Issued at 1100 AM EDT Sat Oct 25 2025
000 WTNT43 KNHC 251458 TCDAT3 Tropical Storm Melissa Discussion Number 17 NWS National Hurricane Center Miami FL AL132025 1100 AM EDT Sat Oct 25 2025 Melissa is very nearly a hurricane. Data from both the Air Force Reserve Hurricane Hunters indicate the storm has become better organized, with a 20 n mi eyewall that has been coming an going. This structure has also been seen on radar images out of Kingston, Jamaica. Compared to last night, Tail Doppler Radar (TDR) data indicates the tropical cyclone is much better aligned vertically, though some residual eastward tilt with height exists in the mid-levels. The peak flight level winds at 700 mb were up to 68 kt. Using a standard 0.9 adjustment factor to surface winds yields an intensity of 60 kt, but Melissa could become a hurricane at any time, as other satellite intensity estimates already support a higher value. The initial motion is crawling along to the west-northwest, estimated between aircraft fixes to be 285/1 kt. Now that the tropical cyclone has become better aligned vertically, it should increasingly feel the deep-layer steering, which has a slight south of due-west component from the latest ECMWF steering diagnostics. The spread in the model solutions even in the next 12-36 hours is higher than usual, with the AI models, Google DeepMind ensemble mean (GDMI) and ECMWF-AI (AIFS) on the south and western end of the guidance envelope showing a westward or even west-southwestward motion in the short-term, while the traditional dynamical aids (ECMWF, HAFS-A/B) show more of a west-northwestward drift towards Jamaica over the next 24-36 hours. Still though, nearly all of the reliable track guidance (discounting the GFS which has been an eastward outlier since the storm formed) shows Melissa making landfall in Jamaica sometime in the 60-72 hour time frame. During this time, a digging mid-latitude trough in the southeastern United States is expected to create a new weakness to the north of Melissa, which should result in the cyclone taking a sharp turn to the northeast. While the guidance is in good agreement on this general turn with relatively small across-track spread, there remains high along-track spread in the solutions, best highlighted by the Google DeepMind ensemble which shows a spread in possible locations in 96 h from still inland over Jamaica to northeast of Cuba in the southwestern Atlantic. The NHC track forecast is a touch south of the prior track for the first 24-48 hours, but converges on the prior track forecast thereafter. This is a little on the eastern side of the track guidance envelope, giving credence to the AI model solutions (GDMI, ECAI) which to date are the best preforming track guidance this hurricane season. Melissa seems to be shaking off the negative effects of westerly shear now that the storm is becoming better vertically aligned. Thus, it appears likely that a period of rapid intensification will occur as the storm moves slowly over very warm ocean waters (30-31C sea-surface temperatures) which is also over the highest oceanic heat content in the entire Atlantic basin, which will limit initial ocean upwelling under the slow moving storm. Similar to the previous cycles, roughly 40/50 Google DeepMind ensemble members show Melissa becoming a Category 5. While I am not ready to forecast that intensity yet given the track uncertainty, that remains a possibility. After 48 h, inner core processes (such as eyewall replacement cycles) could cause fluctuations in intensity, but Melissa is still expected to make landfall in Jamaica as an upper-end Category 4 hurricane, which could be the strongest direct landfall for the island in since tropical cyclone record keeping has been made in the Atlantic Basin. Weakening is expected as Melissa moves over the high terrain of Jamaica and eastern Cuba, with further weakening expected thereafter as southwesterly vertical wind shear increases. The NHC intensity forecast remains on the high end of the guidance, but closest too the Google DeepMind ensemble mean, which has also been on of our best intensity guidance performers this year. Key Messages: 1. Jamaica: Melissa’s slow movement will bring a multi-day period of damaging winds and heavy rainfall beginning tonight, likely causing catastrophic flash flooding, numerous landslides, extensive infrastructural damage, long-duration power and communication outages, and potentially prolonged isolation of communities. A life-threatening storm surge is also likely along portions of the southern coast early next week. All preparations should be completed today. 2. Haiti: Catastrophic and life-threatening flash flooding and landslides are expected across southwestern Haiti into early next week, likely causing extensive infrastructural damage and potentially prolonged isolation of communities. Strong winds could also potentially last for a day or more over the Tiburon peninsula. 3. Dominican Republic: Heavy rainfall could produce potentially catastrophic flash flooding and numerous landslides in southern regions. 4. Eastern Cuba, Southeast Bahamas, and the Turks and Caicos: Monitor Melissa closely. There is an increasing risk of a significant storm surge, damaging winds, and heavy rainfall by the middle of next week. In eastern Cuba, the risk of life-threatening flash flooding and landslides is increasing. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 16.5N 75.1W 60 KT 70 MPH 12H 26/0000Z 16.4N 75.5W 80 KT 90 MPH 24H 26/1200Z 16.5N 76.2W 100 KT 115 MPH 36H 27/0000Z 16.6N 76.8W 120 KT 140 MPH 48H 27/1200Z 16.7N 77.3W 135 KT 155 MPH 60H 28/0000Z 17.2N 77.5W 130 KT 150 MPH 72H 28/1200Z 17.9N 77.2W 115 KT 130 MPH...INLAND 96H 29/1200Z 20.5N 75.1W 95 KT 110 MPH...INLAND 120H 30/1200Z 25.0N 71.0W 75 KT 85 MPH...OVER WATER $$ Forecaster Papin
NHC Atlantic
