NATL: GABRIELLE - Post-Tropical - Discussion

[Sciencerocks]

[CrazyC83]

This is unofficial, but how I would have Gabrielle's BT:

AL072025, GABRIELLE, xx,
20250916, 0600, , LO, 12.8N, 41.0W, 30, 1012,
20250916, 1200, , SD, 13.4N, 41.5W, 30, 1012,
20250916, 1800, , SS, 13.6N, 42.4W, 35, 1011,
20250917, 0000, , SS, 14.9N, 43.8W, 40, 1009,
20250917, 0600, , SS, 16.1N, 45.1W, 45, 1008,
20250917, 1200, , SS, 17.3N, 46.3W, 50, 1006,
20250917, 1800, , SS, 18.2N, 47.5W, 50, 1006,
20250918, 0000, , LO, 19.0N, 48.8W, 45, 1007,
20250918, 0600, , LO, 19.5N, 50.1W, 45, 1007,
20250918, 1200, , LO, 20.0N, 51.2W, 45, 1008,
20250918, 1800, , LO, 20.5N, 52.2W, 40, 1009,
20250919, 0000, , TS, 21.0N, 53.1W, 40, 1009,
20250919, 0600, , TS, 21.5N, 54.1W, 40, 1008,
20250919, 1200, , TS, 21.9N, 55.1W, 45, 1006,
20250919, 1800, , TS, 22.3N, 56.1W, 45, 1005,
20250920, 0000, , TS, 22.9N, 57.0W, 45, 1004,
20250920, 0600, , TS, 23.8N, 57.7W, 50, 1002,
20250920, 1200, , TS, 24.6N, 58.3W, 55, 999,
20250920, 1800, , TS, 25.2N, 58.7W, 60, 996,
20250921, 0000, , TS, 25.9N, 59.0W, 60, 995,
20250921, 0600, , TS, 26.6N, 59.9W, 60, 995,
20250921, 1200, , HU, 27.3N, 60.7W, 65, 994,
20250921, 1800, , HU, 28.1N, 61.5W, 70, 992,
20250922, 0000, , HU, 28.9N, 62.1W, 80, 987,
20250922, 0600, , HU, 29.6N, 62.5W, 90, 977,
20250922, 1200, , HU, 30.4N, 62.5W, 105, 963,
20250922, 1800, , HU, 31.3N, 62.1W, 115, 951,
20250923, 0000, , HU, 32.1N, 61.4W, 120, 947,
20250923, 0600, , HU, 32.8N, 60.4W, 125, 943,
20250923, 1200, , HU, 33.5N, 59.2W, 115, 950,
20250923, 1800, , HU, 34.3N, 57.4W, 105, 956,
20250924, 0000, , HU, 34.9N, 55.2W, 100, 960,
20250924, 0600, , HU, 35.4N, 52.8W, 95, 964,
20250924, 1200, , HU, 35.8N, 50.2W, 85, 970,
20250924, 1800, , HU, 35.9N, 47.2W, 80, 975,
20250925, 0000, , HU, 36.0N, 44.0W, 75, 978,
20250925, 0600, , HU, 36.2N, 40.8W, 70, 980,
20250925, 1200, , HU, 36.4N, 36.7W, 65, 982,
20250925, 1800, , TS, 36.8N, 33.3W, 60, 983,
20250926, 0000, , EX, 37.4N, 30.5W, 60, 983,

A lot to digest, especially in the early life.

* Genesis is moved up a bit, to when an ASCAT pass suggested a center was forming (16/0600, genesis 6 hours later). That is nearly a full day earlier.
* The early life status is as a subtropical depression/subtropical storm. It's very rare to see that in the deep tropics, however, I feel that is warranted as it was embedded in an upper level low with a very large RMW and a comma shape, but deep convection and no fronts. That lasted for 36 hours until the deep convection was sheared away. The 50 kt intensity is based on the ASCAT pass showing 43-45 kt barbs and the low resolution.
* On September 18, there was virtually no deep convection being produced. As a result, I believe it was no longer a TC/STC at that point, but rather just a low pressure area. Convection returned in earnest at 19/0000, at which point it is analyzed as a tropical cyclone.
* Recon coverage was intermittent, hence, a lot of interpolation was necessary. Upgrade to a hurricane is moved up 6 hours, based on a blend of Dvorak T4.5 ratings, an earlier Recon flight supporting 60 kt winds and a near-concurrent ASCAT pass showing 55-60 kt winds and its low resolution.
* The rapid intensification on September 22 was smoothed out. Ignoring constraints, Dvorak already supported a major hurricane by 1200Z, if not sooner, and a solid hurricane by 00-0600Z. There was no Recon at the time, so the satellite estimates were brought in.
* The peak intensity is estimated at 125 kt, at 0600Z September 23. That is about when the satellite signature was most pronounced, and some Dvorak estimates were T6.5. Earlier Recon lined up perfectly with satellite, so that estimate is used. The pressure is estimated to have been 943 mb at that time, using the trends from earlier.
* Minor changes were made as it was decaying, mainly a decrease in intensity slightly at each time.
* Decay to an extratropical cyclone is moved back 6 hours. There still seemed to be semblance of a TC structure at 25/1800, but a frontal structure developed by 26/0000. The "low" status is changed to extratropical there.

[Vince_and_Grace_fan]

In Horta Acores the highest wind gust reached 155 km/h (84 kt) after the storm's core moved trough the island, while the pressure dropped to around 991-992 hPa.
https://www.ogimet.com/cgi-bin/gsynres?lang=en&state=Port&osum=no&fmt=html&ord=REV&ano=2025&mes=09&day=26&hora=18&ndays=1&Send=send

[tolakram]

Gabby coming into Portugal

[cycloneye]

 https://x.com/tonyveco/status/1972431331843027210