ATL: HELENE - Post-Tropical - Discussion

[USTropics]

The MPI (maximum potential intensity) is pretty significant if all other inhibiting atmospheric conditions are null (shear, dry air, etc). There is a loop current eddy that broke off from the Gulf Stream and is positioned to provide high OHC:


In addition, the cutoff low amplifies this weak jet streak, and is oriented so Helene is more in the right entrance region. This promotes increased divergence aloft and convergence ahead of the system:


It's why some of the hurricane models show significant strengthening. The NHC has already mentioned Helene is forecasted to be in the 90th percentile in terms of size for this region, and impacts are going to be felt well outside the cone of uncertainty.

[Noles2016]

Those gators better watch out! lol but seriously, thankfully there's nothing to damage in the bay in the center or eastern side, just swamps and some camp grounds. Aside from the Everglades, that is the least populated coastline in Florida. If you had to pick somewhere in Florida to get hit by a major, this is the spot.

I beg to differ. Panacea is smack on the bay, albeit the western portion.

Has anyone ever heard of Panacea, FL??? I think you just proved the guy's point, that there is no large metropolitan area in the crosshairs. While it will be devasting for a town like Panacea, it is small-scale compared to a Tampa type of event. I hope they fare okay given what is headed their way.

Guy literally said "nothing", and "just swamps and campgrounds". Most definitely did not prove his point, lol.

[AtlanticWind]

Lived in South Florida all my life
We just had a rainband move in from a
Tropical storm that is 500 miles away

Incredible how large Helene is

[Kingarabian]

Convection behavior to the S and W of the CDO almost looks CCC esque.

[caneman]

Wxman57. What is the slosh for Tampa Bay?. They backed it down to 3 to 6 feet but living here as long as I have I feel that 6 ft. Will be the minimum. Thanks.

One of my friends shared that Shore Acres in St. Pete (just north of downtown but easily floods) already had water flooding the streets there….

This has to be from rainfall, not surge

From the ocean. Shore Acres is that low. We've not yet had rain from the system

[fllawyer]

Where are you seeing 3-6? Latest advisory still shows 5-8 feet for Tampa Bay.

I was running SLOSH this morning. A large Cat 3 moving into Apalachee Bay from the south or SSW would produce a 30 ft surge, not 10-15. Forward speed 25 mph at landfall.

Wxman57. What is the slosh for Tampa Bay?. They backed it down to 3 to 6 feet but living here as long as I have I feel that 6 ft. Will be the minimum. Thanks.

[decgirl66]

Does anyone know if Palm Beach District schools will be closed tomorrow, 9/26/24?

I work in Miami-Dade County Schools and we haven’t heard yet. Not sure about Palm Beach. I’m sure those decisions will be made today.

Brevard County schools are closed tomorrow!

[Steve]

Those gators better watch out! lol but seriously, thankfully there's nothing to damage in the bay in the center or eastern side, just swamps and some camp grounds. Aside from the Everglades, that is the least populated coastline in Florida. If you had to pick somewhere in Florida to get hit by a major, this is the spot.

I beg to differ. Panacea is smack on the bay, albeit the western portion.

Has anyone ever heard of Panacea, FL??? I think you just proved the guy's point, that there is no large metropolitan area in the crosshairs. While it will be devasting for a town like Panacea, it is small-scale compared to a Tampa type of event. I hope they fare okay given what is headed their way.

Yes. I've been there. And we have some members here from there. Also Alligator Point is going to get wrecked. Most of the center and eastern part of the bay is state parks and wildlife refuges/estuaries. But there are actually some decent little towns tucked away in what you'd think are nowhere like Shell Point and Live Oak Point. Shell Point has a bunch of homes on canals with boat docks. You'd never even know it was there if you didn't need to know about it. It's getting wrecked too, and I'd be surprised if there was much left if the surge gets as high as it might. It is very sparse beyond that until you get over to Perry and Adams Beach

I get the point though. If somewhere's got to get hit, the least populated portion is best for the common good.

[MetroMike]

Where are you seeing 3-6? Latest advisory still shows 5-8 feet for Tampa Bay.

I was running SLOSH this morning. A large Cat 3 moving into Apalachee Bay from the south or SSW would produce a 30 ft surge, not 10-15. Forward speed 25 mph at landfall.

Wxman57. What is the slosh for Tampa Bay?. They backed it down to 3 to 6 feet but living here as long as I have I feel that 6 ft. Will be the minimum. Thanks.

It is still 5-8 feet as per the 11am update for Tampa Bay area.

[StPeteMike]

One of my friends shared that Shore Acres in St. Pete (just north of downtown but easily floods) already had water flooding the streets there….

This has to be from rainfall, not surge

From the ocean. Shore Acres is that low. We've not yet had rain from the system

Thanks caneman. Yes, we have been dry when it comes to rain. It’s not uncommon for this to happen. We had a cold front in January cause the streets to flood due to the water being pushed in.

[HurricaneBelle]

i am lookign at the weather channel's forecast for Tally, and the highest winds forecast are just above 50 mph and just one hour of 65 mph as it passes by...that seems really low for what they are forecasting the storm to be around landfall and how quickly it moves thru Tally after landfall, what am I missing?

Don't look at TWC, rely on the NWS. This is their official forecast for Leon County:

THURSDAY
HURRICANE CONDITIONS POSSIBLE. SHOWERS WITH A CHANCE
OF THUNDERSTORMS. SOME THUNDERSTORMS MAY PRODUCE HEAVY RAINFALL.
HUMID WITH HIGHS IN THE UPPER 70S. EAST WINDS 10 TO 15 MPH WITH
GUSTS UP TO 30 MPH, INCREASING TO 20 TO 25 MPH WITH GUSTS UP TO
40 MPH IN THE AFTERNOON. CHANCE OF RAIN NEAR 100 PERCENT.

THURSDAY NIGHT
HURRICANE CONDITIONS EXPECTED. SHOWERS WITH A
CHANCE OF THUNDERSTORMS. SOME THUNDERSTORMS MAY PRODUCE HEAVY
RAINFALL. LOWS IN THE LOWER 70S. EAST WINDS 70 TO 80 MPH WITH
GUSTS UP TO 95 MPH, BECOMING SOUTHWEST AND DIMINISHING TO 25 TO
35 MPH WITH GUSTS UP TO 60 MPH AFTER MIDNIGHT. CHANCE OF RAIN NEAR
100 PERCENT.

[Pipelines182]

Those gators better watch out! lol but seriously, thankfully there's nothing to damage in the bay in the center or eastern side, just swamps and some camp grounds. Aside from the Everglades, that is the least populated coastline in Florida. If you had to pick somewhere in Florida to get hit by a major, this is the spot.

I beg to differ. Panacea is smack on the bay, albeit the western portion.

Even further east and closer to the center, there's hundreds of homes in Shell Point/Live Oak Island/Spŕing Creek

yes, that's why I specified the center and eastern sections of the bay. While I haven't seen the slosh model itself, I would assume that 30' is not for the western side where the small towns are, but for the empty center and eastern sides. That west side would need a storm moving NW, not N or NNE to get those types of surge numbers.

[MGC]

NHC keeps bumping up the intensity forecast for Helene with every advisory. I would not be surprised if the hurricane tops out in the 140 to 145 MPH range as there are near perfect intensification conditions ahead of Helene.....MGC

[TampaCE]

This has to be from rainfall, not surge

From the ocean. Shore Acres is that low. We've not yet had rain from the system

Thanks caneman. Yes, we have been dry when it comes to rain. It’s not uncommon for this to happen. We had a cold front in January cause the streets to flood due to the water being pushed in.

I’m still here. Will be leaving Shore Acres a bit later headed to higher ground. The water in the streets is just normal tidal flooding, it’s not the whole neighborhood. Just some of the more low lying streets.

[zal0phus]

NHC keeps bumping up the intensity forecast for Helene with every advisory. I would not be surprised if the hurricane tops out in the 140 to 145 MPH range as there are near perfect intensification conditions ahead of Helene.....MGC

Nothing I say is meteorological gospel by any means, but I feel like we can't rely on official forecasts as perfect truth about the ceiling here. I personally think a category 5 is on the table. Conditions ahead of Helene are ideal, and the only saving grace is that it might landfall in a very isolated region.

[Pipelines182]

Judging from the satellite appearance, Helene is dealing with some wind shear, the CDO has become asymmetric. There's also signs of dry air entrainment, the CDO is warming and there's signs of thunderstorms collapsing with the outflow boundaries streaming off the southern and western sides. No RI for the time being.

[jdjaguar]

I beg to differ. Panacea is smack on the bay, albeit the western portion.

Has anyone ever heard of Panacea, FL??? I think you just proved the guy's point, that there is no large metropolitan area in the crosshairs. While it will be devasting for a town like Panacea, it is small-scale compared to a Tampa type of event. I hope they fare okay given what is headed their way.

Yes. I've been there. And we have some members here from there. Also Alligator Point is going to get wrecked. Most of the center and eastern part of the bay is state parks and wildlife refuges/estuaries. But there are actually some decent little towns tucked away in what you'd think are nowhere like Shell Point and Live Oak Point. Shell Point has a bunch of homes on canals with boat docks. You'd never even know it was there if you didn't need to know about it. It's getting wrecked too, and I'd be surprised if there was much left if the surge gets as high as it might. It is very sparse beyond that until you get over to Perry and Adams Beach

I get the point though. If somewhere's got to get hit, the least populated portion is best for the common good.

I go there twice a year and stay with friends at their coastal home. I guess it was just the callousness of "just gators, swamps and a few campgrounds", and then "has anyone ever heard of Panacea?
just plain cold.

I know its no Tampa, but people should think before they make comments like that.

[psyclone]

Steady westward ticks have eroded the risk of hurricane force winds in tampa down to 2%...50kt wind risk is way down too. Looks like a low end ts wind wise for west central florida but a potentially high end water event. The west coast beaches are going to be crushed with water and wave action and we're just getting the fringes. The landfall is going to be a Katrina like tsunami with 100mph winds if this develops like it should. This is definitely a run for your life situation in the hot zone...

[Steve]

I beg to differ. Panacea is smack on the bay, albeit the western portion.

Even further east and closer to the center, there's hundreds of homes in Shell Point/Live Oak Island/Spŕing Creek

yes, that's why I specified the center and eastern sections of the bay. While I haven't seen the slosh model itself, I would assume that 30' is not for the western side where the small towns are, but for the empty center and eastern sides. That west side would need a storm moving NW, not N or NNE to get those types of surge numbers.

Some of it yeah. But if you look closely at the topography, most of the west part of the bay faces east with inlets to numerous rivers and more inlets. So even if the system went in east of the western portion of the bay, you have counterclockwise flow of an already high surge. So instead of it just flowing offshore as an anti-tide or whatever, it fills up those bays, bayous, canals, inlets and estuaries. if you look at a map program on satellite and zoom in, you'll see what I mean. There's nowhere else for the water to go if it's that high coming around the top of the circulation.

It's extremely shallow pretty far offshore like 20 feet . Check this out:

https://fishing-app.gpsnauticalcharts.c ... 4/-84.1783

[tronbunny]

I was running SLOSH this morning. A large Cat 3 moving into Apalachee Bay from the south or SSW would produce a 30 ft surge, not 10-15. Forward speed 25 mph at landfall.

oh my god. this is not what I wanted to hear from wxman57.
that is biblical proportion.

I will urge my friends to leave Crawfordville/Panacea area immediately, and not wait until tomorrow.

Emphasize the "Leave Now".
I had vulnerable family leave Tallahassee. They are going to wait it out in Central Florida. The sheer number of trees and age of her home makes this a better choice.