ATL: HELENE - Post-Tropical - Discussion

[Pipelines182]

What's the implications of a delayed landfall, further east or west?

[ScottNAtlanta]

You can't say its good news at this time. The NHC says future track adjustments may be made in later cycles.

for now it is good news for us at least

The cone is completely irrelevant as far as potential impacts. The cone is the same for every storm, every advisory, no matter the confidence level or the storm size. In this case strong TS and even hurricane wind will extend outside that cone. Some good news for the western FL Peninsula is that the new ICON run is a bit farther west of Tampa. That would keep Tampa out of sustained hurricane force wind, but he area may still see wind gusts 70-85 mph.

The local met discussion indicates they will be issuing a Tropical Storm Watch for the Atlanta Metro when we get within the timing for it

[TomballEd]

Re: Max surge into the Florida Big Bend and Tampa Bay. I see 5 feet possible in Tampa Bay. Dr. Tang is at U-Albany, which seems to produce more than its share of good mets.

 https://x.com/btangyWx/status/1838615817044308325

[Frank P]

There is the little HT firing on the NE, center at 19.3n and 84.5w

[cycloneye]

A nascent burst.

[Hypercane_Kyle]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

[Ubuntwo]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

The GFS since 18z yesterday has been showing some shear around this period into the Yucatan passage crossing. NHC says shear is starting to let up now, you can see the high clouds are no longer soaring to the northeast on popup convection.

[ScottNAtlanta]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

I respectfully disagree on that one. There is very little shear over the storm right now. Looking at WV you see no shear currently

[3090]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

And thus why they are the world’s best at specifically what they are tasked with.

[3090]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

I respectfully disagree on that one. There is very little shear over the storm right now. Looking at WV you see no shear currently

Light shear but ingesting some drier air.

[emeraldislenc]

I think the air is plenty moist.

[ScottNAtlanta]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

I respectfully disagree on that one. There is very little shear over the storm right now. Looking at WV you see no shear currently

Light shear but ingesting some drier air.

Not really any dry air showing up on WV either. Sometimes it just takes more time for these large systems to pull it all together. It will happen with a little more time. Patience grasshopper, patience.

[xironman]

As others have mentioned a meso starting to circle an nascent eyewall

[Pipelines182]

A nascent burst.

https://i.imgur.com/nfWQBvp.png

That's the very first convective burst I've seen associated with the LLC, if Helene can keep these coming we may be on to something.

[psyclone]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

I really expected a lot more by this point. A naked swirl was not on my bingo card today. The system still looks like complete mess

[Weatherboy1]

I think this erratic short-term movement is actually LIKELY the pre-cursor to the turn. Prior dominant steering force (high N/NE of Florida) giving way to the next dominant steering force (low over AR/SE US), which will take over soon. IF I'm right, we're going to see a turn well before the Yucatan, which could have implications for future landfall point. We'll see.

[Blown Away]

12z GFS tracked that little exposed eddy/LLC and moved it WSW to W for next @18 hrs. The cloud mass continues to move to NW, this has to be the point where a new LLC could reform and change the track models like the GFS have been showing and NHC mentioned as a possibility at 11am.

[ScottNAtlanta]

I still don't think that's the main center. It looks like it is starting to move east indicative of a rotating center

[Frank P]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

I really expected a lot more by this point. A naked swirl was not on my bingo card today. The system still looks like complete mess

Sure looks to me that it's pulling all that convection from the east and SW towards that center..

[psyclone]

Shear is still absolutely ripping over Helene. I don’t think this was well forecast at all by the models. If it can’t establish an inner core and then hits the Yucatán, the bar for intensity will be much lower and more in line with the current NHC forecast.

I really expected a lot more by this point. A naked swirl was not on my bingo card today. The system still looks like complete mess

Sure looks to me that it's pulling all that convection from the east and SW towards that center..

Probably a situation of delayed but not denied