GaWx

It actually warmed only ~0.01C in 2 weeks from ~+1.87C on 11/1 to +1.88C in today’s update. But it has warmed ~0.2C during the last week.

WCS 11/14/23 updates: -Nino 3.4 OISST warmed from +1.85 to +1.88, which is barely warmer than Nov 1st and thus is the warmest so far this Nino -The PDO dropped from -1.19 to -1.27. It has dropped a pretty good bit over the last few days from when it was in the -0.90s.

JAMSTEC actually had a bit larger area of +3+ in the Oct run (see below). It looks to my eyeballs like the implied Nino 3.4 DJF forecast is about the same as what the Oct run had. Oct was at +2.05 per this: https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table Nino 3.4 is probably again only slightly warmer than +2.0 on this like it was on the Oct run although I think that’s going to verify too warm. A very low +2.0s Nino 3.4 can easily have a small area near +3.0 along the equator since it is the warmest area and negates the mainly W portion that is under +2.0. Oct forecast: +2.05 in Nino 3.4 Nov forecast: likely similar to the +2.05 of Oct in 3.4

Here’s something for which I can’t recall the last time it occurred: every one of the 5 weeks of today’s Euro Weeklies has cooled in the E US vs yesterday’s run and is easily the coolest overall run in the E US in a very long time. Instead of warmth dominating the run like for many recent runs, near normal dominates in today’s. For example, look at how much 11/20-7 cooled: Today’s 11/20-7: Yesterday’s 11/20-7:

Latest WCS as of 11/13/23 about steady vs yesterday for both Nino 3.4 (at +1.85) and PDO (at -1.19).

That’s probably why studies I’ve seen often refer to the average of the preceding OND to gauge the strength of the IOD. Thus, there’s almost no doubt that this IOD will end up as one of the strongest on record/very strong relative to other years.

Yeah, I use the CPC based on difference between Iceland and Azores SLP for it. They’ve done well for me.

I was purposely just listing El Niño years in my 2nd paragraph and beyond. But despite my not expecting it, I also remain hopeful for a sustained -NAO. Anything and everything can occur this winter. El Niño with -QBO probably tilts the scale a little bit. As it is, I’m thinking good chance for a Feb -NAO, regardless.

A gutsy call since I assume you realize that even the low end would mean the strongest -NAO for D-M since 2012-3. I’d love for you to be right during these hard to come by -NAO winters. What a winter the E US could have with that! The only El Niño D-M since 1951-2 with a -NAO stronger than the top of your range all had BN temps in most of the E US: 1957-8, 1963-4, 1968-9, 1969-70, 1976-7, and 2009-10. These are the El Niño D-M with an NAO within your range: 1958-9, 1965-6, 1977-8 All 3 of these were also BN in much of the E US. Corrected

Thanks. Did you mean to say slightly negative for Dec-Mar?

Indeed. That’s why I think the odds of a -NAO this winter are pretty low despite the fact that I think this winter will still be ascending (based on Waldmeier effect) and would be content with a neutral NAO. Four of the last six (back to 1979-80) -NAO DJFs were during ascending but as you alluded to, they were only 4, 13, 13, and 25 months past minimum. This winter will be centered on 49 months past minimum. But despite that, I’m also not giving up hope on a -NAO winter mainly because two of the four similarly timed QBO El Niño winters (1986-7 and 2009-10) had a -NAO DJF and both were ascending (though only 4 and 13 months past min, respectively). That’s not too shabby though the sample size is very small. 1991-2 and 2014-5 El Ninos had similar QBO but both had a +NAO in DJF. However, both of these +NAO similar QBO El Nino winters were during descending solar (14 and 9 months after max, respectively) interestingly enough. Hmmm…

Have you made a specific forecast for either the DJFM or DJF NAO? I know that @40/70 Benchmarkis going with neutral for DJFM (+0.15 to -0.20), which I’d take in a heartbeat in this day and age of difficult to attain -NAO winters. I don’t recall any other explicit (with numbers) NAO forecasts to this point. Getting a -NAO in DJF has occurred only six times in the last 44 (14%) winters though two of the six occurred in -QBO El Niño winters (1986-7 and 2009-10). In DJFM, there have also been only six of the last 44 as -NAO though only one during El Niño (2009-10) as 1986-7 dropped out due to a neutral March. I define -NAO as sub -0.25 averaged out over the relevant period. So, of the last 14 El Niño DJFMs, only one was sub -0.25. Fwiw, I’m leaning -NAO in Feb but either neutral or +NAO in DJF. So, I’d take a neutral DJF.

Latest WCS updates as of 11/12/23: -Nino 3.4 cooled back from +1.87 to +1.82 -PDO had the biggest drop for a single day since mid Sept from -1.01 to (per Griteater’s post) -1.18

Updated CPC OHC graph: latest warming topped out. Is this only a temporary halt or is it the start of new cooling?

This is similar to the cooler week on the Euro Weeklies on today’s run where it went from AN to NN. So, not as cool, but same trend toward cooler than prior runs for the end of Nov/start of Dec.

For the first time I can recall, the UKMET (12Z) has TCG for this in their textual product. Actual TCG isn’t until the C Bahamas after which it moves NE toward Bermuda as a 994 mb TS: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 144 HOURS FORECAST POSITION AT T+144 : 22.3N 73.6W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 18.11.2023 144 22.3N 73.6W 1001 32 0000UTC 19.11.2023 156 25.2N 69.9W 1000 40 1200UTC 19.11.2023 168 30.0N 64.9W 994 42

Daily NAO back to 1950: https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii When comparing these to the monthlies, the average of the dailies typically has ~half the amplitude of the monthlies. For example, the tabular monthly has a -2.03 for October of 2023 vs the average of the dailies being ~-0.9. For August of 2023, whereas the tabular monthly is -1.16, the average of the dailies is ~-0.6. Links to other dailies: https://ftp.cpc.ncep.noaa.gov/cwlinks/ The average of the PNA dailies similarly has ~1/2 the amp of the table. Oddly enough, the AO is unlike the NAO and PNA with the average of the dailies being close to the table.

For the first time on any run back to Oct 28th, the EPS weeklies have near normal instead of above normal temperatures most favored for the week 11/27-12/4 throughout the E half of the US fwiw:

Now that I’ve seen yours, I’m most curious about Don’s NAO forecast for this winter. His +NAO forecast for last winter was about the only one I can recall other than your forecast for a weak +NAO (+0.15 to +0.45) for DJFM, who went outright +NAO. If anyone else did, I apologize for not recalling or seeing it. DJF’s NAO ended up at +0.67. DJFM, thanks to the major SSW of Feb 16th leading to a strong -NAO in March, came in at only at +0.23. So, an excellent call on your part. I see you’re going for a DJFM NAO forecast of neutral (+0.15 to -0.20), which I’d take in a heartbeat in this current era of hard/easy to attain -NAO/+NAO winters. Have you or has anyone else seen an NAO forecast from Don for winter of 23-24?

This link shows the 13-month smoothed monthly total sunspot number (what I used to put together my lists) and it has 1.8, the lowest, in 12/2019: https://www.sidc.be/SILSO/DATA/SN_ms_tot_V2.0.txt 2019 10 2019.790 2.6 0.4 1065 2019 11 2019.873 2.0 0.4 832 2019 12 2019.958 1.8 0.4 855 2020 01 2020.042 2.2 0.8 795 2020 02 2020.124 2.7 1.4 967 So, I think the odds are good that the solar max (based on smoothed 13 month average) is going to be after this winter. If it (13 month smoothed average) isn’t after Feb of 2024, I’ll be wrong.

This last solar min was in Dec of 2019 per this found here: https://en.m.wikipedia.org/wiki/Solar_cycle_25 Solar cycle 25 is the current solar cycle, the 25th since 1755, when extensive recording of solar sunspotactivity began. It began in December 2019 with a minimum smoothed sunspot number of 1.8.

We have a clearcut trend conflict. The brand new update for WCS OISST (11/11) has it at +1.87 (up from 11/10’s +1.82). This is about tied with 11/1/23 for the highest so far for this Nino on that dataset. OTOH, three different datasets (CRW, CDAS, and OSTIA) have been trending cooler in recent days. So, this is kind of strange.

Webb isn’t telling us what a good number of us already know regarding moderate+ El Niño climo, Feb is favored as the coldest month in terms of anomalies in the Mid-Atlantic/NE US. That may also be the case in the SE US. He’s also saying that much of Dec is favored by climo to have warm anomalies, again nothing many here don’t already know. So, this isn’t exactly earth-shattering news.

I believe it is highly unlikely that cycle 25 has already reached its peak. Why? The Waldmeier Effect: “The Waldmeier effect describes the observation that the maximum amplitudes of solar cycles are inversely proportional to the time between their solar minima and maxima. Therefore, cycles with larger maximum amplitudes tend to take less time to reach their maxima than cycles with smaller amplitudes.” https://en.m.wikipedia.org/wiki/Solar_cycle If the 13 mo were to turn out to peak, say, in June of 2023, it looks to be no more than ~140. This 140ish peak would be only 3 years, 6 months after the prior minimum. Per Waldmeier, I’d be looking for a large max for it to peak that quickly. A 140 peaking only 3.5 years after the prior min would be very low for such a quick rise to the peak: Shortest rises min to max/peak 13 mo. avg -2 yrs, 11 mos/264 -3 yrs, 2 mos/213 -3 yrs, 3 mos/219 -3 yrs, 3 mos/193 -3 yrs, 4 mos/245 -3 yrs, 5 mos/235 -3 yrs, 5 mos/234 -3 yrs, 7 mos/199 Longest rises min to max/peak 13 mo. average -6 yrs, 10 mos/82 -6 yrs, 6 mos/119 -6 yrs, 4 mos/144 -5 hrs, 10 mos/81 -5 yrs, 4 mos/116 -5 yrs, 3 mos/180 -5 yrs, 0 mos/116 https://en.m.wikipedia.org/wiki/List_of_solar_cycles

Yes, indeed, it is hard to beat weak (not strong) phases 1/2/8 for best cold chances in the E US (especially SE US but applies to E US overall) during El Niño winters as per the following post I did on Oct 9: In that post, I listed 15 MJO diagrams from Nino winters that covered extensive periods of weak MJO (mainly left side of MJO chart) back to 1976-7 and showed how cold each period was for both ATL and NYC. From that post: “Weak 8-1-2 dominating during El Niño often favors a cold to very cold E US, especially SE US. As one who prefers cold, I would want a lot of weak 8-1-2 to keep cold chances the highest.” “So, for ATL, these 15 portions of El Niño winters with weak mainly left-sided MJO averaged a very cold 8 BN over 346 days. The 15 periods varied between -14 (MBN) and -5 (BN) with 11 MBN and 4 BN. So, for NYC, these 15 portions of El Niño winters with weak mainly left-sided MJO averaged a cold 4 BN over 346 days. The 15 periods varied between -15 (MBN) and +1 (N) with 5 MBN, 6BN, and 3N.”