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

[Shell Mound]

A tropical wave is forecast to move off of the west coast of Africa
by late Thursday. Environmental conditions appear somewhat conducive
for gradual development thereafter over the far eastern tropical
Atlantic through the weekend into early next week while the system
moves generally westward at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

https://i.imgur.com/Lz8s69c.png

Orange alert!

Orange fish alert. This one will be a goldfish! I’ll bet that this monsoonal trough may save the U.S. from lots of CV systems. Too many systems will gain latitude too soon to reach land, owing to the benign influence of the strong African monsoon. The 12Z GEFS members, as mentioned, show this upcoming system gaining a full five degrees of latitude in little more than a day, thanks solely to the influence of the monsoonal trough. Even the strongest ridging won’t be able to allow such a system to reach the U.S.

[SFLcane]

A tropical wave is forecast to move off of the west coast of Africa
by late Thursday. Environmental conditions appear somewhat conducive
for gradual development thereafter over the far eastern tropical
Atlantic through the weekend into early next week while the system
moves generally westward at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

https://i.imgur.com/Lz8s69c.png

Orange alert!

Orange fish alert. This one will be a goldfish! I’ll bet that this monsoonal trough may save the U.S. from lots of CV systems. Too many systems will gain latitude too soon to reach land.

Question nothing personal.. are you going to down play and question everything now even the NHC?

[Shell Mound]

Orange alert!

Orange fish alert. This one will be a goldfish! I’ll bet that this monsoonal trough may save the U.S. from lots of CV systems. Too many systems will gain latitude too soon to reach land.

Question nothing personal...are you going to down play and question everything now even the NHC?

I never questioned the NHC. The NHC isn’t talking about a threat to land per se. I agree with the NHC that this is likely to develop, but only affect the CV islands.

In regard to the monsoonal trough: I know that most CV-type systems curve OTS eventually. I think that the strong monsoon makes OTS even more likely than usual.

[captainbarbossa19]

Orange fish alert. This one will be a goldfish! I’ll bet that this monsoonal trough may save the U.S. from lots of CV systems. Too many systems will gain latitude too soon to reach land.

Question nothing personal...are you going to down play and question everything now even the NHC?

I never questioned the NHC. The NHC isn’t talking about a threat to landfall. I agree with the NHC that this is likely to develop, but only affect the CV islands.

Not saying this is going to be like Irma, but models showed early on Irma recurving, but ended up underestimating the strength of the ridge. First, we need to find out where the low develops before we start talking about an OTS track. It has not even emerged yet from Africa. Once models have something clear to track, we should know a lot more. Also, while many models may be showing a recurve, some are showing strong ridging to the north of the wave.

[crownweather]

Orange alert!

Orange fish alert. This one will be a goldfish! I’ll bet that this monsoonal trough may save the U.S. from lots of CV systems. Too many systems will gain latitude too soon to reach land.

Question nothing personal.. are you going to down play and question everything now even the NHC?

Also, GFS/GEFS does have a polar bias in that they tend to turn tropical systems too early (even into ridges sometimes!). How many times have we seen this model "correct" towards a more westward track.

[Shell Mound]

Question nothing personal...are you going to down play and question everything now even the NHC?

I never questioned the NHC. The NHC isn’t talking about a threat to landfall. I agree with the NHC that this is likely to develop, but only affect the CV islands.

Not saying this is going to be like Irma...

If I recall correctly, Irma did not have to contend with such a strong African monsoon in its formative stages, unlike this upcoming system.

[Woofde]

The recurve shown in the GFS ensemble modeling is 250 to 300 hours out. It's bold to be even talking about recurves considering the wave has yet to even leave Africa.

Sent from my SM-G988U1 using Tapatalk

[toad strangler]

Orange fish alert. This one will be a goldfish! I’ll bet that this monsoonal trough may save the U.S. from lots of CV systems. Too many systems will gain latitude too soon to reach land.

Question nothing personal...are you going to down play and question everything now even the NHC?

I never questioned the NHC. The NHC isn’t talking about a threat to land per se. I agree with the NHC that this is likely to develop, but only affect the CV islands.

In regard to the monsoonal trough: I know that most CV-type systems curve OTS eventually. I think that the strong monsoon makes OTS even more likely than usual.

From the horses mouth….



NOAA does not make seasonal hurricane landfall predictions. Hurricane landfalls are largely determined by the weather patterns in place as the hurricane approaches, and those patterns are only predictable when the storm is within several days of making landfall.

Predictions of the location, number, timing, and intensity of hurricane landfalls are ultimately related to the daily weather patterns which determine storm genesis locations and steering patterns. These patterns are not predictable weeks or months in advance. As a result, it is not possible to reliably predict the number or intensity of landfalling hurricanes in a seasonal outlook, or whether a given locality will be impacted by a tropical storm or hurricane this season.

[Category5Kaiju]

While Irma was a good example of a notorious storm that did not recurve OTS as many models initially thought, I think to a degree you could say the same thing for Florence.

[captainbarbossa19]

18z GFS coming in a lot stronger for this system than the 12z run.


12z:


18z:

[aspen]

18z GFS coming in a lot stronger for this system than the 12z run.


12z:
https://i.imgur.com/MYiTIJg.png

18z:
https://i.imgur.com/5f9kGa5.png

It still weakens future Fred after 120hr, but hey, it actually gets a TS this time! The trend for the 5-day forecast is the most important thing.

[cycloneye]

Moderate TS.

[aspen]

Moderate TS.

https://i.imgur.com/73ssv6R.gif

Still a little too north. It’ll be riding right along the boundary between 27/26/25C SSTs, and any further north would make strengthening impossible as well as putting it at risk for SAL ingestion. It’ll need to stick closer to 11-13N until it reaches about 45-50W, but that longitude won’t be reached unlit after 5 days.

[ScottNAtlanta]

I've been wondering when the models were going to start picking up on this wave. It looks about as good as any wave I've seen recently. If it hangs together when it exits, it's going to be trouble for someone. The big TUTT in the middle of the Atlantic is barreling west and I dont see anything that looks to replace it that will move it northerly the next 5 days. I think you will see models correct west...it always seems to happen that way. It's been a known GFS bias for years. I wonder why they cant seem to fix it

[cycloneye]

Big ACE producer if it does what 18Z GFS has. What about a powerful hurricane?

[Kohlecane]

Looks like that front might be able to scoop it.. but then again its over 300 hours out, wouldn't be surprised if this ends up getting pushed more S and west before 60W

[crownweather]

I've been wondering when the models were going to start picking up on this wave. It looks about as good as any wave I've seen recently. If it hangs together when it exits, it's going to be trouble for someone. The big TUTT in the middle of the Atlantic is barreling west and I dont see anything that looks to replace it that will move it northerly the next 5 days. I think you will see models correct west...it always seems to happen that way. It's been a known GFS bias for years. I wonder why they cant seem to fix it

Yes. Said the same thing a little earlier about the GFS model and its polar bias. Too many jump on the early runs of the GFS and don't look at past history of the model.

[aspen]

Good ol’ Happy Hour GFS. The 18z ensembles will be interesting. I do see the potential once this system reaches the warmest waters west of 50-60W and north of 20N, but who knows what the rest of the environment will be like 240+ hours out.

[Category5Kaiju]

While it is a bit too early to know for sure if an OTS track will happen, it looks like Bermuda may not be so happy with this new 18z GFS run

[tolakram]

Quite an uptick in activity from the 12 GEFS ensembles. All of them recurve, but it appears to be due to the wave being tossed a little further north by the monsoon trough...

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.