Strong Tropical Wave Emerging From West Africa (Is Invest 92L)

[ScottNAtlanta]

0z GFS nowhere near as strong as 18z GFS, but the storm does not go OTS; rather, it seems to take one of those dreaded S-curve paths toward the Bahamas (when I say "S-curve," I refer to those paths like Andrew, Dorian, Frances, Floyd, or Donna, where the storm seems to turn north initially but then abruptly heads westward)

Specifically such type track that will likely pose the greatest risk to the SE CONUS, the Bahamas, and notably Florida this year. W. Atlantic ridge heights and especially ridge orientation will ultimately dictate enhanced landfall risk at that time. Aside from what has been a largely predominant strong mid level ridge pattern over the far W. Atlantic basin thus far, August is NOT the month the Florida Chamber of Commerce would want to be eyeballing an intensifying tropical cyclone just north of P.R.

All that I know is that you don't want a system headed NW and then forced West...nothing good ever comes from that. That is a RI pattern most of the time

[MarioProtVI]

1. A tropical wave just inland over Africa is producing a large area of
showers and thunderstorms over the Guinea Highlands. This wave is
expected to move off the west African coast later today.
Environmental conditions appear somewhat conducive for gradual
development, and a tropical depression could form over the eastern
tropical Atlantic by early next week while the system moves westward
to west-northwestward at about 15 mph.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...50 percent.

10/50 now. Should see 92L very soon, likely later today.

[AtlanticWind]

Nada from Euro, but as we know the euro has been pretty terrible on genesis.

[Shell Mound]

 https://twitter.com/AndyHazelton/status/1422952718604378118



 https://twitter.com/AndyHazelton/status/1422956496732704774



 https://twitter.com/AndyHazelton/status/1422960676230864899



 https://twitter.com/dmorris9661/status/1422965145819570179



 https://twitter.com/AndyHazelton/status/1422902530816843776

[aspen]

06z GFS spins up three compact circulations from this wave and an adjacent wave, shoving the main one further north. This run should probably be ignored unless future runs continue to show a mess of a setup.

[tolakram]

I’ll reiterate: this latest 12Z run just proves my earlier supposition that the strong African monsoon will cause lots of systems to eject northward and curve OTS. This will likely save the U.S. from most, if not all, potential CV-type threats, including this one, despite otherwise strong and robust mid-level ridging projected to be in place. The main issue is that the monsoonal trough will cause this system to eject westward at a high latitude that typically results in CV-type long-trackers curving OTS, especially in years in which TCG occurs farther east in the MDR than is usual. Starting in two and a half days the 12Z GEFS members show this prospective system gaining a full five degrees of latitude in little more than a day, thanks to the monsoonal trough. This will likely become a seasonal trend, thankfully, but we shall see.

Looks to me like a normal CV type system that will recurve, hopefully, like 99% of these storm do. I don't see any feature that guarantees this recurve though, and I feel like the timing of development is more important to future track. Quick developers tend to recurve away from the US mainland. I question why suddenly the eastern MDR might be so favorable when it seems some of us thought it wouldn't be.

I don't think I would put a normal recurve % near that high at 99%. I can't imagine 100 storms forming off the coast of Africa and only 1 out of 100 making it to the USA mainland...

Agreed, I actually don't know the percentage but it is pretty high. Does anyone know?

[Shell Mound]

The 00Z EPS largely caved to my idea and now shows this system ejecting northward toward the CV islands and thence OTS, thanks to the strong monsoonal flow.

1. A westward-moving tropical wave just inland over Africa is producing
a large area of disorganized showers and thunderstorms. The wave is
expected to move off of the west African coast later today.
Environmental conditions appear somewhat conducive for gradual
development, and a tropical depression could form over the eastern
tropical Atlantic by late Sunday or early next week while the system
moves westward to west-northwestward at about 15 mph.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...60 percent.

As of 12:00 UTC the NHC’s latest Tropical Weather Outlook also shows this system gaining latitude within the next five days.

[aspen]

06z GEFS ensembles are very active, perhaps the most active so far despite the very strange operational run. Still, the last three OP runs have shown a TD within 72 hours. If it gets itself together earlier, then maybe it’ll have a better shot of surviving whatever unfavorable conditions it comes across, assuming it does get tossed north like that.

[Stormybajan]

Hello 92L

[ouragans]

Hello 92L

Over Africa

[cycloneye]

Invest 92L is up