GaWx

Thanks, Adam. For the period May-July, we’re likely headed to ~-22 avg SOI. One has to go all of the way back to 1905 to find any year at -22 or lower for May-July! Then it was -27. But that was a second year Niño (moderate). The only other one was in 1896, a strong Nino. That was at -28. Per Eric Webb’s tables, 1895-6 barely missed a low end weak Nino because there were only 4 tri-months in a row of +0.5 surrounded by +0.3s! So, 1896-7 was practically a 2nd year Nino. So, 2025-6 with 2024-5 having been La Niña is in uncharted territory going back to the mid-1800s as regards the extremely intense summer -SOI.

Chuck, I don’t follow you. Do you see anything that could prevent a +QBO from starting ~now or in autumn and then going through winter? If so, what? I’ve been banking on it based on the common ~24 month pattern.

How do you know that the El Niño is what caused this? Couldn’t it just be a coincidence? I’m suspicious of that because I couldn’t find even one similar occurrence with any of the other super-Nino events! @40/70 Benchmark@Stormchaserchuck1 https://psl.noaa.gov/data/correlation/qbo.data

Don’t forget that CDAS is slightly cold biased. But this chart isn’t relative. Relative OISST is in the +1.6-+1.7 range. I’m guessing that tomorrow’s weekly relative Nino 3.4 release will have it at +1.5 with +1.6 on the high end.

That July 16th Darwin 1018.25 mb is its 2nd highest on record back to 1991. The highest is only barely higher, 1018.35 (mid-2004). *Corrected

Thanks, Chuck. So, temps are clearly colder with W vs E based. Is some of this because the strongest El Niño winters tend to have warmer 1+2? However, with regard to wintry precip, itself, the SE appears to have done a bit better with C based (3.4 warmest) than W based (4 warmest) if I’m recalling my research correctly.

I realize ‘25-6 DJF was mild overall in the CONUS on a geographic basis. I’m not disputing that. But I think you’re being a bit too harsh on model performance for 25-6. The winter averaged 37.1F, which was 3.1F warmer than the Euro’s climo base of 1993-2016 and 3.0F warmer than the CFSv2’s climo base of 1991-2020. The forecasted mean anomaly for both the 8/1/25 Euro and the mid-July ‘25 avg CFSv2 was ~+2F for the CONUS on a geog. area basis or ~36F. This was actually a bit warmer than the 35.6 of 1994-5. Thus, the models were only ~1F too warm on a geog. area basis. Here are the warmest CONUS winters since 1895-6 (excluding 2025-6): 37.5 in 2023-4 36.8 in 2015-6 36.5 in 1999-00 36.4 in 1991-2 36.3 in 2011-2 36.3 in 1998-9 36.0 in 1999-00 Thus, with their ~36F progged mean, these 2 models were essentially predicting about the 7th-8th warmest CONUS winter since 1895-6. It came out 2nd. I think that’s pretty darn good. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/national/time-series/110/tavg/3/2/1895-2026

Mid July ‘25 CFSv2 2m fcast for winter 25-6: 8/1/25 Euro 2m fcast for winter 25-6: Actual 2m for winter 25-6: So, these 2 were much too warm in the E US, pretty close central, and not nearly warm enough W, especially in/near Rockies. W coast though was fairly close. *Edited for typo

12Z UKMET: 6th run in row with TS but dissipates off TX TROPICAL DEPRESSION 02L ANALYSED POSITION : 27.1N 85.2W ATCF IDENTIFIER : AL022026 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 19.07.2026 0 27.1N 85.2W 1012 22 0000UTC 20.07.2026 12 27.9N 84.9W 1009 22 1200UTC 20.07.2026 24 27.6N 85.5W 1008 27 0000UTC 21.07.2026 36 28.2N 85.5W 1005 30 1200UTC 21.07.2026 48 28.8N 85.7W 1004 35 0000UTC 22.07.2026 60 29.3N 86.0W 1003 35 1200UTC 22.07.2026 72 29.4N 87.1W 1004 46 0000UTC 23.07.2026 84 29.2N 88.2W 1004 40 1200UTC 23.07.2026 96 28.0N 90.7W 1002 48 0000UTC 24.07.2026 108 28.1N 93.9W 1005 33 1200UTC 24.07.2026 120 CEASED TRACKING

TD2 advisories to be initiated at 11AM.

The latest CFSv2 run’s mean is at new highs for peak: Monthly relative 3.4 progged peak ~+3.6 (Nov), which is way above current record (back to 1950) warmest of +2.69 (Jan ‘83) : 3 month relative 3.4 progged peak ~+3.35 (SON and OND), which is way above the record back to 1950 of +2.52 (NDJ 1982-3)

NHC will initiate advisories on Potential Tropical Cyclone Two (formerly AL91) located over the Gulf of America, at 1000 AM CDT (1500 UTC) Please pin this @buckeyefan1or other mod. TIA

I just started a thread on Invest 91L/potential Bertha:

Invest 91L will be investigated by recon today. NHC chances in TWO now very high: Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sun Jul 19 2026 For the North Atlantic...Caribbean Sea and the Gulf of America: Northern Gulf of America and near Florida (AL91): An area of low pressure located over the northeastern Gulf of America continues to become better defined and the associated shower and thunderstorm activity is gradually increasing. Continued gradual development is expected, and a tropical depression is likely to form later today or on Monday as the system moves slowly northward or northwestward. Interests along the northern Gulf coast from Florida, Alabama, Mississippi, and Louisiana should monitor the progress of this system, as tropical storm watches or warnings could be required for portions of the area later today. In addition, this system is expected to bring heavy rains to portions of the northern Gulf coast during the next several days. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the low pressure area later today. * Formation chance through 48 hours...high...80 percent. * Formation chance through 7 days...high...80 percent. $$ Forecaster Cangialosi —————— -Last 5 full (0Z/12Z) UKMET runs, the most consistently enthusiastic of the globals, have had a TS from this moving toward W GOM/LA/TX. -Icon also has been hinting at this for several days with some runs having a TC -0Z Euro was first run with a TC with it near borderline TS S of W FL panhandle

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sun Jul 19 2026 For the North Atlantic...Caribbean Sea and the Gulf of America: Northern Gulf of America and near Florida (AL91): An area of low pressure located over the northeastern Gulf of America continues to become better defined and the associated shower and thunderstorm activity is gradually increasing. Continued gradual development is expected, and a tropical depression is likely to form later today or on Monday as the system moves slowly northward or northwestward. Interests along the northern Gulf coast from Florida, Alabama, Mississippi, and Louisiana should monitor the progress of this system, as tropical storm watches or warnings could be required for portions of the area later today. In addition, this system is expected to bring heavy rains to portions of the northern Gulf coast during the next several days. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the low pressure area later today. * Formation chance through 48 hours...high...80 percent. * Formation chance through 7 days...high...80 percent. $$ Forecaster Cangialosi

The 0Z Euro is the 1st one that I can recall with TCG of 91L. It even gets to borderline TS status S of the W FL panhandle Tue night.

0Z UKMET: 5th run in a row of having a TD (TCG tomorrow) as well as a TS (upgraded Mon night) but doesn’t get as strong as prior 2 runs; mainly WNW movement to SE LA Wed night NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 12 HOURS FORECAST POSITION AT T+ 12 : 27.4N 85.2W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 19.07.2026 12 27.4N 85.2W 1011 23 0000UTC 20.07.2026 24 28.0N 85.1W 1008 25 1200UTC 20.07.2026 36 27.7N 85.5W 1007 27 0000UTC 21.07.2026 48 28.0N 85.4W 1005 31 1200UTC 21.07.2026 60 28.6N 86.1W 1004 36 0000UTC 22.07.2026 72 28.9N 86.6W 1004 38 1200UTC 22.07.2026 84 29.7N 88.3W 1004 46 0000UTC 23.07.2026 96 28.9N 89.5W 1006 36 1200UTC 23.07.2026 108 29.4N 90.7W 1009 35 0000UTC 24.07.2026 120 CEASED TRACKING

There still hasn’t been so far this summer a 100 F high at either Columbia or Augusta. Considering how hot this summer has been and with them often being two of the hottest for highs, that’s kind of surprising even though they’ve been plenty hot with 11-12 days in the upper 90s.

The CFS has been hinting at this possibility based on its very sharp record-paced cooling of 3.4 from Dec to Mar.

By the way, the 12Z UKMET was the 4th full run (full runs are at 0Z/12Z) that developed this into a mainly W moving full fledged TS. The last 2 runs developed it into a TD by early tomorrow morning! Landfall near LA/TX border: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 18 HOURS FORECAST POSITION AT T+ 18 : 27.1N 84.9W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 19.07.2026 24 27.5N 84.9W 1010 25 0000UTC 20.07.2026 36 28.1N 85.2W 1006 28 1200UTC 20.07.2026 48 28.2N 86.0W 1004 30 0000UTC 21.07.2026 60 28.1N 86.1W 1002 33 1200UTC 21.07.2026 72 28.4N 86.1W 1000 38 0000UTC 22.07.2026 84 29.2N 86.2W 997 50 1200UTC 22.07.2026 96 29.6N 86.9W 998 51 0000UTC 23.07.2026 108 29.3N 87.8W 996 52 1200UTC 23.07.2026 120 28.9N 88.8W 999 44 0000UTC 24.07.2026 132 28.7N 90.0W 999 40 1200UTC 24.07.2026 144 29.0N 92.0W 1001 36 0000UTC 25.07.2026 156 29.3N 94.2W 1004 37 1200UTC 25.07.2026 168 CEASED TRACKING

Invest 91-L now

1. The RRFS, which will replace NAM, has been developing this into a TS. 2. 0Z UKMET moves up TCG to 8PM Saturday and is stronger (winds almost to H strength Tue AM, which is high for the typically conservatively low UK) as it moves mainly slowly W to the NW GOM: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 24 HOURS FORECAST POSITION AT T+ 24 : 27.1N 83.8W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 19.07.2026 24 27.1N 83.8W 1011 27 1200UTC 19.07.2026 36 27.6N 84.5W 1008 30 0000UTC 20.07.2026 48 28.0N 85.0W 1004 30 1200UTC 20.07.2026 60 27.9N 85.1W 1002 33 0000UTC 21.07.2026 72 28.0N 85.4W 999 37 1200UTC 21.07.2026 84 28.9N 85.5W 997 46 0000UTC 22.07.2026 96 29.1N 85.4W 993 56 1200UTC 22.07.2026 108 29.6N 85.4W 995 59 0000UTC 23.07.2026 120 29.2N 86.1W 996 53 1200UTC 23.07.2026 132 28.6N 87.2W 999 44 0000UTC 24.07.2026 144 28.0N 88.6W 998 41 1200UTC 24.07.2026 156 27.6N 89.9W 999 39 0000UTC 25.07.2026 168 29.0N 91.4W 1002 35

Will CAE finally reach 100? They’ve already reached 99.

12Z UKMET has moved TCG back up to Sunday (AM) and in E GOM. Becomes TS Mon night. It initially moves WNW followed by slowly SW/SSW after hr 144 into N Central GOM, similar to 0Z run (slow movement throughout): NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 42 HOURS FORECAST POSITION AT T+ 42 : 26.9N 84.8W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 19.07.2026 48 27.4N 85.1W 1012 25 0000UTC 20.07.2026 60 27.8N 85.7W 1009 26 1200UTC 20.07.2026 72 28.2N 86.5W 1008 27 0000UTC 21.07.2026 84 28.1N 87.3W 1005 31 1200UTC 21.07.2026 96 27.9N 87.5W 1002 38 0000UTC 22.07.2026 108 28.6N 87.6W 1000 43 1200UTC 22.07.2026 120 29.3N 88.2W 1003 44 0000UTC 23.07.2026 132 29.5N 88.6W 1004 35 1200UTC 23.07.2026 144 29.2N 89.1W 1005 33 0000UTC 24.07.2026 156 28.4N 89.5W 1003 36 1200UTC 24.07.2026 168 27.7N 89.7W 1002 40

The CFS AAM at this site FINALLY updated for the 1st time in 2 weeks! Prior run from July 3rd: New one from today: +2 now but progged on 7/25 to drop to +1 vs the ~+2.2 mean on old run; progged mean doesn’t rise back to +2 til Aug 4th. Old run mean for Aug 4th was way up >+3. All of this is added evidence of a significant + bias out >2 weeks. Regardless, +AAM in full control, which is continued evidence of an intact steadily strengthening Nino: