557
AXNT20 KNHC 180605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0615 UTC Sat Oct 18 2025

Tropical Weather Discussion for North America, Central America
Gulf of America, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

Atlantic Large Swell Event:
Northerly swell generated from a storm force low over the Atlantic
waters north of the discussion area will support rough to very
rough seas over the western Atlantic through this weekend. Seas in
excess of 12 ft and greater, with period of 12-14 seconds will
continue to spread southeastward on Sat, covering the waters north
of 27N between 43W and 70W by Sat night. The swell will then
start to subside over the discussion waters allowing for seas to
drop below 12 ft Sun night. Seas with this swell will peak near 18
ft over the waters north of about 30N between 50W and 65W on Sat.

Please read the latest HIGH SEAS FORECAST issued by the National
Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis near 18W from
from 02N to 16N moving westward around 10 kt. Scattered moderate
to isolated strong convection is within 120 nm west of the wave
from 06N to 09N.

A central Atlantic tropical wave has its axis near 31W from 02N
to 10N, moving westward at 10 to 15 kt. Scattered moderate to
isolated strong convection is within 60 nm either side of the
wave from 05N to 08N.

A central Atlantic tropical wave has its axis near 45W from 04N
to 17N, moving westward at 15 kt. Earlier observed scattered
moderate to isolated strong convection has diminished. Scattered
moderate to strong convection is seen from 08N to 12N between the
wave 48W from 07N to 13N. A 2312Z ASCAT pass showed fresh to
strong northeast to southeast winds across the wave axis from 11N
to 14.5N. Gradual development of this system is possible over the
next several days while it moves generally westward. Regardless of
development, this system is expected to bring heavy rainfall and
gusty winds to the Windward Islands late this weekend, then move
across the Caribbean Sea much of next week. This wave has a low
chance of tropical development within the next 7 days.

A central Atlantic tropical wave has its axis near 55W south of
16N. It is moving westward near 15 kt. Scattered moderate to
isolated strong convection is noted from 08N to 13N between 52W
and 59W. Numerous moderate to strong convection is within 120 nm
either side of the wave from 08N to 13N.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic near 12N16W and
extends southwestward to near 05N26W and west to 05N32W, where
it transitions to the ITCZ to 06N38W. Aside from convection
related with the tropical waves as described above, scattered
moderate to isolated strong convection is within 180 nm north of
the trough between 20W-30W and also between 32W-37W.

...GULF OF AMERICA...

High pressure ridging extends southwestward from high pressure of
1018 mb that is centered along the southeastern U.S coast to the
NE Gulf. The related pressure gradient is allowing for generally
gentle to moderate east to southeast winds north of about 22N east
of 94W, and light to gentle winds elsewhere. Seas are in the range
of 2 to 4 ft, except for slightly higher seas of 3 to 5 ft in the
north-central Gulf, the NE and in the southeastern Gulf, with
the exception of the Straits of Florida where higher seas of 5 to
7 ft are present. Isolated small showers are over the NW Gulf
from 26N to 28N between 92W and 94W, otherwise ample dry sinking
air aloft is inhibiting convection from forming over the basin, at
least for the time being.

For the forecast, moderate east to southeast winds and slight to
moderate seas are expected over much of the Gulf through late Sat
as high pressure prevails over the southeastern United States.
Occasionally fresh east winds will be possible in the central and
eastern basin. A cold front is forecast to enter the NW Gulf on
Sun and progress southeastward across the basin into early next
week. Moderate to locally fresh north to northeast winds are
expected in the wake of the front Sun into Mon. High pressure will
build in the wake of the front, with generally moderate winds and
slight to moderate seas returning over the region.

...CARIBBEAN SEA...

A frontal trough extends from Hispaniola, to Jamaica and northwest
to just east of the northeast portion of the Yucatan Peninsula.
Satellite imagery shows scattered showers and thunderstorms near
the trough. This activity is more concentrated over the eastern
portion of Hispaniola reaching eastward to the Mona Passage and
just offshore the western part of Puerto Rico. Otherwise, a weak
pressure gradient is generally supporting gentle to moderate east
to southeast winds east of about 67W, and light to gentle winds
elsewhere as noted in recent scatterometer satellite data passes.
Recent altimeter satellite data passes indicated seas in the
range of 2 to 4 ft across the basin.

For the forecast, light to gentle, with locally moderate, winds
and slight seas are expected over the Caribbean through Sat.
Moderate to locally fresh trade winds and moderate seas will
develop over the central and eastern Caribbean this weekend as
high pressure builds N of the area. Fresh to strong winds and
rough seas will accompany a tropical wave as it moves across the
tropical Atlantic waters this weekend. The wave will move into the
eastern Caribbean Sun night. Gradual development of this system
is possible over the next several days. Regardless of development,
this system is expected to bring building seas, heavy rainfall and
gusty winds over the tropical Atlantic waters this weekend, and
across the Caribbean Sea much of next week.

...ATLANTIC OCEAN...

Please refer to the Special Features section for further details
on a large swell event that will continue to impact some sections
of the north-central waters through the weekend.

A cold front is analyzed from near 31N54W southwestward to 29N55W
and to 24N70W, where it transitions to a stationary front to the
central Bahamas. Fresh to strong winds are presently north of 22N
east of the front, and also north of 27N west of the front to 70W.
To the east, a 1007 mb low is north of the area at 33N34W. A
second cold front extends from the low southwestward to near
25N55W, where it transitions to a stationary front to 21N63W, and
as frontal trough from there to across Hispaniola and to the
north-central Caribbean Sea. Satellite imagery shows scattered
showers and thunderstorms along the stationary front and trough,
with the activity extending within 60 nm south of the trough.
Moderate to fresh winds, and rough seas are noted between the
fronts. High pressure located along the coast of the Carolinas
is shifting eastward, with its associated ridging building
southeastward across the northwest part of the area. In the
eastern part of the Atlantic, a weak 1018 mb high center is near
23N33W. Light to gentle winds are around the high center, while
gentle to moderate winds mostly remain elsewhere. Seas are in the
moderate range.

For the forecast W of 55W, the aforementioned first cold front
will propagate southeastward and stall along 22N this weekend.
Winds will diminish from west to east through late Sat into Sun.
Widespread rough seas prevail north of 20N and east of 60W, and
north of 26N between 60W and 75W. Very rough seas over 12 ft can
be expected north of 25N and east of 71W through Sun. The rough
seas will spread southeastward covering most of the waters east of
75W by early on Sun, then will slowly subside from west to east Sun
into next week. High pressure will continue to build in behind
the front, with improving conditions early next week.

$$
Aguirre