ATL: IAN - Post-Tropical - Discussion

[Keldeo1997]

Got a Eyewall

[Iceresistance]

https://cdn.discordapp.com/attachments/1021831616605200516/1023733344606883890/Screenshot_132.png

Got a Eyewall

Oh my goodness, that eyewall is extremely tiny!

[ThetaE]

1000x this. Shallow convection has clearly done the work of intensifying Ian into a shallow and small, but also robust, vortex.

What stands out to me is that dropsonde profiles suggests that Ian is not fully stacked (much closer than this morning), and that some of the SFMR readings are stronger than FL winds (though those readings may be rain-contaminated). This isn't because of shear, but because +PV in the mid-levels is generated by deep convection and there hasn't been enough of that to couple the mid-level wind field with the surface vortex. I really have no clue why Ian has taken so long to fire off deep convection, but it looks like it is beginning to now and so any appearance of misalignment should be taken care of in the next few hours.

 https://twitter.com/webberweather/status/1574169603147587585

[Teban54]

1000x this. Shallow convection has clearly done the work of intensifying Ian into a shallow and small, but also robust, vortex.

What stands out to me is that dropsonde profiles suggests that Ian is not fully stacked (much closer than this morning), and that some of the SFMR readings are stronger than FL winds (though those readings may be rain-contaminated). This isn't because of shear, but because +PV in the mid-levels is generated by deep convection and there hasn't been enough of that to couple the mid-level wind field with the surface vortex. I really have no clue why Ian has taken so long to fire off deep convection, but it looks like it is beginning to now and so any appearance of misalignment should be taken care of in the next few hours.

https://twitter.com/webberweather/status/1574169603147587585

I believe Webb meant "sufficient but not necessary", not "necessary but not sufficient". The latter suggests you NEED deep convection for intensification but it might not be enough, which is the exact opposite of what's happening.

[shah83]

Too me, the big and consequential aspect of finding the pressure so much lower than expected, is that this system may well get the chance to successfully conclude an EWC and get bigger and intensify further, increasing the chances of a hard cat-3+ landfall.

[Hypercane_Kyle]

Very dramatic improvements on the recon. Pressures have dropped to about 990 mb with the VDM showing an eyewall developing.

Ian is well on its way to hurricane status.

[StPeteMike]

Such a small core doesn't question the chance we could get a Cat 4 before landfall around 21.8 N/84.4 W.

[Torgo]

Sub -80 C° cloud tops starting to show up

 https://twitter.com/DSM4USA/status/1574177258633400320

[Teban54]

THERE's the big convective burst!

The eyewall was open to the W when recon made the pass. I suspect this will close off the eyewall in no time.

[ScottNAtlanta]

There is a 4 degree (C) variance in the eye temperature (in and out). When it's really ready to crank that difference will be much higher (for example it was about 10 degrees (C) when Fiona was cranking).

[InfernoFlameCat]

I think we could see extreme rapid intensification shortly. With a closed or near closed eyewall, as well as it being a pinhole, we might see something like Wilma or Delta in terms of strengthening.

[tolakram]

[Iceresistance]

I think we could see extreme rapid intensification shortly. With a closed or near closed eyewall, as well as it being a pinhole, we might see something like Wilma or Delta in terms of strengthening.

That eyewall is extremely tiny, it's just like a tornado! The tighter the pressure gradient, the faster the winds will become.

[Owasso]

[ScottNAtlanta]

I think we could see extreme rapid intensification shortly. With a closed or near closed eyewall, as well as it being a pinhole, we might see something like Wilma or Delta in terms of strengthening.

What you will probably see is an EWRC sooner rather than later. Recon said 18 miles...that's small but hardly remarkable
Wilma...fyi was 8 at it's smallest.

[aspen]

I think we could see extreme rapid intensification shortly. With a closed or near closed eyewall, as well as it being a pinhole, we might see something like Wilma or Delta in terms of strengthening.

What you will probably see is an EWRC sooner rather than later. Recon said 18 miles...that's small but hardly remarkable
Wilma...fyi was 8 at it's smallest.

Based on the microwave pass above, I think we’ll see a bit of an eyewall meld, with the W gap in the current eyewall being filled it by one of the outer bands.

[kevin]

I don't want to jump the hype bandwagon, but Ian is looking extremely primed for RI right now. Chances are it has already begun (next recon pass will indicate how fast it's deepening). Idk about Wilma-level deepening like was suggested earlier in this thread (Wilma's ERI is pretty much unique in the Atlantic basin), but I can imagine this could go Delta. Exciting hours for a hurricane watcher, but also very anxious hours for anyone in Ian's path. Stay safe everyone and prepare!

[AJC3]

C18 isn't a pinhole eye, gang.

[InfernoFlameCat]

I think we could see extreme rapid intensification shortly. With a closed or near closed eyewall, as well as it being a pinhole, we might see something like Wilma or Delta in terms of strengthening.

What you will probably see is an EWRC sooner rather than later. Recon said 18 miles...that's small but hardly remarkable
Wilma...fyi was 8 at it's smallest.

I misread the VDM. thanks. Thought it said 8

[Iceresistance]

C18 isn't a pinhole eye, gang.

A pinhole eye must have a circular diameter of less than 10 miles. This is not a pinhole eye like you mentioned, but a tiny one indeed.