Tropical Wave over the Eastern Atlantic (10/50)

[cycloneye]

00z European develops it to a cat 4 recurving east of Bermuda.

[ChrisH-UK]

The run today from Google Weather Lab showing their ML/AI models and ECMWF ensemble models. Some of the runs have it going to cat 4 and taking aim at Florida. Of course still a long way out so most likely will never happen.

https://deepmind.google.com/science/go/JXvgVM6wsf9trHGA

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sun Aug 31 2025

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

1. Eastern Tropical Atlantic:
A tropical wave is about emerge off of the west coast of Africa.
Environmental conditions are conducive for slow development of this
system while it moves westward to west-northwestward at around 15
mph across the eastern and central tropical Atlantic this week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 percent.



Forecaster Beven

[Category5Kaiju]

As always, Andy with his input.


 https://x.com/AndyHazelton/status/1962155116355621096

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Aug 31 2025

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

Eastern Tropical Atlantic:
A tropical wave is now moving westward from the west coast of
Africa. Environmental conditions are conducive for slow development
of this system while it moves westward to west-northwestward at
around 15 mph across the eastern and central tropical Atlantic this
week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 percent.

$$
Forecaster Beven

[cycloneye]

12z EURO has a monster cane that recurves from the islands.

[Kingarabian]

12z EURO has a monster cane that recurves from the islands.

https://i.imgur.com/jD4h55z.gif

ACE for days in the Atlantic.

[crownweather]

12z EURO has a monster cane that recurves from the islands.

https://i.imgur.com/jD4h55z.gif

And for what it's worth, it trended south/west of its 00Z model run. Weaker it stays the next several days, the higher the eventual threat to the NE Caribbean Islands.

[TampaWxLurker]

What a few weeks, lower model support and a persistent recurve pattern will do. At this point in Erin's pre-Invest AOI thread, it was pushing 10 pages.
But then again, the models were VERY bullish on that one.

[TomballEd]

What a few weeks, lower model support and a persistent recurve pattern will do. At this point in Erin's pre-Invest AOI thread, it was pushing 10 pages.
But then again, the models were VERY bullish on that one.

I commented on looking forward to seeing satellite imagery of a major hurricane, either in the AOI thread or invest thread. Someone replied finding that boring. For some, a land threat or nothing. At least they have an Epac system which could be a land threat although that requires threading a needle.

Clear wave axis but dry air not far to the N.

[LarryWx]

12z EURO has a monster cane that recurves from the islands.

https://i.imgur.com/jD4h55z.gif

Thanks, Luis.

Here’s a summary of all of the major 12Z ops for the E MDR lemon including the Euro you just posted:

Today’s 12Z ops are much more active than the runs from 24 hours ago:

-Euro has a MH hit Bermuda on 9/14 (fwiw)

-GFS has a H pass 250 miles E of Bermuda on 9/13 (fwiw).

-ICON has a minimal TS moving ~due W at 180 hours near 16N, 45W. That would be far enough S when also considering its near due W movement and a 600 dam H5 high to its N to be a potential concern for at least the NE Caribbean.

-CMC has a TD that later dissipates.

-UKMET has two separate weak lows and no TC. I’m throwing this weird solution out since it’s a clear outlier.

-JMA has a TD the furthest S of any major model with a TC. It’s at 14N, 45W, and moving WSW (unlike any other model with a TC) at end of its run (192). If that were to be real, it could be a legit concern for the Lesser Antilles and beyond. But all others are up at 16-19N then. And this is the JMA. An outlier JMA, especially to the left, is usually wrong. But we’ll see.

[TomballEd]

The passing near or even E of Bermuda for Erin models trended far enough west as time went on for TS and surge advisories for the Mid-Atlantic from Erin. Not saying past performance is indictive of future results.

[Nimbus]

The passing near or even E of Bermuda for Erin models trended far enough west as time went on for TS and surge advisories for the Mid-Atlantic from Erin. Not saying past performance is indictive of future results.

Today both the ICON and JMA show a ridge to the north at the 7 day mark as the track nears -45 degrees longitude.
So the current TUTT may not be as persistent as I was -removed-.

They tagged 99L Aug 19th, there is a reason these storms never make it to Hawaii.

[LAF92]

The passing near or even E of Bermuda for Erin models trended far enough west as time went on for TS and surge advisories for the Mid-Atlantic from Erin. Not saying past performance is indictive of future results.

Today both the ICON and JMA show a ridge to the north at the 7 day mark as the track nears -45 degrees longitude.
So the current TUTT may not be as persistent as I was -removed-.

They tagged 99L Aug 19th, there is a reason these storms never make it to Hawaii.

So that ridge would force whatever if it even develops more west?

[chaser1]

12z EURO has a monster cane that recurves from the islands.

https://i.imgur.com/jD4h55z.gif

-ICON has a minimal TS moving ~due W at 180 hours near 16N, 45W. That would be far enough S when also considering its near due W movement and a 600 dam H5 high to its N to be a potential concern for at least the NE Caribbean.

-JMA has a TD the furthest S of any major model with a TC. It’s at 14N, 45W..... But all others are up at 16-19N then. And this is the JMA. An outlier JMA, especially to the left, is usually wrong. But we’ll see.

Larry, I agree with you regarding the JMA typically being wrong HOWEVER.... I would not consider this model run as an outlier. ICON has earned some legit "cred" recently and I see the 12Z runs by JMA & ICON as very similar. They both imply some pretty beefy mid level heights across the Central Atlantic around that 180 hr range. If 600 dam heights were to verify then I'm thinking perhaps fairly stout heights might exist from top - down. Any close by TUTT might very well fill (or be shoved north and east. The fact that both models essentially agree on a predominant west motion is at minimum mildly curious.

[Category5Kaiju]

The 18z GFS shows a rather interesting steering pattern: the storm recurves east of Bermuda and strengthens into a significant hurricane in the process; however, a blocking ridge then builds to its east, and because of this the storm looks to head due north (rather than safely northeast) by the run's end and menace Atlantic Canada.

Combined with the JMA/ICON's line of thinking, perhaps a subtle early sign that unlike Erin, the steering patterns for this storm may not be as permitting for a safe recurve?

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sun Aug 31 2025

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

1. Eastern Tropical Atlantic:
A tropical wave located over the far eastern tropical Atlantic is
producing disorganized showers and thunderstorms. Environmental
conditions appear conducive for slow development of this system, and
a tropical depression could form late this week or next weekend.
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...near 0 percent.
* Formation chance through 7 days...medium...40 percent.



Forecaster Cangialosi

[AnnularCane]

 https://x.com/DCAreaWx/status/1962222712635425107

[chaser1]

With just hours away from rolling into September, I am "almost" certain that our far Eastern Atlantic tropical wave would not evolve to be a threat to the Antilles or the U.S. My reasoning is primarily based on this season's (E. Atlantic) "pattern persistence", and in conjunction with the calendar. Thus far this year has produced Erin & Fernand; Two E. Atlantic named storms which recurved prior to posing a direct threat to the Lesser Antilles. Generally speaking, for such years that exhibit similar recurring storm tracks I would anticipate that any subsequent E. Atlantic storms would also be apt to recurve (perhaps turning poleward even faster as the season progresses). BUT, I would never say fully certain simply because the 2025 Hurricane Season could wanna party like it's 1989.

1989 started to show the E. Atlantic basin steering tendencies with Dean which turned northwestward well east of the Caribbean. Then, that season's own (weaker) Erin followed. Followed by Felix and then Gabrielle (that year's massive sized hurricane). All of these storms comfortably turning northwest without posing a threat to the Caribbean. Then on September 10th, Hugo formed and developed into that season's 2nd major Hurricane. I remember this storm very-very well! In spite of predictions that Hugo would also turn northwestward, there appeared to be a greater risk for Hugo to track further west than prior E. Atlantic storms had that year. It was then that I along with several Hurricane chase friends got on a plane and flew to San Juan in anticipation that Hurricane Hugo would hit Puerto Rico. Point being that this storm was also projected to recurve northwestward but didn't do so until hammering the N.E. Caribbean, Eastern Puerto Rico, and even striking the U.S.

This is the kind of potential threat that comes to mind when I see the ICON showing a potentially more westward long range steering forecast than what the GFS or EURO presently forecast.

[Category5Kaiju]

00z ICON has the storm taking a pronounced WSW dip in the western MDR around the September 7-8 timeframe. There seems to be roughly 10 degrees of longitude between where this happens and the Lesser Antilles, but assuming this storm heads due west going forward, it would inevitably crash into the islands.