Windspeed

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...

Agreed; that's always a factor and much more likely regardless of intensity.

Someone earlier in the thread mentioned Elena. Interestingly, these patterned loops are popping up on several repeated runs of the global OPs. If this disturbance does wind up in the EGOM and does a loop over water instead of the Peninsula, it could open the door for some rather dramatic intensification and forecasting chaos for the coastline. It's a mitigating nightmare for evacuations. I've always wondered what another Elena would be like in recent years. At any rate, it's only worth mentioning due to that potential loop. I am certainly not suggesting that will occur. The loop or stall might occur over land. Or it might just be incorrectly modeled within the pattern this far out, and no stall or loop even resolves if a hypothetical TC even reaches that far west.

I know you didn't intend in your post that we already have a center, so I am just going to clarify here in my words for everyone else to understand. Keep in mind that we do not have a center yet. Based on satellite observation and TAFB surface analysis, the yet to be labeled invest is merely a broad tropical wave (the axis of which is cutting through the NE Leewards). Bubbling of convection has been occurring along the boundary where the moist fetch is established out of the ITCZ. However, strong convection is now beginning to consolidate within the northern wave axis. You may see this now in the IR animation I am including in this reply. Now that we have an envelope of convection, we'll have to closely watch where the most intense CBs get going. If that gains consistency in the northern axis, our disturbance may begin to fold north of the GA. Also, just because strong convection takes off this evening, the process may still take a few days to consolidate into a tighter surface low and vorticity maximum. But it is important to note that we have convection in the northern periphery of the tropical wave. So, the potential remains for either model suite to win out here on when and where TCG occurs. It might still be over the Antilles or it could be in more of a heading towards the Bahamas as the ECMWF OPs and EPS ensembles have repeatedly suggested. Again, this wave is still broad. It's going to take some time for convection to concentrate and tighten this disturbance into a potential TC. I am still leaning towards the EPS, especially now that CBs are blossoming in the northern axis, and that looks more intense than the spotty stuff down in the NE Leewards. Regardless of TCG, when and where, it really is something how modeling has flirted with the development of this behometh of a tropical wave that's spent the better part of a week devoid of convection. Precipitable water anomalies (PWATa) were always there near the 950-700 hPa level, the system just needed enough time for SAL-induced dry mid-levels to moderate with the attached southerly backside connection to the ITCZ and increasing lapse rate potential due to bathwater SSTs in the western MDR. I do think this disturbance becomes a TC in 2-3 days. I still think it's too early to know if we'll see an ECONUS hit. We need to see how fast genesis occurs and how much initial latitude is gained versus the weakness that will open a door for poleward recurve. Everything is still on the table from EGOM to Carolinas to OTS.

I'm not sure why anyone here would entertain their opinion. At any rate, I like the ECMWF's right hook if TCG occurs north of the GA or near the Bahamas. Any position there does appear to time favorably with a weakness to allow poleward interaction with a westerly jet streak. Uncertainty will remain until late week/weekend with regards to any potential ECONUS interaction, though, until (if/when) genesis occurs and we have a better understanding of any potential turn. I kind of like 2004's Alex as a potential development and track analog. A similar tropical wave [in comparison to OP] moved north of the GA and positioned east of the Bahamas. Interaction between the disturbance and the surface trough occurred initiating TCG. I don't imagine any kind of late stall like 2005's Ophelia, another potential analog, though that system did hook out eventually. Obviously, it's too early to rule out Bahamas, Florida, or the Carolinas. If no TCG occurs pre-Bahamas or north of the GA, then the wave could slip into the GS straits or eastern GOM, missing the trough, which would obviously increase CONUS threat, though whether that would be anything organized or merely a tropical disturbance and rain is just a guess at this point. We've got the better part of a week to go before we'll have a better idea.

That's due to SPH placement. I mentioned last night that it's really the only thing suppressing TC development. Keeping the bottle corked, per se. Once the A-B begins to slightly weaken and gain latitude into a more typical position for ASO, given other factors in place, the fireworks should begin. There will always be a plume here or there, but once the ITCZ lifts, the MDR will become more favorable for CV waves.

This is a reminder that we had this microwave presentation in the Caribbean Sea, in the Atlantic, on.... July 2nd.... Better thank the current interseasonal behometh Azores-Bermuda ridge suppressive regime right now. That's the only thing holding in the cork. Every other climatological factor is a bloody damn powder keg. This season is going to suck. And yes, that is intense hyperbolic acid coming from me to pour in your stiff drink. It's going to be very bad.....

We've seen these crazy cyclonic loops in the past in interaction with the mountainous island of Taiwan. It's still quite eye-opening, no pun intended.

Gaemi has thrown on the brakes and made a hard left turn down the eastern coastline. It's absolutely incredible to see such a scenario unfold in real-time.