GaWx

Today’s Euro Weeklies 10 mb zonal wind update fwiw:

60 knot increase from 5AM EDT Saturday’s 60 knots to 5AM today’s 120 knots!

Yeah, it was first at 10:54AM. All of it was later vs average release time.

That wasn’t released til 10:56 AM EDT. That’s very late for the 11AM. And discussion still wasn’t out yet. It wasn’t released til 10:59AM!

There was only 39 ACE through Sept 16th. There has been 67 ACE Sept 17th through 12Z today with likely 20+ more to come from Melissa, alone. This heavy late season vs earlier has been more common in recent years, especially during La Niña.

BULLETIN Hurricane Melissa Intermediate Advisory Number 20A NWS National Hurricane Center Miami FL AL132025 800 AM EDT Sun Oct 26 2025 ...NOAA HURRICANE HUNTERS SAMPLING MELISSA... ...LIFE-THREATENING AND CATASTROPHIC FLASH FLOODING AND LANDSLIDES EXPECTED IN PORTIONS OF JAMAICA AND SOUTHERN HISPANIOLA THROUGH MIDWEEK... SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...16.3N 76.4W ABOUT 120 MI...195 KM SSE OF KINGSTON JAMAICA ABOUT 280 MI...450 KM SSW OF GUANTANAMO CUBA MAXIMUM SUSTAINED WINDS...140 MPH...220 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 5 MPH...7 KM/H MINIMUM CENTRAL PRESSURE...952 MB...28.12 INCHES Maximum sustained winds are near 140 mph (220 km/h) with higher gusts. Melissa is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Further rapid intensification is expected through tonight, followed by fluctuations in intensity. Melissa is expected to be a major hurricane when making landfall in Jamaica Monday night or Tuesday morning and southeastern Cuba late Tuesday. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). The minimum central pressure estimated by aircraft dropsonde data is 952 mb (28.12 inches).

This will be a great test to see how much cooling of the surface there is by 10/29. Here was the SST map as of 10/24: note the large area of 30-31C surrounding Jamaica, which is the warmest in the Atlantic basin:

It will cool the water at least slowly because it’s taking the potential energy from the warm ocean and converting it into kinetic energy (its a heat engine). That’s related to tropical cyclones redistributing heat to higher latitudes. That’s in addition to any cooling of the surface from upwelling. I believe these are two separate processes.

Lowest SLP on record Jamaica 958 Charlie followed by 960 Gilbert.

18z Best Track up to 75kt. AL, 13, 2025102518, , BEST, 0, 165N, 752W 75, 976,HU

12Z Euro: goes back to an extent to the pre 0Z/6Z runs by being a bit further S of Jamaica thus helping it to get stronger (962) and thus it hits Jamaica at 971 instead of 986-8. It then goes back to a NE move over Jamaica and exits at 977 vs 992 of 0Z/6Z. As a result, the 20” line goes back further W to center of Jamaica.

UKMET has been even worse with a number of runs early on hitting Nicaragua and with it then correcting NE but only slowly. This issue was likely mainly due to it having it too weak. It is such a hot or miss model as it was stellar/the best with Imelda as well with Ian among others.

12Z GFS is the furthest west run yet with it going NNE over Kingston at 969 while strengthening during the 6 hour crossover. Kingston gets 35” But otoh, SW Haiti gets way less than prior runs gave.

Josh is on his way to Jamaica:

Not yet: BULLETIN Tropical Storm Melissa Advisory Number 17 NWS National Hurricane Center Miami FL AL132025 1100 AM EDT Sat Oct 25 2025 ...MELISSA NEAR HURRICANE STRENGTH AND FORECAST TO RAPIDLY INTENSIFY THIS WEEKEND... ...LIFE-THREATENING AND CATASTROPHIC FLASH FLOODING AND LANDSLIDES EXPECTED IN PORTIONS OF SOUTHERN HISPANIOLA AND JAMAICA THROUGH THE WEEKEND... SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...16.5N 75.1W ABOUT 155 MI...245 KM SE OF KINGSTON JAMAICA ABOUT 235 MI...375 KM SW OF PORT AU PRINCE HAITI MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 1 MPH...2 KM/H MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES

Best for Jamaica but worst for SW Haiti with insane amounts of rainfall

Hopefully the hurricane models are somewhat too strong as is not uncommon. 0Z and 6Z Euro say it won’t quite make it to cat 3 status before landfall although it was too weak as of 8AM (991 mb) and only down to 988 mb at 2PM. So, the implication is likely at least cat 3 offshore. But then it weakens her 20 mb by the time it gets to Kingston with ENE movement over E Jamaica. Is that a realistic possibility? Regardless, Kingston eastward still gets extremely heavy rain (15-20”+), which likely remains the biggest danger. ——————- Recon through 9:10AM:

8:27 AM EDT: 986 mb very near H status 943 URNT12 KWBC 251227VORTEX DATA MESSAGE AL132025A. 25/12:03:08ZB. 16.41 deg N 074.88 deg WC. NAD. 986 mbE. 195 deg 16 ktF. OPEN SWG. C18H. NAI. NAJ. 167 deg 65 ktK. 067 deg 10 nm 12:00:31ZL. NAM. NAN. 325 deg 46 ktO. 242 deg 13 nm 12:06:34ZP. 14 C / 2460 mQ. 21 C / 2443 mR. 15 C / NAS. 12345 / NAT. 0.01 / 1 nmU. NOAA2 1113A MELISSA OB 14MAX FL WIND 68 KT 299 / 16 NM 10:47:30Z

BULLETIN Tropical Storm Melissa Intermediate Advisory Number 16A NWS National Hurricane Center Miami FL AL132025 800 AM EDT Sat Oct 25 2025 ...MELISSA NEAR HURRICANE STRENGTH AND FORECAST TO RAPIDLY INTENSIFY THIS WEEKEND... ...LIFE-THREATENING AND CATASTROPHIC FLASH FLOODING AND LANDSLIDES EXPECTED IN PORTIONS OF SOUTHERN HISPANIOLA AND JAMAICA THROUGH THE WEEKEND... SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...16.4N 75.0W ABOUT 160 MI...260 KM SE OF KINGSTON JAMAICA ABOUT 235 MI...375 KM SW OF PORT AU PRINCE HAITI MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...WNW OR 290 DEGREES AT 1 MPH...2 KM/H MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES

6Z Euro is very similar to the 0Z with strongest again at 968 S of C Jamaica, 988 near Kingston, and sharp right turn to E tip of Jamaica exiting at 992.

If this is realistic, it could mean that the W 1/2 of Jamaica is saved from as devastating a blow as earlier feared although there’d still be extremely heavy rainfall especially in SE Jamaica along with the devastating consequences of that in that portion of the island.

BULLETIN Tropical Storm Melissa Intermediate Advisory Number 15A NWS National Hurricane Center Miami FL AL132025 200 AM EDT Sat Oct 25 2025 ...AIR FORCE HURRICANE HUNTER DATA SUGGEST MELISSA IS ALMOST A HURRICANE... ...LIFE-THREATENING AND CATASTROPHIC FLASH FLOODING AND LANDSLIDES EXPECTED IN PORTIONS OF SOUTHERN HISPANIOLA AND JAMAICA THROUGH THE WEEKEND... SUMMARY OF 200 AM EDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...16.3N 74.9W ABOUT 170 MI...275 KM SE OF KINGSTON JAMAICA ABOUT 235 MI...375 KM SW OF PORT AU PRINCE HAITI MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 315 DEGREES AT 3 MPH...6 KM/H MINIMUM CENTRAL PRESSURE...986 MB...29.12 INCHES

Also, the 0Z Euro is not nearly as strong as prior runs with 968 mb the strongest when 35 miles S of C Jamaica at hour 54. Then it landfalls at hour 72 at 982 before a sharp turn ENE to E tip at 992. That is a change in the heading from NE across the island on prior runs. Rainfall is still torrential in E Jamaica with 18” at Kingston.

As someone else who also hates the spread of misinfo, especially when it is done purposefully to overhype/get more attention and sell more of a product, I fully endorse his post about this error about the AMO. Spreading misinfo on the internet is a pet peeve of mine. We’re in the Age of Misinfo, sadly. It’s the least we can do to try to reduce the spread of it. Even unintentional errors should be corrected. Keep in mind that there are numerous less informed guests that read these threads. So, we’re not just targeting members in our attempt to make corrections.