eastern Atlantic blob 0/40

[BarryStantonGBP]

Eastern Tropical Atlantic:
A tropical wave is forecast to emerge off the west coast of Africa
by this weekend to the south of the Cabo Verde Islands. Thereafter,
environmental conditions appear favorable for some slow development
of this system as it moves westward to west-northwestward at 15 to
20 mph, moving across the eastern into central Tropical Atlantic
through the middle of next week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

[A-L-E-K]

miami or bust obv

[GaWx]

 Though support has waned significantly since all but the GFS had it on Monday, the 0Z UKMET brought the E MDR AEW back from the dead (albeit with later TCG) with a minimal TS due to a strong pressure gradient below a rather strong Azores high moving WNW:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 156 HOURS
              FORECAST POSITION AT T+156 : 15.6N  33.8W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 03.09.2025  156  15.6N  33.8W     1010            34
    0000UTC 04.09.2025  168  16.9N  35.9W     1011            35

——-

 But GFS/Icon/CMC/Euro have no more than a weak reflection at the sfc. Yesterday’s 12Z JMA has close to a TD but it doesn’t develop further and weakens. 
 
 If this were to develop, it like Erin due to latitude would be a good recurve safely candidate as of the current model consensus of steering fwiw but a long ways to go if it were to actually develop.

 Edit: Some EPS members develop this but only a pretty small percentage do that. The GEFS is very quiet, however.

[GaWx]

Followup on AEW coming off Africa as early as tomorrow:

12Z UKMET: has a TS that is already recurving before 40W:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 138 HOURS
FORECAST POSITION AT T+138 : 15.3N 32.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 03.09.2025 144 16.0N 33.0W 1010 37
0000UTC 04.09.2025 156 16.9N 35.4W 1010 40
1200UTC 04.09.2025 168 18.6N 37.0W 1010 38

 

[BarryStantonGBP]

1 hour ago, GaWx said:

Followup on AEW coming off Africa as early as tomorrow:

12Z UKMET: has a TS that is already recurving before 40W:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 138 HOURS
FORECAST POSITION AT T+138 : 15.3N 32.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 03.09.2025 144 16.0N 33.0W 1010 37
0000UTC 04.09.2025 156 16.9N 35.4W 1010 40
1200UTC 04.09.2025 168 18.6N 37.0W 1010 38

 

made a poll

[GaWx]

 The 12Z GFS has this and makes it a H. The 12Z Euro has just a weak low.

 For the record: after 4 12Z JMA runs in a row with a TC from this, today’s 12Z JMA had no TC.

[Wannabehippie]

1 hour ago, GaWx said:

 The 12Z GFS has this and makes it a H. The 12Z Euro has just a weak low.

 For the record: after 4 12Z JMA runs in a row with a TC from this, today’s 12Z JMA had no TC.

Too far south, and too much SAL.

[BarryStantonGBP]

2 minutes ago, Wannabehippie said:

Too far south, and too much SAL.

So you think it won’t form 

[GaWx]

19 minutes ago, Wannabehippie said:

Too far south, and too much SAL.

 This wave won’t be coming off Africa til sometime this weekend.

[Wannabehippie]

3 minutes ago, GaWx said:

 This wave won’t be coming off Africa til sometime this weekend.

Satellite photo of Africa is unimpressive to me. Until you get way out by Sudan/South Sudan.

[GaWx]

9 minutes ago, Wannabehippie said:

Satellite photo of Africa is unimpressive to me. Until you get way out by Sudan/South Sudan.

 I‘m guessing that the unimpressiveness of the wave over W Africa, the one the lemon is addressing, is why the models have backed off so much since Mon, when all major ops other than the GFS had this develop into a TC in the E MDR near the CV Islands.

[BarryStantonGBP]

22 minutes ago, Wannabehippie said:

Satellite photo of Africa is unimpressive to me. Until you get way out by Sudan/South Sudan.

 

14 minutes ago, GaWx said:

 I‘m guessing that the unimpressiveness of the wave over W Africa, the one the lemon is addressing, is why the models have backed off so much since Mon, when all major ops other than the GFS had this develop into a TC in the E MDR near the CV Islands.

I already know gabs will be an mdr struggle bus

[GaWx]

0Z UKMET for system leaving Africa over weekend (E MDR lemon): 

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 108 HOURS
FORECAST POSITION AT T+108 : 13.5N 28.4W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 02.09.2025 108 13.5N 28.4W 1010 31
0000UTC 03.09.2025 120 14.0N 30.9W 1011 33
1200UTC 03.09.2025 132 15.9N 31.8W 1010 34
0000UTC 04.09.2025 144 16.4N 34.6W 1012 28
1200UTC 04.09.2025 156 17.2N 35.4W 1013 26
0000UTC 05.09.2025 168 18.4N 36.8W 1013 24

[GaWx]

0Z UK

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 120 HOURS
FORECAST POSITION AT T+120 : 14.4N 35.2W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 04.09.2025 120 14.4N 35.2W 1012 30
1200UTC 04.09.2025 132 15.2N 36.8W 1012 30
0000UTC 05.09.2025 144 15.8N 38.4W 1012 26
1200UTC 05.09.2025 156 16.8N 40.3W 1012 27
0000UTC 06.09.2025 168 17.5N 42.4W 1013 25

[GaWx]

12Z models:
UKMET/GFS/Icon: TD but it then dissipates pretty quickly
CMC: just weak low
Euro: TD that recurves just offshore NC 9/12:

JMA: nada

[BarryStantonGBP]

On 8/30/2025 at 7:15 PM, GaWx said:

12Z models:
UKMET/GFS/Icon: TD but it then dissipates pretty quickly
CMC: just weak low
Euro: TD that recurves just offshore NC 9/12:

JMA: nada

Might get another storm 

not just gabsy wabsy

 

 

[BarryStantonGBP]

@GaWxthoughts on that run? Thoughts on the lemon giving birth / splitting?

[GaWx]

On 8/30/2025 at 2:15 PM, GaWx said:

12Z models:
UKMET/GFS/Icon: TD but it then dissipates pretty quickly
CMC: just weak low
Euro: TD that recurves just offshore NC 9/12:

JMA: nada

Today’s 12Z ops are much more active for the E MDR lemon 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.

@BarryStantonGBP

[BarryStantonGBP]

3 minutes ago, GaWx said:

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.

@BarryStantonGBP

Any other storms?

[BarryStantonGBP]

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 Patel

 

[GaWx]

Some 0Z models:

-GFS has a MH that goes E of Bermuda but then gets blocked by a big high

-Like for the 12Z, the 0Z UKMET text has no TC. I’ll see how the maps look when they come out. The 12Z was kind of wacky with two weak lows.

-CMC again has a possible TD in the E MDR that weakens later.

-0Z JMA goes out only 72 hours.

-So, Icon, GFS, UKMET, and CMC are fairly similar at 0Z to their respective 12Z runs. 
Next up is the all-knowing Euro!