 +PNAs. Nearly all of the coldest E US El Niño winters had a +PNA in Oct (mainly weak to moderate). The 9/30 0Z GEFS suddenly switched to a strong +PNA for the first half of Oct. I’ll be following this closely as Oct appears to a canary in the coal mine for El Niño winters.

Iceland minus Azores SLP anom difference (correlates to -NAO) -Dec went from ~+4 mb (~-0.25 NAO) on the prior run to ~+0.5 mb (~-0.05 NAO) on this one -Jan went from ~+3 mb (~-0.2 NAO) to ~+4.5 mb (~-0.3 NAO) -Feb went from ~+6.5 mb (~-0.55 NAO) to ~+9 (~-0.75 NAO) So, DJF NAO went from ~-0.33 to ~-0.37

El Niño Oct PNA: Strong +PNA: 53, 65, 79, 15 Mod +PNA: 63, 76, 77, 86, 87, 14 Weak +PNA: 57, 68, 69, 09 Neutral PNA: 51, 58, 94, 18 Weak -PNA: 97 Mod -PNA: 82, 02, 06 Strong -PNA: 72, 91, 04 SE US from coldest to warmest Nino winters 57, 63, 65, 69, 76, 77, 09: cold 68, 86, 87, 02, 14: cool 58, 72, 79, 82, 04: NN 94, 97, 06: mild 51, 53, 91, 15, 18: warm ——————— Correlation of Oct PNA to SE US winter for Nino -25% of the 4 strong +PNA (+1+) in Oct followed by cool to cold SE winter - A whopping 100% of the 10 weak to moderate +PNA (+0.25 to +0.99) in Oct followed by cold to cool SE winters - None of the 4 neutral PNA (-0.24 to +0.24) in Oct followed by cool to cold SE winter - 14% of the 7 -PNA (<-0.24) in Oct followed by cool to cold SE winter - So, only 13% of the 15 Octs that had either strong +PNA, neutral PNA, or -PNA followed by cool to cold SE winters - So, sweet spot by far for best shot at cool to cold SE Nino winters is Oct PNA of +0.25 to +0.99. Needless to say after just today discovering this, I’ll be rooting very hard for a +0.25 to +0.99 PNA in Oct! ** The data I’m basing this on is from the monthly PNA table seen at the 1st link below as opposed to the dailies (2nd link). That’s important to note because the monthlies average ~twice the amplitude of the dailies’ average. ———————— Today’s GEFS PNA prog for Oct 1-14 based on dailies is ~+0.6. However, keep in mind that the absolute value of the corresponding monthly amplitude averages ~twice as high as what the dailies would suggest. So, in this case, the equiv for the first half of Oct could easily be ~+1.2. That bodes very well for the chances of this full Oct’s PNA coming in as a +PNA when the monthly is released. But hopefully it would come in within the +0.25 to +0.99 interval so as to hit the sweet spot for the chances of a cool to cold winter: Monthly PNA (higher amp vs avg of dailies): https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table Daily PNA (lower amp vs monthly): https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Today’s GEFS PNA prog for Oct 1-14 based on dailies is ~+0.6. However, keep in mind that the absolute value of the corresponding monthly amplitude has averaged ~twice what the average of the dailies would suggest. So, in this case, the equiv for the first half of Oct could easily be ~+1.2. That bodes very well for the chances of this full Oct’s PNA coming in as a +PNA when the monthly is released. From what I’ve just learned about the relationship between Oct PNA and the following winter during El Niño per data going back to 1950, that alone might bode well for the rare shot at a cool to cold E US winter assuming a monthly +PNA actually does verify as long as it isn’t 1+. The stats suggest an Oct PNA sweet spot of +0.25 to +0.99 for the highest cool to cold E US winter chances with +0.5 to +0.75 most preferred.

@snowman19is full of knowledge, provides a lot of useful info, and has helped make this thread as lively as anyone has. That’s all greatly appreciated. The thread wouldn’t be the same without him/her. However, there’s much room for improvement regarding objectivity imo. Then again, he/she is far from the only one with much room for improvement in this regard imo. It isn’t easy to keep one’s biases from influencing the nature of one’s posts.

El Niño Oct PNA: Strong +PNA: 53, 65, 79, 15 Mod +PNA: 63, 76, 77, 86, 87, 14 Weak +PNA: 57, 68, 69, 09 Neutral PNA: 51, 58, 94, 18 Weak -PNA: 97 Mod -PNA: 82, 02, 06 Strong -PNA: 72, 91, 04 ———————— Nino Oct: +PNA: 56%, Neutral PNA: 16%, -PNA: 28% Non-Nino Oct: +PNA: 48%, Neutral PNA: 13%, -PNA: 40% So, Oct +PNA moderately more favored in Nino vs non-Nino E US from coldest to warmest Nino winters 69, 76, 77: cold 14, 02: cold NE, cool SE 58: cold NE, NN SE 63, 09: cool NE, cold SE 68: cool 57, 65: NN NE, cold SE 86, 87: NN NE, cool SE 79, 04: NN 18: NN NE, warm SE 72, 82: mild NE, NN SE 06: mild 94, 97: warm NE, mild SE 51, 53, 91, 15: warm ——————— Correlation of Oct PNA to E US winter for Nino - Only 0%/25% of the 4 strong +PNA (+1+) in Oct followed by cool to cold NE/SE winters - A whopping 70%/100% of the 10 weak to moderate +PNA (+0.25 to +0.99) in Oct followed by cold to cool NE/SE winters - Only 25%/0% of the 4 neutral PNA (-0.24 to +0.24) in Oct followed by cool to cold NE/SE winters - Only 14% of the 7 -PNA (<-0.24) in Oct followed by cool to cold NE/SE winters - So, only 13%/13% of the 15 Octs that had either strong +PNA, neutral PNA, or -PNA followed by cool to cold NE/SE winters - So, sweet spot by far for best shot at cool to cold NE/SE Nino winters is Oct PNA of +0.25 to +0.99. Needless to say after just today discovering this, I’ll be rooting very hard for a +0.25 to +0.99 PNA in Oct! ** The data I’m basing this on is from the monthly PNA table seen at the 1st link below as opposed to the dailies (2nd link). That’s important to note because the monthlies average ~twice the amplitude of the dailies’ average. Monthly PNA (higher amp vs avg of dailies): https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table Daily PNA (lower amp vs monthly): https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

-Note that all were between 7/3 and 10/1. -9/1/2021: post Ida interacting with front -9/4/1913: not directly from TC that moved W into SE US 9/3-4 -7/28/1913: frontal -7/3/1930: offshore frontal low -7/12/1937: frontal low -10/1/1913: frontal low that moved offshore and later became H that hit SC 10/8 -8/10/2006: frontal -8/21/2021: from nontropical event well ahead of Henri/not directly from it -9/8/2004: post Frances interacting with front -So, none directly from TC but some indirect or post TC

OHC hasn’t warmed back any as of ~9/23 per the following image. I had said I expected the start of rewarming by around that date per the most recent@so_whats_happeninganimation but it still hasn’t happened on this (clock is ticking):

Based on data since 1950, this summer’s strongly -NAO itself isn’t at all predictive of a -NAO for the upcoming winter. The factors leading to summer -NAOs, which have become much more frequent since 2007 (2/3 of those summers vs only 1/5 of summers 1950-2006), don’t necessarily continue into winter, which has had much less frequent -NAOs in recent decades. Here are years with sub -0.50 summer NAO followed by the subsequent winter’s NAO (data goes back to 1950): * = El Niño winter -2023: -1.27/????* -2019: -1.23/+1.27 -2016: -1.28/+0.65 -2015: -1.34/+1.31* -2014: -0.82/+1.66* -2012: -1.61/+0.02 -2011: -1.38/+1.37 -2010: -0.82/-0.68 -2009: -1.18/-1.67* -2008: -1.27/-0.08 -2007: -0.68/+0.65 -1998: -1.07/+0.64 -1993: -1.22/+1.22 -1987: -0.71/+0.70* -1989: -1.01/+0.69 -1974: -0.51/+0.49 -1963: -0.61/-1.43* -1962: -0.72/-1.47 -1958: -1.56/-0.30* -1957: -0.82/-0.49* -1956: -0.67/+0.42 -1954: -0.92/-0.76 Anal. of 21 DJF NAO after sub -0.5 NAO summers: - Subsequent winter: 57% (12) +NAO, 10% (2) neutral NAO, 33% (7) -NAO - There have been 11 sub -1.00 NAO summers since 1950 (excluding 2023). Of these 11, 64% (7) of the subsequent winters had a +NAO. - Of the last five of these sub -1.00 summer NAOs (2019, 2016, 2015, 2012, 2011), four were followed by a +NAO winter, including 3 of the 4 strongest +NAO winters (2019, 2015, 2011). - However, for the 7 El Niño winters, alone: 43% (3) were +NAO and 57% (4) were -NAO despite a -NAO occurring during only one of last four El Niño winter cases (2009). - Of the 7 -NAO winter cases, 4 were during El Niño Conclusions: - No correlation is suggested in general between summer -NAO, even if sub -1.00, and following winter -NAO. - Summer -NAOs have become much more frequent recently even while winter -NAOs have been less frequent in recent decades. - But 2023 being El Niño MIGHT help -NAO chances somewhat for upcoming winter. - However, El Niño sample size pretty small and most recent two El Niño cases (2015 and 2014) had two of the three strongest +NAO winters. - There have been only 6 -NAO winters during the last 44 and those all had low (~30 or fewer) sunspots. In contrast, the upcoming winter sunspot # is expected to be very high (~150+). - Based on all the above, I’m maintaining my earlier prediction that despite this summer’s strong -NAO that the upcoming winter NAO will not average sub -0.25 (my def of -NAO) though I’m currently leaning -NAO for February. Monthly NAO: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

I’m not a big Bastardi fan these days due to what I feel is a serious lack of objectivity and apparent hidden agendas, but I suspect that many here will agree with this at least to some extent (sounds like a RONI better indicator than ONI idea, which I think has merit):

I said per the above that the -SOI streak would probably end by yesterday. It still hasn’t ended with the streak barely hanging on with -3 today making it a 39 day -SOI streak per this: https://www.longpaddock.qld.gov.au/soi/

Just to clarify since this has come up before, there’s no indication that 1925-6 was anything close to a super strong El Niño. These two sources suggest it peaked at only low end strong: https://www.webberweather.com/ensemble-oceanic-nino-index.html https://data.coaps.fsu.edu/pub/JMA_SST_Index/jmasst1868-today.filter-5 -1896-7 and 1930-1 were stronger per these sources though still short of super. -1877-8 was almost certainly super and 1888-9 was probably super per these

There’s very likely not going to be much left of Philippe once getting close to PR if it takes this track instead of recurving. It would pretty much be a nonentity with it sheared to near nothing as this NHC map shows. OTOH, a recurve would keep it going much longer and possibly allow for restrengthening. See the 12Z GFS for example.

I need to rethink this because I was neglecting to keep in mind that the wet Indian monsoon season is only in summer with winter monsoon being dry. So, I don’t know if there’s much value to this correlation map between DJF Indian monsoon precip and E US BN temperature correlation. Only if the typically limited winter Indian monsoon rainfall is less limited on average during +IOD could this be of much value. So, only if that’s the case would the posted map have any value in trying to determine a relationship between winter +IOD and winter US temperatures.

Although not at all resembling a typical moderate to strong El Niño in terms of ACE and # of systems, it has resembled El Niño in terms of dominant general tracks due to a weaker than average Bermuda high. Fortunately, only one of six hurricanes to this point made landfall at that strength along with minimal casualties (though any is too many) from the one that did, Idalia.

The PDF “corrected” CFS had Sep as a whole at only 1.1 a few weeks back. I remember posting ~9/7 that with the 1.5+ for 9/1-7 that the dailies would have to plunge to ~0.75 within ~2 weeks for a mere 1.1 to occur, which of course nobody believed possible. You can see that this one initialized Sep with 1.6, which is about where Sep will end up. This means that that “corrected” CFS will end up verifying ~0.5 too cool! This run has Oct at a mere 1.2. This will almost certainly similarly verify too cool and very likely much too cool, perhaps with a similar or greater error. Ironically, the “corrected” CFS runs seem to be much less correct than the uncorrected! If it ain’t broke, don’t fix it.

I saw that as that area is cooler than it had been. However, note that the sub-0C portion that had been located within 125-300 m depth from 130 to 180W as of the 9/19 five day map warmed rather substantially/diminished in volume from then through the final map after having cooled and expanded substantially from the start til then. I expect that portion in itself will have a notable impact on the overall average OHC warming in addition to the notable warming near 120W. That’s why I’m leaning to notable warming coming on the next few OHC graphs, which are 5 days behind your last map.

After looking at this great animation, which goes up to the 5 day period centered on Sep 23, I feel pretty confident that the next 180-100W OHC graph that I post will finally be warmer and with possibly enough warming to make it somewhat noteworthy. (After looking again at the animation more closely, I’m leaning toward it being a noteworthy warming.) The last one available goes only through ~9/18. Thus your animation goes out five days further and allows me to get a feel for its next update.

Regardless, are you aware that Aug of 2023 was > 1/2C colder in the WPAC region covering 15N to 15S, 120-160E, than Aug of 2022? (see the 27.959 C highlighted in the table below). It will be interesting to see where Sep of 2023 ends up. Is Aug just a blip or is it a sign of somewhat cooler SSTs there this winter vs recent ones? If it is, maybe that will help decrease the dominance of its forcing and thus hopefully decrease the dominance of the dreaded SE ridge: https://psl.noaa.gov/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=SST&level=2000&lat1=15&lat2=-15&lon1=120&lon2=160&iseas=0&mon1=0&mon2=11&iarea=0&typeout=1&Submit=Create+Timeseries This is an area being followed by a pro met (Brad Harvey) whom I follow. He’s who marked that box and highlighted the cooler Aug of 23 two weeks ago in an email to me. I was waiting for the right time to share this and this is the time. But regardless, he told me to share if and when I wanted to. I know him well and he has no hidden agenda as far as I can tell. Just tells it exactly like he sees it using objective data/facts. Doesn’t favor warm or cold or wet or dry. He’s not a weenie. He’s an anti-Bastardi in that respect.

I’d take the 1C AN that it is showing down here, especially with it vs 1984-2009 climo instead of the warmer 1991-2020 climo, though the weenie in me is hoping for NN to 1C BN since El Niño is the best shot at a BN SE.

He/she knows it won’t happen. Besides, this is just one of the daily runs of the awful CFS that happens to be cold (though I wonder if it really is as cold as this WxBell map shows) and it is looking out 3-6 months. Individual runs as one would expect jump around so much from run to run and have hardly any value. In contrast, here is the much more believable mean of the last 12 CFS runs (from TT), which shows much of the E US 2-4F warmer than the 1984-2009 baseline vs the totally unbelievable 5-9F colder than the 1981-2010 baseline map from today’s 0Z run: