042 
AXNT20 KNHC 180901
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1215 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 
0900 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 generate 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 today, covering the waters north
of 27N between 43W and 70W by tonight. 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 today.

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 19W from 
from 02N to 16N moving westward around 10 kt. Nearby convection is
discussed in the monsoon trough/ITCZ section below. 

A central Atlantic tropical wave has its axis near 33W from 02N 
to 10N, moving westward at 10 to 15 kt. Nearby convection is 
discussed in the monsoon trough/ITCZ section below.

An Atlantic tropical wave has its axis near 46W from 04N to 17N, 
moving westward at 15 kt. The wave is producing a large area of 
showers and thunderstorms. Gradual development of this system is 
possible during the next several days while it moves generally 
westward at around 20 mph. 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 through much of next week. The wave will also produce strong 
winds and gusty seas across the tropical Atlantic waters this 
weekend and the Caribbean next week. 

An Atlantic tropical wave has its axis near 56W 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 60W. 

...MONSOON TROUGH/ITCZ... 

The monsoon trough enters the Atlantic near 12N16W and extends 
southwestward to near 05N26W and west to 05N31W. The ITCZ extends
from 05N34W to 05N40W. Scattered moderate and isolated strong
convection is noted from 01N to 10N between 14W and 40W. 
 
...GULF OF AMERICA...

High pressure prevails over the Gulf waters. Moderate to locally
fresh winds are over the NE Gulf, with gentle to moderate winds
elsewhere. Seas are in the 2-4 ft range over the E Gulf, and 1-3
ft elsewhere. 

For the forecast, moderate E to SE winds and slight to moderate 
seas are expected over much of the Gulf through late today as high
pressure prevails over the southeastern United States. A cold 
front will enter the northwestern Gulf on Sun and progress 
southeastward across the basin into early next week. Moderate to 
locally fresh N to NE 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. Satellite 
imagery shows scattered showers and isolated thunderstorms near 
the trough. Otherwise, a weak pressure gradient is supporting 
gentle to moderate east to southeast winds east of about 68W, and
light to gentle winds elsewhere. Seas are in the 3-4 ft range E of
67W and 1-3 ft elsewhere.

For the forecast, light to gentle, with locally moderate, winds and
slight seas are expected over the Caribbean today. 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, and into the eastern Caribbean Sun night. 
Gradual development of this system is possible, and there is a low
chance of tropical development within the next 7 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 impact some sections of the 
north-central waters through the weekend.

A cold front extends from 31N51W to 23N68W. A dissipating 
stationary front is from 31N42W to 23N56W, with a frontal trough 
then extending to Hispaniola. Scattered moderate to isolated 
strong convection in the vicinity of these fronts. Fresh to 
strong winds are found N of 23N E of the cold front to 44W. Fresh
to near gale winds are N of 27N W of the front to 70W. Gentle to
moderate winds generally prevail elsewhere W of the fronts. Seas
of 8-14 ft are found N of 23N E of the cold front to 42W, and N 
of 25N W of the front to 75W. Elsewhere W of the front, seas are 
in the 5-7 ft range. Fresh to strong winds, and rough seas, 
accompany a tropical wave near 47W. High pressure dominates the 
remainder of the discussion waters N of 20N, anchored by a 1020 mb
high centered near 25N33W. Light winds are around the high 
center, with gentle to moderate winds elsewhere. Aside from seas 
mentioned above, 4-7 ft seas prevail. 

For the forecast W of 55W, the front will propagate southeastward
and stall along 22N this weekend. Fresh to strong winds are N of 
24N and E of the front. Strong to near gale winds are N of 28N W 
of the front to 67W. Winds will diminish from west to east late 
today into Sun. Widespread rough seas prevail north of 23N and 
east of 75W. The rough seas will spread SE to cover much of the 
waters E of 75W by early Sun, then will slowly subside from west 
to east Sun into next week. Very rough seas can be expected north 
of 27N and east of 71W through Sun. High pressure will build in 
the wake of the front with improving conditions late this weekend 
into early next week.

$$
AL