GaWx

July ‘26 BoM relative 3.4 was ~+1.6 per eyeballing this graph: July ‘26 ERSSTv6 relative 3.4 was +1.333 per this: https://www.cpc.ncep.noaa.gov/data/indices/Rnino34.ascii.txt The difference between those two in July ‘26 was slightly under 0.3. Do you have a link to the monthly GAMSSA data?

Thanks, Mitch. That means the WCS PDO has warmed ~0.92 over just the last 9 reporting days, and that’s the highest daily WCS PDO since way back on June 30th:

This is what I predicted on 8/24/26 for monthly/trimonthly RONI peaks (+3.0/+2.8), which would still be record warm peaks. I’m sticking with these for now. Let’s see what happens. I’ll use NOAA for verification, of course: “I’m now predicting that the actual monthly RONI peak (in or near Nov) will only be ~+3.0 with a trimonthly peak only ~+2.8. That +2.8 trimonthly would still be a record warm RONI going back to 1950 beating 1982’s +2.4. So, it would still be historic for sure. But it wouldn’t be nearly as warm as the ~+3.3-3.5 trimonthly RONI peak of many runs of various models.”

I said in my post that EVERY month since April verified significantly too warm. That’s five months in a row, not just August. I pointed out Aug because your two maps showed how much Aug had to be revised down. But April, May, June, and July also had to be similarly revised significantly down. Like for Aug, I’m talking about when each was the then current month. In other words, these were very poor forecasts considering they were then the first month. I’ve got all of the maps saved and can post them if necessary.

In Sept of 2023, the UKMET did much better than the way too warm BoM and was about the best of all models. Sept ‘23 UKMET progged ONI peak ~+2.0, which verified almost perfectly: I’ll be anxiously awaiting the Sept ‘26 UKMET ONI peak forecast. Here’s August of ‘26: ~+3.0. Keep in mind that this is ONI, not RONI! https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/el-nino-la-nina

Yep, the BoM monthly relative peak actually rose ~0.1 over the last month to ~+3.7, very much unlike the drop of 0.5 of the CFSv2 RONI trimonthly peak. Also, it unlike most others keeps it almost that high in Dec. I expect BoM will bust significantly too warm for this progged relative monthly peak of +3.7 like it did in 2023, when it was the warmest and verified way too warm. Also, note that every month since April on the BoM has busted significantly too warm. One can even see that for Aug by comparing your two graphs: the Aug 8th run had Aug way up at +2.7. The Sep 5th run lowered it down to +2.35. (I believe that the BoM uses a different dataset anomaly that makes it warmer than NOAA as you probably realize. I think it uses the warmer CRW as a base at least to an extent. That only adds to confusion.) The BoM (AUS-Access) had a whopping +2.9 for its peak forecast in its Sept ‘23 run! NDJ verified 0.9 too warm and DJF verified 1.1 too warm vs the NOAA ONI table seen at the link at the bottom of this post: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/oni/v6/

The MEI v2 was just released for JA: +2.5 vs +2.4 for JJ. That’s the 2nd bimonthly in a row at a record high for the bimonth (back to 1979). The record high for any bimonth is +2.9. Here’s the rundown for JAs of +0.5+: 2026: +2.5 1997: +2.3 2015: +2.0 1982: +1.9 1987: +1.5 2002: +1.0 1986: +1.0 1994: +0.9 2004: +0.8 2009: +0.6 2006: +0.6 1993: +0.6 2023: +0.5 2018: +0.5 1979: +0.5

The ONI peak in OND fell by the same 0.5 over the same period: Aug 1-10: ONI peak +4.15 Aug 30-Sep 8: ONI peak +3.65 and likely to fall further just like RONI as per the location of the blue lines So, the difference between the peaks of ONI and RONI didn’t widen.

I know ‘26 became the most E based of any Nino on record in early Sep as I posted that here 2 days ago: Although 1+2 has warmed in Sep, it like RONI has also fallen in OND fwiw though by not as much (0.3 vs 0.5) making it slightly more E based in OND than it had before: Aug 9-18: 1+2 OND +4.2 Aug 19-28: 1+2 OND +4.0 Aug 29-Sep 7: 1+2 OND +3.9

Heavy showers have moved from offshore W to my home at 1:40AM, a total surprise! Edit 11:45AM: Follow-up: I’ve been getting more showers moving W from offshore on and off since ~10AM to add to what I got late last night. I’ll check later to see if all of this added up to all that much. Edit #2: Heavy showers moved W from offshore to my home at 2:25PM.

The CFSv2 progged RONI peak continues to drop steadily with more drops likely: 7/22-31: ASO/OND +3.5 8/9-18: OND +3.45 8/19-28: OND +3.2 8/29-9/7: OND +3.0 with most of the blue lines (most recent 8 runs) lower

Here’s the preliminary winter outlook from pro met. Chris Martz: here is my preliminary thinking. . . As y'all probably know by now because of the endless hysteria in the news cycle, we are in an El Niño, which is just the warm phase of the larger El Niño–Southern Oscillation (ENSO). This year, the developing El Niño is unusually intense, and it is expected to officially be a “very strong” El Niño by early winter at the latest. This is marked by very warm sea surface temperatures in the equatorial Pacific Ocean. The news media and the United Nations have spun this as some sort of crazy event that will “turbocharge” extreme weather all over the globe, but that's not really how it works. Now, normally in the tropical Pacific Ocean, easterly wind stress associated with the Walker Circulation imparted on the sea surface acts to pile warm water near the surface in the western half of the basin; that is, closer to Asia. This pushes the thermocline down towards the west as warm water pools up north of the Maritime Continent and east of the Philippines. But during El Niño, the easterlies weaken or temporarily reverse (westerly wind bursts), which causes that pool of warm water to slosh back east. That's what's happening right now. There are a lot of meteorological factors to consider when it comes to predicting long-range temperatures, precipitation, and storm tracks. But this year, this “very strong” El Niño will play a dominant role I think as it has in years past (e.g., 1982–83, 1997–98, and 2015–16). Those are my top post-1950 analogs, and I added 1972–73 into the mix as it behaved similarly to the others, although it was only a “strong” El Niño at peak intensity. 1827–28 and 1877–78 would have been good analogs too, but we don't have enough climate data from back then to work with. A key feature of “very strong” El Niño events is that wintertime temperatures are particularly mild relative to average. This is pronounced in the Upper Plains / Midwest and Great Lakes / Northeast. Temperatures across the Desert Southwest and Four Corners region, however, typically run below average. The southeast can swing either way, but generally winds up near “average” (and I use scare quotes there because the weather is rarely “average”). However, these exceptionally mild temperatures do not necessarily persist all winter. In fact, most of this composite is due to “blowtorch” Decembers. And I do expect December to end up 5–10°F above average in the areas you see orange and red contours in the first analog composite map I made below. But the roaring Pacific Jet typically relaxes from mid-January through mid-February, so temperatures will tumble a bit closer to “seasonable.” If this El Niño were weaker, there'd be a good chance of a frigid December in the east. But I doubt that's going to happen. As far as precipitation goes, well, there should be an active subtropical jet stream. So, air parcels moving from west-to-east will tap into Gulf moisture and then be advected northward into the southeast. I expect a lot of rain in the Gulf Coast states (Texas to Florida) and then northward up the east coast into the DMV. Similarly, the western U.S. should expect some major drought relief due to atmospheric river events. After a near-record low snowpack last winter, the ski resorts will be back in business. Elsewhere, it will likely be a bit drier than normal due to persistent high-pressure ridging over the northern flank of the country. Storm tracks are going to favor the southern states. With respect to snowfall, overall, I do expect less of it nationwide outside of high elevation areas simply due to higher-than-average temperatures. But I cannot rule out ONE crippling blizzard in the Mid-Atlantic or in the southeast. It happened in the southeast (Florida, Georgia, and Carolina coastline) in February 1973 and in the lower Mid-Atlantic (Virginia, D.C., Maryland, and southeastern Pennsylvania) in both February 1983 and January 2016. However, it did not happen in 1827–28 or 1877–78 (I checked NOAA NCEI FORT data) or in 1997–98. So, whether or not we get the “big one” remains up in the air for now. But it will be that one storm that will ultimately determine where the seasonal snowfall will stand (above / below climatology) in the southeast and Mid-Atlantic. If it occurs, many folks will get their seasonal spoonful of snow in one dumping. If it does not occur, it's just going to be a wet winter.

A shower coming moving SW from offshore started here ~5 minutes ago. It likely won’t amount to too much due to it likely being brief due to rapid movement and it not being large. It ended up amounting to no more than a couple of hundredths.

Thanks for posting that. Regarding the PNA based on analyses I’ve done on snowfall for SE cities like RDU and ATL, a +PNA is the #1 most correlated index to snow in the SE. Since El Niño and +PNA are well correlated, having El Niño on average tends to be good relative to other ENSO for SE snow chances in general.

For anyone who happens to care, this is what I just posted elsewhere about my up to date general feelings about AGW/CC: 1) Anthropogenic Global Warming (human-caused CC) is real, has caused mean global temperature to warm ~2-3F, and is causing it to warm further. 2) Regarding CC reducing snowfall, that’s been true overall, which is intuitive. But for a specific location, the relationship between CC and change in avg snowfall is complex as it can actually cause heavier snowstorms in some cases since warmer air holds more moisture. This is especially the case where normals are well below 32F. 3) What’s debatable are four main things as I see it: a) Projections of rate of future warming because of realistic possibility of negative feedback loops, on which climate models likely don’t have a good handle. One example is “CO2 Fertilization Effect”: ^CO2 leads to ^photosynthesis, which leads to greener planet. Also, warmer planet means longer growing seasons and growing in higher latitudes than before. Greener means ^CO2 absorption for globe. So, at some point increase in CO2 would likely decelerate and perhaps later completely stop. b) I’m not at all saying AGW/CC’s good. The main concern I have is rising sea level caused by combo of melting land based ice and expansion of oceans due to warming waters. Also, it likely leads to increased flooding events since warmer air holds more H2O. That includes wetter TCs. But CC isn’t all bad. Why? - It’s likely leading to larger crops overall due to a combo of CO2 Fert. Effect, longer growing seasons due to warming, and ability to grow crops at higher latitudes due to warming. That means larger food supply and at least in theory less hunger. -Cold in the past has killed many more than heat globally. Thus so far, CC has actually lead to reduced deaths from extreme temps. But admittedly assuming globe continues to warm, increased heat related deaths will likely overtake reduced cold related deaths. c) Storminess: CC may actually be reducing the avg storm strength. Why? It has caused much more rapid warming in Arctic than in tropics. That means reduced temp. difference from poles to tropics, which means slower jet stream, which means less energy available for storms to strengthen. Possibly related to this: typhoon activity has come down in recent decades. d) There’s a lot of controversy concerning the connection of CC to individual extreme events aka “CC attribution”. I feel it’s overdone at times or at least there’s often a rush to attribute extreme events to CC without enough time or evidence to soundly prove it. I’m not saying no extreme events have been made worse by it. Almost certainly extreme heatwaves have been made worse by it than would otherwise have been the case. Example: the March SW US heatwave. But here are some examples of a rush to judgement about the CC connection that needs much more time to study it: -Nepal disaster. Whereas CC probably was at least a minor cause since it has been leading to melting glaciers overall, was it actually a major cause as some have already claimed? If bedrock failure was indeed the major cause, was that in itself due to GW? This needs much more time to study as it is very complex. -Wildfire disasters: Whereas a warmer globe has likely helped lead to increased fires in some cases, that likely hasn’t been the case for many fires. Also note that global burnt acreage year to date has actually been during the last 2 years the lowest it has been as of this date since 2012! ———————— Edit: I forgot to mention that the UHI effect needs to be taken into account when comparing temperatures in past decades to today. This is especially the case for comparing temps for large cities/metro pop. that had much smaller pop. in those past decades.

Per my post from two days ago ITT that analyzed El Niño seasons with <4.3 ACE as of then, I’d be wary that despite the very slow start there likely will be some dangerous activity in some areas late Sept to mid Oct especially if I were a (near) coastal resident.

The warming related to AGW is itself a factor helping to cause 2026-7 to be so much warmer than these prior Ninos since the globe continues to warm. Without that, although 2026-7 would possibly still be the warmest, it at a minimum wouldn’t be as far above these others. In other words, this graph isn’t a fair way to determine the strength of each of these El Niños, themselves, since AGW gives an advantage to later ones.

The Nino is likely going to greatly help some ski resorts this winter.

Not Atlantic basin per se but this is interesting: The UKMET has for the 2nd run in a row a TC in the Mediterranean Sea: 12Z UKMET: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 132 HOURS FORECAST POSITION AT T+132 : 35.8N 21.0E LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 14.09.2026 132 35.8N 21.0E 1008 31 1200UTC 14.09.2026 144 38.7N 24.0E 1007 27 0000UTC 15.09.2026 156 40.5N 24.6E 1007 27 1200UTC 15.09.2026 168 39.6N 22.6E 1008 25

For the first run I’ve ever seen, the CFSv2 ensemble AAM forecast has its key at the bottom of the graph because there’s no room on top on either side! It is approaching 3. Three of the four members of the 9/7/26 12Z run have it exceed 4 on Sept 15th (day 9). I’ve still never seen the AAM get to 4 by the way. Will it finally do so this time?

More decent rain falling here last few minutes (since 3:45), to add to my 0.35”, but radar shows and skies suggest it won’t last more than a few more minutes most likely. Edit: 3rd rain from a shower fell just after 5PM. Looks like another quick one. Edit: updated total for Sept 7th here: ~0.4”

Despite the high level of activity in the EPAC, they’ve almost entirely avoided getting close to MX. Only the two TS Boris and Cristina were right next to MX or C America and those were in early June, well before the Aug 14-Sep 4th period you showed the 250mb wind component anomalies for. The only 4 during Aug 14th-Sep 4th that even show MX on the map were the four I’m noting below and one can see that MX isn’t even that close. All of these mainly avoided the areas with average 250 mb wind anomalies of +6+ on your map as their tracks were mainly within the +2 to +6 anomalies (yes still + but not large + anomalies and they may have formed when actual anomalies were lower since your map is just the avg for a 3 week period): -TS Iselle: TS Julio: H Karina: H Maria: closest to MX of these 4 but still 375 miles away from Cabo Here’s ‘26 season to date: Compare the above ‘26 season to date map with the 2015 full season below. Note that in 2015 by today’s date, the following had already occurred that were either right at or nearer MX than the ‘26 tracks excluding Boris: -Blanca (cat 4 H) -Carlos (cat 1 H) -Dolores (cat 4 H) -Kevin (60 mph TS) not too far from Cabo -Linda (cat 3H) not too far from Baja

A batch of showers formed along the cosst in SC 2 hours ago and has just moved SW into my area with heavy rains and initial gusty winds starting ~2PM. This is adding up nicely and is this my first significant rain of the month. Edit: It rained for only ~20 minutes and this didn’t add up to as much as I had hoped for. But I still got a not too shabby ~0.35”, the most by far this month to date.

After being pretty flat in August/first few days of Sept, the relative 3.4 OISST anomaly has risen sharply the last two days: Sept 4th relative 3.4: +2.254 Sept 6th relative 3.4 anomaly: +2.429, a rise of 0.175 in just two days…that’s the most rapid two day rise on this entire chart as it is the most rapid two day rise since June 3rd-5th, which is not on this chart:

The daily WCS PDO has risen back substantially the last 7 days ending yesterday with it up to -0.9, the highest since way back on July 2nd, vs ~-1.65 one week earlier: