GaWx

Excellent post as a whopping ~90% of the daily graphs since July 1st have averaged a -AAM in the 30N to 40N corridor! The 40N to 50N corridor also has a very high % that are -AAM although not quite as high as the 90% especially due to the last few weeks.

Thanks, Ray. Indeed, that 9/21/26 graph has the only significant pocket of -AAM centered at our latitudes as you noted. However, I assume you realize that these lat. based graphs are quite fluid, and thus it could look quite different at our latitudes within just a few days for all anyone knows. Also, the extremely + tropical latitudes overall have little choice but to drop back at least some soon. I’ll try to follow these daily from this point on. Here’s the brand new update for 0Z on 9/22/26: note that the -AAM pocket at our latitudes is still there and still the most significant -AAM area but isn’t as negative. Also, although 52N-61N has dropped, 63N to 90N is significantly more positive vs yesterday with a peak of +2 SDs at 78N vs +1.3 yesterday: Compare to yesterday’s: The corresponding global mean for 9/22/26 is as expected per prior days’ CFSv2 progs on its last legs of the extreme level of +4+ although it fwiw keeps a very strong +3+ mean on all but a few days in early Oct:

Thanks for posting this. For the first time I examined past versions of this because I just realized that the excellent website has these graphs going back to 4/11/2022. So, there’s ~1,000 of these to compare to. Now I know why the relative global AAM standardized anomaly graphs have been at extreme levels (>+4). This latitudinal based graph for 9/21/26 is an absolute beast overall and thus exhibits the strength of this Nino very well! Why? 1. Back to 4/11/22, I couldn’t find even one other day’s graph with a more positive avg std. AAM anomaly for the area from -40 to +30! The straight avg std. dev above the mean for that huge area on 9/21/26 is clearly >2. Keep in mind that 2 std dev above the mean at any one latitude is way up at the 98th percentile and thus nearly 1/3 of the globe (20N to 17S) is >>+2 std dev/>>98th percentile! 2. The # of degrees of latitude with a negative AAM anomaly of the 180 total degrees on this 9/21/26 graph adds to only 29 degrees of the 180 total (16%). I couldn’t find even one other with that small a % of latitudes <0! 3. As one can see, most of the latitudes with a -AAM anomaly on 9/21/26 are only down to the 0 to -0.3 std dev range. The lowest is only down to -1.1, which is quite high for the lowest vs the other ~1,000 graphs. The highest lowest I could find is only barely higher (~-0.9) and it overall still had a much larger area below the 0 line than 9/21/26: So, it appears that 9/21/26 has the smallest area <0 of any back to 2022! Here again is this 9/21/26 beast of a +AAM anom by latitude. Keep in mind that just 1 std dev above the mean is up at the 84th percentile: Below is the corresponding relative global AAM, which since 0Z of 9/19/26 has been at an extreme level of >+4 std dev! This is probably the peak day as it should get back to <+4 by 9/23/26. How rare is 4 std dev above the mean? Per stat. formulas, only 1 in 31,574 days (that’s once per 87 years) gets to that level! (For 3 std dev, it’s ~once/year):

WB CFSv2 temp maps: 1. Have algo issues that lead to bad artifacts. I’ve posted on this here in the past. Here are some examples -note the cold spot over S Lake Michigan and warm spot only 250 miles to the north over N Lake Michigan that are almost always on these WB maps; the real CFSv2 output essentially never has these -note the E coast down to FL usually looks like a thin sharp warm barrier to any colder anomalies to the west; again, this essentially never is on the real output 2. WB CFSv2 maps are strongly cold biased for much of the E US. And this is the case even with WB using the colder 1981-2010 climo instead of 1991-2010, which the CFSv2 site uses! All one has to do to know this is to compare to the maps at the CFSv2 site. All 4 (DJFM) are notably too cold in almost all of the area away from the E coast. But I’ll focus on the Dec map to illustrate the strong cold bias: -Chicago’s +0.5C/1F vs 1981-2010 on WB but the CFS site’s relevant 10 day mean maps (see below) are all significantly warmer and they average +2.25C/4F vs the warmer 1991-2020 meaning WB is ~4F too cold. -SL’s 0.0 C/F vs 1981-2010 on WB but CFS actual maps are all significantly warmer and average +1.5C/3F vs 1991-2020 meaning WB is ~4F too cold -Knoxville’s -1C/-2F vs 1981-2010 on WB but CFS actual maps have it at +0.6C/+1F vs 1991-2020 meaning WB’s ~4F too cold -Despite the CFS site’s maps averaging AN from TN-NC north, WB in inland areas doesn’t have AN start til 500 miles to the N in N IL to N OH to NW PA and that’s even vs a colder climo base! That’s ignoring the immediate E coast, which has its own problems as already noted and is actually a bit too warm overall despite it being 4F too cold for much of the inland areas! Relevant 10 day mean Dec maps at CFSv2 site: 9/10-19: 8/31-9/9: 8/21-30: 8/12-21: @Stormchaserchuck1@donsutherland1

I’ve already compared the current Nino to the prior one for both GLAAM and for OHC (like night and day). 1. Here’s a similar comparison of PDO: Current: -0.71 Sept of 2023: ~-2.4 on Sept 19th though these are admittedly volatile as one can see it rose steeply Oct 1-20th: 2. SOI: 90 day mean is now way down at ~-22. The mean was down to only -8 for the same 90 day period in 2023. It was -18 in 2015 and -14 in 1997. A rough estimate using monthlies (due to no dailies that far back) for 1982 is -19 to -20. The only other 90 day mean as of Sept 20th back to 1876 that realistically could be about as low as 2026’s -22 based on monthlies is 1896 (incoming strong Nino) though that chance is <50% as it is more likely in the -20 to -21 range. So in summary: 2026: -22 2023: -8 2015: -18 1997: -14 1982: -19 to -20 1896: -20 to -21 The other super-Ninos’ rough estimates: none even close to 2026, 1896, 1982, 2015: 1972: -13 1965: -14 1957: -5 1888: -11 1877: -10

OHC of 180-100W appears to currently be at its highest yet (~+3.3): To compare, look how low was the same point in Sept of 2023 (only ~+1): Highest 2023-4 ever got was only just over +1.5:

Further to my global relative AAM post above showing it >+4 since yesterday and to show the huge contrast to the prior El Nino, here are some of the graphs I saved from 2023-4, which all show a much lower amplitude (keep in mind that CFSv2 progs looking out especially past 2 weeks have been biased positive as comparing these graphs to each other clearly show): 11/6/23: +0.15 12/16/23: +0.7: 12/30/23: +1.15 (highest of any I saved from 2023-4) 1/8/24: +0.15 2/3/24: +0.5 2/21/24: +0.2 3/1/24: -0.35

The global relative AAM remains in historic territory of +4+, which should last into tomorrow. This is probably its highest since Feb of 1998. For comparison, 2023-4 was no more than in the low +1 region on any of the graphs I saved with most of them <+0.5:

The AAM went over +4 as expected yesterday (9/19) per the image below, an extremely rare/historic event. The last time it was this high may very well have been in early Feb of 1998. It appears that it will likely stay >+4 into Sept 21st:

https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml

The main CFS site actually has 40 run averages (10 days x 4 runs/day).

Also, the TT maps use colder 1984-2009 climo instead of the CFS site’s 1991-2020. The TT 3 day (12 run) avg does jump around more than the CFS site 10 day (40 run) avg. Regardless, I haven’t seen any 3 day avg Feb recently nearly as cold as those record cold Febs that were on some Aug 3 day means in the SE to S Plains. Then again, that degree of cold was hardly believable especially that far out. They were dreamable for me but not believable. I’ll keep following the trends of both the TT 3 day means and the CFS site 10 day means.

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sat Sep 19 2026 For the North Atlantic...Caribbean Sea and the Gulf of America: 1. Eastern Subtropical Atlantic (AL99): Showers and thunderstorms have become more concentrated near the center of a low pressure system located several hundred miles southwest of the western Azores since yesterday. A short-lived tropical depression or tropical storm is expected to form later today or tonight while moving north-northeastward at about 5 mph, but remaining well to the southwest of the Azores. Upper-level winds are forecast to become less conducive for development beginning late Sunday. * Formation chance through 48 hours...high...90 percent. * Formation chance through 7 days...high...90 percent. Forecaster Berg

Recent 3 day mean CFS’ have cut way back on the degree of cold in Feb: 9/16-18 Compare that to this from 8/7-9:

There indeed have been UK runs with false TCs though not false canes. But in this case, all models have a low off the NE coast as opposed to it being just on the UK. But would it be T, ST, or ET and would it stay offshore?

Watch off the E coast next week. Here’s a hint of that from 0Z Uk: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 150 HOURS FORECAST POSITION AT T+150 : 36.1N 70.8W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 25.09.2026 156 36.9N 69.7W 1000 47 0000UTC 26.09.2026 168 39.1N 67.9W 997 41

Google Deep Mind

AAM +3.9 & rising to very extreme levels. Should be off the chart on next runs:

Did you see this?

There may very well be a reduction in the # of storms due to GW because it has warmed the poles much more than the tropics. Because tropical systems bring heat out of the tropics to higher latitudes, it’s possible that the lower contrast means fewer storms albeit with perhaps stronger storms on average due to the warming oceans. Indeed, we’ve had stronger storms in the Atlantic basin with more cat 5 since 2016 per year than for the prior period. But OTOH, I do wonder if just having warmer oceans is enough to generate stronger storms. Isn’t it the contrast of the avg tropical ocean temp vs the avg global temp that matters most? The oceans in the tropical/subtropical regions are obviously warmer, but the rest of the globe is warmer, too. It used to be that ~79F was a crucial SST to support TCG. Is that crucial SST going to warm up due to GW? Your thoughts?

Follow-up: I emailed the 2 contacts who are listed at this CFSv2 site. Just minutes later, the site was updated! Here’s the brand new latest 10 day mean RONI forecast: as expected, the progged peak dropped even further to +2.8. Compare that to the +3.5 runs of late July. It appears it could even drop to +2.75 later this month based on the red vs blue lines:

I don’t know about “ever increasing disaster”, but you must know that there have been some bad seasons since including 2008, 2012, and most of 2016-24. 2016-24 was one of the worst 9 year periods for the SE US overall. Fortunately 2025 as well as 2026 so far have given us a much needed break, especially after the horrible 2024. But that’s less than 2 seasons.

Yesterday’s Euro Weeklies suggested a pretty active period in and near FL during the week of Sept 28-Oct 3rd. This suggests a recurving TC in that area is quite possible: This matches long-term climo well, which is at least close to the most active period for FL throughout the season: These 5 strong+ El Niño analogs with hits in FL during or near this active period shown on the Weeklies suggest to be wary especially in FL then although it’s interesting that these 5 were all 1902 and earlier as the subsequent 11 strong+ Ninos didn’t have a FL hit around then: 1902: 1899: 1896: 1888: 1877:

99L is now a cherry: 1. Eastern Subtropical Atlantic (AL99): Showers and thunderstorms have changed little in organization since this morning in association with an area of low pressure located several hundred miles southwest of the Azores. However, just a small increase in organization is likely to result in the formation of a tropical depression as soon as later today. The system is expected to move slowly over the next couple of days remaining southwest of the Azores, followed by a turn to the southwest by early next week, when environmental conditions are forecast to become less favorable for additional development. * Formation chance through 48 hours...high...70 percent. * Formation chance through 7 days...high...70 percent.

Is 99L going to be the first TC formation of the month? Edouard became a TC in August. When was the last Sept that didn’t have a TC formation by now? 2025 took til Sep 17th. 1976 didn’t have one that later became a TS til the TD that formed on 9/26 and that became TS Gloria on 9/27. And there was a ST storm on Sept 13th. So, that doesn’t count as a TC. However, 1976 also had 2 TCs that maxed out as only TDs early in Sep. in the satellite era. So, even if a TD is declared today, 2026 has already beaten 2025 for the latest 1st TC declared in Sept. during the satellite era. Now, if it becomes a TS, that would mean that 1976 would remain the season with the latest first named TS in Sept. in the satellite era, which is Sept 27th.