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Potential Tropical Cyclone 9 likely to become significant Hurricane Helene with widespread Florida & Southeast impacts – The Eyewall

Potential Tropical Cyclone 9 likely to become significant Hurricane Helene with widespread Florida & Southeast impacts – The Eyewall

Published Date and Time: 2024-09-23 12:15:22


Headlines

  • Potential Tropical Cyclone 9 is likely to become a depression and/or tropical storm by tonight or tomorrow morning.
  • It will accelerate north toward the coast of Florida, with a landfall likely on Thursday somewhere between Pensacola and Tampa. Hurricane impacts will spread across Florida’s west coast and Panhandle.
  • PTC 9 or Helene is expected to be a significant storm and potentially a major hurricane (cat 3+).
  • Because of fast forward motion, PTC 9 or Helene will spread damaging wind far inland from the coast, across South Georgia, possibly into the Atlanta area (depending on track) and into the Carolinas.
  • PTC 9/Helene will be a significant, disruptive storm for the Southeast Thursday, Friday, and possibly beyond.

Give our site a bookmark and check back in later today and/or tonight for some additional updates to this post.

Potential Tropical Cyclone 9

The forecast track for PTC 9 suggests a storm tonight or tomorrow morning, and a hurricane by Wednesday, with impacts beginning in Florida by Thursday. (NOAA NHC)

We have our potential tropical cyclone now, and it will be known as PTC 9. Expect this to formally become a depression later today and a tropical storm tonight or tomorrow morning. This should take on the name Helene.

The first forecast track from the NHC is very much in line with strong model consensus right now, which takes Helene somewhere between about Pensacola and Tampa, with the majority of guidance favoring the Panama City to Cedar Key corridor, close to the Big Bend of Florida. One thing to be very, very clear about: There is still a fair bit of spread among individual ensemble and tropical model members. You can use the slider here to compare the 6z runs of the European and GFS ensemble member forecasts for Thursday around midnight.

The 6z European ensemble (white background) and GFS ensemble show clustering of tracks in the Panama City-Cedar Key corridor with some tracks as far southeast as Sarasota or Fort Myers and some back closer to Pensacola. (Weathernerds.org)

The latest tropical models are very clustered on the west side of Apalachee Bay, with a track very near Tallahassee once inland. So you can see that the model guidance is in great agreement right now on the broad picture of things. I would still watch this very closely in Tampa and Sarasota, as well as Pensacola, as those locations are in the “margin of error” as you might say.

There is also a fair bit of cross-track spread in timing, with some models showing landfall as early as Thursday afternoon and others more into Thursday night. Assume you have until Thursday morning to finalize your preparations on the coast. Anything beyond that is just proverbial icing on the cake.

PTC 9’s intensity outlook

One thing we are unfortunately continuing to be confident in is that this storm has a high ceiling in terms of intensity. There remains a significant spread within tropical model guidance with intensity, as some models suggest tropical storm intensity, while others are at the top end of major hurricane intensity, perhaps a higher end cat 3 or cat 4.

Model guidance shows a substantial spread in intensity forecasts with a handful just at tropical storm intensity, while some more hurricane-focused models show high end Cat 3 or Cat 4 potential. (Tomer Burg)

The NHC projecting a peak intensity of around 110 mph, just on the cusp of major hurricane strength is a good place to be right now, but do realize that the risk for a stronger storm is very much on the table. As we’ve been noting, this track is about the worst possible one a storm could take from a “fuel” standpoint in the Gulf of Mexico. PTC 9 is likely to travel over significant ocean heat content the majority of its life cycle, and water temperatures never really cool off much on approach to landfall. Given the anticipated forward speed of PTC 9, we are likely to see this storm come ashore at or near peak intensity.

The forecast track from the NHC underlaid by ocean heat content and water temperatures shows a storm that is likely to spend most of its time over some of the warmest water in the Gulf or Atlantic. (Tomer Burg)

Folks in Florida should be preparing for a major hurricane impact in the Big Bend or Apalachee Bay with all the threats you’d expect: Surge, wind, waves, flooding, etc. This has the potential to be as bad or worse than Idalia and much worse than Debby in the Big Bend.

Inland risks

The threats from PTC 9 are going to extend much farther inland than usual. The storm will be hauling as it moves inland. Even if it comes ashore weaker than forecast right now, it is likely to carry tropical storm and hurricane force winds well inland from the coast. Those impacts should begin Thursday night and continue much of Friday. This includes much of South Georgia, as well as possibly South Carolina, north Georgia, and portions of North Carolina or Tennessee. The map below shows wind gusts as forecast by the GFS model earlier today. Keep in mind that the final track will determine exactly where those winds occur. A track closer to Tallahassee will shift this farther west. A track closer to Cedar Key will shift this a little to the east.

Tropical storm force winds are likely to extend far inland from PTC 9, with widespread wind damage possible across Georgia and into South Carolina. (Weather Bell)

This is important because this type of scenario could mean widespread, significant power outages and wind damage across Georgia and South Carolina. Metro areas, including Tallahassee, Atlantic, Macon, Savannah, Columbia, Charleston, Greenville-Spartanburg, and Charlotte should be prepared for this scenario and prepare with at least a few days of food and water should this come to fruition.

In addition, heavy rainfall will occur with PTC 9, and flash flooding will be possible, especially in mountainous areas well inland from landfall.

Significant rainfall is likely well inland from landfall with PTC 9, and flash flooding is likely. Thankfully, the forward speed may help mitigate total rainfall a bit. (Pivotal Weather)

This is going to be a significant, disruptive storm for portions of Florida and the Southeast U.S., in addition to perhaps western Cuba and the Cayman Islands where 10 to 12 inches of rain may fall. Impacts will be widespread and damage could be significant. Folks should begin preparing immediately and follow forecast changes closely in the days ahead.



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