ATL: HELENE - Post-Tropical - Discussion

[Frank P]

On the edge of the east side of the cone.

[kevin]

677
WTNT34 KNHC 261139
TCPAT4

BULLETIN
Hurricane Helene Intermediate Advisory Number 12A
NWS National Hurricane Center Miami FL AL092024
700 AM CDT Thu Sep 26 2024

...HELENE BECOMES A CATEGORY 2 HURRICANE WITH SIGNIFICANT
ADDITIONAL STRENGTHENING EXPECTED BEFORE LANDFALL IN FLORIDA...
...PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO
COMPLETION...


SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...24.5N 85.9W
ABOUT 320 MI...515 KM SW OF TAMPA FLORIDA
ABOUT 365 MI...585 KM S OF APALACHICOLA FLORIDA
MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H
PRESENT MOVEMENT...NNE OR 15 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...960 MB...28.35 INCHES

960 mb is a few mb lower than I saw any of the recon planes or dropsondes measure. Lowest dropsonde was 963 mb as far as I recall. Did I miss one of them or does anyone know how they probably came to that estimate?

Edit: I guess they might've used the 961.6 mb extrapolated pressure with 6 kt winds nearby by NOAA3 combined with the intensification trend.

[ScottNAtlanta]

Been checking river levels in the Atlanta Metro...it isn't going to take much and several counties are already under flood warnings and river flood warnings. Big Creek, Yellow River, and Sweetwater Creek are all going to be way over flood stage

[Cat5James]

On the edge of the east side of the cone.
https://i.ibb.co/XDcxjXK/Radar-Omega-screenshot-2024-09-26-11-40-21.png

Eastern edge of the cone would put some real nasty weather over the Tampa Bay area when extrapolated.

[jlauderdal]

VDM just came in from Miss Piggy.
The outer eyewall took over and is closed.
Doubt we will see another EWRC.
Cat 4 at landfall is probable.

F. Eye Character: Closed
G. Eye Shape & Diameter: Circular with a diameter of 36 nautical miles (41 statute miles)

The tornado threat increased significantly, thus the rare tornado watch in Florida. Good dynamics a few hundred miles away

[Laser30033003]

looks like she is a cat 2...

[Hypercane_Kyle]

Quickly on its way to major hurricane status...

[kevin]

Wow, recon measured 64 kt FL 110 nm (200 km, 130 miles) to the south of Helene. That's almost hurricane strength winds 110 nm from the center. Latest advisory by NHC had the radii below, looks like they might need to be updated soon as Helene's wind field is expanding.

64 KT....... 50NE 50SE 30SW 0NW.
50 KT....... 80NE 80SE 40SW 40NW.
34 KT.......250NE 300SE 100SW 120NW.

[Michele B]

I need advise. My grown kids live in Tallahassee. They follow Mike's Weather page ( I don't, been a member here for 20 years.) They are freaking out because he's saying a catastrophic CAT 5. I told them don't listen to him just follow NHC or come here. What are your thoughts on this Mike's weather?

Well, I don’t know. Where does Mike live? Perhaps it’s really nice out today.

Seriously though, National Hurricane Center and National Weather Service Tallahassee. It’s their best source of information.

I'm a little surprised if Mike is saying that. He's very knowledgeable and I follow him from time to time, too.

He has links for all the usual sites, included NHC so his information isn't just hype. He's very trustworthy.

In fact, I have a tab with his site open as well as this one right now. HE doesn't actually "say" anything, except for local weather....but there are links to just about everything we watch on here.

I will say this: If they are saying "Mike says Cat 5" then they should get OUT of there! He's doing you a favor. It WILL get very, very bad up there.

[redingtonbeach]

Looking more and more like a Cedar Key’’ish landfall.

[Michele B]

Man, that setup when she just crosses the FL/GA border is insane.
The cutoff low to her west and UL anticyclone to her east.
This will create a massive UL Jet.
Could spawn some very significant tornadoes then.
SE GA and SC could see a major, destructive tornado outbreak.

Yeah I'm here near Beaufort that's my concern

About all you can do is "batten down" and have extra water, batteries, flashlight, radio, etc. in your interior bathroom or hallway....along with a MATTRESS so you can drape it over you in the event of a tornado over your house. Bike helmets can help protect you, too.

Good luck. Here's praying there are NO significant tornadoes in your area.

[Bamagirl2408]

Good morning- watching from Mobile. Not sure if any of you have this channel but recent subscriber to youtube tv and they have Fox Weather that is like the TWC but better. Less hype. Mike Seidel, Bryan Norcross and others on it. Less theatrics. Enjoyed much better during Francine coverage. No one pretending they cannot stand while citizens walk dogs in the background.

[blueskies]

I need advise. My grown kids live in Tallahassee. They follow Mike's Weather page ( I don't, been a member here for 20 years.) They are freaking out because he's saying a catastrophic CAT 5. I told them don't listen to him just follow NHC or come here. What are your thoughts on this Mike's weather?

The information from the NHC and Storm2k indicates that anyone in Tallahassee should take this storm very, very seriously and expect big impacts.

[technikal]

Woke up relieved here in Tally. Same eyewall problems from last night persisted into the morning. The window for RI is rapidly closing and it still doesn’t look close to having that symmetry and tight eyewall for a true boom.

Knock on wood but feeling pretty confident we avoid a high end major.

[InfernoFlameCat]

Woke up relieved here in Tally. Same eyewall problems from last night persisted into the morning. The window for RI is rapidly closing and it still doesn’t look close to having that symmetry and tight eyewall for a true boom.

Knock on wood but feeling pretty confident we avoid a high end major.

Ms Piggy did just verify a closed Eyewall. It is also Circular in nature. I suspect that will remedy very shortly. I would suggest evacuating.

[Frank P]

Good morning- watching from Mobile. Not sure if any of you have this channel but recent subscriber to youtube tv and they have Fox Weather that is like the TWC but better. Less hype. Mike Seidel, Bryan Norcross and others on it. Less theatrics. Enjoyed much better during Francine coverage. No one pretending they cannot stand while citizens walk dogs in the background.

Actually, it was Mike Seidel who was videoed struggling with the winds while the two boys walking normally in the background with no troubles standing up
https://scroll.in/video/894517/watch-we ... ly-walk-by

[StPeteMike]

Looking more and more like a Cedar Key’’ish landfall.

Would have to have a major shift east to hit Cedar Key. Not saying it’s impossible, but would take a crazy right bump to cause it. Also, I don’t want that because that would put the Tampa Bay region in for higher than expect storm surge.

Does anyone know the conditions of the ridging to the east?

[GCANE]

Mesoscale Discussion 2110
NWS Storm Prediction Center Norman OK
0636 AM CDT Thu Sep 26 2024

https://www.spc.noaa.gov/products/md/md2110.html

Areas affected...Far Eastern Georgia...Southern and Central South
Carolina

Concerning...Severe potential...Watch possible

Valid 261136Z - 261330Z

Probability of Watch Issuance...60 percent

SUMMARY...An isolated tornado threat is expected to continue over
the several hours from far eastern Georgia into southern and central
South Carolina. Tornado watch issuance may become necessary.

DISCUSSION...Hurricane Helene continues to move northward across the
eastern Gulf of Mexico. Ahead of the system, onshore flow is present
across much of the southern Atlantic Seaboard. Low-level convergence
is maximized near the coast of Georgia and South Carolina where
isolated storms have been generating over the last hour. RAP
analysis shows weak instability near the coast, but also has an 850
mb speed max located over eastern Georgia with wind speeds in the 30
to 35 knot range. This is reflected on the Charleston, South
Carolina WSR-88D VWP, which has 0-6 km shear near 40 knots, and 0-3
km storm-relative helicity of near 170 m2/s2. This should be enough
for tornado development associated with short-topped supercells. The
tornado threat may spread northward into central South Carolina over
the next few hours.

..Broyles/Guyer.. 09/26/2024

[NDG]

Based on my calculation from the recon fixes on Helene during between 1:48 AM & 6:38 AM, Helene's average heading has been at 29 degrees at 12.6 mph.

[Hypercane_Kyle]

Every other frame shows a dramatic improvement in Helene's visual appearance.

I do think this is finally about to rapidly intensify. 120-125mph seems about right.