Tropical Wave well south of the Cabo Verde Islands (Is Invest 95L)

[kevin]

Almost all operational models show TD formation within the next 3 days. Further strengthening into a TS is slow, however. If we use the standard Dvorak estimate values of 1010 mb and 1005 mb for a TD and TS, respectively than this is the formation time according to the 00z/06z operational model runs.

06z GFS = TD at +78hr, TS at +138hr
00z GFS = TD at +90hr, TS at +138hr

06z Euro = TD at +69hr, no TS during this run (runs until +144hr)
00z Euro = TD at +150hr, TS at +186hr

06z ICON = TD at +69hr, no TS during this run (runs until +120hr)
00z ICON = TD at +75 hr, no TS during this run (runs until +180hr)

00z CMC = TD at +60hr, TS at +90hr

[LarryWx]

Almost all operational models show TD formation within the next 3 days. Further strengthening into a TS is slow, however. If we use the standard Dvorak estimate values of 1010 mb and 1005 mb for a TD and TS, respectively than this is the formation time according to the 00z/06z operational model runs.

06z GFS = TD at +78hr, TS at +138hr
00z GFS = TD at +90hr, TS at +138hr

06z Euro = TD at +69hr, no TS during this run (runs until +144hr)
00z Euro = TD at +150hr, TS at +186hr

06z ICON = TD at +69hr, no TS during this run (runs until +120hr)
00z ICON = TD at +75 hr, no TS during this run (runs until +180hr)

00z CMC = TD at +60hr, TS at +90hr

Fwiw, the 0Z UKMET gets the surface low down to as low as 1008 mb at hour 102, but the textual output doesn’t first classify it as a TC til hour 132, when the gradient is stronger:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 132 HOURS
FORECAST POSITION AT T+132 : 15.7N 53.2W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 08.10.2025 132 15.7N 53.2W 1009 40
0000UTC 09.10.2025 144 17.5N 56.5W 1009 39
1200UTC 09.10.2025 156 18.8N 59.3W 1009 34
0000UTC 10.10.2025 168 19.7N 61.4W 1008 31

[LarryWx]

12Z UKMET: 3rd in a row with TCG from this; similar TCG to prior run but moves NW instead of WNW and thus ends up further N than prior run although not quite as far N as two runs ago; Also this one has it become declassified at 168:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 126 HOURS
FORECAST POSITION AT T+126 : 16.6N 54.6W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 09.10.2025 132 17.8N 56.3W 1009 36
1200UTC 09.10.2025 144 19.9N 59.3W 1010 30
0000UTC 10.10.2025 156 21.8N 61.2W 1009 29
1200UTC 10.10.2025 168 CEASED TRACKING

[cycloneye]

2 PM:

Tropical Atlantic:
A tropical wave has just emerged off the coast of Africa. The wave
is forecast to interact with another disturbance over the eastern
tropical Atlantic, and then move westward after that.
Environmental conditions are expected to become conducive for some
slow development of the system in a few days, and a tropical
depression could form near or east of the Lesser Antilles by the end
of next week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

[LarryWx]

The 12Z Euro for this “pumpkin” (I got that description from someone else): no TC til ~192 hours when it’s 1005 mb that’s ~125 miles N of PR. But it’s already recurving sharply then and never gets stronger than 1005 mb til it gets to 30N way out in the middle of the ocean.

[AnnularCane]

The 12Z Euro for this “pumpkin” (I got that description from someone else): no TC til ~192 hours when it’s 1005 mb that’s ~125 miles N of PR. But it’s already recurving sharply then and never gets stronger than 1005 mb til it gets to 30N way out in the middle of the ocean.

In October, the orange circles/ovals/whatever should be pumpkins.

[LarryWx]

12Z GEFS: only one of 30 hits Conus (hits S FL as an hurricane) and that’s because it is the furthest SW member (at Barbados) as it approaches the Lesser Antilles. The rest are at that time from PR to the Leewards (~50%) with ~50% then well NE of the Leewards.

Edit/aside: the one hitting the Outer Banks isn’t from this and is instead from a NW Caribbean system.

Edit: I don’t think any 12Z EPS are hitting the CONUS. If there are any, I can’t tell.

[cycloneye]

8 PM:

Tropical Atlantic:
A tropical wave just off the coast of Africa is producing a broad
area of disorganized showers and thunderstorms. The wave is
forecast to interact with another disturbance over the eastern
tropical Atlantic, and then move westward after that. Environmental
conditions are expected to become conducive for some slow
development of the system in a few days, and a tropical depression
could form near or east of the Lesser Antilles by the end of next
week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

[Kazmit]

0z ICON bombs it out to potentially our third open Atlantic cat 5 of the season.

[LarryWx]

0Z UK: similar to 12Z with the recurve

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 108 HOURS
FORECAST POSITION AT T+108 : 15.2N 53.0W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 08.10.2025 108 15.2N 53.0W 1009 36
0000UTC 09.10.2025 120 17.2N 56.5W 1010 32
1200UTC 09.10.2025 132 19.0N 59.6W 1010 30
0000UTC 10.10.2025 144 20.1N 61.4W 1010 26
1200UTC 10.10.2025 156 21.4N 62.9W 1010 29
0000UTC 11.10.2025 168 23.2N 63.8W 1009 27

[cycloneye]

Good news for the residents of the Leewards, U.S / British Virgin islands and Puerto Rico as the models GFS, ICON, CMC are trending to recurving with a powerful hurricane except Euro that does not develop and stays as strong wave as it moves thru the islands and UKMET that has a TD going away. What will do is to pump up the ACE. This is 06z GFS.

[cycloneye]

8 AM:

Tropical Atlantic:
A tropical wave between the west coast of Africa and Cabo Verde
Islands is producing a broad area of disorganized showers and
thunderstorms. Gradual development of the wave is possible over
the next few days, and it could become a tropical depression by the
middle to latter part of next week while moving across the
central tropical Atlantic and approaching portions of the Leeward
Islands.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

[kevin]

A hurricane as depicted by 06z GFS (or most likely 00z/06z ICON if it ran further) would rack up ACE like crazy. Using Dvorak to translate pressure to wind, the 06z GFS run for this specific TC alone would result in 30 - 35 ACE, bringing the season total to 122 - 127 ACE. And that's not counting at least two short-lived (sub-)tropical storms and another MH blowing up in the WCar that also form in this run.

[MarioProtVI]

AI models and op Euro seem to have dropped this completely. I’m not believing anything forms until it actually looks like it will, given this was the exact same thing that happened to 91L a month ago (where the AI models similarly didn’t develop and then every model dropped it afterward).

[DorkyMcDorkface]

AI models and op Euro seem to have dropped this completely. I’m not believing anything forms until it actually looks like it will, given this was the exact same thing that happened to 91L a month ago (where the AI models similarly didn’t develop and then every model dropped it afterward).

The wave signature is actually better defined on the 06z OP Euro vs. the prior two runs, to the point where it looks like it does develops a TD east of the Antilles. The EPS has followed suit in showing a bit of a stronger signal than either of those runs as well. I do agree on the AIFS though, we'll have to see if it hops back on board or continues to show little to no development, because it was sort of a harbinger for 91L ultimately failing to develop, which was interesting.

[Teban54]

12z ICON finishes the run at 928 mb just NE of the Caribbean islands. I believe it's the strongest that ICON had shown so far.

[LarryWx]

12z ICON finishes the run at 928 mb just NE of the Caribbean islands. I believe it's the strongest that ICON had shown so far.

https://i.postimg.cc/jdMwDPXw/icon-mslp-pcpn-eatl-fh3-180.gif

The SE US is being protected from this hitting partially by the TS near S FL. Of course, it’s extremely hard this late in the season for a MDR TC E of 55W to hit the US. This sort of reminds me of the Imelda/Humberto combo.

12Z UKMET dropped the FL TC but still has this though it doesn’t form til 162, moving WNW to the SSW of Bermuda:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 162 HOURS
FORECAST POSITION AT T+162 : 22.7N 67.7W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 11.10.2025 168 23.0N 68.5W 1009 24

[WeatherBoy2000]

The gfs is weaker this run, although not in a particularly notable way. If the uptrend on the euro continues, then I won't be surprised if development chances are increased soon.

[cycloneye]

Tropical Atlantic:
Recent satellite-derived wind data indicate that a broad area of
low pressure, associated with a tropical wave, has formed several
hundred miles south of the Cabo Verde Islands. Environmental
conditions appear conducive for gradual development of this system,
and it could become a tropical depression by the middle to latter
part of next week while moving across the central tropical Atlantic
and approaching portions of the Leeward Islands.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...medium...60 percent.

[cycloneye]

This may be a invest sooner than expected. Rotation around 6N-24W.