Tropical Wave west of the Cabo Verde Islands (Is Invest 90L)

[AutoPenalti]

The 12Z Euro and GFS have this as a weak low well NE of the Northern Lesser Antilles heading NW, Both models now recurve and develop this in the long-range once it is out of the MDR and in the subtropics with a possible threat to Bermuda.

https://i.postimg.cc/XvGgFG1V/5-AF1-E8-D8-B020-43-ED-8785-CA754559461-F.png
https://i.postimg.cc/Vk59Q08j/0-EE85179-00-B9-409-A-88-F3-638-FF48-ACBFD.png

Yup, looking forward to 45 degree fall like temps across SFL

[LarryWx]

The 12Z EPS is somewhat more active with this low fwiw.

[Teban54]

Looks like 18z GFS tries to spin this up in the subtropics, but it gets disrupted by the second wave/hurricane's outflow. Interestingly, the vorticity then goes due west towards Georgia.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sun Aug 21 2022

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

1. Eastern Tropical Atlantic:
A tropical wave located just west of the Cabo Verde Islands
continues to produce disorganized showers and thunderstorms.
Environmental conditions could support some slow development of
this system while it moves westward to west-northwestward at around
15 mph across the tropical Atlantic during the next several days.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

Forecaster Cangialosi

[LarryWx]

SAL as of 21Z/5 PM EDT: image showing the SE edge of SAL a couple of hundred miles NW of this low, which is near 30W and 16N:

[cycloneye]

8 PM TWD:

A tropical wave extends along 27W from 09N-22N, moving west at
15 kt. A 1011 mb low pressure is analyzed along the wave axis
near 15N. Scattered moderate convection is noted from 14N-17N
between 26W and 30W. The most recent altimeter data indicate seas
of 6-8 ft on the E side of the wave axis. Environmental conditions
could support some slow development of this system while it
moves westward to west-northwestward at 10-15 kt across the
eastern and central tropical Atlantic for the next several days.
Currently, this system has a low chance of tropical cyclone
development through 5 days.

[HurricaneBelle]

SAL as of 21Z/5 PM EDT: image showing the SE edge of SAL a couple of hundred miles NW of this low, which is near 30W and 16N:

1977 may have been the Summer of Sam, but 2022 is the Summer of SAL

[LarryWx]

As mentioned, the 12Z EPS was more active with this than the 6Z/0Z. The 18Z EPS is even a bit more active with this in having 5 members (10%) with SLP 1000-1003 mb at hour 144. The 12Z run had only 3 that strong, the 6Z had only 2, and the 0Z had none.

[Kingarabian]

00z GFS has this wave the most organized since the 18z run of 8/19. GFS Could show a SECONUS threat here. If the ridging returns.

[ElectricStorm]

0z GFS is trying to develop this a bit at hour 270. This wave is going to have to be watched even if it doesn't do much in the near term

EDIT: Becomes a hurricane in the very long range

[Teban54]

0z GFS is trying to develop this a bit at hour 270. This wave is going to have to be watched even if it doesn't do much in the near term

EDIT: Becomes a hurricane in the very long range

A nice OTS hurricane in the subtropics would definitely be worth the wait... If it happens lol.

Seems like the first wave may encounter favorable conditions in the western parts of the basin if it's not too close to the second wave. 0z GFS being so slow with the second wave today is probably what changed the outcome.

[USTropics]

00z ECMWF develops this just north of PR now:


Steering pattern/track aside, both ECMWF/GFS showing favorable conditions as the wave approaches the western basin:

[LarryWx]

At DMAX, one can clearly see on this (06Z on 8/22/22) a pickup in convection centered on the westward moving weak surface low centered near 16N, 30W, as it stays away from the back edge of the SAL, which is just to its NW and N also moving westward:



Next is a view of that SAL for the same timeframe. Note the new convection with the weak low that is on the edge of the SAL:

[cycloneye]

This is the most convective it has been helped by DMAX. They may raise the % at 8 AM.

[Nimbus]

I think the trough axis may be further west than the convection at -30 but this clearly demonstrates that the ITCZ is making its annual migration north. Persistent TUTT north of the islands is there again now but could roll northwest or lift out by the time this wave arrives.

[cycloneye]

From 12:05 UTC TWD.

A far eastern Atlantic tropical wave has its axis along 29W from
08N to 22N moving westward at 15 kt. A 1011 mb low pressure is
analyzed along the wave axis near 16N. Recently developed
scattered moderate to isolated strong convection is within 90
nm of the low in the NE quadrant. Scattered moderate convection
is within 180 nm of the low in the SW quadrant, and within 120 nm
of the low in the NW quadrant. Isolated showers and thunderstorms
are seen within 240 nm E of the wave from 11N-14N. Environmental
conditions could support some slow development of this system
while it moves W-WNW at 10-15 kt across the eastern and central
tropical Atlantic for the next several days. Currently, this
system has a low chance of tropical cyclone development through 5
days.

[LarryWx]

This is the most convective it has been helped by DMAX. They may raise the % at 8 AM.

https://i.imgur.com/6qkwW2E.gif

The lighter broken cloudcover to the NW of the low's convection is likely stratocumulus associated with the drier SAL. The SAL is located above the stratocumulus. This will be an interesting test case to see how the more moist air/convection associated with the low interacts with the drier air and dust of the SAL not too far to its NW and N.

[cycloneye]

No change.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Mon Aug 22 2022

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

1. Eastern Tropical Atlantic:
A tropical wave located a few hundred miles west of the Cabo Verde
Islands continues to produce disorganized showers and thunderstorms.
Environmental conditions could support some slow development of this
system while it moves westward to west-northwestward at around 10 to
15 mph across the tropical Atlantic during the next several days.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

Forecaster Latto

[cycloneye]

Invest 90L is up