Windspeed

It's interesting that you make that bold statement. A recent article published in the Bermudian presents the what ifs and hypotheticals about high-end hurricanes and Bermuda, answered by Andy Moore, whom I believe used to frequent this board quite often as @OSUmetstud , though it's been a while since I have seen him post. Now, please do not think that just because I am posting this article, I am in any way suggesting that the eventual hurricane that this thread seeks to analyze will hit Bermuda. That being said, Bermuda has had some close calls with direct hits over the past thirty years by high-end TCs. I do not think it bold to predict that a Category 5 will eventually strike that island in the next few centuries. We are seeing increased OHC in the shallower immediate surface layer creeping upwards of 29-30°C. A real possible scenario is a rapidly intensifying and fast-moving major hurricane imbedded within a favorable upper trough. It is the inevitable worst-case scenario that will unfold that Bermuda takes a direct impact from a Category 5, even if not in our lifetimes. https://www.thebermudian.com/home-a-garden/hurricane-season-2024/__trashed-7/

Though the official forecast calls for PTC5 to eventually reach Category 2 status in the WATL, I do feel confident now that this system will reach major hurricane intensity north of the Antilles on its trek north. That would give us three hurricanes prior to August 26th (climo. norm is two), including two majors by September 1st (climo. norm for one). I would be surprised if there isn't a third major prior to September 1st. Additionally, we should remain on pace to reach hyperactive numbers by season's end following PTC5/Ernesto's completion, which should put us over 50 by August 20th (climo. norm is September 6th).

If sustained convection can tighten the broad circulation, 98L shouldn't be long for classification. Note the strong, westerly motion within the low-level cloud flow on visible in the southern half of the disturbance. Low pressure is defined, and the wave axis has folded. If the system can tighten up a bit, it may outperform prior to the Antilles. There is a notable diffluent pattern aloft for a TC in this setup on the approach to the Leewards that would support an intensifying hurricane. Hopefully, it takes time for the broad circulation to tighten. Good post on the aforementioned setup here:

If you're looking for pattern scenarios to favor higher ECONUS threats of a major hurricane landfall, the upcoming short-term cutoff trough is one of the patterns you would entertain in the coming week. Of course, such a pattern may still lead to a recurve of a hypothetical TC and no land interaction for the continental US. However, as opposed to a strong mid-level trough with jetstream, a cutoff opens the door for mischief in the steering layer. If a TC is positioned north of the GA and has gained enough longitude, reaching nearto the Bahamas, rebound of the SPH and a Canadian block NE of an ECONUS cuttoff could allow hypothetical TC to turn back NW into the Eastern Seaboard, or recurve from a position where the Carolinas and New England are under threat. We aren't looking at sure fire OTS jetstream-induced recurve here. Even if the hypothetical TC turns N, it may get caught under rebounding heights. Just be very skeptical with this setup on the ECENS of early suggestive OTS tracks until 1) we actually know how low in latitude the TC is going to track with respect to the ECARIB, and 2) timing of ECONUS cutoff trough. There will be a wide degree of any possible positions and tracking scenarios seven days out that may change drastically without a true longwave trough. Increased uncertainty around the fact there will be strong 500 hPa heights postion north of the cutoff that may expand east just in time for the hypothetical TC to have lifted near or just east of the Bahamas. The midrange models may not begin to handle that feature better until we are a few more days advanced. We have seen this occur in previous years. Dorian comes to mind. Nearly all modeling swung back drastically from an OTS to a sharp bend back west when the ensembles had a better grip on the ECAN dome. First and foremost, this system has a high chance of land interaction. So regardless of any potential ECONUS threat or non-threat, if a TC develops, it's likely to be at a low enough latitude to impact the Lesser Antilles and eventually one of the GA.

That is a mid-to-upper level low you are seeing. It is not a tropical surface low. Though it is aiding in ventilating outflow off of Debby, it's not directly influencing the steering layer where Debby is positioned. Low and mid-level flow will bring Debby inland and on up the ECONUS interior the next few days.

This feed that is evolving is most concerning. Multiple mesoscales keep that feed ongoing through tonight and much of the day tomorrow, even after Debby is tracking back to the NW and towards the interior SC-NC border. It does not appear that NC is going to escape high hourly rates and localized destructive totals.

Last hour radar indicated 2-3" and pushing 5-6" last three. I'm not sure how slow to update that site data is currently you posted. It's either incorrect, delayed, or radar is a temporary simulation experiment. I'll take one of the first two options.

Wilmington, NC, and areas just inland have been getting slammed nonstop through the evening. I'd expect flash flood emergencies are underway. 2"/hr rates are ongoing, and the band pivot is taking forever. It's not a good situation developing.

Debby's core appears to have wrapped banding around the MLC, a sign that it is mixing out stable airmass. Remains to be seen if the core band will intensify now into a closed eyewall, but Debby does appear to be improving structurally. The small pseudo-eye feature remains. In fact, it has evolved into concentric rings. That inner band may actually collapse pretty fast if the stronger outer band takes off and intensifies. At any rate, Debby is most likely nearing hurricane intensity.

I completely missed there was a 993 mb reading on that last splashdown.

It's getting a tad too busy this early into ASO, isn't it? Bad omens, no doubt. lol.. Perhaps these seasoned tropical climatologists like Klotzbach know more than SM armchair experts.

Downshear LLC reformation was occurring while reconnaissance was sampling the vortex. The LLC is now currently aligned, at least temporarily. We'll just have to see if the improving structure holds. If it does hold, intensification should be underway. Webb and Hazelton both recently made posts about this evolution of the vortex. It's also not uncommon in slightly sheared systems that are moving in a vector of the upper-level flow. Debby is a well-ventilated system even if there is shear to contend with, and there is net gain within the environment to support intensification (i.e. divergence aloft versus vortex tilt). We've seen this too often with northward moving systems in the GOM. The hope is that the presence of dry air in the western circulation in the mid-levels might get advected into the core circulation. But we're not dealing with strong shear either. Debby could close off and protect its core if these intense CBs keep wrapping it. Here's a few posts about the vort evolution mentioned above.

Debby's lopsided look this morning is a little deceiving. Certainly, the eastern half of the larger circulation is more convectively active on satellite and radar; however, keep in mind that Debby's RMW is still relatively small despite the circulation being large with a large wind field. It's an organizing tropical cyclone, not a reorganizing former hurricane with a sloppy spread out RMW. As pressures begin to fall, it should tighten rather significantly. The core also now has multiple CBs rotating around that should aid in pressure falls and an increase in gradient. 24 hours remaining over very hot SSTs is plenty of time to reach hurricane intensity, and I am confident Debby will become a Category 1 prior to landfall along the Big Bend of Florida. Hopefully, there isn't enough time for RI to begin, but unfortunately, it can't be ruled out. A category 2 is quite possible here, and certainly any higher category potential made worse in that Debby will be undergoing intensification through landfall versus being a TC that is weakening.

Core convection is beginning to organize. Evident banding starting to consolidate around the low-level vortex. Should be stacking now with the MLC.

TS Debby is now officially forecast to become a hurricane by landfall in NW Florida / Big Bend.

First good visible animation of our TD, soon to be TS Debby. The broad circulation appears to be over the Cuban landmass now. There is still MLC rotation to the cloud canopy south of the broader COC, but nothing appears to be forming vorticity at the surface, south of Cuba, or E of Isla de la Juventud (Island of Youth). If all continues status quo, the broad COC should move off the north coast of Cuba by this evening. We'll just have to see how quickly convection can organize and tighten the a low-level vortex. I still think the favorable upper environment will allow Debby to develop a core and intensify into a hurricane prior to landfall in the NE GOM / upper west Florida Peninsula. How quickly that process evolves obviously dictates landfall intensity. Regardless, as has been repeated, flooding up the entirety of the peninsula is going to be the biggest issue versus potential wind and surge impacts.

I'll post it for you. But realize that it's the convective burst south of the broader circulation that gives the overall appearance that the system is moving more W of WNW at the moment. Granted, if you read my post above, that is my big worry right now. Eventually, one of these CBs south of the broader surface center is going to go bonkers and form smaller surface vorticity south of the forecast track. A reformation, if you will.

I guess I'm going to say it. The intensity forecast seems way underdone. I get the OPs, even the TC models, are keeping the circulation rather broad until the NE GOM, but there is a big caveat here. 1) This does not account for persistent convective blow-ups near the Caymans that have been tugging the COC south of Cuba, and 2) there is literally an MLC rotating S of the broader circulation right now that has ongoing convection. It is worriesome to me that, if this structure persists long enough, eventually, we're going to get a smaller surface vortex that remains over water longer. Naturally, the models will catch up after the fact. I have a hard time convincing myself that this TC is merely a tropical storm landfall in the EGOM and merely a flooding rain event, though, granted, that could be horrible enough. Too much time over water and too much of a swing out over EGOM waters prior to right hook and stall.

*shrug* not close enough to assist in ventilating our newly forming TC. Well, perhaps a small amount of upper-level ventilation to the east, but still pretty minute. Not worth mentioning.

That's a mid-to-upper level low. No relationship directly on steering flow. Perhaps some displacement to hell exhaust upper outflow. But very minimal.

You linked an old animation, sir.

Hard not to notice. Wouldn't hurt to have a flight investigate south of the Cuban landmass. The idea here is that the overall circulation remains broad, which is mostly over Cuba. If a specific location persists with deep convection long enough, the localized surface convergence under it might at least form a new mid level circulation. If such remains convective, a new low-level vortex could eventually spawn as well. Just have to keep an eye on that feature as that would open the door for a much higher ceiling for intensification prior to land interaction with NW Cuba.

Welp, there it is... The GFS 00Z OP just showed what a hypothetical TC in the EGOM might do if it loops far enough offshore as opposed to over the coast. Not even going to post it. No need. I'm sure you've all seen it by now anyway. Expect large variations in output intensity from these operational runs from here on out as any slight deviation in TCG position and steering pattern is going to either park the system near-to-over land or offshore, which, of course has huge intensity implications. It's all still very much beyond realistic modeling range and most likely flat wrong. We have no idea what we're going to be dealing with in 4-5 days other than lots of rain for someone. At any rate, I was half expecting one of these OPs to eventually go nuts if that looping pattern kept showing up. Just please realize these outputs of an intense TC may come and go every so often over the next couple of days, perhaps more, as long as a loop/stall keeps getting simulated, and don't let them get to your head! lol...