Area of low pressure in Central Atlantic (Is Invest 92L)

[cycloneye]

Eastern Tropical Atlantic Ocean:
A tropical wave over western Africa is forecast to move offshore on
Monday. Thereafter, environmental conditions could support some
slow development throughout the week while the system moves slowly
westward or west-northwestward over the eastern tropical Atlantic
Ocean.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

[Teban54]

I didn't know that at a time when everyone is grasping the straws for a named storm to form, the thread for a brand new AOI named by the NHC can get zero replies in 7 hours

Anyway, I'm reposting a comment I made in the global models thread last night about the system. Of course, just after the post and NHC's mention, 12z GFS drops it. (So does 12z CMC, but it was already the least consistent global model and the outlier for this system to begin with.)

If the disappearance of the Eastern Atlantic 0/10 AOI earlier made you think nothing in that region will spin up in the foreseeable future (or that no named storms will develop by September 15), there's a good chance you would be wrong.

Models seem very enthusiastic on the development of a tropical storm in the Eastern Atlantic, from a wave that leaves Africa over this long weekend (which is immediately behind the former 0/10 AOI). While earlier models from a few days ago couldn't decide which of the two Eastern Atlantic waves to develop, it looks like they've finally made up their mind. GFS, ECMWF, CMC, ICON, as well as the GEFS and EPS ensembles have all been showing the 9/1 wave spinning up. In fact, I'm surprised it hasn't gotten a mention from the NHC yet (some models show development within 7 days now), and even more surprised with the total lack of discussions about it here!

The catch is that they expected the system to stay weak, as even ensembles are showing fewer and fewer strong members, if any. Current consensus is that the system will recurve north near 40W while suffering from shear and dry air. It may then be pushed back to W/NW briefly due to ridge building back to the NE.

... Until now.

On tonight's 0z GFS, the ridge seems stronger, and the system doesn't move as far north as most runs indicated. Then it somehow gets on the dreaded WSW track. Thankfully, not all WSW dives are created equal, and it stays weak throughout (though it did get to 999 mb at one point). The dive ends just north of the Lesser Antilles, at which point it resembles more of a classic Western Atlantic track, becoming a 968 mb hurricane en route to Bermuda as the run ends.

To be clear, this is an outlier from all previous model runs -- even ensembles almost never got the system so far SW. It's probably just a fluke, but I think it should at least get a mention lol.

https://i.postimg.cc/J0dBvWMH/gfs-mslp-pcpn-atl-fh6-384.gif

[mantis83]

looks like an early recurve candidate, if anything forms.....

[Hurricane2022]

looks like an early recurve candidate, if anything forms.....

This system is a candidate for going OTS. But only one candidate wins, and we don't know for sure where in the world this tropical wave is headed. So I ask (again?) to you...please be patient. And, starting today...please, for God sake, always wait some more before making these statements about storms that don't even exist yet. Period!!

[cycloneye]

Eastern Tropical Atlantic Ocean:
A tropical wave over western Africa is forecast to move offshore by
Monday. Thereafter, environmental conditions could support some
slow development of this system throughout the week while it moves
slowly westward or west-northwestward over the eastern tropical
Atlantic Ocean.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

[cycloneye]

Eastern Tropical Atlantic Ocean:
A tropical wave is forecast to move offshore of the west coast of
Africa by Monday. Thereafter, environmental conditions could
support some slow development of this system throughout the week
while it moves slowly westward or west-northwestward over the
eastern tropical Atlantic Ocean.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 percent

[cycloneye]

Tropical wave has emerged from west africa.

[Teban54]

Up to 10/40.

3. Eastern Tropical Atlantic Ocean:
A tropical wave along the west coast of Africa is producing a large
area of showers and thunderstorms. Environmental conditions are
forecast to gradually become more favorable for development, and a
tropical depression could form in a few days while the disturbance
moves slowly west-northwestward or northwestward over the eastern
tropical Atlantic Ocean.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...medium...40 percent.

Never thought I'd use this meme for anything other than EPAC this season, but here we are.

[cycloneye]

Annularcane, looks like this wave will be tagged soon with the infamous number 99L.

[cycloneye]

Eastern Tropical Atlantic Ocean:
A tropical wave just offshore of the west coast of Africa is
producing disorganized showers and thunderstorms. Environmental
conditions are forecast to gradually become more conducive for
development, and a tropical depression could form in a few days
while the disturbance moves slowly west-northwestward or
northwestward over the eastern tropical Atlantic Ocean. This system
could produce areas of heavy rain and gusty winds across portions of
the Cabo Verde Islands in a day or two.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...medium...40 percent.

[AnnularCane]

Annularcane, looks like this wave will be tagged soon with the infamous number 99L.

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

Well, I guess they can't control whatever designation gets slapped on them. But whatever they get called, so far the Antilles wave seems like 99L at heart.

[Teban54]

Ensemble support for TS winds dropped, if not plummeted, on the 12z runs. On Weathernerds, GEFS still has some members showing tracks with 30+ kt winds, but much fewer than 6z. EPS shows a less drastic reduction of 30+ kts tracks, but the proportion of such members was lower to begin with.

One reason could be that 12z models were trending towards less of a northward movement (stronger ridge?). It may be that lack of visible tracks is just visual, and that some of the members remain stationary in the MDR while intensifying to a TS, but don't leave an easily recognizable trace on the map. But it could also be an issue with the actual strength of the system.

Regardless, GEFS and EPS have different solutions on where else to focus the energy on. GEFS has now increased support for the Central Atlantic wave that NHC had written off 2 days ago, with a few hurricanes on both 0z and 12z runs. EPS has minimal -- but not zero -- members developing it. On the other hand, EPS really loves the next wave that splashes down on September 10, with two-thirds of members showing a low or TS near Cabo Verde. GEFS support for this wave is inconsistent, possibly because the GFS suite keeps the vorticity of several waves tangled much longer (and in a messier fashion) than the Euro suite.

[TomballEd]

This is SW of NHC's Orange X, but looking good at the moment.

[cycloneye]

Eastern Tropical Atlantic Ocean:
A tropical wave over the far eastern Atlantic is producing
disorganized showers and thunderstorms. Environmental conditions
are forecast to become a little more conducive for development, and
a tropical depression could form in a few days while the disturbance
moves slowly west-northwestward or northwestward over the eastern
tropical Atlantic Ocean. This system could produce locally heavy
rains and gusty winds across portions of the Cabo Verde Islands in
a day or two.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...medium...40 percent.

[cycloneye]

Eastern Tropical Atlantic Ocean:
A tropical wave over the far eastern Atlantic is producing
disorganized shower activity. Some slow development of this system
is possible during the next few days as it moves west-northwestward
or northwestward over the eastern tropical Atlantic Ocean.
Environmental conditions are expected to become less conducive by
the end of the week. This system could produce locally heavy rains
and gusty winds across portions of the Cabo Verde Islands in a day
or two.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...30 percent.

[cycloneye]

Eastern Tropical Atlantic Ocean:
A third tropical wave over the far eastern Atlantic is also
producing disorganized shower activity. Some slow development of
this system is possible during the next few days while it moves
slowly northwestward at 5 to 10 mph over the eastern tropical
Atlantic Ocean. Environmental conditions are expected to become
less conducive for development by the end of the week. This system
could produce locally heavy rains across portions of the Cabo Verde
Islands overnight and on Wednesday.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...30 percent.

[cycloneye]

Down to 10/20.

Eastern Tropical Atlantic Ocean:
A third tropical wave over the far eastern Atlantic is also
producing disorganized shower activity. Some slow development of
this system is possible during the next few days while it moves
slowly northwestward at 5 to 10 mph over the eastern tropical
Atlantic Ocean. This system could produce locally heavy rains
across portions of the Cabo Verde Islands today.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...20 percent.

[Teban54]

Wording changed to a trough rather than a wave, perhaps also including the possible monsoon trough breakdown solution.

4. Eastern Tropical Atlantic Ocean:
An elongated trough of low pressure over the eastern tropical
Atlantic is producing disorganized showers and thunderstorms. Some
slow development of this system is possible during the next few days
while it drifts northwestward.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...20 percent.

[Teban54]

Euro has been trending stronger with this throughout the day, though still not much.

[cycloneye]

Northwestern Caribbean Sea and Southwestern Gulf of Mexico:
A tropical wave located over the western Caribbean Sea is producing
a large area of disorganized shower and thunderstorm activity.
Development is not expected before the system reaches Belize and the
Yucatan Peninsula by early Friday. Some slow development is possible
later this weekend after the system emerges over the southwestern
Gulf of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.