427 
WTNT43 KNHC 211445
TCDAT3
 
Tropical Storm Melissa Discussion Number   1
NWS National Hurricane Center Miami FL       AL132025
1100 AM EDT Tue Oct 21 2025
 
Satellite images, regional Caribbean radar data, and surface 
observations indicate that invest 98L has developed a well-defined 
center and organized deep convection to be designated a tropical 
cyclone.  A ship report that recently passed near the center of the 
system reported a minimum pressure of about 1003 mb.  Satellite 
imagery shows the system is asymmetric, with the low-level center 
near the western edge of the central dense overcast.  The initial 
intensity is set at 45 kt, based on a blend of the latest satellite 
intensity estimates, marking the formation of Tropical Storm 
Melissa.  An  Air Force Hurricane Hunter aircraft is scheduled to 
investigate the system this afternoon, and their data should provide 
a better assessment of Melissa's strength and structure.  

The system was moving very quickly westward over the past several 
days, but it has slowed down significantly this morning, which has 
likely helped Melissa form.  The initial motion is estimated to be 
280/12 kt.  Melissa should continue to slow down and gradually turn 
to the northwest and then north during the next couple of days 
toward a weakness in the subtropical ridge.  This motion will likely 
take the storm very near the southwestern tip of Haiti and Jamaica 
by Thursday.  After that time, the guidance diverges significantly 
with some models like the GFS and HWRF showing a motion to the 
northeast into the weakness, while the other solutions show a stall 
or a westward drift on the south side of a building ridge.  An 
examination of the GFS, ECMWF, and Google DeepMind ensemble suites 
suggest that the majority of the members show Melissa not moving 
into the weakness and remaining in the Caribbean Sea throughout the 
week and into the weekend.  The NHC official track forecast lies 
between the Google DeepMind ensemble mean track and the correct 
consensus aid, HCCA.

Melissa is expected to be over the very warm waters of the 
Caribbean, but the models suggest that vertical wind shear will be 
moderate with some dry air in the vicinity of the storm during the 
next few days.  Based on these mixed signals, the strengthening 
trend is expected to be slow and steady, not rapid.  However, the 
future intensity of Melissa is linked to the track and since that is 
quite uncertain beyond a couple of days, the strength of the storm 
is also quite uncertain.  The NHC intensity forecast is in best 
agreement with the HCCA model.

Key Messages:

1. Melissa is expected to bring heavy rainfall and the risk of 
significant flash flooding and the danger of landslides to portions 
of Haiti and the Dominican Republic through the weekend.

2. A Hurricane Watch has been issued for the southern coast and 
Tiburon peninsula of Haiti.  A Tropical Storm Watch has been issued 
for Jamaica.  Preparations to protect life and property should be 
completed by Thursday.

3. There is significant uncertainty in the track and intensity 
forecast of Melissa.  Interests elsewhere in Hispaniola and Cuba 
should continue to monitor the latest forecasts.


FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 14.3N  71.7W   45 KT  50 MPH
 12H  22/0000Z 14.4N  72.8W   50 KT  60 MPH
 24H  22/1200Z 14.8N  73.5W   55 KT  65 MPH
 36H  23/0000Z 15.3N  74.2W   60 KT  70 MPH
 48H  23/1200Z 15.7N  74.5W   60 KT  70 MPH
 60H  24/0000Z 16.1N  74.6W   60 KT  70 MPH
 72H  24/1200Z 16.5N  74.5W   60 KT  70 MPH
 96H  25/1200Z 16.9N  74.5W   65 KT  75 MPH
120H  26/1200Z 17.2N  74.9W   70 KT  80 MPH
 
$$
Forecaster Cangialosi/Bucci