RSS NHC Tropical Weather Discussion

NHC Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 172055
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0015 UTC Thu Dec 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 1800 UTC surface analysis and satellite imagery through
2000 UTC.

...SPECIAL FEATURES...

Western and Central Atlantic Gale Warning: A stationary front
extends from 31N50W to 25.5N66W then continuing as a remnant
frontal trough to the SE Bahamas. A low pressure is forecast to
develop along the frontal system tonight into Thu near 29N60W.
Gale force winds and rough to very rough seas are expected across
the W semicircle of the low center Thu through early Fri as the
low moves NE and deepens, before gradually exiting the forecast
area Fri night. Peak seas under the strongest winds are
anticipated to be at 13 to 18 ft by late Thu afternoon and evening
and will persist through Fri evening before subsiding as well as
moving north of the area. Please read the latest High Seas and
Offshore Waters Forecasts issued by the National Hurricane Center
at website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and
https://www.nhc.noaa.gov/marine/offshores.php for more information
this event.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic along the Liberia coast near
06N10.5W, then runs west-southwestward to 06N15.5W. The ITCZ
continues from 06N15.5W to 07.5N26W to 03N46.5W to the NE of the
northern coast of Brazil. Widely scattered moderate convection
is seen S of 17N to the Equator between Africa and 37W.

The eastern end of the East Pacific monsoon trough is triggering
widely scattered showers across the Caribbean waters near
Nicaragua and Panama, although thunderstorms seemed to have
diminished in the past few hours per recent conventional infrared
satellite imagery.

...GULF OF AMERICA...

A surface trough reaches southward from near Corpus Christi,
Texas through a 1012 mb low east of Brownsville, Texas to another
1012 mb low just southeast of Tampico, Mexico. Scattered showers
and isolated thunderstorms are occurring offshore from
southeastern Texas and northeastern Mexico, mainly to the east of
these features. Farther southeast, a surface trough generating
scattered showers at the south-central Gulf, including the
Yucatan Channel. Moderate to fresh E to SE winds and seas of 4 to
6 ft are seen across the northwestern, west-central and eastern
Gulf, including the Straits of Florida. Gentle to moderate E to
SE winds with 2 to 4 ft seas prevail for the rest of the Gulf.

For the forecast, a ridge will dominate the Gulf region through
Thu, with winds veering to the south and southwest ahead of the
next cold front, forecast to move into the NW Gulf Thu evening.
This front will reach from the Florida Big Bend to near
Brownsville, Texas by Fri morning, and from SW Florida to NE
Mexico Fri evening, then begin to lift northward and dissipate
through Sat. High pressure will move into the NE Gulf Sat night
and Sun.

...CARIBBEAN SEA...

The southern end of a surface trough is causing scattered showers
at the northwestern basin, including the Gulf of Honduras and
Yucatan Channel. Refer to the Monsoon Trough/ITCZ section for
additional weather in the Caribbean Sea. Otherwise, a trade-wind
regime continues across much of the Caribbean Sea. Fresh to strong
ENE to E winds and seas of 6 to 8 ft are present at the south-
central basin offshore northern Colombia. Gentle to moderate NE
to E winds and 3 to 5 ft seas are noted at the far northwestern
and far southwestern basin. Moderate with locally fresh easterly
winds and seas at 4 to 6 ft prevail elsewhere in the Caribbean
Sea, including the lee of Cuba. SEas are locally 6 to 8 ft near NE
and eastern Caribbean-Atlantic passages.

For the forecast, fresh to locally strong trade winds and
moderate to rough seas will prevail over the south-central
Caribbean through Thu as high pressure shifts eastward into the
western Atlantic. Elsewhere, moderate to fresh winds are expected,
with the exception of gentle to moderate winds over the NW
Caribbean. Large E swell will persist over the tropical Atlantic
waters, through the Atlantic passages and into the eastern part of
the basin through Thu night. High pressure will strengthen north
of the basin Thu night into the weekend to bring a return to fresh
to strong trades across the central and southwest Caribbean.

...ATLANTIC OCEAN...

Please see the Special Features section at the very beginning
about a Gale Warning in the western and central Atlantic.

A stationary front extends from 31N50W to 25.5N66W then continuing
as a remnant frontal trough to the SE Bahamas. Scattered
moderate convection is evident up to 120 nm along the southern
side of the frontal system, s well as north of the frontal system
between 47W and 68W. Refer to the Monsoon Trough/ITCZ section for
additional convection in the Atlantic Basin.

Fresh to now near gale-force NE to ENE winds and seas at 7 to 11
ft in large N swell are found near and north of the frontal system
east of 68W. A 1028 mb high is to the east of the front near
31N23.5W. A ridge extends southwestward from the high and ahead of
the front to near 27N55W. Gentle to moderate anticyclonic winds
and 5 to 8 ft seas are present under the ridge mainly north of 26N
and east of the front to 23W. Fresh to locally strong NE to E
trades prevail across the remainder of the waters southeast-south
of the ridge and frontal system, as well as offshore northern
Africa. Seas are 7 to 11 ft across the area of fresh to strong
winds, except higher, at 9 to 13 ft northeast of the Canary
Islands and offshore far northern Africa.

For the forecast W of 55W, a low pressure is forecast to develop
along the frontal system tonight into Thu near 29N60W. Gale force
winds and rough to very rough seas are expected across the W
semicircle of the low center Thu through early Fri as the low
moves NE and deepens, before gradually exiting the forecast area
Fri night. Peak seas under the strongest winds are anticipated to
be at 13 to 18 ft by late Thu afternoon and evening and will
persist through Fri evening before subsiding as well as moving
north of the area. The next cold front will move into the NW
waters Fri, reach from near Bermuda to the Straits of Florida Sat
morning, then stall and weaken from 31N60W to the central Bahamas
Sat evening. Another cold front may move off NE Florida by Sun
night.

$$
Lewitsky