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000
WTNT43 KNHC 212035
TCDAT3
Tropical Storm Melissa Discussion Number 2
NWS National Hurricane Center Miami FL AL132025
500 PM EDT Tue Oct 21 2025
Satellite data indicate that Melissa is struggling in strong shear,
which has been the theme for many systems over the deep tropics this
year. The low-level center of the storm is exposed to the west of
the main area of thunderstorms. Air Force Hurricane Hunters have
been investigating the system this afternoon and found that the
minimum pressure is around 1003 mb. Based on their observations,
ASCAT passes, and Dvorak estimates, the initial intensity is held at
45 kt. Melissa's wind field is also quite asymmetric, with most of
the tropical-storm-force winds occurring on the system's east side.
Some of the outermost northern bands are approaching Hispaniola, and
these heavy rains are expected to spread across that island during
the next couple of days.
Melissa is a little south of the previous track and it continues to
move westward at about 13 kt. There has been no change to the track
forecast scenario, which remains complicated. Over the next couple
of days, there is fair confidence that Melissa should slow down and
gradually turn to the northwest or north and approach Haiti and
Jamaica late this week. The motion after that appears to be linked
to how strong and vertically aligned the system gets, and
that is when the models diverge. If Melissa organizes like the GFS
predicts, it could turn northeastward into the weakness in the
ridge and move over Hispaniola. Conversely, if Melissa remains
sheared and lopsided, it will likely stall and eventually drift
westward as a ridge builds north of it. Given the expected
continued shear, the NHC track forecast leans toward the latter
scenario. This prediction is a little left of the previous forecast
and remains a blend of the latest Google DeepMind ensemble mean,
the corrected consensus aid HCCA, and simple consensus TVCA.
Although the ocean is very warm, the models suggest that the
vertical wind shear could persist over Melissa during the next few
days. In addition, there is also some dry air in the storm's
vicinity. Based on these mixed signals, the strengthening trend is
expected to be slow. In fact, the new guidance supports nudging the
short term intensity down a bit. If Melissa remains over the
Caribbean late this week and over the weekend, the upper-level winds
could become more conducive for more significant strengthening.
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. Hurricane conditions are possible in the southwestern peninsula
of Haiti where a Hurricane Watch is in effect. A Tropical Storm
Watch is in effect 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 21/2100Z 14.2N 73.0W 45 KT 50 MPH
12H 22/0600Z 14.5N 73.7W 45 KT 50 MPH
24H 22/1800Z 15.0N 74.4W 50 KT 60 MPH
36H 23/0600Z 15.5N 75.0W 55 KT 65 MPH
48H 23/1800Z 16.1N 75.1W 60 KT 70 MPH
60H 24/0600Z 16.5N 75.0W 60 KT 70 MPH
72H 24/1800Z 16.9N 75.0W 60 KT 70 MPH
96H 25/1800Z 17.3N 75.0W 65 KT 75 MPH
120H 26/1800Z 17.5N 75.2W 75 KT 85 MPH
$$
Forecaster Cangialosi
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楼主: 大水台6
发表于 2025-10-21 08:00
发表于 2025-10-22 09:47
