Tropical Wave WSW of the Cabo Verde Islands (40/80)

[BobHarlem]

ULL over south carolina basically pulls it in right over the low country, near Edisto, Charleston gets the right front quad.

[kevin]

12z GFS +354h, 954 mb and the final frame before a landfall SE of Charleston.

[BobHarlem]

Between the vast spread between all the ensembles of the various models, ULL and the TUTT and this you are probably going to see a lot of the phrase "low confidence" in future outlooks/discussions. If a system gets that far west, the ULL would pull it inland -- post landfall it gets to Illinois, but GFS maybe still has a poleward bias. This system just got a whole lot more interesting today.

[LarryWx]

12Z UKMET: N of 0Z…aiming for just N of Leewards

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 96 HOURS
FORECAST POSITION AT T+ 96 : 13.8N 43.4W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 07.09.2025 96 13.8N 43.4W 1012 25
0000UTC 08.09.2025 108 13.9N 46.1W 1011 28
1200UTC 08.09.2025 120 13.9N 48.8W 1010 28
0000UTC 09.09.2025 132 14.3N 51.3W 1009 31
1200UTC 09.09.2025 144 15.6N 53.6W 1010 32
0000UTC 10.09.2025 156 16.8N 56.0W 1010 32
1200UTC 10.09.2025 168 17.8N 58.6W 1010 34

[MGC]

Yeah, this could be a potential US hit. Might get a closed low by this weekend. Past GFS runs have been too fast and too far east. Could even impact islands. All depends on the upper pattern a week from now.......MGC

[Stratton23]

Euro 12z looks like its headed for the central leeward islands, farther south than 00z run through 7 days so fas

[Pelicane]

Looks like Lorena in the EPAC will play a future role with this system. Her remnants seem to help form a cutoff low in the SE as potential future Gabrielle turns north. Important to watch since if Gabrielle trends far enough west and that low is strong enough it could pinwheel around it. Already happened on the 9/1 0z run of the GFS, albeit with a seperate feature.

If this is a US threat than it will come down to Gabrielle's speed and strength, and where that ULL is placed and how strong it is. You never want anything to cutoff down there when a hurricane is trying to head north.

Most of the time it goes to OTS and that's still imo the most likely solution, but the setup is there for trouble.

[Kazmit]

GFS so far a repeat of Erin so far... maybe a couple of degrees further north of the Islands, still heading WNW. No trough in sight, wow.

https://i.imgur.com/Z7QZO9Z.png

More like Hugo.

[Cachondo23]

Yup, the new 12oz GFS will have a lot of talk on all social media, get ready. At least until 18oz…

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
Issued by the NWS Weather Prediction Center College Park MD
200 PM EDT Wed Sep 3 2025

For the North Atlantic...Caribbean Sea and the Gulf of America:

Eastern Tropical Atlantic:
A tropical wave located over the eastern tropical Atlantic a few
hundred miles west-southwest of the Cabo Verde islands continues to
produce disorganized showers and thunderstorms. Environmental
conditions remain conducive for additional development of this
system during the next several days, and a tropical depression is
likely to form late this week or this weekend. This system is
expected to move westward to west-northwestward at around 15 mph
across the eastern and central tropical Atlantic into early next
week.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...high...80 percent.

$$
Forecaster Bann

[lsuhurricane]

The GFS Ensembles are in complete disagreement with the operational, sending each member out to sea. Weird stuff.

[AutoPenalti]

12z Euro further South.

[TomballEd]

The GFS Ensembles are in complete disagreement with the operational, sending each member out to sea. Weird stuff.

I know ensemble models used to be run at lower resolution to reduce computer demand. I believe the Euro ensembles are the same resolution as the op, or there is no need for a control run member.

I suspect GFS is still run at a lower resolution. If the control run is different it suggests lower resolution changes the model solution. I think some PPV boards have control runs (sane initialization as the op) identified.

[Stratton23]

Euro is weaker after interaction with the islands, and recurves in the bahamas, but just barely misses florida, I dont think the 12z ensembles will reflect these changes in the global model runs, typically have to wait another cycle or two to see if ensembles change

[IcyTundra]

Wow the 12Z ECMWF has a TS moving WNW in the vicinity of Dominica and Martinique.

[BobHarlem]

12z Euro gets into the Caribbean and goes for Puerto Rico. Really weak though. Then gets caught up in the DR some, which rips it apart. It does get into the Bahamas later though, and it goes up along the east side of the ULL and out on the Euro. Set the model windshield wipers on max for the next few days.

[MEANINGLESS_NUMBERS]

ULL over south carolina basically pulls it in right over the low country, near Edisto, Charleston gets the right front quad.

https://i.postimg.cc/g2RbS1bg/floop-gfs-2025090312-sfcwind-mslp-swatl.gif

That looks expensive.

[Cachondo23]

12z Euro gets into the Caribbean and goes for Puerto Rico. Really weak though. Then gets caught up in the DR some, which rips it apart. It does get into the Bahamas later though, and it goes up along the east side of the ULL and out on the Euro. Set the model windshield wipers on max for the next few days.
https://i.imgur.com/ORjmkmN.png
https://i.imgur.com/PkwOXXc.png

If it reaches the Leeward Islands it might encounter shear and maybe some dry air but after it pases those islands and continues in a NW direction, those waters are prime in the Caribbean Sea with 30C and some spots in the 31sC!

[ScottNAtlanta]

Just something to remember...
There is a fine line between a TUTT that causes shear and a TUTT that ventilates a storm. Each causes quite the opposite outcome.

[jlauderdal]

The GFS Ensembles are in complete disagreement with the operational, sending each member out to sea. Weird stuff.

At this range, ensembles or bust.