Tropical Storm Melissa Discussion Number 8
NWS National Hurricane Center Miami FL AL132025
500 AM EDT Thu Oct 23 2025
Melissa continues to struggle in strong westerly vertical wind
shear. Surface observations and Air Force aircraft data show that
the system is vertically tilted with the low-level center partially
exposed and located nearly 100 miles west of the mid-level center
that is apparent in satellite images. The wind field of the storm
also remains lopsided, with most of the strong winds confined to the
eastern half of the circulation. The initial intensity is held at
45 kt, but this is probably generous based on the aircraft data and
an ASCAT pass from last evening.
The storm has been crawling and moving erratically. In general,
Melissa is likely to inch northward during the next 36 to 48 hours
as the storm is influenced by a weakness in the subtropical ridge.
By late Friday, a mid-level ridge is forecast to build eastward to
the north of the storm, and that pattern change should induce a slow
westward or west-northwestward motion over the weekend. By early
next week, that ridge is expected to move away as a large-scale
trough amplifies over the eastern U.S. This change in the steering
flow should cause Melissa to begin to gain more latitude again by
the end of the forecast period. Given the complex steering pattern
and continued model differences in the predicted vertical depth of
Melissa, there remains a significant spread in the deterministic
guidance and the ensemble solutions. One thing we feel confident
about is that Melissa is likely to move slowly and remain in the
vicinity of Haiti, Jamaica, and eastern Cuba for several days. The
NHC track forecast is shifted a little to the right of the previous
one, trending toward a blend of the latest Google DeepMind ensemble
mean and HCCA solution.
The current westerly vertical wind shear over Melissa is expected to
linger for about another day, and that should keep the storm at
around the same intensity during that time. However, after that,
the upper-level wind pattern will gradually become more conducive
while the system remains over the very warm waters of the central
and northwestern Caribbean Sea. These conditions should allow
Melissa to become vertically aligned and strengthen significantly.
In fact, rapid intensification appears likely this weekend and
early next week. The NHC intensity forecast lies near the middle of
the guidance envelope from 12 to 72 hours, but leans toward the
upper end of the guidance at days 4 and 5. As Melissa intensifies,
its wind field is expected to grow and become more symmetric.
Key Messages:
1. Melissa is expected to meander over the central Caribbean Sea for
several days and is forecast to become a major hurricane by late
this weekend or early next week. Interests in Jamaica, Haiti, Cuba,
and the Dominican Republic are urged to continue monitoring the
latest forecasts.
2. Due to Melissa’s slow motion, the risk of a prolonged period of
strong winds, possibly lasting for a day or more, is increasing for
Jamaica and the Tiburon peninsula of Haiti. Preparations to protect
life and property should be rushed to completion, since strong winds
could begin in these areas on Friday and continue increasing over
the weekend.
3. Melissa is expected to produce heavy rainfall across portions of
the Dominican Republic, Haiti, and Jamaica through the weekend,
bringing a risk of significant, life-threatening flash flooding and
numerous landslides.
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