ATL: IAN - Post-Tropical - Discussion

[TheHurricaneGod]

So east coast probably out of the question? It was looking like just 12 hours ago a more significant east coast threat. Preparing accordingly regardless.

[ColdMiser123]

This illustrates what I think is and will be occurring today. If you look at that eddy (yellow dot) on vis satellite, it's actually moving NNW. Because it's moving away from the deep convection, it's unlikely to survive. You'll also notice the overall circulation is becoming distorted/elongated, with some tightening curvature near the orange dot. This appears to me as if it might be a new center trying to form via VHT and CISK. It may not form in that exact location, but I think it'll contribute to the vorticity pocket shifting or propagating downshear (westward) today. Whatever the case, don't look for any RI of this system in the immediate future.

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

That's a similar idea to what the GFS was showing before moving west of Jamaica's longitude, with the center trying to reform downshear closer to the convection, which has a net effect of moving the storm a bit to the west with the Florida approach.

[AJC3]

 https://twitter.com/MeteoAtlas/status/1573295562992263171

This illustrates what I think is and will be occurring today. If you look at that eddy (yellow dot) on vis satellite, it's actually moving NNW. Because it's moving away from the deep convection, it's unlikely to survive. You'll also notice the overall circulation is becoming distorted/elongated E-W, with some tightening curvature near the orange dot. This appears to me as if it might be a new center trying to form via VHT and CISK. It may not form in that exact location, but I think it'll contribute to the vorticity pocket shifting or propagating downshear (westward) today. Whatever the case, don't look for any RI of this system in the immediate future.

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

[Hypercane_Kyle]

Even if it's rather poorly organized, it's genuinely impressive this system managed to close off enough to become a TC in the middle of the Central Caribbean. This region of the Caribbean is usually very hostile to TC genesis.



SHIPS showing the probability for a 65 knot RI episode in 72 hours as being 49%, 9.3x the climatological mean.

[wxman57]

I see 2-3 eddies rotating around a broad center. It's going to take time to organize.

[SFLcane]

 https://twitter.com/TropicsWatch/status/1573298833295032321

[cane5]

This illustrates what I think is and will be occurring today. If you look at that eddy (yellow dot) on vis satellite, it's actually moving NNW. Because it's moving away from the deep convection, it's unlikely to survive. You'll also notice the overall circulation is becoming distorted/elongated E-W, with some tightening curvature near the orange dot. This appears to me as if it might be a new center trying to form via VHT and CISK. It may not form in that exact location, but I think it'll contribute to the vorticity pocket shifting or propagating downshear (westward) today. Whatever the case, don't look for any RI of this system in the immediate future.

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

What it’s doing you say seems to be based on visual observations but lack any atmospheric conclusions as we are very far out from basing any clear direction at this point. A strong dipping trough will have much more impact in my opinion than any short term wobble etc.

[ScottNAtlanta]

I'd say this is a win for the GFS as it has been predicting that the center would end up on the southern side of the wave envelope as opposed to the Euro. On high resolution satellite you can see that the center is reforming under the convection.

[cycloneye]

AL, 09, 2022092312, , BEST, 0, 141N, 694W, 30, 1006, TD

https://ftp.nhc.noaa.gov/atcf/btk/bal092022.dat

[T-man]

Good morning, S2K regulars. Watching anxiously here in bayou country Louisiana. Won't relax much until Sunday, I have a feeling this will track close enough to the Yucatan peninsula to escape right through the opening into the GOM. Could be a major brewing. Will it feel the trough and get picked up? Let's see if it gains some latitude today. I should change my name to Sir Lurksalot, going back under my rock,

[AJC3]

This illustrates what I think is and will be occurring today. If you look at that eddy (yellow dot) on vis satellite, it's actually moving NNW. Because it's moving away from the deep convection, it's unlikely to survive. You'll also notice the overall circulation is becoming distorted/elongated E-W, with some tightening curvature near the orange dot. This appears to me as if it might be a new center trying to form via VHT and CISK. It may not form in that exact location, but I think it'll contribute to the vorticity pocket shifting or propagating downshear (westward) today. Whatever the case, don't look for any RI of this system in the immediate future.

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

What it’s doing you say seems to be based on visual observations but lack any atmospheric conclusions as we are very far out from basing any clear direction at this point. A strong dipping trough will have much more impact in my opinion than any short term wobble etc.

I said as much in a post earlier this morning...

Welp, another related issue seems to have reared its head. Based on the the last few hours of 3.9UM IR and vis imagery, it appears that the erstwhile "well defined" center has degenerated into multiple smaller eddies, one of which you can see rotating northward in some of the post-sunrise vis imagery posted above by Mark. This is a product of the high shear displacing the convection (and thus the latent heat release) downshear of said LLC. IMO this would support the likelihood of one or more downshear center reformations today. We'll see if this comes to fruition.

And if this were to happen would that make it eject more quickly to the east or track further to west?

In the short term, of course more westward. Probably in the longer term as well, but that depends more on the amplitude/position/orientation of the trough that's forecast to turn this N and NE. Still a long way to go to speculate too much on this.

[ScottNAtlanta]

High resolution satellite
https://weather.cod.edu/satrad/?parms=m ... =undefined

[wxman57]

I'd say this is a win for the GFS as it has been predicting that the center would end up on the southern side of the wave envelope as opposed to the Euro. On high resolution satellite you can see that the center is reforming under the convection.

BIG loss for the GFS. It won't stall off the Louisiana coast for days or make landfall in Lake Charles, as it predicted yesterday. GFS has consistently been the worst model to follow.

[Iceresistance]

First ADT on TD 9

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 23 SEP 2022 Time : 130020 UTC
Lat : 14:08:49 N Lon : 69:17:25 W


CI# /Pressure/ Vmax
2.2 / 1008mb / 32kts


Final T# Adj T# Raw T#
2.2 2.2 2.2

Center Temp : +17.6C Cloud Region Temp : 5.4C

Scene Type : SHEAR (0.72^ TO DG)

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : N/A
- Environmental MSLP : 1010mb

Satellite Name : GOES16
Satellite Viewing Angle : 17.9 degrees

[wxman57]

Good morning, S2K regulars. Watching anxiously here in bayou country Louisiana. Won't relax much until Sunday, I have a feeling this will track close enough to the Yucatan peninsula to escape right through the opening into the GOM. Could be a major brewing. Will it feel the trough and get picked up? Let's see if it gains some latitude today. I should change my name to Sir Lurksalot, going back under my rock,

You will definitely be fine in Lafite. Strong west to east jet stream across the northern Gulf won't let it come to Louisiana.

[tolakram]

saved loop

[ScottNAtlanta]

I'd say this is a win for the GFS as it has been predicting that the center would end up on the southern side of the wave envelope as opposed to the Euro. On high resolution satellite you can see that the center is reforming under the convection.

BIG loss for the GFS. It won't stall off the Louisiana coast for days or make landfall in Lake Charles, as it predicted yesterday. GFS has consistently been the worst model to follow.

Not in terms of where it initialized. Track...not so much, but I think Euro is too far east, but looking at the model tracks this morning (with all caveats that come with long range) This sure is looking like a Donna type track. JB must be having fits.

[toad strangler]

I'd say this is a win for the GFS as it has been predicting that the center would end up on the southern side of the wave envelope as opposed to the Euro. On high resolution satellite you can see that the center is reforming under the convection.

BIG loss for the GFS. It won't stall off the Louisiana coast for days or make landfall in Lake Charles, as it predicted yesterday. GFS has consistently been the worst model to follow.

Not in terms of where it initialized. Track...not so much, but I think Euro is too far east, but looking at the model tracks this morning (with all caveats that come with long range) This sure is looking like a Donna type track. JB must be having fits.

This is forming in area some call the "Carla Cradle" (Hurricane Carla 1961) - Josh Morgerman uses this term with affection lol.

Carla hit much further west though in mid TX and a couple weeks earlier than now but TD 9 is in the same local area as the fledgling Carla in her Cradle.

[SFLcane]

Good morning, S2K regulars. Watching anxiously here in bayou country Louisiana. Won't relax much until Sunday, I have a feeling this will track close enough to the Yucatan peninsula to escape right through the opening into the GOM. Could be a major brewing. Will it feel the trough and get picked up? Let's see if it gains some latitude today. I should change my name to Sir Lurksalot, going back under my rock,

You will definitely be fine in Lafite. Strong west to east jet stream across the northern Gulf won't let it come to Louisiana.

Wxman57, If your track plans out give or take i always plan for 1 category higher i would assume there will be wide spread power outges all across Sfl?

[Fishing]

Those 35-40kt SFMR all look suspect. Organization barely qualifies as a depression this morning (naked swirl moving away from the convection), but the NHC wanted to start advisories today. This isn't a TS. It's a poorly-organized depression, if that. Wait for the shear to drop off tomorrow afternoon. Back to my advisory. Striking near Ft. Myers Tuesday night as an 85kt hurricane (Cat 2). Watch out Carolinas, it may be stronger once it passes Florida.

Watch out Carolinas , I’m in Mount Pleasant outside Charleston . Guess we need to fill those gas cans or is it safe to wait sitting where we are?


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