ATL: HELENE - Post-Tropical - Discussion

[Travorum]

This is about 6 hours old because my normal microwave data source is offline and I missed this one, but it looks like the structure under the hood has been developing:

[Pipelines182]

Looking at the IR right now and this latest convective burst looks nuts. Seems the pink cloud tops have given way as if the eye is clearing rapidly. What is going on LOL?

There is no eye, the center isn’t even in that convective burst

[Hurricane Mike]

11:30pm Video on Helene
https://www.youtube.com/watch?v=HvD91NN-bfY

[Xyls]

Looking at the IR right now and this latest convective burst looks nuts. Seems the pink cloud tops have given way as if the eye is clearing rapidly. What is going on LOL?

There is no eye, the center isn’t even in that convective burst

I didn't think it was that's why the IR presentation looks crazy lol.

[MGC]

All systems go for intensification. Might have some dry air issues in the short term. Thinking Helene will approach or meet Cat-4 intensity. Gonna be a bad one.....MGC

[weeniepatrol]

A look at the TDR center fix data provides good insight into the up-and-down pressure readings at buoy 42056 earlier this evening. You can see over the first three passes that the LLC is wobbling around the rough location of the buoy (19.82N 84.98W):
https://i.imgur.com/B9tj4vE.png

I'm a bit confused.. from the 11pm advisory:

Helene continues to become better organized with increased
convective banding features and an overall more symmetrical-looking
cloud pattern. The convection is very deep with cloud tops to -80
deg C or colder. Doppler velocity data from a NOAA Hurricane
Hunter aircraft indicate no significant vertical tilt of the
vortex in the low- to mid-troposphere. This suggests that the
vertical wind shear is low. Earlier flight-level wind data from the
aircraft indicate the the maximum winds are near 50 kt, although
this may be conservative.

This is saying that the vortex is stacked vertically, which is a prerequisite to any significant strengthening event, as is currently expected.

But TDR data showed that the vortex is not stacked vertically, per the graphic below



I am not saying NHC is wrong, I am just clarifying why I was confused.

[grapealcoholic]

possiblly a center reloaction or the LLC gets dragged north

[AnnularCane]

They said they will watch my house while they are cooking out.

I pretty much facepalmed when I read that.

[Teban54]

So "center relocation" is becoming the new "annular" and "EWRC"?

[BobHarlem]

[Kazmit]

So "center relocation" is becoming the new "annular" and "EWRC"?

Dry slot or eye forming?

[Jag95]

Looking at the IR right now and this latest convective burst looks nuts. Seems the pink cloud tops have given way as if the eye is clearing rapidly. What is going on LOL?

There is no eye, the center isn’t even in that convective burst

I didn't think it was that's why the IR presentation looks crazy lol.

Cancun radar does look like an eyewall trying to wrap up.
https://www.accuweather.com/en/mx/canc% ... 35049_1_al

[cheezyWXguy]

So "center relocation" is becoming the new "annular" and "EWRC"?

I do feel like this system makes you question though. The displacement between the mlc and llc, the offset of the llc from convection despite the reduction in shear (radar suggests this too), and the lack of a developing core around the llc found by recon do kind of raise some questions. That said, whether it genuinely relocates or just gets sucked under the convection seems like a moot point by now, it looks like it’s intensifying again.

[Pipelines182]

So "center relocation" is becoming the new "annular" and "EWRC"?

Dry slot or eye forming?

Pinhole eye alert?

[Xyls]

Lightning definitely picking up in what I now assume is the CDO. Think we are starting the main intensification phase. Gotta go to bed will be interested to see the presentation tomorrow morning.

[Beef Stew]

The aspect that may ultimately cap Helene's ceiling may also be the one that makes it such a potentially impactful storm- her massive windfield. I wouldn't be surprised if we end up seeing something akin to Ike at landfall- a large, sprawling hurricane with substantial winds, but catastrophic surge and widespread inland damage covering a broad area.

[REDHurricane]

Well I'll be dadgummed, am I looking at -95ºC cloud tops here??

[grapealcoholic]

HAFS-B has the center moving due north next few hours.. possibly to align with convection

[Poonwalker]

That’s wrapping around for sure. Theres no doubt it’s on an intensification burst right now. I don’t see the dry slot anymore on the WV imagery.

[CrazyC83]

Well I'll be dadgummed, am I looking at -95ºC cloud tops here??

https://i.ibb.co/YWK8Wf5/c4f60292-b838-45af-be7a-201ae95e1191.jpg

That's almost unheard-of in the Atlantic. Even in the WPAC that would be on the high end.