ATL: IAN - Post-Tropical - Discussion

[Iceresistance]

This system must be absolutely ready to RI if it was not for the Northerly Wind Shear. But it's still producing very intense convection despite being somewhat displaced to the south to southwest.


https://s4.gifyu.com/images/39217846.gif

[cane5]

New one on me, and I'm iffy on whether it's "a thing", but now I want to see something similar for Louisiana.

Ask and you shall receive, LARanger:

[url]https://i.ibb.co/ryRX7gF/Cajun-boxes.jpg [/url]

(I think the US boundaries are a little bit off...)

As an "Hebert" living in SELA, this gave me a good chuckle. Thanks for the laugh!

BTW Andrew completely missed the boxes…

[Blown Away]

And so TD9 joins a small group of storms to have a 95 kt or higher value in their first forecast. Here are all the other storms from that list since the modern advisory archives started in 1998. Of the previous storms with such a forecast 6 of the 9 eventually became MHs. It also makes TD9 the most aggressive forecast (at least since 1998) which includes Florida in its first cone. I hope it won't be as bad as some models show, but this really shows the uniqueness of TD9. So if you're in the area that could be affected I'd highly encourage you to prepare today or tomorrow before the remaining millions of people also realize they have to prepare.

100 kt
Sam - 2021
Tomas - 2010

95 kt
TD9 - 2022
Ida - 2021
Iota - 2020
Lorenzo - 2019
Isaac - 2012
Danielle - 2010
Philippe - 2005
Karl - 2004

First thought when I saw 110 at day 5, unusual the NHC was so aggressive with first advisory. Great post!

[kevin]

Tons of 40+ kt SFMR measurements in TD9 so it certanly qualifies as a TS in that regard. The question is whether it has a well-defined center & circulation which is deemed organized enough to upgrade it already.

[cycloneye]

And so TD9 joins a small group of storms to have a 95 kt or higher value in their first forecast. Here are all the other storms from that list since the modern advisory archives started in 1998. Of the previous storms with such a forecast 6 of the 9 eventually became MHs. It also makes TD9 the most aggressive forecast (at least since 1998) which includes Florida in its first cone. I hope it won't be as bad as some models show, but this really shows the uniqueness of TD9. So if you're in the area that could be affected I'd highly encourage you to prepare today or tomorrow before the remaining millions of people also realize they have to prepare.

100 kt
Sam - 2021
Tomas - 2010

95 kt
TD9 - 2022
Ida - 2021
Iota - 2020
Lorenzo - 2019
Isaac - 2012
Danielle - 2010
Philippe - 2005
Karl - 2004

Excellent post that brings a perspective about this system that causes people to start preparations.

[jlauderdal]

Time to dust off the old login for this year

NWS Miami forecast calls for Tropical Storm conditions possible for Tuesday night

Should be an interesting weekend here in South Florida

TS winds knockout power where I live, the lines are overhead, roh roh. Filling the gas cans in the next hour, enough for 10 days, the new generator(inverter) sips gas while the old one made the gas companies some real money. I'm preparing for a major hurricane in SE Florida, hopefully, my preps are overkill.

Out here in Broward/Weston FPL has been working on the overhead main lines with improved towers as part of their multiyear hardening. Communities are all underground. Some models appear to soften onshore sw Fl to a 1 to low 2 on a NE trajectory. Publix then a refresh lube spray on the shutters over the weekend.

Our overhead lines did well in Irma and due to FPL's hardening plan, power restoration was inside of two days, wilma we were out for far longer. Have to prepare like we are going to take a direct hit. Gas, food, and water you can use later. Don't be one of those people in a huge time suck line.

[NDG]

As expected TD 9 is still getting hit with shear this morning, but by this evening SHIPS forecasts shear to drop near 10 knots, it should start the strengthening phase by then.

[Hypercane_Kyle]

Tons of 40+ kt SFMR measurements in TD9 so it certanly qualifies as a TS in that regard. The question is whether it has a well-defined center & circulation which is deemed organized enough to upgrade it already.

That's not in question. It's already a TD, so if TS winds are found, they'll upgrade to TS Hermine.

[Iceresistance]

VDM on TD 9 from AF306

VORTEX DATA MESSAGE AL092022
A. 23/11:02:30Z
B. 13.92 deg N 069.27 deg W
C. 925 mb 743 m
D. EXTRAP 1007 mb
E. NA
F. NA
G. NA
H. NA
I. NA
J. 112 deg 33 kt
K. 032 deg 108 nm 10:33:30Z
L. NA
M. NA
N. 264 deg 25 kt
O. 227 deg 27 nm 11:10:00Z
P. 20 C / 771 m
Q. 22 C / 764 m
R. 18 C / NA
S. 134 / 9
T. 0.02 / 7 nm
U. AF306 0209A CYCLONE OB 02
MAX FL WIND 33 KT 032 / 108 NM 10:33:30Z
SLP EXTRAP FROM 925 MB
MAX FL TEMP 23 C 018 / 41 NM FROM FL CNTR
VISUAL MAX SFC WINDS 30 KTS NE QUAD

[blp]

Time to dust off the old login for this year

NWS Miami forecast calls for Tropical Storm conditions possible for Tuesday night

Should be an interesting weekend here in South Florida

TS winds knockout power where I live, the lines are overhead, roh roh. Filling the gas cans in the next hour, enough for 10 days, the new generator(inverter) sips gas while the old one made the gas companies some real money. I'm preparing for a major hurricane in SE Florida, hopefully, my preps are overkill.

I am in the same boat overhead lines and lose power always. How many gallons you got stocked up? I still need to fill a few more cans today.

[aspen]

Tons of 40+ kt SFMR measurements in TD9 so it certanly qualifies as a TS in that regard. The question is whether it has a well-defined center & circulation which is deemed organized enough to upgrade it already.

That's not in question. It's already a TD, so if TS winds are found, they'll upgrade to TS Hermine.

There are finally some TS flight level winds south of the center, displaced from the convection. Might be enough for an upgrade.

[tolakram]

saved loop


floater: https://weather.cod.edu/satrad/?parms=meso-meso1-02-96-1-100-1&checked=map&colorbar=undefined

[AJC3]

'The center hasn't even formed yet' talk is quickly on its way to becoming null and void from here on out. In fact, this morning's scatterometer data (13Z-14Z) and satellite derived winds showed a pretty well-defined surface-850MB vorticity center that should have gone into the initialization of the 18Z model guidance, and I suspect it will be at least as well-defined in the upcoming 00Z runs. How well the model guidance initializes it is another matter, however we're at the point now where we have a decent LL center fix to work with.

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.

[caneman]

'The center hasn't even formed yet' talk is quickly on its way to becoming null and void from here on out. In fact, this morning's scatterometer data (13Z-14Z) and satellite derived winds showed a pretty well-defined surface-850MB vorticity center that should have gone into the initialization of the 18Z model guidance, and I suspect it will be at least as well-defined in the upcoming 00Z runs. How well the model guidance initializes it is another matter, however we're at the point now where we have a decent LL center fix to work with.

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?

[AJC3]

'The center hasn't even formed yet' talk is quickly on its way to becoming null and void from here on out. In fact, this morning's scatterometer data (13Z-14Z) and satellite derived winds showed a pretty well-defined surface-850MB vorticity center that should have gone into the initialization of the 18Z model guidance, and I suspect it will be at least as well-defined in the upcoming 00Z runs. How well the model guidance initializes it is another matter, however we're at the point now where we have a decent LL center fix to work with.

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.

[TheHurricaneGod]

The center appears to be wobbling due NW the past few frames. This would have an impact on future track. More north wobbles and this ends up more of an east coast threat.

[otowntiger]

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.

sooo…. Westward shifts in modeling could be in the offing for later today?

[ColdMiser123]

Recon found peak FL wind of 38 kt, as well as plenty of unflagged 40 kt SFMR. In the outer vortex this flight level wind converts to below TS intensity, so that might be what the NHC goes with since SFMR may run high here.

[wxman57]

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.

[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.