Tropical Wave South of the Cabo Verde Islands (20/60)

[Hypercane_Kyle]

I know it's early but considering the current synoptic pattern over the CONUS right now it would be incredibly hard for a system to make it even as far west as Erin did. We'll see of course but my bet is on a hard recurve.

[zzzh]

AI models (EC Aifs, Google DM) have the track a lot further south compared to the global models.

[Category5Kaiju]

I've recently wondered about this concept quite a bit, especially while looking at the models for this current AOI as well as the models when Erin was active. I do want to hear others' thoughts about it if possible.

When Erin happened, there were quite a few comments that basically were like, "oh, it's early, you can't say Erin is going OTS, look how the models initially had Irma going OTS," to which such were rebutted with comments like "models have gotten a lot better since 2017." Upon looking back at Erin and some of the recent big fish storms that at some point in their lives raised suspicions that they could impact land (Sam or Lee to name a few), it's hard not to ignore the idea that models did very well, even early-on, with nailing the general track (in other words, if it smelled fishy at first, it ultimately did turn out fishy).

So...I guess the thought I want to raise is: do you think the models we currently have would've better seen Irma (or Florence for that matter too) impacting land early-on? Do you think that these same models would've correctly seen the westward bend if they were theoretically tasked to track a storm like Hugo, Isabel, or Andrew? Or....do you think that no matter what, due to the high volatility of steering patterns, such an early diagnosis wouldn't really be possible and that the models' default idea would always be a spaghetti of OTS tracks?

[LarryWx]

I've recently wondered about this concept quite a bit, especially while looking at the models for this current AOI as well as the models when Erin was active. I do want to hear others' thoughts about it if possible.

When Erin happened, there were quite a few comments that basically were like, "oh, it's early, you can't say Erin is going OTS, look how the models initially had Irma going OTS," to which such were rebutted with comments like "models have gotten a lot better since 2017." Upon looking back at Erin and some of the recent big fish storms that at some point in their lives raised suspicions that they could impact land (Sam or Lee to name a few), it's hard not to ignore the idea that models did very well, even early-on, with nailing the general track (in other words, if it smelled fishy at first, it ultimately did turn out fishy).

So...I guess the thought I want to raise is: do you think the models we currently have would've better seen Irma (or Florence for that matter too) impacting land early-on? Do you think that these same models would've correctly seen the westward bend if they were theoretically tasked to track a storm like Hugo, Isabel, or Andrew? Or....do you think that no matter what, due to the high volatility of steering patterns, such an early diagnosis wouldn't really be possible and that the models' default idea would always be a spaghetti of OTS tracks?

Keep in mind though that Erin ended up tracking 200 miles NW of where the NHC had its westernmost point <4 days prior thanks to model consensus having been that much off. That meant the difference between a minimal TS wind impact along with significant storm surge and having much less than that. This really wasn’t a fish storm with regard to significant impacts on the US.

[OuterBanker]

Both GFS and Euro go fishing. One note though. The 12Z GFS went fishing around 58W. 18z around 70w. Pretty big shift west.

But it is the 18z usually the dramatic outlier.

[LarryWx]

For the first time in a couple of days, the UKMET (0Z) has TCG for this. However, after moving WNW, then WSW for a short time, and then back to WNW, it dissipates at 16.4N, 48.3W:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 72 HOURS
FORECAST POSITION AT T+ 72 : 15.0N 35.4W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 05.09.2025 72 15.0N 35.4W 1011 28
1200UTC 05.09.2025 84 15.6N 37.0W 1012 26
0000UTC 06.09.2025 96 15.9N 39.8W 1012 28
1200UTC 06.09.2025 108 16.4N 42.7W 1012 32
0000UTC 07.09.2025 120 16.0N 45.7W 1013 29
1200UTC 07.09.2025 132 16.4N 48.3W 1013 29
0000UTC 08.09.2025 144 CEASED TRACKING

[ouragans]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Tue Sep 2 2025

Eastern Tropical Atlantic:
A tropical wave located over the far eastern tropical Atlantic south
of the Cabo Verde islands is producing disorganized showers and
thunderstorms. Environmental conditions appear conducive for
gradual development of this system, and a tropical depression could
form by the middle or latter part of this week. This system is
expected to move westward to west-northwestward at around 15 mph
across the eastern and central tropical Atlantic throughout the
week.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...medium...60 percent.

[kevin]

00z GFS is slightly west of 18z, but also way faster. Recurves just east of Bermuda. Already forms within 48 hours and becomes a hurricane within 5 days. Not sure I buy the fast development GFS keeps showing.



00z ICON shows slower development than GFS and is very similar to 12z ICON. TS genesis in 3 - 4 days and a hurricane around day 6 - 7. Way more south than GFS.



00z Euro is the other extreme with extremely slow development. Doesn't even get below 1000 mb until 12 days out and develops as it recurves. Goes just east of Bermuda.

[kevin]

So in conclusion, still very uncertain. The 00z GEFS seems to indicate recurve all the way with the only potential threat being for Bermuda, while 00z Euro is about as ominous as an ensemble has been so far this season for the islands (and potentially the US).

GEFS



Euro