GaWx

Here in the SE, I prefer either EPAC or CPAC dominating it to the MC dominating because that would normally mean a much reduced influence of the SE ridge/colder overall.

The Sep of 2026 MJO has been very different from that of Sep of 2023: Sep of 2023 (blue): all in MC/IO Sep of 2026: none in MC/IO

The differences between the traditional (non-relative) NOAA weeklies and their official relative counterparts have increased notably since early June: 1. 6/3/26: Non-relative for 6/3/26: 03JUN2026 2.5 1.5 1.3 1.2 Relative for 6/3/26: 03JUN2026 2.0 0.9 0.7 0.7 So, the differences between traditional and relative for 6/3/26 were: +0.5 +0.6 +0.6 +0.5 ———————— 2. 9/23/26: Non-relative for 9/23/26: 23SEP2026 4.7 3.9 3.1 1.1 Relative for 9/23/26: 23SEP2026 3.9 3.1 2.2 0.1 So, the differences for 9/23/26 are: +0.8 +0.8 +0.9 +1.0 ————————— Thus the differences between traditional and relative for NOAA have increased from 6/3/26 to 9/23/26 by these amounts as GW’s influence over the traditional way of measuring anomalies (30 year) has increased since early summer: 0.3 0.2 0.3 0.5

The 0Z UKMET like prior runs going back days continues to keep Fay alive through the entire run. It has Fay at her strongest late in the run only barely missing going back to TS strength! TROPICAL DEPRESSION FAY ANALYSED POSITION : 28.7N 44.0W ATCF IDENTIFIER : AL062026 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 28.09.2026 0 28.7N 44.0W 1015 23 1200UTC 28.09.2026 12 27.4N 44.6W 1014 23 0000UTC 29.09.2026 24 26.4N 45.6W 1013 22 1200UTC 29.09.2026 36 25.4N 47.2W 1013 22 0000UTC 30.09.2026 48 24.7N 48.9W 1012 23 1200UTC 30.09.2026 60 24.3N 51.1W 1013 25 0000UTC 01.10.2026 72 24.1N 53.1W 1013 27 1200UTC 01.10.2026 84 24.6N 55.1W 1014 24 0000UTC 02.10.2026 96 25.2N 56.6W 1014 24 1200UTC 02.10.2026 108 26.2N 58.0W 1013 27 0000UTC 03.10.2026 120 27.1N 58.8W 1012 31 1200UTC 03.10.2026 132 28.2N 59.1W 1010 33 0000UTC 04.10.2026 144 29.0N 58.9W 1009 33 1200UTC 04.10.2026 156 29.7N 58.5W 1009 34 0000UTC 05.10.2026 168 30.1N 57.9W 1009 31

^Thanks. Here is this morning’s NOAA weekly update for relative (for those who don’t know, this much better takes into account GW and thus became the official way of measuring by NOAA a good while ago) Nino anomalies for the average of last week compared to the avg for the prior week: this shows 1+2 still at +3.9 and the other 3 having warmed 0.1. Below that are the comparable weeks in 1997 and 1982: 16SEP2026 3.9 3.0 2.1 0.0 23SEP2026 3.9 3.1 2.2 0.1 24SEP1997 3.8 2.7 1.8 0.5 (the most E based prior to 2026) 22SEP1982 1.5 2.1 2.0 0.6 Compared to past years for the same week, 1+2 region’s +3.9 remains at its highest (weekly records back to 1981) for the 2nd week in a row, beating 1997’s +3.8. Next Monday’s release will likely be the 3rd week in a row at its highest. Nino 3’s +3.1 is its 2nd week in a row of being at a high with it easily beating 1997’s +2.7. Nino 3.4’s +2.2 beats 1982’s +2.0 for the warmest for that week and is its 3rd week in a row at a high. Nino 4’s +0.1 is way cooler than the other regions and also is significantly cooler than many years thus showing how much more E based 2026 is vs any other year on record as of late Sept including the prior most E based 1997: 1994 +0.9 1986 +0.8 2019 +0.7 2002 +0.7 2006 +0.6 2004 +0.6 2023 +0.5 1997 +0.5 https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt @bluewave@OSUmetstud@40/70 Benchmark

Ok, here we go again with the BoM RONI progs. As I’ve posted, the early near month prog of every near month of Apr-Aug ended up having been too warm as per their charts showing notably cooler in their final analyses vs these early progs. I now feel safe in saying that that’s happening with Sep, too, which would make 6 months in a row! Here was a Sep 5th prog, which had Sep near +3.0: Compare that to the brand new run (Sep 26th…see below), which has Sep MTD at only +2.4 with only 5 days to go (note the line from Aug to Sep is almost flat vs the steep slope of the Sep 5th run)! To compare, NOAA appears to be headed to a Sep of only ~+2.0 to +2.2. We’ll see next week where Sep. settles for both BoM and NOAA. I bet BoM settles at ~+2.5 or +2.6, well below its Sep 5th run’s +3.0 prog. Thus, I continue to expect that the ~+3.8 peak that it still shows for Nov will end up not verifying even closely. Before that, I predict with confidence that the +3.5 of Oct won’t verify closely. Why would the clearcut pattern of significantly too warm near month progs change now? Besides, it would take pretty much a record warming for a one month period to reach from Sep’s mid +2s to Oct’s +3.5. Sound familiar? Several models earlier had predicted a record warming from July to August, which we know ended up busting badly. To show how out of touch with reality this has been the last 3 months, this Jul 4th run had July at +2.0, Aug at +2.7, and Sep at +3.0. Jul/Aug BoM verified at only +1.7/+2.3 and Sep should verify only in the +2.5 to +2.6 area as mentioned. This warm bias is Déjà vu from 2023:

Hawaii now has the most outages in the U.S. with ~11K. Almost all are on Maui, where a whopping 15% are without power. https://poweroutage.us/area/state/hawaii

Why do you think they’re getting warmer?

1. The best hope for 2027-8 might be for it to be like 3 of these 8 analogs and not be La Niña for the NE: 1878-9: near to AN snow 1966-7: well AN snow 1992-3: BN to AN snow 2. Regarding the snow for the 5 that did become LN, not good: 1889-90: BN 1973-4: NN 1983-4: BN 1998-9: BN 2016-7: MBN

Lowest hourly SLP at reporting land-based station I found was 29.37” (994.6 mb) at Toms River, NJ, at 9AM and 10AM. Next lowest Atlantic City 29.39” (995.3 mb) at 11AM.

Thanks. If that makes it to TS status and avoids getting to H status, I think that would tie an Atlantic Basin record for most named storms in a row from start of season not making it to H status.

Looking at El Niño seasons that at some point maxed out at +2.0C for a trimonthly in Nino 3.4 (using Eric Webb’s tables for pre-1950 and the latest version of NOAA RONI for 1950+), this is what followed in ASO as well as the subsequent fall/winter: 1877-8: ASO +0.1 followed by cold neutral 1888-9: ASO -1.1 followed by strong La Niña 1965-6: ASO 0.0 followed by cold neutral 1972-3: ASO -1.3 followed by strong La Niña 1982-3: ASO -0.6 followed by moderate La Niña 1991-2: ASO +0.1 followed by weak El Niño 1997-8: ASO -1.2 followed by strong La Niña 2015-6: ASO -0.9 followed by moderate La Niña Tally for these 8 strongest El Niños on record: 5 La Niña (3 strong, 2 moderate) (62.5%) 2 cold neutral (25%) 1 weak El Niño (12.5%) So, this suggests the best chance is clearly for La Niña although it also suggests to not dismiss the possibility of something else, mainly cold neutral, especially IF this were to peak later than model consensus has been suggesting (say, in Jan instead of Nov). Of the 3 of these that didn’t go to La Niña, 1877-8 peaked between NDJ and DJF while 1991-2 peaked in DJF. OTOH, 1965-6 peaked early (OND) and still didn’t go all the way to La Niña the following year as it stopped at cold neutral. Note that the 3 that were neutral in ASO never made it to La Niña. ____________________ Sources of data: 1. Webb’s tables (used for pre-1950): https://www.webberweather.com/ensemble-oceanic-nino-index.html 2. NOAA RONI (1950+): https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/

Thanks. Glad it wasn’t that bad there then. Between Fri and Sun, the delays at LGA were shortest on Sat due largely to the normal fewer scheduled flights that day allowing for them to handle the use of just one runway. But today’s avg delay is still getting longer with the arrival delay averaging 2 hrs, 19 min, at last report though that’s still not as bad as the ~2 hrs, 45 min of late Fri. The departure delays are averaging just over an hour: Due to WEATHER / WIND, there is a Traffic Management Program in effect for traffic arriving La Guardia Airport, New York, NY (LGA). This is causing some arriving flights to be delayed an average of 2 hours and 19 minutes. To see if you may be affected, select your departure airport and check "Delays by Destination". Delays by Destination: Due to WEATHER / WIND, departure traffic destined to La Guardia Airport, New York, NY (LGA) is currently experiencing delays averaging 2 hours and 19 minutes. General Departure Delays: Due to WX:Wind, traffic is experiencing Gate Hold and Taxi delays between 1 hour and 1 minute and 1 hour and 15 minutes in length and increasing.

Is the long length of it noteworthy in relation to others? Isn’t this going to end up as a 48++ hour event in many locations?

The new LGA update shows much longer delays than earlier with the quite strong winds along with lingering light rain/fog: LAGUARDIA ARPT LGT RAIN 61 59 93 NE30G47 29.54R FOG Due to WEATHER / WIND and WEATHER / WIND, there is a Traffic Management Program in effect for traffic arriving La Guardia Airport, New York, NY (LGA). This is causing some arriving flights to be delayed an average of 1 hour and 43 minutes. To see if you may be affected, select your departure airport and check "Delays by Destination". Delays by Destination: Due to WEATHER / WIND, departure traffic destined to La Guardia Airport, New York, NY (LGA) is currently experiencing delays averaging 1 hour and 43 minutes. General Departure Delays: Due to WX:Wind, traffic is experiencing Gate Hold and Taxi delays between 1 hour and 1 minute and 1 hour and 15 minutes in length and increasing.