ATL: TEN - Post-Tropical - Discussion

[gatorcane]

Not looking too bad today. Vorticity looks strong and just enough convection is maintaining. We need to hope the TUTT shear zone near the NE Lesser Antilles can rip this thing apart as there should be favorable conditions for this invest as it nears the Bahamas and possibly Florida after that. One thing to watch for - the shear might actually induce a good amount of convection as the invest nears the Ne Lesser Antilles which could actually help maintain this for future development.

[SFLcane]

Looks choked you can see the SAL just to the north sinking air

[TheStormExpert]

12z...

Shear starts increasing again in 5 days (120hrs.) FWIW after decreasing very briefly in 4-1/2 days.

[SouthFLTropics]

Vorticity looks excellent on visible, IR, and on MIMIC. Convection is lacking due to the SAL but if that Vort can sustain itself through the TUTT then conditions both shear and SAL wise should get better as it approaches the Bahamas. Too early to tell...we could be dealing with anything from a TD to a major this time next week. What gives me pause is that we've seen vigorous circulations survive hostile environments before to later go on and become monsters.

[Bocadude85]

12z...

Shear starts increasing again in 5 days (120hrs.) FWIW after decreasing very briefly in 4-1/2 days.

Ships isn't exactly stellar when it comes to 5 day shear forecast..

[WeatherEmperor]

I pulled this image from Ventrice's Twitter site. It shows the TUTT extending down to neat the Turks and Caicos islands. Gert was able to form just to the north of the upper low but for 92L to affect Florida as a tropical cyclone...I am not too sure because it wont have much time if it survives the shear to develop that quickly before potentially impacting Florida. Maybe if it can make it into the Eastern GOM or meander right off the SE coast can it develop?? What are your thoughts guys?


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[Bocadude85]

I pulled this image from Ventrice's Twitter site. It shows the TUTT extending down to neat the Turks and Caicos islands. Gert was able to form just to the north of the upper low but for 92L to affect Florida as a tropical cyclone...I am not too sure because it wont have much time if it survives the shear to develop that quickly before potentially impacting Florida. Maybe if it can make it into the Eastern GOM or meander right off the SE coast can it develop?? What are your thoughts guys?.
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That's assuming that the tutt will be in the exact same position in 5-6 days, Katrina went from a tropical wave in the central Bahamas to a strengthening cat 1 at landfall in S.Fla

[HurricaneEric]

12z...

Shear starts increasing again in 5 days (120hrs.) FWIW after decreasing very briefly in 4-1/2 days.

Also, stupid question, but isn't below 20kt wind shear not that detrimental to tropical cyclone genesis?

[TheStormExpert]

I pulled this image from Ventrice's Twitter site. It shows the TUTT extending down to neat the Turks and Caicos islands. Gert was able to form just to the north of the upper low but for 92L to affect Florida as a tropical cyclone...I am not too sure because it wont have much time if it survives the shear to develop that quickly before potentially impacting Florida. Maybe if it can make it into the Eastern GOM or meander right off the SE coast can it develop?? What are your thoughts guys?.
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That's assuming that the tutt will be in the exact same position in 5-6 days, Katrina went from a tropical wave in the central Bahamas to a strengthening cat 1 at landfall in S.Fla

Here is another example that storms can rapidly intensify once in the Bahamas.

 https://twitter.com/philklotzbach/status/897823260649242626

[Hurricaneman]

I pulled this image from Ventrice's Twitter site. It shows the TUTT extending down to neat the Turks and Caicos islands. Gert was able to form just to the north of the upper low but for 92L to affect Florida as a tropical cyclone...I am not too sure because it wont have much time if it survives the shear to develop that quickly before potentially impacting Florida. Maybe if it can make it into the Eastern GOM or meander right off the SE coast can it develop?? What are your thoughts guys?.
Sent from my iPhone 7 using Tapatalk

That's assuming that the tutt will be in the exact same position in 5-6 days, Katrina went from a tropical wave in the central Bahamas to a strengthening cat 1 at landfall in S.Fla

Here is another example that storms can rapidly intensify once in the Bahamas.

 https://twitter.com/philklotzbach/status/897823260649242626

That is a good analog and another good analog could be Erin 1995 but those are worst case scenarios imo maybe a tropical storm landfall somewhere on the Florida peninsula then somewhere in the GOM

[Blown Away]

Near 14N/35W...

[ronjon]

12z...

Shear starts increasing again in 5 days (120hrs.) FWIW after decreasing very briefly in 4-1/2 days.

Also, stupid question, but isn't below 20kt wind shear not that detrimental to tropical cyclone genesis?

Actually according to that forecast, shear will only be a problem for development from 48-72 hours. Tropical cyclones can slowly develop with 15-20 kts of shear - rapidly develop with less than 10 kts.

[weathaguyry]

That is a good analog and another good analog could be Erin 1995 but those are worst case scenarios imo maybe a tropical storm landfall somewhere on the Florida peninsula then somewhere in the GOM

It would be nice if you did a daily tropical weather forecast, since I'd like to hear your opinion on Gert, 91L, 92L, and future 93L

[HurricaneBelle]

I don't know that we'll ever see a situation similar to Andrew again. The stair-step north of the islands, almost getting ripped part but then running into a brutally strong SE US high. What storm is even a slight analog to that? The closest I can think of is Betsy (similar results albeit a more jagged, circuitous route). Something like Georges does seem to be a far more typical late August into September track, where it just rides a big subtropical high all the way.

Well put. There seems to be an over-tendency on here to compare every storm that struggles in the MDR and heads toward the Bahamas to Andrew, just like every disturbance in the Gulf that starts to organize gets compared to Humberto. Those were unusual or freakish events that aren't likely to recur and every storm is different.

[AtlanticWind]

92L has a pretty good spin, one good burst of convection and we could have something.

[gatorcane]

How strong 92L may get down the road could depend greatly on how strong 91l gets (not 93L as was previously thought). In fact while 91l could be a big problem for Central America it could also be what keeps 92l from being a big problem for the US.

[blp]

I think the ULL currently at 30N 45W will be the biggest shear contributor as it drops to the SW and not the ULL in the Turks which will be long gone to the west. If it can skirt a little further south it could be out of the worst shear.

Current


54hr

[hd44]

Up to 40/50.

[cycloneye]

2 PM TWO up to 40%-50%



A second area of low pressure is located about 800 miles west
of the Cabo Verde Islands, and its associated shower and
thunderstorm activity remains disorganized. Gradual development of
this system is possible during the next few days while it moves
west-northwestward at 15 to 20 mph, but upper-level winds are
expected to become less conducive for tropical cyclone formation
when the disturbance moves north of the Leeward Islands this
weekend.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...50 percent.

[SoupBone]

How strong 92L may get down the road could depend greatly on how strong 91l gets (not 93L as was previously thought). In fact while 91l could be a big problem for Central America it could also be what keeps 92l from being a big problem for the US.

As close as they are, why wouldn't 92l follow 91L? Is it too high in lattitude?