GaWx

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.

Yeah, I realize that. I’m just looking ahead.

BULLETIN Tropical Storm Melissa Advisory Number 13 NWS National Hurricane Center Miami FL AL132025 1100 AM EDT Fri Oct 24 2025 ...AIRCRAFT DATA SUGGEST THAT MELISSA COULD BE REFORMING TO THE EAST... ...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...15.7N 74.6W ABOUT 215 MI...345 KM SE OF KINGSTON JAMAICA ABOUT 250 MI...405 KM SW OF PORT AU PRINCE HAITI MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...ESE OR 105 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... * Southwestern peninsula of Haiti from the border with the Dominican Republic to Port-Au-Prince * Jamaica A Tropical Storm Warning in effect for... * Southwestern peninsula of Haiti from the border with the Dominican Republic to Port-Au-Prince * Jamaica Tropical Storm Melissa Discussion Number 13 NWS National Hurricane Center Miami FL AL132025 1100 AM EDT Fri Oct 24 2025 The Air Force Reserve reconnaissance that has been flying through Melissa this morning found the center significantly further to the east-southeast than what was observed last night. How much of this position is related to a real motion, or a center reformation is unclear at this time. The storm remains about the same on satellite imagery this morning, with a large burst of deep convection, primarily along its southeastern flank, with evidence of northwesterly shear still undercutting the outflow. A WSFM microwave pass shows very deep hot towers, but not with that much structure beyond that. In addition, there hasn't been a significant change to Melissa's intensity, with peak 850 mb flight level winds of 49 kt, and these winds support maintaining 40 kt intensity this advisory. As has been stated for the last few days, the lack of persistent steering currents, due to competing mid-level ridges to the southeast and northwest of Melissa, is responsible for the storm's very slow motion. This is likely to continue for the next day or so, and much of the system's motion could be just as influenced by center reformations during this time period. After 24 hours, the mid-level ridge located to the northwest is expected to strengthen to the north of Melissa, and the guidance is coming into better agreement on a very slow westward motion through 72 hours. Beyond that time frame, a strengthening mid-latitude trough expected to move into the Southeastern U.S., should provide an avenue for Melissa to escape the Caribbean Sea to the northeast by the end of the forecast period. The track guidance overall has shifted south over the first few days, but there is still substantial spread in solutions at the end of the forecast period, related to when and how fast Melissa turns to the northeast. The latest NHC track forecast is a little south of the prior one early on, but is shifted a little eastward in 4-5 days, roughly a blend of the latest HCCA and GDMI model aid solutions. On the forecast track, Melissa could potentially be near western Jamaica by day 4 and near or over southeastern Cuba by day 5, though timing still remains more uncertain than usual. The GFS and ECMWF-based SHIPS shear guidance indicates the deep-layer shear is lower than yesterday, between 14-17 kt, but there still appears to be mid-level shear undercutting the outflow layer. Until Melissa also become better aligned vertically, any intensification is likely to be slow to occur over the next 12 h or so. After that, once Melissa's structure improves, environmental conditions still appear favorable for a period of rapid intensification (RI). Every single Google DeepMind member shows the system become a Category 4 hurricane or higher, and the uncertainty is more related on the timing of when RI occurs. After 96 hours, Melissa could weaken some due to the combined effects of land interaction, and an increase in southwesterly vertical wind shear by the end of the forecast period. The latest NHC intensity forecast is on the higher end of the model solutions, but more or less in line with the latest GDMI guidance. Key Messages: 1. Jamaica: Due to Melissa’s slow motion, the risk of a prolonged multi-day period of potentially damaging winds, heavy rainfall resulting in life-threatening flash flooding and numerous landslides, and storm surge continues to increase for Jamaica. Preparations to protect life and property should be rushed to completion, since strong winds and flooding rains could begin in Jamaica on Saturday or Sunday. 2. Haiti: Heavy rainfall will result in catastrophic flash flooding and landslides across southwestern Haiti into early next week. Extensive damage to roads and buildings is expected, potentially isolating communities for an extended period of time. This is a life-threatening situation and immediate preparations to protect life and property should be taken. Strong winds could also potentially last for a day or more over the Tiburon peninsula of Haiti. 3. Remainder of Hispaniola and Eastern Cuba: Heavy rainfall could also produce significant, life-threatening flash flooding and numerous landslides in southern Dominican Republic. Interests in Cuba should monitor the progress of Melissa since the risk of heavy rainfall, damaging winds, and storm surge appears to be increasing. FORECAST POSITIONS AND MAX WINDS INIT 24/1500Z 15.7N 74.6W 40 KT 45 MPH 12H 25/0000Z 15.9N 74.5W 45 KT 50 MPH 24H 25/1200Z 16.3N 74.6W 60 KT 70 MPH 36H 26/0000Z 16.5N 75.3W 70 KT 80 MPH 48H 26/1200Z 16.6N 76.0W 85 KT 100 MPH 60H 27/0000Z 16.6N 76.8W 105 KT 120 MPH 72H 27/1200Z 16.6N 77.5W 125 KT 145 MPH 96H 28/1200Z 17.5N 78.3W 130 KT 150 MPH 120H 29/1200Z 20.4N 76.7W 105 KT 120 MPH...INLAND $$ Forecaster Papin