ATL: FLORENCE - Post-Tropical - Discussion

[PandaCitrus]

We could wake up tomorrow morning to yet another eyewall replacement cycle that ends with a 50+ mile wide eye and more wind field expansion.

 https://twitter.com/pppapin/status/1039680417928900608

[wx98]

I recall Irma last year going through multiple EWRCs in a 24-36 hour period, it's just that Irma was such a monster that it maintained a ridiculous intensity throughout the process.

Not really, at least in the short term. Some slight mid-level shear right now that's probably causing a little dry air to wrap into the core associated with a dissipating low-level trough off the states, however that will lessen and tomorrow will be prime intensification. Recon continues to support a Cat 4.

Not that pass SFMRs only as high as 105 kt and the reduction from FL only yields about 113 kt.

... which is Cat 4 intensity.

Oh I'm aware, but it's by like 2 kts of wind. But maybe they haven't found the strongest winds yet. Will wait for next pass.

[ConvergenceZone]

Well tomorrow is definitely the deadline for intensification, and I think if I read the NHC discussion correctly, the slow weakening trend should begin by tomorrow night.......So probably about 18 to 20 hours left for potential strengthening before the slow weakening phase begins.

[Aric Dunn]

hurricane force winds extend 42 miles to the SW of the center. and well over a 100 miles NE of the center..

[MississippiWx]

Would be odd for there to be another EWRC with such a large eye in place. Normally, the eye contracts a bit before having a new replacement cycle.

[tolakram]

Can dry air ingestion initiate an ERC?

Yes,

Within my years of watching these I can clearly say without a doubt that dry air causes a unlimited number of these.

Ike 2008
Rita 2005
Frances 2004

For a few examples.

I don't know of any science that describes exactly what causes an ERC.

https://en.wikipedia.org/wiki/Eyewall_replacement_cycle

Do you know of any?

[jlauderdal]

It appears to be re-organizing, no reason to think a decrease intensity is going to last, strong 4 maybe 5 tomorrow then all eyes turn to the track because the modeling is sketchy beyond 36 hours..its turning into a nowcast starting tomorrow night

With a pressure that low if the max winds have come down the windfield has likely expanded so pick your poison. One way or another there's a price to be paid. I would only take comfort if recon showed a persistent increase in pressure.

[PandaCitrus]

This wind field expansion is going to dramatically increase the storm surge risk.

[psyclone]

hurricane force winds extend 42 miles to the SW of the center. and well over a 100 miles NE of the center..

that would generate crushing surge and battering waves over a huge stretch of coastline

[Hammy]

IR looks remarkably close to what the models indicated it would a few days ago.

[CrazyC83]

This wind field expansion is going to dramatically increase the storm surge risk.

Both spatially and in magnitude. I'd be upping the numbers especially in Hampton Roads.

[BobHarlem]

From the Area Forecast Discussion out of Wilmington:

"This will likely be the storm of a lifetime for portions of the
Carolina coast, and that`s saying a lot given the impacts
we`ve seen from Hurricanes Diana, Hugo, Fran, Bonnie, Floyd,
and Matthew. I can`t emphasize enough the potential for
unbelievable damage from wind, storm surge, and inland flooding
with this storm."

[NDG]

Based on SFMR Hurricane force winds have expanded to around 100 miles in diameter, per my calculations.

[drezee]

Windfield has expanded though...

Do you all realize that recon is showing 80 miles of cat2 flight level winds!!! That is a huge wow from the EWRC...not good for storm surge

Recon has been in hurricane force flight level winds for 40 mins+

[drezee]

Based on SFMR Hurricane force winds have expanded to around 100 miles in diameter, per my calculations.

Yes and Cat2 flight level beyond that...gusts to hurricane force for sure...

[TexasSam]

I hope they don't have deal with the huge storm surge that we got from Ike.

[gfsperpendicular]

Windfield has expanded though...

Do you all realize that recon is showing 80 miles of cat2 flight level winds!!! That is a huge wow from the EWRC...not good for storm surge

Recon has been in hurricane force flight level winds for 40 mins+

Unbelievable. And yet another EWRC is about to start; storm surge risk could be terrible.

In Hampton Roads, they are not very prepared to evacuate for storm surge. I hope it doesn't come to that.

[GeneratorPower]

I wonder if we will get some live storm surge video this time around. It’s so hard to really stream live surge because it’s so dangerous. If we could see it live I think people would take it more seriously.

[tolakram]

With these closeups sometimes we lose sight at how big these storms can get. The eye is bigger than a city (Cincinnati anyway).

[1900hurricane]

Based on recent microwave imagery, it wouldn't surprise me if the NW quad housed the strongest winds right now.