ATL: DELTA - Post-Tropical - Discussion

[ElectricStorm]

How strong will 26 be?
A TD
B TS
C 1
D 2
E 3

At peak or landfall?
Based on conditions in the Caribbean, and watching what Gamma was able to do in the short time before landfall, I'm going with Cat 4 peak

[HurricaneAndre2008]

How strong will 26 be?
A TD
B TS
C 1
D 2
E 3

At peak or landfall?

Peak

[Blinhart]

I'm not liking that this is already getting up a borderline Cat 2/3 Hurricane and hasn't even gotten a LLC yet, this is very scary, and the Northern GoM in the bullseye also. This just sucks.

[edu2703]

Future Delta will not be a slow-moving storm like Sally, so I think the effects of the cooler SST on nothern Gulf coast will not be so severe as to induce a rapid weakening, since will not stay there for long. The same can be said for the shear in this region, which also appears it won't be very strong when Delta moves into the gulf by Wednesday. So, I expect a weakening but nothing very dramatic before landfall. A Cat 1/2 landfall is definitely not out of question.

Of course, the intensity forecasts depend on how long it will take for the 92L to organize and develop a well defined core structure. Once it succeeds, RI is likely to happen while it is still in the Caribbean and a peak above the NHC forecast cannot be ruled out.

[aspen]

This is the most bullish I’ve ever felt on a TC this year. I’m not excluding the potential for this to become a Cat 5, especially if it tracks a little further south and avoids landfall in Cuba. Other conditions after so favorable that I don’t see any reason why this can’t bomb out once shear dies down and it gets the opportunity to build an inner core.

If Delta starts intensifying at the same rate as Gamma (~1.7 mb/hr) starting in 12-18 hours, it would peak below 935 mbar by the time it nears Cuba in 60-66 hours.

[Ian2401]

Any chance this ends up in the Big Bend area? Would think climatology would bring future delta there

[Aric Dunn]

Any chance this ends up in the Big Bend area? Would think climatology would bring future delta there

A few scenarios could lead to such a track.

everything depends on Gamma.

[CrazyC83]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

[Aric Dunn]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

Yeppers.. could see a strong Cat 3 maye low 4 as it enters the gulf.

[underthwx]

Any chance this ends up in the Big Bend area? Would think climatology would bring future delta there

A few scenarios could lead to such a track.

everything depends on Gamma.

Aric...would you mind explaining a s enario or two, in a nutshell?....Im curious

[CrazyC83]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

Yeppers.. could see a strong Cat 3 maye low 4 as it enters the gulf.

Yep, but if it goes straight north to the northern Gulf, it would be hard to maintain that intensity.

[psyclone]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

Could this be a situation where a higher ceiling in the northwest Caribbean = a greater potential to degrade in the Gulf? I'm tending to side with wxman 57 here at this point (don't roast me bro!)...with the caveat that things can always change..

[Aric Dunn]

Any chance this ends up in the Big Bend area? Would think climatology would bring future delta there

A few scenarios could lead to such a track.

everything depends on Gamma.

Aric...would you mind explaining a s enario or two, in a nutshell?....Im curious

I will tell what we dont want to see.

we dont want to see Gamma weaken and dive SW far into the BOC.

this would likely allow for less of prolonged WNW/NW motion and much sooner NE turn farther south staying over the much warmer water as it approaches the big bend area.

Gamma holds all the cards right now. there are a lot of subtle things Gamma could do that would affect Delta. So going with a model blend right now is the best approach until we see what gamma does.

[ElectricStorm]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

Could this be a situation where a higher ceiling in the northwest Caribbean = a greater potential to degrade in the Gulf? I'm tending to side with wxman 57 here at this point (don't roast me bro!)...with the caveat that things can always change..

Wouldn't it be the opposite? A weaker storm entering the gulf would weaken faster. I don't know. My prediction is a cat 4 peak before entering the gulf, then weakening to strong 1/weak 2 at landfall.

[ClarCari]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

Could this be a situation where a higher ceiling in the northwest Caribbean = a greater potential to degrade in the Gulf? I'm tending to side with wxman 57 here at this point (don't roast me bro!)...with the caveat that things can always change..

That’s not how things can work since a stronger storm exponentially decreases the effect shear and dry air has on it.
A 65mph TS could be shredded 35mph down to a 30mph TD
whilst the same exact shear and or dry air would only knock 5 or 10mph down in intensity in the same timespan on a major.

[psyclone]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

Could this be a situation where a higher ceiling in the northwest Caribbean = a greater potential to degrade in the Gulf? I'm tending to side with wxman 57 here at this point (don't roast me bro!)...with the caveat that things can always change..

That’s not how things can work since a stronger storm exponentially decreases the effect shear and dry air has on it.
A 65mph TS could be shredded 35mph down to a 30mph TD
whilst the same exact shear and or dry air would only knock 5 or 10mph down in intensity in the same timespan on a major.

I'm not following. the more rungs on the ladder it climbs in the Caribbean the more downside there is when it departs such a favorable environment...especially with the drastic change in sea surface temps relative to earlier storms this season. we don't need upwelling in the northern gulf now. the cool water is there lying in wait. of course if it makes to a high end storm it could still be a significant event...think of all the big storms that affect areas that never have warm water up against their coast...like atlantic canada for instance. just thinking aloud here.

[ClarCari]

Could this be a situation where a higher ceiling in the northwest Caribbean = a greater potential to degrade in the Gulf? I'm tending to side with wxman 57 here at this point (don't roast me bro!)...with the caveat that things can always change..

That’s not how things can work since a stronger storm exponentially decreases the effect shear and dry air has on it.
A 65mph TS could be shredded 35mph down to a 30mph TD
whilst the same exact shear and or dry air would only knock 5 or 10mph down in intensity in the same timespan on a major.

I'm not following. the more rungs on the ladder it climbs in the Caribbean the more downside there is when it departs such a favorable environment...especially with the drastic change in sea surface temps relative to earlier storms this season. we don't need upwelling in the northern gulf now. the cool water is there lying in wait. of course if it makes to a high end storm it could still be a significant event...think of all the big storms that affect areas that never have warm water up against their coast...like atlantic canada for instance. just thinking aloud here.

That’s assuming a stronger storm will pull it northeastward which is NOT always the case. There are plenty of strong storms that did not move to the North and or East. It’s not a hard cold rule in the tropics.
I’m not expecting it to remain over Cuba long at all, if it even does...

[CrazyC83]

Could this be a situation where a higher ceiling in the northwest Caribbean = a greater potential to degrade in the Gulf? I'm tending to side with wxman 57 here at this point (don't roast me bro!)...with the caveat that things can always change..

That’s not how things can work since a stronger storm exponentially decreases the effect shear and dry air has on it.
A 65mph TS could be shredded 35mph down to a 30mph TD
whilst the same exact shear and or dry air would only knock 5 or 10mph down in intensity in the same timespan on a major.

I'm not following. the more rungs on the ladder it climbs in the Caribbean the more downside there is when it departs such a favorable environment...especially with the drastic change in sea surface temps relative to earlier storms this season. we don't need upwelling in the northern gulf now. the cool water is there lying in wait. of course if it makes to a high end storm it could still be a significant event...think of all the big storms that affect areas that never have warm water up against their coast...like atlantic canada for instance. just thinking aloud here.

Stronger storms in cooler water (like near Atlantic Canada) usually have baroclinic processes that help out. That's what happened to the extreme with Sandy in 2012. It's a bit more likely you'll have that in the Gulf in October than in August, but you still don't normally see such south of 30-35N.

[ronjon]

Any chance this ends up in the Big Bend area? Would think climatology would bring future delta there

I would think if any shifts occur in the future track it would be east given climatology. There is a pretty stout mid level ridge forecast to strengthen from the bahamas to the northern gulf coast in the next 3 days. Afterward, a weakness is forecast over the northern gulf coast and a midlatitude trough will swing by. Still 5-6 days out so expect lots to change in forecast track after 3 days. NHC even discusses this with 4-5 day track forecast. And of course there's Gamma strength and motion which is uncertain.

[Keldeo1997]

This is the part of the forecast discussion that concerns me the most for the short term:

“The disturbance is located over warm waters and in a moist environment, but there is some modest northeasterly shear over the system. The global models indicate that the shear will decrease overnight, and the oceanic and atmospheric environment is expected to be quite favorable for both the development of a tropical cyclone and subsequent strengthening of the system over the northwestern Caribbean Sea during the next couple of days.”

So shear might only be an issue for another ~12 hours, and after that, PTC26/Delta will be in an extremely favorable environment with another 48-52 hours until landfall in SW Cuba. That’s plenty of time for it to undergo RI like Gamma, and that is very concerning for everyone in Delta’s path.

Also doesn't help that baring a shift East there won't as much or any at all disruption from Cuba