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

[BobHarlem]

0z Icon is coming in slightly to the right and MUCH stronger (968mb vs 999mb) than the 12z out to 162 hours so far.

Run Ends at 963mb, 18.2N 49.4W, heading nw (curving north safely east of the islands at this point).

18z Euro is alone out that far south (and a lot weaker) compared to all the other operationals so far. (12z GFS/12z Canadian/0z Icon) 12z Canadian is also weak, but also gains latitude well before the others. I'd assume a weaker system would be able to sneak further south/west (at least in the central Atlantic) in this setup. Icon has it spinning up this weekend. Most ensembles (And all on the 18z GEFS) recurve it before the islands, so that's still probably the most likely scenario, but the euro does put some doubt into all of it. Getting it Invest tagged isn't a guarantee tomorrow either, especially if it remains the way it looks right now.

[Pelicane]

0z Icon is coming in slightly to the right and MUCH stronger (968mb vs 999mb) than the 12z out to 162 hours so far.

Run Ends at 963mb, 18.2N 49.4W, heading nw (curving north safely east of the islands at this point).

18z Euro is alone out that far south (and a lot weaker) compared to all the other operationals so far. (12z GFS/12z Canadian/0z Icon) 12z Canadian is also weak, but also gains latitude well before the others. I'd assume a weaker system would be able to sneak further south/west (at least in the central Atlantic) in this setup. Icon has it spinning up this weekend. Most ensembles (And all on the 18z GEFS) recurve it before the islands, so that's still probably the most likely scenario, but the euro does put some doubt into all of it. Getting it Invest tagged isn't a guarantee tomorrow either, especially if it remains the way it looks right now.

And of course as the ICON trends stronger, the GFS goes in the opposite direction

[LarryWx]

0Z UKMET: This run is back to a TD. Once formed, it remains the same strength. It is significantly further S than the prior run with a TD (24 hrs ago). At 168, it’s on a trajectory toward the Leewards only 150 miles away:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 132 HOURS
FORECAST POSITION AT T+132 : 13.3N 51.7W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 08.09.2025 132 13.3N 51.7W 1011 27
0000UTC 09.09.2025 144 14.1N 54.6W 1010 29
1200UTC 09.09.2025 156 15.0N 57.4W 1011 31
0000UTC 10.09.2025 168 16.0N 59.5W 1010 31

[BobHarlem]

The 0z GFS is weaker and recurves well right/east of the 18z and 12z runs out to 180 hours (looks a lot like the 6z gfs) and also is safely east of Bermuda. It gets to a latitude north of the islands at 47.9W. 0z Canadian is north of the islands at 52W. 0z Icon/GFS/CMC showing recurve before the islands. 0z UKMet and 18z Euro aren't. Major difference between the two camps is the strength of the TUTT.

[Stratton23]

GFS has a blocking ridge that captures this system and tries to turn it west, definitely not a clean recurve run

[ronjon]

00z Euro moves into the northern Leeward Islands as a weakening tropical storm.

[Cachondo23]

Models backing off a bit for strong development?

[cycloneye]

The best thing to do at this point is to watch how the wave does in real time and see how the models adjust to that.

[cycloneye]

The only change from past outlooks is that is now WSW of the Cabo Verde Islands.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM 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 gradual 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...low...30 percent.
* Formation chance through 7 days...high...70 percent.

$$
Forecaster Hagen

[BobHarlem]

The 6z GFS still curves east of the islands but does a nasty stall close to Bermuda, if a storm like that stalls around Bermuda it would not be great for them. That stall is very much in fantasy range though. Euro does get it very weak into the islands, including over Puerto Rico, and the TUTT just does a number to it. The Canadian curves north of the islands but bends it back west toward the end of its run. The system itself still looks kinda blah around 30 west on satellite. All the 0z GFS ensembles are curvers east of the islands, most of the Euros are (and the ones that don't are very weak). So nothing really new today.

[jconsor]

Lots of uncertainty on how quickly and how far south the east Atlantic system consolidates! I went into depth on its prospects in my Substack post:

https://hurricanehacker.substack.com/p/ ... re-changin

[MarioProtVI]

06z euro has a major in the MDR at 144h which is a big 180 from the 00z which had it weakening in Leewards

[cycloneye]

Who has the graphic of the Euro 06z at 144 hours? Dont have pivotal plus.

[WeatherBoy2000]

The 6z GFS still curves east of the islands but does a nasty stall close to Bermuda, if a storm like that stalls around Bermuda it would not be great for them. That stall is very much in fantasy range though. Euro does get it very weak into the islands, including over Puerto Rico, and the TUTT just does a number to it. The Canadian curves north of the islands but bends it back west toward the end of its run. The system itself still looks kinda blah around 30 west on satellite. All the 0z GFS ensembles are curvers east of the islands, most of the Euros are (and the ones that don't are very weak). So nothing really new today.

Any changes in the position/strength of the TUTT will have big implications on whether we get another long-lived powerful storm or something that gets shredded further west. At least the operational euro/gfs is showing a more hostile set up further west this morning.

[cycloneye]

Modest curvature in the clouds but still no well defined circulation.

[BobHarlem]

6z euro. Tutt seems to be making the models a bit scattershot run to run. Here with intensity vs 0z.

[WeatherBoy2000]

6z euro. Tutt seems to be making the models a bit scattershot run to run. Here with intensity vs 0z.
https://i.imgur.com/2zazFBD.png

Despite the Tutt, I think we're going to have to see notable strides towards development today for something like the 06z run to occur.

[ChrisH-UK]

There wave has progressed in coalescing together on it north east corner (12N 34W). There's plenty of convection with it but on the northern side of it there is a bit of a SAL layer which could hinder its development.

GOES-19 Red Band 3hr Loop

[cycloneye]

It looks like this wave will be a invest later today or tonight and here is the link to the invests and TC's. Refresh it to see if 91L appears and anyone can start the invest 91L discussion thread. I will not as I have done it many times and we are looking for the members to have participation.

https://ftp.nhc.noaa.gov/atcf/btk/

Let's see if the invest is up today.

[LarryWx]

Good post from MIchael Lowry.

 https://x.com/MichaelRLowry/status/1962863383767638380

Has anyone seen a Google Deepmind ensemble update since this Lowry tweet about the somewhat threatening 0Z 9/2 run to the Caribbean (it had 6 TCs into the E Caribbean)?