ATL: HELENE - Post-Tropical - Discussion

[jlauderdal]

I'd pay close attention to the ICON model. It did better than any other model for Beryl an Francine. It takes the center pretty close to Tampa on Thursday. Close enough for near hurricane force wind and a 10-12 ft surge.

ICON and a wobble and you have an eyewall into Tampa, Francine hugged the right side into NO, different storm but have to be ready for these situations.

[Pipelines182]

Plenty of west winds to define the center

There were plenty of west winds yesterday, the circulation has been closed for a long time, just broad and naked. I'm assuming the NHC is waiting for some actual convection over the center or at least close to it, once that happens (could be happening now?) I think we'll see Helene.

[cycloneye]

 https://x.com/NDGMETCHEF/status/1838566766630314263

[cycloneye]

 https://x.com/KeviShader/status/1838570775910949051

[Steve]

The upper low is now NW of the Yucatan with some trailing energy. It should deflect some of the outflow influence from John seen at the bottom left of the view. 9 is likely to feed off some of this if it establishes that Pacific Channel.

https://www.tropicaltidbits.com/sat/sat ... uct=wv_mid

Take it a little farther out to the W Atlantic view and you can see the future pattern reversal. Should be good upper support almost to the coast. Not sure how far right it can get with that ridge off the coast meaning I don't think it will go offshore of the east coast of Florida. But it still can come in anywhere.

https://www.tropicaltidbits.com/sat/sat ... uct=wv_mid

[3090]

Tapping fingers....awaiting a wxman57 post... Tell me I'm not the only one...

Edit to state I see he just posted...me no likey that one

The other day he said CAT2 into the Apalachicola area. What is his thoughts now? CAT5 into where?

[jlauderdal]

The upper low is now NW of the Yucatan with some trailing energy. It should deflect some of the outflow influence from John seen at the bottom left of the view. 9 is likely to feed off some of this if it establishes that Pacific Channel.

https://www.tropicaltidbits.com/sat/sat ... uct=wv_mid

Take it a little farther out to the W Atlantic view and you can see the future pattern reversal. Should be good upper support almost to the coast. Not sure how far right it can get with that ridge off the coast meaning I don't think it will go offshore of the east coast of Florida. But it still can come in anywhere.

https://www.tropicaltidbits.com/sat/sat ... uct=wv_mid

WV doesn't get enough love. Look at the trough digging. For days, we have waited to see where it would set up and how sharp. It is still developing, but you could not look at a model the next couple of days and put together a good track with just the WV. Keep your fingers crossed, Tampa and points south.

[CronkPSU]

Tapping fingers....awaiting a wxman57 post... Tell me I'm not the only one...

Edit to state I see he just posted...me no likey that one

The other day he said CAT2 into the Apalachicola area. What is his thoughts now? CAT5 into where?

he said to keep a close eye on the ICON model

https://www.tropicaltidbits.com/analysis/models/?model=icon

[NAVAIDNICK]

Just for fun, I went back and did some research on Hurricane Ian. Around 48-60 hours before it made landfall near Fort Myers, the NHC had it making landfall some 150 miles north around the Pinellas/Pasco border. In fact, most all the models had it going right through Tampa Bay with hardly any going through Fort Myers. It didn't change until it officially made that right turn earlier than expected and it was a harder right turn than they thought.

And I know Charley did the same thing with a less turnaround time but I brought up Ian because modeling and forecasting is supposed to be so much better in the 2020s than 2000s and it's more recent.

So things can still change a lot either direction and I wouldn't be shocked if they do.

I vividly remember this. I'm in south Sarasota County, and I recall authorities issuing the evacuation order in Tampa just over 24 hours before Ian made landfall. Wxman57 had predicted a sharper right turn at least a day before the evac order, so I took it seriously and prepared for the worst. Sure enough, that's exactly what happened. Now, whenever a storm threatens the west coast of FL, I always check what Wxman57 has to say. His opinion is gold to me. Thanks to his analysis and insights from people like you, those of us who consider ourselves weather "enthusiasts" (not full-blown nerds) have learned so much. I can't thank y'all enough!

[wxman57]

I see a lot of talk about the right hooks many storms make on approach to landfall along the west coast of Florida and the Big Bend. I was thinking that was likely to occur too; however, one item sticks out as a difference to those situations. The upper low over the southeast is going to impart a NW motion after landfall. A right hook followed by a left hook means I think the track forecast could more likely error in either direction versus the normal trough pulling the storm northeast.

That is true. The storm will be steered by the upper low over Arkansas Wednesday that is moving SW. That will result in a gradual turn to the NW Thursday night/Friday. Uncertainty is how close to Tampa will it pass Thursday morning before the more northerly track?

[DunedinDave]

I don’t know how many remember Hurricane Maria here, but it took 48 hours to go from a weak TS to a category 5 monster. And this water is warmer than what Maria went through.

Katrina is another good example. It went from a weak TS leaving the Florida coast to a 175mph storm within 48 hours.

So for anyone who says it doesn’t have time to get to cat 4 or higher status, I’d say that history would disagree with you.

[Pipelines182]

I don’t know how many remember Hurricane Maria here, but it took 48 hours to go from a weak TS to a category 5 monster. And this water is warmer than what Maria went through.

Katrina is another good example. It went from a weak TS leaving the Florida coast to a 175mph storm within 48 hours.

So for anyone who says it doesn’t have time to get to cat 4 or higher status, I’d say that history would disagree with you.

the rule of thumb I generally have in my head is that if there's at least 48 hours, hot water, no shear, organized system, no dry air, cat 5 is the ceiling. I believe Beryl went from TS to Cat 5 in just 42 hours this year.

[Powellrm]

The ICON has really caught my attention over the last few years. Has a history of being ahead of the curve and sticking to it's guns. ICON has had some really sharp calls. I need to learn more about the ICON.

[DunedinDave]

I see a lot of talk about the right hooks many storms make on approach to landfall along the west coast of Florida and the Big Bend. I was thinking that was likely to occur too; however, one item sticks out as a difference to those situations. The upper low over the southeast is going to impart a NW motion after landfall. A right hook followed by a left hook means I think the track forecast could more likely error in either direction versus the normal trough pulling the storm northeast.

That is true. The storm will be steered by the upper low over Arkansas Wednesday that is moving SW. That will result in a gradual turn to the NW Thursday night/Friday. Uncertainty is how close to Tampa will it pass Thursday morning before the more northerly track?

I think that’s what makes this storm so hard to predict. Just seems like so many turns in 36-48 hour window. We’ve seen that the timing of just one turn can change everything (I.e. Ian and Irma) and this thing is forecast to have a few of them. It’s supposed to change from WNW to N to NE and then back to NNE or N all in a 36-hour window. That’s crazy.

[3090]

I don’t know how many remember Hurricane Maria here, but it took 48 hours to go from a weak TS to a category 5 monster. And this water is warmer than what Maria went through.

Katrina is another good example. It went from a weak TS leaving the Florida coast to a 175mph storm within 48 hours.

So for anyone who says it doesn’t have time to get to cat 4 or higher status, I’d say that history would disagree with you.

I dont think any of the NHC folks saying it cannot reach CAT4/5 status. Just that at this time it is not in the forecast. Things can and do change. Just be prepared is the understatement.

[kevin]

Wxman is one of the forum's most experienced and knowlegable members. Thank you for all your valuable contributions. I guess his years of experience have made him a bit more conservative regarding storm intensity compared to others on the forum (like me ). Because of this, whenever he does put out concerning messages or warnings regarding a TC I'm immediately on high alert. We all know what happened to Ian's east shifts, it doesn't take much for this to change to a MH storm surge event for Tampa.

[cycloneye]

Center looks to be relocated under the convection.

[Michele B]

12z Best Track has no upgrade to TD or TS, but the presure is down to 1000 mbs.

AL, 09, 2024092412, , BEST, 0, 194N, 837W, 30, 1000, DB

At this point the delayed TD/TS designation might actually give NINE the possibility to compete for some of the Atlantic all-time intensification records. TD to C5 seems like the most realistic one (if NINE reaches that intensity at all). The other Wilma records feel like they're out of reach, what an unbelievable storm that was.

Fastest intensification from a TD to a hurricane = 12 hours (Harvey 1981)
Fastest intensification from a TD to a C5 hurricane = 54 hours (Wilma 2005, Felix 2007)
Fastest intensification from a TS to a C5 hurricane = 24 hours (Wilma 2005)
Maximum pressure drop in 12 hours = 83 mbar (Wilma 2005, 975 mbar -> 892 mbar)
Maximum pressure drop in 24 hours – 97 mbar (Wilma 2005, 979 mbar -> 882 mbar)

Is there a category for how long a PTC takes to become a named storm?!?! I think NINE is in the running for this award.

[beachnut]

Tapping fingers....awaiting a wxman57 post... Tell me I'm not the only one...

Edit to state I see he just posted...me no likey that one

The other day he said CAT2 into the Apalachicola area. What is his thoughts now? CAT5 into where?

he said to keep a close eye on the ICON model

https://www.tropicaltidbits.com/analysis/models/?model=icon

Ok, I put my eye on it ... this is not what the local mets are saying In the meantime I continue to prep for that just in case.

[SoupBone]

I see a lot of talk about the right hooks many storms make on approach to landfall along the west coast of Florida and the Big Bend. I was thinking that was likely to occur too; however, one item sticks out as a difference to those situations. The upper low over the southeast is going to impart a NW motion after landfall. A right hook followed by a left hook means I think the track forecast could more likely error in either direction versus the normal trough pulling the storm northeast.

That is true. The storm will be steered by the upper low over Arkansas Wednesday that is moving SW. That will result in a gradual turn to the NW Thursday night/Friday. Uncertainty is how close to Tampa will it pass Thursday morning before the more northerly track?

With that eventual left turn, I'm curious how close this gets to Atlanta, and how much punch she will still be packing at that time. Atlanta doesn't really do well with tropical systems. This isn't to take away from the immediate Florida threat, just something I've been thinking about with that NW trajectory after landfall.