Windspeed

Melissa leveled off earlier ~906 mb. But I think we should be prepared that Melissa may be driving down pressure further now. The wider -90°C strong banding rings are suggestive of intensifying banding, but without any degradation of eye symmetry here or significant contraction, it's indicative of some mergers of the outer band into a portion of the inner eyewall. If that is the case, we may be looking at a sub 900 mb run tonight prior to landfall.

My goodness... https://bsky.app/profile/jeremydehartwx.bsky.social/post/3m46sngepdc2r

We can really hammer this home. Best case scenario is the trough lifting Melissa out fast. Actually, this track has unfolded better than some of the model runs a few days ago that had the slow down and drift west we are seeing this morning occurring just off the southern coast in much closer proximity before turning inland. Hopefully, Melissa's core won't spend too much time over the island on Tuesday. It will still be a catastrophic impact, and mudflows off the ridges and down into low-lying areas is the most dangerous aspect of the event.

Dorian was embedded in higher background pressures. You have to take into account the position and surrounding environment. That's why we don't go by a strict pressure to wind chart. Also, the size of the vorticity's radius of maximum wind (RMI) matters as well.

The reason I thought they were missing the NE eyewall a few posts ago is due to this. It appears they flew through the more eastern eyewall than the NE quadrant and might have even missed the center of the eye here. But then I had to remind myself of that pesky parallax positoning of the satellite image.

910 extrap

Recon may be positioning to make an east to west pass. I say that because their current flight path would miss the eye unless they turn due west. Nevermind. I don't know what I was looking at there. It is still a NE to SW pass.

Most recent long-range radar scan. The eyewall remains uniform and intense. It does appear a concentric outer band is trying to form around the periphery of the eyewall. We still have 24-28 hours until landfall. That is plenty of time for an EWRC to begin. The forecast is for Melissa to be a Category 5 at landfall, but internal structural changes could still bring down that intensity to Category 4. But again, that is not necessarily a good thing for the island, as the windfield would expand east towards higher populated areas. I actually do think the intensity will fluctuate down by landfall as I still think outer banding will get its act together and weaken the small eye by tonight. It is very difficult for a high-end TC like this to maintain that intensity for that many hours without fluctuations. Time will tell.

Looks like we are around 30 hours from landfall give or take a few depending on timing of the trough influenced deep layer southerly flow. We should start to see northward motion begin by midday or noon'ish. Timing on this is critical for the eventual landfall point.

The trough is also moving into influence which can begin to affect symmetry and convection on the periphery of the TC, including the outflow channels. Otherwise, Melissa's core is about as textbook as it gets for a powerful Atlantic Caribbean hurricane. Current appearance kind of reminds me of Matthew.

Nothing to say, really. Wilma had recon support for its peak.

Let me get it out of the way first. Melissa is definitely a Category 5 right now based on initial recon. But clearly there is something to be said about inflated ADT numbers due to CT temperatures. ADT is spitting out sub 900 hPa estimates and we're no where near that. I think while recon is out there they will sample in the 910s range before they leave. But we're going to start having to curb CT temps based on background characteristics of the Autumn tropopause height. A ring of sub -80 to -90°C is still impressive regardless of date. But it is becoming quite apparent that given the later months (late Oct, Nov., Dec.) that the tropopause height in the deep tropics allows tops to get colder than the Summer and late Summer months. It inflates dvorak numbers. We have had suspicions for years that WPAC deep tropic super typhoons may have been over estimated. Again, it doesn't take away from the fact highest-end TCs are Category 5s on the Saffir Simpson. But the later the seasonal date, ADT is estimating too low a pressure. 895 versus operational ~20 hPa off is ridiculous.

Two insane IR loops with lightning data for posterity. New IR and the older AVN. No doubt about it, Melissa's eyewall is absolutely cranking at present.

Perhaps.They're definitely en route again based on flight path now.

Given what ADT is cranking out, if Melissa maintains this appearance through the 5AM, it may still get the upgrade. Conservative estimates are still >140 kts.

And here I was just talking about mechanical issues with recon and Eta's peak. History repeating itself. Damn...

Recon just made a 180. Hrmm...

Granted, Melissa's ADT is stronger than ETA's ever was. Eta got down to around 912 hPa on ADT, but recon found it to be 10 mb higher. Thus, it never achieved Cat 5 officially. Eta was also embedded inside of a WCARIB surface trough. Melissa's pressure regime is a little higher. So if it is indeed found by recon to be pushing the 910s or 900s hPa tonight, the gradient should support 140+ kt surface winds. But, yes, it would be surprising if ADT busted that hard again. Edit: I revisited Eta's estimates. It had a raw ADT of 8.0 and 7.0 blend at 912 hPa. But recon found 922 hPa when they finally arrived. The previous recon mission had mechanical problems, and the next mission may have missed peak. Also, we need to keep in mind that it is late October. The tropopause is a little lower even at a low latitude, and cloud tops can get a little colder on IR. So, dvorak satellite estimate algorithm can overdo the raw T numbers. Though I will always argue Eta should have been a Category 5 on reanalysis.

Seeing a classic example of what deep oceanic heat content can support. Melissa has been barely moving the past six hours. More or less a drift W-WSW with wobbles. Yet the satellite presentation has continued to improve. The eyewall is cooling the immediate shallow layer, but instead of upwelling driving down heat support, upwelling is mixing up water that is still above the threshold to support Melissa's MPI. The 26°C isotherm is very deep in this part of the Atlantic. Somewhere between 100 and 150 meters. Interestingly, if Melissa did remain stalled for several days, it would eventually cool and mix down SSTs enough to begin impeding its MPI, and would eventually start to weaken. Unfortunately, timing is such with the trough to begin lifting Melissa's core north back over untapped deep OHC. So I don't think SSTs are going to be a caveat for a powerful TC weakening into landfall. We'll have to look at other dynamics for such, like the onset of fast ERC or structural changes. In other words, Melissa may still have enough time to attain Category 5 status and make landfall as a Category 4. But the differences here are pretty moot points. Despite the potential devastation at the location of landfall for the eye, the still bigger life-threatening event here remains the incredible rainfall totals over the south sloping ridges of Jamaica. Landslides and mudflows are killers.

Most recent long-range radar image.

No, they didn't get ahead of themselves. Their discussion followed ADT. Without reconnaissance data, you use what you have access to. Obviously, satellite isn't always as accurate, but it's usually close. Structurally, Melissa looks to be intensifying based on remote sensing data. But recon shows it's a little behind satellite trends. Visually, I don't think anyone would argue that Melissa looks like an intensifying Category 4. I don't think it will matter by this afternoon, regardless.

That was a NW to SE pass. I'd imagine the NE quadrant isn't too far off from ADT. Also, the pressure is still dropping, and there is a bit of lag time. It is good we have recon out there at present because I'd expect to see continued signs of intensification on the next four passes for the mission.

Melissa's eye is clearing out fast now.

Mesovorticies rotating around the eyewall. it shouldn't be long until we start seeing pressure dropping like a rock.

Here's some heat content and isotherm depth maps as well. Melissa's core, despite being a slow-mover, has plenty of energy to tap prior to land interaction. Credit to RSMAS at Miami for maintaining these to the public.