NATL: MELISSA - Aftermath - Discussion

[MEANINGLESS_NUMBERS]

This page has complete obs (wind, pressure, etc) from the airport over the last 24 hours. Pressure falling quickly now.

https://www.weather.bm/tools/graphics.a ... 24HR&user=

[Hurricane Mike]

11pm Video on Melissa
https://www.youtube.com/watch?v=wdrHT6jig1Q

[HurricaneRyan]

Looks like Melissa is ready to make her exit and join her Mom and grandma in retirement.

[ncforecaster89]

This is UNOFFICIAL, but here is how - up to now - I would update the BT for Melissa, adding the post-Jamaica track. A full explanation will come after becoming ET. That said, two landfalls in the Bahamas have been added on Long Island and San Salvador Island.

AL132025, MELISSA, xx,
20251020, 1200, , LO, 13.5N, 66.5W, 30, 1008,
20251020, 1800, , LO, 13.7N, 67.7W, 35, 1006,
20251021, 0000, , LO, 13.9N, 68.9W, 35, 1005,
20251021, 0600, , LO, 14.1N, 70.1W, 40, 1004,
20251021, 1200, , LO, 14.1N, 71.3W, 40, 1003,
20251021, 1800, , LO, 14.1N, 72.5W, 40, 1002,
20251022, 0000, , TS, 14.1N, 73.2W, 45, 1002,
20251022, 0600, , TS, 14.2N, 73.4W, 45, 1001,
20251022, 1200, , TS, 14.3N, 73.6W, 45, 1000,
20251022, 1800, , TS, 14.4N, 73.9W, 40, 1002,
20251023, 0000, , TS, 14.6N, 74.3W, 40, 1004,
20251023, 0600, , TS, 14.8N, 74.6W, 35, 1005,
20251023, 1200, , TS, 15.2N, 75.0W, 35, 1005,
20251023, 1800, , TS, 15.5N, 75.3W, 40, 1002,
20251024, 0000, , TS, 15.7N, 75.6W, 40, 1001,
20251024, 0600, , TS, 16.0N, 75.3W, 40, 1001,
20251024, 1200, , TS, 15.8N, 74.9W, 45, 1000,
20251024, 1800, , TS, 15.8N, 74.5W, 50, 996,
20251025, 0000, , TS, 16.1N, 74.7W, 55, 993,
20251025, 0600, , TS, 16.3N, 74.9W, 60, 986,
20251025, 1200, , HU, 16.4N, 75.1W, 65, 983,
20251025, 1800, , HU, 16.5N, 75.3W, 70, 977,
20251026, 0000, , HU, 16.4N, 75.7W, 85, 970,
20251026, 0600, , HU, 16.3N, 76.0W, 100, 957,
20251026, 1200, , HU, 16.4N, 76.4W, 110, 952,
20251026, 1800, , HU, 16.4N, 76.9W, 120, 944,
20251027, 0000, , HU, 16.4N, 77.3W, 130, 932,
20251027, 0600, , HU, 16.3N, 77.7W, 135, 922,
20251027, 1200, , HU, 16.4N, 78.0W, 145, 913,
20251027, 1800, , HU, 16.4N, 78.3W, 155, 906,
20251028, 0000, , HU, 16.5N, 78.6W, 155, 905,
20251028, 0600, , HU, 16.9N, 78.4W, 155, 900,
20251028, 1200, , HU, 17.5N, 78.1W, 165, 894,
20251028, 1400, I, HU, 17.7N, 78.0W, 170, 892,
20251028, 1700, L, HU, 18.1N, 78.0W, 160, 897,
20251028, 1800, , HU, 18.2N, 77.9W, 140, 910,
20251028, 2200, R, HU, 18.7N, 77.4W, 95, 955,
20251029, 0000, , HU, 18.9N, 77.2W, 100, 954,
20251029, 0600, , HU, 19.8N, 76.3W, 105, 951,
20251029, 0715, L, HU, 20.0N, 76.1W, 105, 950,
20251029, 1200, , HU, 20.9N, 75.8W, 75, 972,
20251029, 1800, , HU, 22.1N, 75.3W, 80, 974,
20251029, 2130, L, HU, 22.5N, 75.0W, 85, 971,
20251030, 0000, , HU, 23.5N, 74.8W, 90, 969,
20251030, 0200, L, HU, 24.0N, 74.5W, 90, 967,

Hi Crazy, I’m in complete agreement that there was likely a 10 kt differential between its peak around 1330-1400z and landfall at 1700z. The only difference is that I’d set the aforementioned peak intensity at 165 kt/892 mb and landfall intensity at 155 kt/899 mb.

The meteorological reasoning:

Reconnaissance aircraft released a dropsonde that recorded a lowest central pressure of 892 mb at 1302z. The next (and last) pass through the eye found that the pressure was up 2 mb to 894 mb, but measured the peak 700 mb FLW of 172 kt at 1346z. These in-situ observations coincided with Melissa’s most impressive satellite presentation and this was reflected on the various satellite intensity estimates. The CIMSS-ADT analyzed the peak at 1410z, for one such example.

From that point, there was a significant and obvious warming of cloud tops within the CDO…which was most pronounced in the eyewall convection…that occurred during those remaining 3 hours from Melissa’s peak through landfall of the center at 1700z. Furthermore, the eye was certainly filling and losing definition/symmetry and was already beginning to close prior to that time. As we’ve seen in numerous cases, these high-end category five hurricanes typically weaken much more quickly than one that has a larger starting RMW. The CIMSS-ADT analyzed a 7 mb filling from 1400z to landfall and it’s conceivable it may have risen a little further than that.

Assessing the Intensity:

The 172 kt FLWs equate to 155 kt at the surface using the standard 90% conversion factor.

The 188 kt WL150 wind obs equate to 156 kt after applying the typical 83% conversion rate.

These data show, as would be expected, that there was a very efficient mixing rate of FLWs to the surface. As such, and given the possibility that there may have been stronger winds in the NE portion of the eyewall, I’d increase the MSW peak intensity from the current operational estimate of 160 kt to 165 kt. One important thing to note, we’re assuming RECON would’ve potentially measured higher FLWs in the unsampled NE quadrant but there’s no way to know if that would’ve been true. In many prior case, where an intensifying high-end hurricane was moving in a general NE’erly direction, the maximum wind speeds were actually located in the SE quadrant of the eyewall. Even so, and taking all the available data into consideration, I feel 165 kt/892 mb is the most accurate estimation of this historic hurricane’s extraordinary peak strength.

Landfall:

Unfortunately, and understandably, there was no additional direct sampling of Melissa’s eye or eyewall (by RECON) after 1350z for obvious safety reasons. Consequently, we’re left with a far more subjective interpretation of how much weakening may have transpired between 1400z and 1700z.

As noted above, CIMSS-ADT analyzed a 7 mb rise in the central pressure over that span. However, If the aforementioned 2 mb differential in pressure between the last two RECON observations (45 minutes apart) is more accurate, from 1302z onwards, that’d equate to about 901 mb at landfall. And, it’s also possible that the filling rate may have increased given the notable satellite degradation from its peak.

Taking all the aforementioned into account, I’d set the landfall intensity at a somewhat uncertain 155 kt/899 mb. I’ll conclude by saying that no matter what one may determine, themselves, it’s virtually impossible to argue that Melissa retained its peak strength through landfall and/or it was actually still intensifying at that time.

[GCANE]

 https://x.com/AndyHazelton/status/1984013949323329983

[GCANE]

 https://x.com/WeatherNation/status/1983962354284102000

[GCANE]

 https://x.com/GerWeather/status/1983665166488305808

[GCANE]

 https://x.com/CIRA_CSU/status/1984016736098849123

[GCANE]

 https://x.com/CIRA_CSU/status/1983961609832653270

[Nimbus]

This page has complete obs (wind, pressure, etc) from the airport over the last 24 hours. Pressure falling quickly now.

https://www.weather.bm/tools/graphics.a ... 24HR&user=

69 knots will take out power for a while in Bermuda, the storm is moving fast and forward speed added to the tropical storm strength winds on the east side.

Lowest pressure argument would need to take into account the mesovortex pentagram at landfall.
There were 5 different lowest pressures beyond our skill to determine.

https://journals.ametsoc.org/view/journ ... 0.co_2.xml

[GCANE]

2 Corinthians 1:8-9

We were crushed and overwhelmed beyond our ability to endure, and we thought we would never live through it.
In fact, we expected to die.
But as a result, we stopped relying on ourselves and learned to rely only on God, who raises the dead.

[Dean_175]

Are we really still looking at a cyclone that is still tropical? Just has a bit more to go before it is definitively merged with that frontal system.

[ncforecaster89]

 https://x.com/tbrite89/status/1984217097711292792



Because I’m unfamiliar with how to post images here, I’m going to simply provide my most recent post on twitter/X. It contains the pertinent satellite imagery that clearly shows the significant degradation of the satellite appearance during the last three hours prior to landfall, as noted in the previous post, above.

[Teban54]

I believe that the most common arguments for some weakening between recon and landfall were due to warming CDO in the final moments (when a quarter - and eventually half - of the CDO was over land, despite the center remaining offshore).

Do we know for sure that such "CDO warming just before landfall" indeed translates to weakening in surface wind? Or could it possibly be just changes in appearance due to land interaction?

Were there any precedents from past storms (leaning one way or another)?

[MGC]

Good riddance Melissa.....interesting to see if Melissa tie or surpassed the Labor Day Hurricane of 1935 landfall pressure of 892mb.......MGC

[Teban54]

Melissa officially became extratropical at 11am EDT today, October 31, 2025.

To me personally, Melissa was one of the most memorable and fascinating storms to witness and to track, if not the single most. I started tracking in 2018, so I missed Irma and Maria... But it still compares to many Atlantic storms that I did track in the years since then -- Michael, Dorian, Eta, Sam, Ian, Lee, Milton, etc. -- if not above them.

So many things about Melissa are unique, impressive, and sometimes even bizarre:

• The contrast between a weak, sheared TS that stalled for days, vs. an MH and then top-tier Cat 5 that also stalled for days
• The enormous model uncertainty ranging from Puerto Rico to Honduras -- and GFS's spectacular failure to acknowledge a Jamaica landfall until it was force-fed into the model
• The countless center reformations in its early life: the number of LLCs that Melissa ever had was likely equal to the category number it eventually reached
• The insane sub-900 model runs from HAFS and Google DeepMind (the latter even relied heavily upon by NHC) -- and the fact that they actually verified, in even more impressive manners than depicted
• The two nights of cold cloud tops and ADT showing record-high numbers (eventually to an unholy 8.5), and, especially during the first night, the shocking low actual intensities from recon in comparison
• The repeated eyewall melds, long duration at Cat 5 intensity, and the absolute refusal to undergo an EWRC or weaken by more than a few mb
• The living example to disprove that reaching sub-900 requires ERI with a pinhole eye, instead getting there slowly but steadily
• The near-worst-case scenario for impacts on Jamaica: Days of rainfall from a stalling storm nearby, followed by a historic landfall and flooding well detached from the path
• The multiple scientific debates and future research directions it will (hopefully) leave behind: the role of the tropopause in Dvorak and its factors; the use of dropsonades, SFMR and FL reduction ratios; and the effect of shear direction on EWRCs vs. eyewall melds
• And of course, the strongest, truly once-in-a-lifetime landfall on record, in both winds and pressure

[sasha_B]

Melissa officially became extratropical at 11am EDT today, October 31, 2025.

To me personally, Melissa was one of the most memorable and fascinating storms to witness and to track, if not the single most. I started tracking in 2018, so I missed Irma and Maria... But it still compares to many Atlantic storms that I did track in the years since then -- Michael, Dorian, Eta, Sam, Ian, Lee, Milton, etc. -- if not above them.

As someone who also started tracking in 2018, I couldn't agree more. Lee, Beryl, and Milton were all special, but none quite rose to Melissa's level, for all the reasons you've stated. In particular, it seems likely that analysis of Melissa in years to come will yield a wealth of knowledge on TC formation, intensification, and structure to aid forecasters in working to prevent the kind of tragic impacts the storm has caused. This was a very promising early outing for operational use of AI models like GDM; the NHC's willingness to weigh it so heavily in their track and intensity forecast may well have saved lives, and it will be interesting to see if its impressive accuracy here will continue to bear out with future storms in complicated forecasting environments.

[Kazmit]

Melissa was surprisingly potent here in Bermuda. Over half the island lost power (including myself) which is more than Imelda. The forward speed must have contributed quite a bit to the SW winds we experienced. And to think it was only a shell of what it was earlier in its life. These are the peak wind/gust observations I saw last night, before my service stopped working. This station is well above sea level but still impressive.

[ncforecaster89]

I believe that the most common arguments for some weakening between recon and landfall were due to warming CDO in the final moments (when a quarter - and eventually half - of the CDO was over land, despite the center remaining offshore).

Do we know for sure that such "CDO warming just before landfall" indeed translates to weakening in surface wind? Or could it possibly be just changes in appearance due to land interaction?

Were there any precedents from past storms (leaning one way or another)?

Hi Teban! I appreciate your question. Yes, CDO warming 100% is indicative of weakening regardless of whether land interaction influences it. Not only was there significant warming of the cloud tops within the CDO, but it was most pronounced in the eyewall region. Moreover, the eye was filling, losing symmetry, and beginning to close even before it made landfall. All signs of definitive weakening.

As such, there’s simply no meteorological argument to support the idea that Melissa didn’t weaken prior to landfall. The harder question to answer is to what degree did it do so? Barring in-situ observations (pressure readings) from the landfall area (preferably from within the eye), it’s going to be a more subjective determination than usual, unfortunately.

I’ll add that I totally understand why so many might want Melissa to retain its status as supposedly the strongest and most intense hurricane landfall on record in the Atlantic basin, but as a meteorologist, I can’t allow emotion to influence a wholly objective analysis of the applicable data. More than anything else, I care about truth and accuracy and just simply want to know truly how strong Melissa was at both its peak and landfall. Frustratingly, I also realize there’s a lot more subjectively involved than I’d like…especially in cases like these without the benefit of Doppler radar like we have here in the states.

[ljmac75]

Some assorted thoughts on the intensity:

From what I can find, Melissa had the most impressive flight-level and 150 meter average dropsonde winds of the 160 kt hurricanes in this archive I'm looking at. Wilma maxed out with FL winds of 168 kts and none of the best dropsondes made it to the surface. Dorian maxed out at 161 kts flight level and 177 kt 150 meter averaged dropsonde wind. Melissa maxed out at 173 kts at flight level and a 188 kt meter averaged dropsonde wind. Wilma and Dorian are kinda carried by having an insanely low pressure and insanely high SFMR values, respectively, but Melissa can justify 160 kts with the ol reliable flight level and dropsonde winds alone.

The satellite and in-situ estimates are out of alignment enough that I really hope we have some kind of other data for the landfall intensity because otherwise nobody is ever going to shut up about it. Still waiting on what Josh Morgerman got. If he was in the RMW the whole time and didn't get any sort of noticeable drop in winds for the minimum pressure then if I'm using the Schloemer equation right a <900 mbar pressure could be justified by a pressure reading in the 930s, which would also be vaguely unsatisfying. Basically, the only hope we have is for the NHC to determine that Melissa didn't actually make landfall at all so we don't have to argue about this.