GaWx

You must be thinking of 2019’s Humberto. I’m referring to 2007’s, which hit upper TX/W LA.

-Just for the record fwiw, the 6Z GFS hits Daytona on Aug 29 (way out at 2 weeks) -Much more statistically significant than just a fantasyland op run, its ensemble is unsettlingly pretty active in/near the SE US during Aug 26-30. Here’s a snapshot as of hour 294 (12Z on 8/27): -During this active period, GEFS has the MJO in/near phase 5. It’s not either of the 2 most active phases for H hits per day during Jul-Sep since 1975 (phases 2 and 8), but phase 5 has had the 3rd highest ratio of hits/day. - During phase 5, these 10 Hs hit the Conus: Francine (2024), Ike (2008), Humberto (2007), Ophelia (2005), Isabel (2003), Bertha (1996), Fran (1996), Bob (1991), Elena (1985), and Babe (1977). Two areas were most impacted by these 10: NC (Ophelia, Isabel, Bertha, Fran, and Bob) and upper TX to FL panhandle (Francine, Ike, Humberto, Elena, and Babe).

Copied from another BB: 998 mb is a pretty high SLP for a hurricane but there’s a rather strong sfc high to its north adding to the gradient: First hurricane of 2025 season AL, 05, 2025081512, , BEST, 0, 180N, 553W, 65, 998, HU

0Z UKMET shifted a bit E with recurve at 69.6W (vs 71.9W on 12Z) meaning passing by closer to Bermuda: TROPICAL STORM ERIN ANALYSED POSITION : 17.1N 51.9W ATCF IDENTIFIER : AL052025 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 15.08.2025 0 17.1N 51.9W 1004 34 1200UTC 15.08.2025 12 18.0N 55.1W 1003 37 0000UTC 16.08.2025 24 19.5N 58.1W 1001 39 1200UTC 16.08.2025 36 20.3N 61.6W 999 41 0000UTC 17.08.2025 48 20.8N 64.4W 996 40 1200UTC 17.08.2025 60 21.4N 66.5W 992 46 0000UTC 18.08.2025 72 22.5N 67.7W 989 48 1200UTC 18.08.2025 84 24.1N 68.7W 987 50 0000UTC 19.08.2025 96 25.9N 69.2W 985 52 1200UTC 19.08.2025 108 27.5N 69.4W 983 57 0000UTC 20.08.2025 120 29.4N 69.6W 979 60 1200UTC 20.08.2025 132 31.7N 68.7W 971 64 0000UTC 21.08.2025 144 33.8N 67.2W 964 70 1200UTC 21.08.2025 156 35.8N 64.0W 960 73 0000UTC 22.08.2025 168 37.6N 59.0W 954 75

I’ve already had the equivalent of a very wet TC with 12” of rain so far this month even without a TC! The last thing this area needs is more heavy rain as well as trees being easily toppled due to a high water table. After strong effects in ‘24 from the combo of Debby (10.9” of rain) and Helene (115 hour power outage/loss of food that took only high end TS winds/gusts to ~75 mph), I’d especially love a break. (By the way, FEMA never paid me for the food losses it promised even though I applied on the phone. ) Of course what I got pales in comparison to what others got from Helene to my W and NW and from Milton in FL. They’re the ones that especially need a break! Among other problems, the homeowner’s insurance situation is already ugly in much of the SE. I obviously like to follow and discuss these monsters and enjoy the challenge of forecasting what they’ll do. They’re also pretty to look at on satellite pics and are absolutely fascinating, but I want no part of them! Because of that, a boring quiet rest of the season wouldn’t bother me. However, I won’t let that desire bias my posts away from objectivity. Back to the present: 0Z UKMET has no followup TC to Erin unlike the prior runs.

I don’t know but I will note that Nick was in MJO phase 3 when it hit NC/N TX. I didn’t include it in my S or C TX hit list though it almost could have been included.

Unpredictable

Invest 98L up to 40% from 20%: recon in there now Southwestern Gulf (AL98): Shower and thunderstorm activity has increased in association with an area of low pressure located over the Bay of Campeche. The low is forecast to move west-northwestward across the southwestern Gulf during the next day or so, where environmental conditions are marginally conducive for further development. A tropical depression could form before this system moves inland over northeastern Mexico or southern Texas by late Friday ending its chances for tropical development. Regardless of development, locally heavy rainfall is possible along portions of northeastern Mexico and southern Texas over the next few days. An Air Force Reserve Hurricane Hunter is en route to investigate this system. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 7 days...medium...40 percent.

Followup: this looks like an AEW preceding the one the last two UKMET runs had with a TD forming 200 miles E of Guadalupe 12Z UKMET NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 168 HOURS FORECAST POSITION AT T+168 : 16.4N 58.4W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 21.08.2025 168 16.4N 58.4W 1009 32

MJO climo to keep in mind regarding Invest 98L: Hurricanes since 1975 in Jul-Sep that hit S or C coast of TX in MJO phase 2: -Hanna of 2020 -Harvey of 2017 -Claudette of 2003 -Bret of 1999 All S or C coast of TX H landfalls Jul-Sep since 1975 by MJO phase: -1: Allen 1980 -2: Hanna, Harvey, Claudette, Bret -3: Beryl 2024, Dolly 2008 -4-8: none So, of the 7 Hs to landfall on S or C TX Jul-Sep since 1975, 4 (57%) hit during phase 2 and 6 (86%) hit during either phase 2 or 3! The MJO is in phase 2 today and is progged to likely be in phase 2 tomorrow though phase 3 is a slight possibility. Just some climo for thought.

12Z UKMET: similar to last two with recurve at 71.9W: TROPICAL STORM ERIN ANALYSED POSITION : 16.6N 49.1W ATCF IDENTIFIER : AL052025 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 14.08.2025 0 16.6N 49.1W 1005 33 0000UTC 15.08.2025 12 17.5N 51.8W 1006 33 1200UTC 15.08.2025 24 18.5N 55.5W 1004 34 0000UTC 16.08.2025 36 19.2N 58.9W 1003 35 1200UTC 16.08.2025 48 19.7N 62.3W 999 36 0000UTC 17.08.2025 60 20.1N 65.0W 996 37 1200UTC 17.08.2025 72 20.8N 67.3W 993 41 0000UTC 18.08.2025 84 22.0N 68.9W 990 44 1200UTC 18.08.2025 96 23.8N 70.3W 988 49 0000UTC 19.08.2025 108 26.0N 71.2W 985 50 1200UTC 19.08.2025 120 28.3N 71.7W 981 52 0000UTC 20.08.2025 132 30.5N 71.9W 979 52 1200UTC 20.08.2025 144 32.6N 71.0W 976 59 0000UTC 21.08.2025 156 34.6N 68.7W 970 66 1200UTC 21.08.2025 168 36.4N 65.0W 969 63

This is convectively active this morning. The SW Gulf often over-performs with regard to the models.

The last two UKMET runs also have this followup to Erin.

Landfall (Conus) has for quite awhile seemed unlikely to me. But unfortunately there’s a lingering small chance. This small chance is best shown by the somewhat scarier 6Z GFS ensemble that was just posted. Based on that and other models, I’d keep it near 10%. Also, there’s a higher chance when you add in significant effects from fairly close misses of the center.

0Z Euro: 200 miles E of 12Z/recurves near 72.5W vs 75W of 12Z and yesterday’s 0Z recurving near 70W.

Followup to above: 0Z UKMET has a similarly placed TD following Erin vs the 12Z run: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 156 HOURS FORECAST POSITION AT T+156 : 15.9N 28.1W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 1200UTC 20.08.2025 156 15.9N 28.1W 1010 33 0000UTC 21.08.2025 168 15.8N 30.4W 1009 29

0Z UKMET is similar to 12Z with recurve at 71.7W TROPICAL STORM ERIN ANALYSED POSITION : 16.4N 45.8W ATCF IDENTIFIER : AL052025 LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 14.08.2025 0 16.4N 45.8W 1007 31 1200UTC 14.08.2025 12 16.7N 48.8W 1006 31 0000UTC 15.08.2025 24 17.8N 51.8W 1006 32 1200UTC 15.08.2025 36 19.0N 55.5W 1006 32 0000UTC 16.08.2025 48 20.0N 58.9W 1005 33 1200UTC 16.08.2025 60 20.5N 62.6W 1002 33 0000UTC 17.08.2025 72 20.4N 65.4W 999 32 1200UTC 17.08.2025 84 20.6N 67.2W 997 34 0000UTC 18.08.2025 96 22.3N 68.2W 994 40 1200UTC 18.08.2025 108 24.2N 69.6W 992 44 0000UTC 19.08.2025 120 26.1N 70.6W 989 46 1200UTC 19.08.2025 132 27.9N 71.3W 986 50 0000UTC 20.08.2025 144 30.0N 71.7W 982 52 1200UTC 20.08.2025 156 32.5N 71.5W 979 58 0000UTC 21.08.2025 168 35.0N 70.3W 972 62

At Least 3 Killed in Tennessee Flooding as More Rain Is Forecast Rescue crews pulled people out of submerged cars and homes overnight as floods swept the southeastern part of the state. A family of three was killed outside Chattanooga and emergency crews conducted water rescues as floods swept through Tennessee overnight. More flooding was expected in the eastern part of the state on Wednesday. After midnight, a large tree fell and crushed the car of a family in East Ridge, a suburb of Chattanooga, said Amy Maxwell, a spokeswoman for the Hamilton County Office of Emergency Management. “They died on the scene,” she said. “It’s obviously due to the loose soil that caused the tree to fall.” https://www.nytimes.com/2025/08/12/us/flooding-chattanooga-tennessee.html

From elsewhere: all progging majors 12z, August 13, hurricane model blend, Erin--- Model peak intensity ---HWRF = 944mb/117ktHMON = 952mb/115ktHAFS-A = 932mb/126ktHAFS-B = 928mb/127kt

12Z Euro: it doesn’t recurve til 75W and thus comes within 150 miles of NC! The OB are directly affected by its NW side. Gary Slezak, is that you?

12Z UK: for several runs has had this after Erin: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 156 HOURS FORECAST POSITION AT T+156 : 15.9N 24.3W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 20.08.2025 156 15.9N 24.3W 1010 28 1200UTC 20.08.2025 168 15.7N 28.1W 1009 32

~25 total ACE for those 3 progged storms, combined

I’m glad you asked because despite the 80% of 2005-24 avg ACE, it’s predicting ~3 NS for Sep 1-14. That’s actually slightly above the 2005-24 avg of 2.5 NS. That implies shorter tracks/possible W basin.

The Bay of Campeche/SW Gulf has often over performed. A TC from this wouldn’t at all surprise me. The NHC is probably too low with its percentages.

The latest Euro Weeklies are showing only 80% of ACE for 9/1-14, a big drop from the progged 400% for 8/18-24 due to Erin to ~1/2 the ACE for each of those weeks vs its 8/18-24 prog (likely MJO related). But then again, it’s 80% of the very active 2005-24 climo for near peak season. So, even if the 80% were to verify well, that would still mean an active period (even though not to the degree of the Erin week) and would end up way more active than for that period in 2024. Sep 1-14 of 2024 had only ~5-6 ACE, which is a mere <20% of the ~31 ACE avg for Sep 1-14 of 2005-24. Compare that to the EW’s 80% prog, which would be ~25 ACE for Sep 1-14 of 2025 or 4-5 times as high as 2024.