ATL: DELTA - Post-Tropical - Discussion

[NDG]

ASCAT pass from two hours ago showed not quiet there yet.

[chaser1]

Area of low pressure certainly there and convection popping on it's eastern side; Still, I think a combination of brisk forward speed and light to moderate upper level shear from Gamma will result in this feature not being tagged a T.D. until late tomorrow or Tuesday perhaps.

[Aric Dunn]

ASCAT pass from two hours ago showed not quiet there yet.

https://i.imgur.com/9ONjmxW.png

Still a big difference from 12 hours ago.. a little burst of convection and off it goes..

[NDG]

GFS 06z run keeps it a weak system (too much shear): https://www.tropicaltidbits.com/analysi ... 506&fh=360

What are you trying to show at the 360th hr?
What shear are you talking about?

[underthwx]

Looks like the only certainty with 92L....is uncertainty for the time being...to me it seems that whatever evolves from this system, would occur in the Eastern Gulf?....are there not cold fronts pushing any systems in that general direction?...

[cp79]

I’m really surprised at the central gulf solution and lack of East movement in its future. Doesn’t make much sense but nothing in this year has so far.

[chaser1]

Looks like the only certainty with 92L....is uncertainty for the time being...to me it seems that whatever evolves from this system, would occur in the Eastern Gulf?....are there not cold fronts pushing any systems in that general direction?...

Naw, not really. Seems like there's a shortwave impulse dipping south of the Great Lakes around the 50-60 hr.s time range but the flow is very progressive and this doesn't really do much to break down the mid level ridging over Florida and Eastern GOM. 'Course if this were the same set up in the middle of the MDR, i'd bet we'd see 92L shoot northward into the decaying ridge faster then 100 chain-saw's pushing through a beaver dam LOL. Now, interestingly the GFS long range (around Oct. 14-18) does depict a strong and very deep short wave trough that extends south to the NW GOM and appears to progress east over time. This looks like that set up that would need to keep Cuba and Florida on it's toes for any potential W. Caribbean systems that would likely track primarily northward in response to deep layer steering. Long way off though and it'll remain to be seen if this trough and related cold front will verify (let along whether any developing TC is in place to our south.

[chaser1]

I’m really surprised at the central gulf solution and lack of East movement in its future. Doesn’t make much sense but nothing in this year has so far.

I think more then anything, we're all so used to seeing a Fall long wave pattern of troughing along the CONUS east coast. With the typical southward migration of Westerlies and steering flow out of the southwest, this would have generally suggested a more northward to NNE motion ahead of strong fronts approaching the US Seaboard. La Nina generally enhances stronger ridging across the southern tier states so unless a strong enough trough can temporarily break down that "protective ridging", there's less of a sharp poleward influence for storm tracks to take.

[edu2703]

A tropical wave accompanied by a low pressure system is located over
the central Caribbean Sea a couple of hundred miles southeast of
Jamaica. The associated shower and thunderstorm activity is
beginning to show some signs of organization. Environmental
conditions are expected to be conducive for additional development,
and a tropical depression is likely to form within the next day or
two. The system should move west-northwestward at 10 to 15 mph
across the central and western Caribbean Sea today through Tuesday,
and then move into the southern or southeastern Gulf of Mexico on
Tuesday night and Wednesday. Locally heavy rainfall and gusty
winds will be possible across portions of Hispaniola, Jamaica, Cuba,
and the Cayman Islands during the next few days, and interests on
those islands should monitor the progress of this disturbance.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

[cycloneye]

A broad area of low pressure is located over the central Caribbean
Sea, a little less than 100 miles south-southeast of eastern
Jamaica. Recent satellite wind data and visible satellite imagery
indicate that the circulation is gradually becoming better defined,
however, the associated shower and thunderstorm activity has
changed little in organization since this morning. Environmental
conditions are expected to be conducive for additional development,
and a tropical depression is likely to form within the next day or
so, while the system moves over the central and northwestern
Caribbean Sea. The disturbance is forecast to move near Jamaica
through Monday, and then pass near the Cayman Islands early Tuesday
and approach western Cuba by late Tuesday, and interests in those
areas should closely monitor the progress of this system. The low
is forecast to move into the southern or southeastern Gulf of
Mexico Tuesday night or Wednesday. Regardless of development,
locally heavy rainfall and gusty winds will be possible across
portions of Hispaniola, Jamaica, the Cayman Islands, and Cuba
during the next few days. This rainfall could lead to
life-threatening flash floods and mudslides.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...80 percent.

[NDG]

The GOM has been a a hot spot this season, future Delta will be the 8th name system to track in the GOM.

[aspen]

The GOM has been a a hot spot this season, future Delta will be the 8th name system to track in the GOM.

https://i.imgur.com/Uee6qYV.gif

It seems to have a decently healthy spin, but shear needs to relax to allow its convection to organize. I think it could become TD26 or Delta as early as tomorrow morning.

[Aric Dunn]

nice tower popping up.

overall low level structure is improving quickly.

HWRF looks to be nailing this one as well. at least for the next 48 to 72 hours.

[edu2703]

If the 92L develops a well-defined core structure soon, that would allow a RI while is still over the Caribbean. Enviromental conditions are near perfect for that once it moves NW.

[psyclone]

How many majors has the HWRF spun out this year? Seems like an awful lot although I don't know the actual number. I do know that we have had 25 numbered systems and only 2 have graduated to major status...an 8% conversion rate.

[aspen]

If 92L has a more southern track like the 12 HMON, it could avoid Cuba entirely and have 69-72 hours before entering the Gulf. Assuming Delta develops in 24-36 hours, that’ll give it anywhere from 33 to 48 hours to intensify. That could be enough time for it to become a major if it’s able to build a solid core and fend off any dry air that might be around.

[ElectricStorm]

I bet this will be the 3rd major of the year

[underthwx]

Looks like the only certainty with 92L....is uncertainty for the time being...to me it seems that whatever evolves from this system, would occur in the Eastern Gulf?....are there not cold fronts pushing any systems in that general direction?...

Naw, not really. Seems like there's a shortwave impulse dipping south of the Great Lakes around the 50-60 hr.s time range but the flow is very progressive and this doesn't really do much to break down the mid level ridging over Florida and Eastern GOM. 'Course if this were the same set up in the middle of the MDR, i'd bet we'd see 92L shoot northward into the decaying ridge faster then 100 chain-saw's pushing through a beaver dam LOL. Now, interestingly the GFS long range (around Oct. 14-18) does depict a strong and very deep short wave trough that extends south to the NW GOM and appears to progress east over time. This looks like that set up that would need to keep Cuba and Florida on it's toes for any potential W. Caribbean systems that would likely track primarily northward in response to deep layer steering. Long way off though and it'll remain to be seen if this trough and related cold front will verify (let along whether any developing TC is in place to our south.

I could not ask for a better informational response than than that chaser.....thank you for that...

[sikkar]

Is Gamma's outflow negatively impacting this wave?

[aspen]

Could this be designated PTC-26 soon? It’s not far off from becoming a TC, and it’ll pass by Jamaica tomorrow.