ATL: HELENE - Post-Tropical - Discussion

[cycloneye]

[url]https://i.postimg.cc/15QykB04/IMG-0301.jpg [/url]
06z
[url]https://i.postimg.cc/ydpSf53J/IMG-0300.jpg [/url]
00z

06z estimated “L” repositioned @60 miles E of 00z… I still think @degree E of that is where the LLC will setup…

There is the whole best track and the NE shift at 06z.

[3090]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

[underthwx]

Tampa forecast discussion.........National Weather Service Tampa Bay Ruskin FL
321 AM EDT Mon Sep 23 2024

...THERE IS A HIGH CHANCE OF TROPICAL CYCLONE DEVELOPMENT THIS
WEEK, NOW IS THE TIME TO ENSURE HURRICANE PLANS ARE IN PLACE...

.SHORT TERM...
(Now through Tuesday)
Issued at 321 AM EDT Mon Sep 23 2024

* Key Point: Mostly quiet weather today and tomorrow with just a few
storms across the southern interior and SWFL.

A sprawling ridge axis is situated over the Western Gulf with weak
surface high pressure dominant across the SE and Gulf Coast regions.
In response to this upper-level ridge, a northerly upper-level flow
is advecting a continental airmass across the region. Thus, mid and
upper-level dry air remains persistent across the region, with very
few clouds even of note. There is also subsidence suppressing
overall instability. This means that conditions - for most - are
favored to be warm and sunny, with a light easterly surface flow.

However, there does look to be enough moisture and instability over
the southern interior and SWFL to perhaps support a few isolated to
scattered thunderstorms late this afternoon. While ridging remains
dominant, there is a weak trough feature over Florida, associated
with a remnant frontal boundary that pushed through. This
combination could be just enough late today for storms, especially
as the sea breeze tries (rather unsuccessfully given the prevailing
10 kts of easterly flow) to form late this afternoon and evening.
What storms do form, will probably be low-topped and short-lived in
an environment that is not particularly conducive.

Tuesday is not shaping up to be much different, but the gradient
does begin to tighten as the ridge axis is eroded from the north by
a digging trough and from the south by a developing tropical system.
An easterly flow looks to prevail in response, but becomes stronger
with the tightening gradient. A late day surge in PWATs will again
be in place to support a few storms late in they day across the
southern interior and SWFL.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 321 AM EDT Mon Sep 23 2024

What We Know:

* There is a 70% chance that a tropical system will develop in the
next 48 hours and a 90% chance that a tropical system will develop
this week.

* The system is forecast to strengthen while moving northward over
the Gulf of Mexico. There is the potential for storm surge, heavy
rainfall, and strong winds across portions of our area.

* Dangerous marine conditions are expected. High seas offshore,
large breaking waves at beaches, and a high risk of rip currents
will accompany this system.

What We Don`t Know:

* The exact magnitude of impacts. This will become more clear in
the next 24 to 48 hours.

* Track and intensity specifics. Reconnaissance aircraft flights
later today and over the next few days, along with extra weather
balloon releases for offices along the Gulf coast will provide
more insight. These items will ramp up today and into tonight.

There is a lot of uncertainty in the extended range as a tropical
system lifts northward into the Gulf of Mexico. These discrepancies
will have a significant impact on exactly what conditions are
realized across West Central and SWFL. However, confidence is
increasing in a tropical system moving into the Gulf and
facilitating an environment conducive storm surge, heavy
rainfall, and strong winds, along with poor marine and beach
conditions. The worst of the weather appears to take place between
late Wednesday and early Friday.

It is important to continue monitoring the forecasts from the
National Hurricane Center as well as from local NWS Offices. Now is
a great time to ensure hurricane plans are in place. More specifics
are likely to be flushed out in the next 24 to 48 hours as
additional data becomes available and the storm system begins to
become better organized.

As the system clears the Gulf region by late week and into the week,
the forecast gradually returns to a more typical late summerlike
pattern. However, the moisture pulled northward by the system may
linger. It also looks like a WSW flow will be dominant through the
weekend. Thus the combo supports decent rain chances and an overall
warm and muggy pattern to take us into next week.

&&

[Blown Away]

[url]https://i.postimg.cc/15QykB04/IMG-0301.jpg [/url]
06z
[url]https://i.postimg.cc/ydpSf53J/IMG-0300.jpg [/url]
00z

06z estimated “L” repositioned @60 miles E of 00z… I still think @degree E of that is where the LLC will setup…

There is the whole best track and the NE shift at 06z.

https://i.imgur.com/j4SS8Ek.png

Where this LLC sets up in the next 24-36 IMO will determine the fate of the down the road landfall… Any farther E or NE shifts will likely bring 97L over W Cuba then points Tampa S are likely… Current position points from Tampa to Panhandle are likely…

Currently I don’t see much signs near 06z position of 16N/82W and the energy is just ENE of this position… JMHO

[underthwx]

Here's a point to remember yall...."Once 97L gets
picked up by the upper low, it will move to the north very
quickly. While this is good news from an impacts standpoint (as
the storm is not going to linger around for multiple days), this
will leave very little time for preparations, especially if one is
waiting for the system to develop and acquire a name/cone/etc".......from Mobile Forecast Discussion

[wxman57]

For now, I have landfall northern Apalachee Bay Thursday afternoon. Moving north at 20 kts at landfall. Lots of SW shear across northern Gulf. Initial forecast has 75 kts at landfall. Large wind field, particularly east of the center. Could produce tides 5-10 ft into Tampa - higher if the track shifts any east.

[underthwx]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

97L is under an anti cyclone which is very favorable and low shear...from the CA Gyre...thats what I read a moment ago...wdym?

[Nimbus]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

Its under an anti cyclone which is very favorable and low shear...from the CA Gyre...thats what I read a moment ago...wdym?

Don't forget the loop current energy

[underthwx]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

Its under an anti cyclone which is very favorable and low shear...from the CA Gyre...thats what I read a moment ago...wdym?

Don't forget the loop current energy

That too...wassup nimbus

[3090]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

97L is under an anti cyclone which is very favorable and low shear...from the CA Gyre...thats what I read a moment ago...wdym?

Look at the satellite imagery if you don’t understand. It is still not together. It will over time. Not currently.

[StPeteMike]

Glad to see some disorganization this morning while waking up but I doubt that will last all day. Even with the disorganization, could we still get a PTC before noon?

[cycloneye]

 https://x.com/WxPatel/status/1838173037981556790

[underthwx]

Glad to see some disorganization this morning while waking up but I doubt that will last all day. Even with the disorganization, could we still get a PTC before noon?

With recon scheduled later today....I would not be surprised to see PTC advisories begin....the data from recon will provide needed info for models....etc...

[underthwx]

For now, I have landfall northern Apalachee Bay Thursday afternoon. Moving north at 20 kts at landfall. Lots of SW shear across northern Gulf. Initial forecast has 75 kts at landfall. Large wind field, particularly east of the center. Could produce tides 5-10 ft into Tampa - higher if the track shifts any east.

Like Xman57 says....this system moving north at 20 knots will be a good thing impacts wise.....versus a slow moving system.....so that's a positive feature....I have read on forecast discussions....that the system should exit the region quickly.....so...to me...thats a silver lining.....

[GCANE]

That escalated quickly

https://tropic.ssec.wisc.edu/real-time/ ... g8vor5.GIF

[xironman]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

97L is under an anti cyclone which is very favorable and low shear...from the CA Gyre...thats what I read a moment ago...wdym?

There is still some very strong upper level winds on the northern half of the system, you can see the cirrus being ripped away NE. You can also see the convection start to refire near the center

[AutoPenalti]

https://x.com/craigsetzer/status/183817 ... 81029?s=46

[3090]

For now, I have landfall northern Apalachee Bay Thursday afternoon. Moving north at 20 kts at landfall. Lots of SW shear across northern Gulf. Initial forecast has 75 kts at landfall. Large wind field, particularly east of the center. Could produce tides 5-10 ft into Tampa - higher if the track shifts any east.

Like Xman57 says....this system moving north at 20 knots will be a good thing impacts wise.....versus a slow moving system.....so that's a positive fearure....I have read on forecast discussions....that the system should exit the region quickly.....so...to me...thats a silver lining.....

And with a fast movement that MAY inhibit rapid intensification as well. Just be prepared for an intense system and hope for a lesser one.

[3090]

Glad to see some disorganization this morning while waking up but I doubt that will last all day. Even with the disorganization, could we still get a PTC before noon?

Doubt it. Probably not until overnite tonight.

[underthwx]

Not a very favorable environment where it is currently. It is getting the tops of the tstorms blown off to tbe east. It is naked.

97L is under an anti cyclone which is very favorable and low shear...from the CA Gyre...thats what I read a moment ago...wdym?

There is still some very strong upper level winds on the northern half of the system, you can see the cirrus being ripped away NE. You can also see the convection start to refire near the center

https://i.imgur.com/2K5s2H7.gif

I do see that now....thanks for showing me this....