ATL: HELENE - Post-Tropical - Discussion

[Frank P]

Quick question regarding storm surge. Does a faster storm mean stronger surge? I know the larger the hurricane, the higher the waves but does speed play a role as well? I imagine it probably does.

So the main three factors in storm surge are wind speed, fetch and duration. Fetch is the distance the winds blow, and duration is how long they blow. So a faster moving storm would have less duration than a slower moving storm, so less surge. However, this is a very large storm, so fetch is higher than usual.

Good explanation.

But mandatory:

https://media.tenor.com/99JJtoCMVXcAAAAM/fetch-mean-girls.gif

A powerful storm with a large wind field, coming in at high tide, and perpendicular to the shore line, moving slowly in an area with a shallow continental shelf is the worse conditions for storm surge.

[cheezyWXguy]

Don't know why the eye became elliptical earlier, but latest frames are back to a classic round eye. (RAMMB uses a different color scale than Tropical Tidbits, which makes convection look much shallower than it actually is.)

https://i.postimg.cc/wBNWXbrD/ezgif-2-f64a1292dd.gif

Could be stretched in weird ways by the intense mesovorts revolving around the eyewall

[kevin]

Looking incredible right now. CI# supports 112 kt and raw T# even 127 kt. I expect the next recon to find a high-end cat 3 or low-end cat 4.

[Stormgodess]

Tornadoes spinning up to the west, Franklin County, Carrabelle

[Teban54]

5pm advisory up to 110 kt. Pressure 951 mb.

[JBCycloneStan]

It’s been hours of wrapping convective bursts, and the eye has still not cleared. I’m doubtful it will; several hurricane model runs predicted this.

lol and the eye is clearing out as we speak

[MetroMike]

Now 26,000 without power in Pinellas Co/St.Pete now!

[Stormgodess]

THIS IS INSANE!!



 https://x.com/BayNews9Jeff/status/1839385288801718386

[BIFF_THE_UNRULY]

Now 26,000 without power in Pinellas Co/St.Pete now!

They are getting the worst in the next 30 minutes

[caneman]

Oh my I love that website

I use zoom earth. They finally moved track very close to Perry now. In fact our eyes weren't deceiving us. 20 or 30 miles closer to the west coast.

I think tho it will it up with the Northward component later.

Klystron 9 appears to me to be heading due north almost.

It will eventually but that movement brought it 20 or 30 miles closer to us. I think we'll get a little lucky on surge and won't be quite as bad as landfall will occur prior to high tide. Hopefully be on the lower end of forecast but still bad.

[BIFF_THE_UNRULY]

THIS IS INSANE!!



 https://x.com/BayNews9Jeff/status/1839385288801718386

haha that bridge is always like that during any sort of tropical storm. Its fine. Officials have certain conditions for closing it and those conditions have not been met

[LandoWill]

Now 26,000 without power in Pinellas Co/St.Pete now!

My son's aunt is out of power along the st pete beach area on the south gandy side, if i lived that close to the beach ,i'd been gone

[Bocadude85]

The 5pm update has her at 27.9N 84.6W.. she is south of that point according to radar

[Teban54]

(More hot towers were popping up in the southern eyewall after this frame, but TT hadn't loaded them yet.)

[FLLurker32]

NHC 5pm forecast is interesting. Certainly a cave to the East in track. Cone encompasses Taylor county a smidge more than previous and put Tallahassee just west of the new cone BUT official forecast track is to the west of the cone.

Also of interest, despite the official forecast track the discussion itself says the current ENE @25 degree motion is not expected to turn more to the north until possibly tomorrow.

I can’t think of another reason for doing this outside of an abundance of caution against complacency for the ATL metro area.

[Soluna16]

THIS IS INSANE!!



 https://x.com/BayNews9Jeff/status/1839385288801718386

It was closed right after this

[Kingarabian]

Based on Dvorak estimates its a 6.0, which would equate to cat.4 115kts. Winds still need to catch up of course.

[johngaltfla]

The bands are really starting to come ashore now. Siesta Key, Lido, and all of Manatee County beaches taking a beating.

[Hurrilurker]

From what I see
https://zoom.earth/maps/radar/#view=28.0715,-82.3422,7.56z/date=2024-09-26,16:25,-4/overlays=wind,crosshair
Helene is east and slightly south of track center right now
https://imgur.com/a/RtazyZo

Oh my I love that website

Yeah, that's a really nice visualization, thanks for the link. Only thing is the circulation center seems to be offset from where they have Helene's center marked but not a big deal.

[MetroMike]

Local Met Denis Phillips said possible record storm surge numbers have come in for Pinellas Co.
Up to 10ft surge.Will get very rough this evening here.