ATL: IDA - Remnants - Discussion

[ThetaE]

This system is so elongated and moving fast on all the GFS runs so far that it makes me wonder if it will get enough time to intensify. It's literally a wave moving through the Caribbean on the models. Maybe the Gulf coast gets lucky?

You... saw how those GFS runs ended, right?

Although, I dunno if speed/elongation will have much to do with it, but there is a good argument to watch a broad but weak upper level low currently to the NW of 99L. You can see how this is already impacting/going to impact the system on visible satellite: notice the boundary of cirrus clouds not really making much progress westward?

This feature will probably impart shear on 99L in the nearer term for a few days. In fact, the GFS shows an associated PV streamer near 99L even thru Sunday, well into the Gulf:


I've highlighted a few features on this image: the PV streamer with a dashed line, and the outflows of both 99L and 95E with a solid line. Notice how the PV streamer is a thin filament wedged between these outflows: a stronger 95E really helps sharpen this filament and push it towards 99L, ultimately imparting wind shear. This is basically another view of the same thing Eric Webb is talking about. If 99L does get organized more quickly than the GFS shows (doesn't really get going til near the Gulf), it'll also probably deal with this PVS faster.

So in conclusion, a weaker 95E and/or stronger 99L in the short term will definitely increase chances for a stronger landfall intensity. But even with this PVS keeping a lid on things until Sunday, the GFS argues that two days over the scorching SSTs of the northern Gulf is more than enough for a concerning amount of RI.

[Shell Mound]

This system is so elongated and moving fast on all the GFS runs so far that it makes me wonder if it will get enough time to intensify. It's literally a wave moving through the Caribbean on the models. Maybe the Gulf coast gets lucky?

You... saw how those GFS runs ended, right?

Although, I dunno if speed/elongation will have much to do with it, but there is a good argument to watch a broad but weak upper level low currently to the NW of 99L. You can see how this is already impacting/going to impact the system on visible satellite: notice the boundary of cirrus clouds not really making much progress westward?

This feature will probably impart shear on 99L in the nearer term for a few days. In fact, the GFS shows an associated PV streamer near 99L even thru Sunday, well into the Gulf:
https://i.imgur.com/K1jrYkG.png

I've highlighted a few features on this image: the PV streamer with a dashed line, and the outflows of both 99L and 95E with a solid line. Notice how the PV streamer is a thin filament wedged between these outflows: a stronger 95E really helps sharpen this filament and push it towards 99L, ultimately imparting wind shear. This is basically another view of the same thing Eric Webb is talking about. If 99L does get organized more quickly than the GFS shows (doesn't really get going til near the Gulf), it'll also probably deal with this PVS faster.

So in conclusion, a weaker 95E and/or stronger 99L in the short term will definitely increase chances for a stronger landfall intensity. But even with this PVS keeping a lid on things until Sunday, the GFS argues that two days over the scorching SSTs of the northern Gulf is more than enough for a concerning amount of RI.

The past several cycles have definitely trended toward a weaker 99L in the Caribbean, so 95E’s proximity to 99L while the latter is in the Gulf of Mexico will prove critical for the latter’s potential ceiling, intensity-wise. Personally, I suspect that the G(E)FS deepens 99L excessively over the Gulf, given the PVS’s proximity to 99L and modelled trends favouring a slower, more easterly 95E during the same timeframe. Rather than a strong Category-4+, I think a high-end Category-2 TC is more plausible, with a chance that 99L reaches major-hurricane status just prior to landfall on the U.S. Gulf Coast. If I recall correctly, Laura also contended with a PVS just to its west, hence westerly shear, while transiting the Gulf, though in Laura’s case the PVS was weaker and/or farther west than in 99L’s case. This suggests that 99L will likely end up being weaker than Laura was, unless 95E were to end up much farther west and/or weaker, or 99L were to end up being much smaller in size.

[ScottNAtlanta]

95E is experiencing quite a bit of easterly shear. It does not look like that is going to develop in the near term.

[psyclone]

"weaker than Laura"...What a useless level of pontification providing cold comfort to those in the potential impact zone. We don't know what the system will do but the ceiling is high. It can be less than a high end cat 4 and still be a hellish impact. I'd suggest a hurricane, and possibly a major is a distinct possibility here...details are unknowable but late August has a history of producing west pac style typhoons in the central and western gulf.

[ScottNAtlanta]

This sure does seem to be organizing quickly. It already has some good mid level spin that wasn't there this morning. HWRF might be right with a depression/TS south of Jamaica.

[Category5Kaiju]

"weaker than Laura"...What a useless level of pontification providing cold comfort to those in the potential impact zone. We don't know what the system will do but the ceiling is high. It can be less than a high end cat 4 and still be a hellish impact. I'd suggest a hurricane, and possibly a major is a distinct possibility here...details are unknowable but late August has a history of producing west pac style typhoons in the central and western gulf.

I’m pretty sure if a hurricane “weaker than Laura” with 145 mph winds and a pressure of 941 mbar were to be barreling toward Houston or Corpus, then the last thing in mind for residents there is the fact that it is “weaker than Laura.” That’s pretty much an irrelevant fact should something like that occur.

[tolakram]

This sure does seem to be organizing quickly. It already has some good mid level spin that wasn't there this morning. HWRF might be right with a depression/TS south of Jamaica.

Most of the models track this, the CMC goes over Jamaica while the GFS and Euro both show a vorticity pattern SW of Jamaica and west of Cuba as it moves NW. Use vorticity plots with the globals during early formation.

[Blinhart]

"weaker than Laura"...What a useless level of pontification providing cold comfort to those in the potential impact zone. We don't know what the system will do but the ceiling is high. It can be less than a high end cat 4 and still be a hellish impact. I'd suggest a hurricane, and possibly a major is a distinct possibility here...details are unknowable but late August has a history of producing west pac style typhoons in the central and western gulf.

I’m pretty sure if a hurricane “weaker than Laura” with 145 mph winds and a pressure of 941 mbar were to be barreling toward Houston or Corpus, then the last thing in mind for residents there is the fact that it is “weaker than Laura.” That’s pretty much an irrelevant fact should something like that occur.

Also a Cat 2 will still cause a lot of damage in Lake Charles and surrounding areas, there is a ton of debris and damaged buildings still there.

[Kohlecane]

This system is so elongated and moving fast on all the GFS runs so far that it makes me wonder if it will get enough time to intensify. It's literally a wave moving through the Caribbean on the models. Maybe the Gulf coast gets lucky?

You... saw how those GFS runs ended, right?

Although, I dunno if speed/elongation will have much to do with it, but there is a good argument to watch a broad but weak upper level low currently to the NW of 99L. You can see how this is already impacting/going to impact the system on visible satellite: notice the boundary of cirrus clouds not really making much progress westward?

This feature will probably impart shear on 99L in the nearer term for a few days. In fact, the GFS shows an associated PV streamer near 99L even thru Sunday, well into the Gulf:
https://i.imgur.com/K1jrYkG.png

I've highlighted a few features on this image: the PV streamer with a dashed line, and the outflows of both 99L and 95E with a solid line. Notice how the PV streamer is a thin filament wedged between these outflows: a stronger 95E really helps sharpen this filament and push it towards 99L, ultimately imparting wind shear. This is basically another view of the same thing Eric Webb is talking about. If 99L does get organized more quickly than the GFS shows (doesn't really get going til near the Gulf), it'll also probably deal with this PVS faster.

So in conclusion, a weaker 95E and/or stronger 99L in the short term will definitely increase chances for a stronger landfall intensity. But even with this PVS keeping a lid on things until Sunday, the GFS argues that two days over the scorching SSTs of the northern Gulf is more than enough for a concerning amount of RI.

I just think about the PVS in front of Grace while it was near Jamaica and how quickly that resolved ?

[captainbarbossa19]

I am hoping all this does is fail to develop and bring rain to my area. We could use some rain, but no hurricanes! I am hoping this stays away from the Lake Charles area too. They got hit by Laura and Delta last year. My area was fortunate and actually had stronger impacts from Delta. I am just thinking that my area may not be fortunate this time. In recorded history, Jefferson and Chambers counties in Texas have had more major hurricanes within a 50 mile radius compared to Calcasieu Parish in Louisiana. Galveston County is #1 in the state for major hurricanes.

[tolakram]

[youtube]https://youtu.be/YyZIpmf6AwU[/youtube]

[Shell Mound]

"weaker than Laura"...What a useless level of pontification providing cold comfort to those in the potential impact zone. We don't know what the system will do but the ceiling is high. It can be less than a high end cat 4 and still be a hellish impact. I'd suggest a hurricane, and possibly a major is a distinct possibility here...details are unknowable but late August has a history of producing west pac style typhoons in the central and western gulf.

I’m pretty sure if a hurricane “weaker than Laura” with 145 mph winds and a pressure of 941 mbar were to be barreling toward Houston or Corpus, then the last thing in mind for residents there is the fact that it is “weaker than Laura.” That’s pretty much an irrelevant fact should something like that occur.

Also a Cat 2 will still cause a lot of damage in Lake Charles and surrounding areas, there is a ton of debris and damaged buildings still there.

For the record, my saying that this will likely be weaker than Laura does not imply that a weaker system would not be capable of severe impacts. People should definitely take this system seriously and are certainly already doing so. Anyway, short-term trends, including those on current satellite imagery, indicate that the MLC is rather vigorous, notwithstanding strong westerly shear. Should the MLC remain intact, 99L will certainly be in a position to intensify farther west, although I would still opine that most of 99L’s intensification will not occur prior to the system’s reaching the Gulf of Mexico.

[ouragans]

Do we have Recon on stand-by for this system? If so, what is their flight plan?

1st flight is planned for tomorrow

FLIGHT ONE - TEAL 71
A. 26/2000Z
B. AFXXX 01DDA INVEST
C. 26/1600Z
D. 13.5N 81.5W
E. 26/2000Z TO 26/2300Z
F. SFC TO 10,000 FT

[SoupBone]

Do we have Recon on stand-by for this system? If so, what is their flight plan?

1st flight is planned for tomorrow

FLIGHT ONE - TEAL 71
A. 26/2000Z
B. AFXXX 01DDA INVEST
C. 26/1600Z
D. 13.5N 81.5W
E. 26/2000Z TO 26/2300Z
F. SFC TO 10,000 FT

Those coordinates are way west of where people currently think the "center" is forming. Hmmm....what do they think at this point?

[InfernoFlameCat]

If I could get a feel on what Wxman57 had to say on this I would feel a lot better. He warned about grace when a lot of us talked about it dissipating over the GA. Once again he just has that knowledge of what a tc will do.

[ouragans]

Those coordinates are way west of where people currently think the "center" is forming. Hmmm....what do they think at this point?

It will be adjusted tomorrow. We're more than 24 hrs ahead

[Steve]

If I could get a feel on what Wxman57 had to say on this I would feel a lot better. He warned about grace when a lot of us talked about it dissipating over the GA. Once again he just has that knowledge of what a tc will do.

He posted a page or two back. He said he's now thinking more along the lines of LA. Check his "view user's recent posts."

[Frank P]

99L continues to look better this afternoon. Additionally it appears the overall system is gaining latitude over time. Big question where will the center finally consolidate, gonna play a huge part in ultimate track..

[Steve]

99L continues to look better this afternoon. Additionally it appears the overall system is gaining latitude over time. Big question will the center finally consolidate, gonna play a huge part in ultimate track..

https://i.ibb.co/cvcgmzf/goes16-truecolor-watl.gif

Levi thinks maybe Saturday at the Yucatan

[Frank P]

99L continues to look better this afternoon. Additionally it appears the overall system is gaining latitude over time. Big question will the center finally consolidate, gonna play a huge part in ultimate track..

https://i.ibb.co/cvcgmzf/goes16-truecolor-watl.gif

Levi thinks maybe Saturday at the Yucatan

Yeah, I saw that but I though he gave three possible locations, north off the coast, or center near Cancun or southern Yucatán?