[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201729
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Wed Dec 20 2023

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, 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 1200 UTC surface analysis and satellite imagery through
1710 UTC.

...SPECIAL FEATURES...

...Central Atlantic Ocean Significant Swell Event...

Very rough seas are from 22N northward between 40W and
60W, and from 27N northward between 30W and 40W.
The sea heights range from 11 feet to 12 feet from 16N to
22N between 40W and 60W. Strong NE winds are from 11N to
25N from the Cabo Verde Islands eastward. Strong
anticyclonic wind flow covers the area that is from 16N
northward between the Cabo Verde Islands and 36W. Strong
E to SE winds are from 25N northward between 45W and 58W.
Fresh to strong NE winds are from 05N to 16N between the
Cabo Verde Islands and 36W. A 1053 mb high pressure center
is near 46N27W. The ridge will slide eastward and weaken
during the next few days. The wind speeds will slow down,
and the sea heights will subside to less than 12 feet
on Thursday.

Please read the latest NWS High Seas Forecasts, and the
Offshore Waters Forecasts, that are issued by the National
Hurricane Center, at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and
www.nhc.noaa.gov/marine/offshores.php, for more details
about the Very Rough Seas.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the Prime Meridian
along 03N, to 07W. The ITCZ continues from 03N07W, to
03N14W and 02N40W. Precipitation: isolated moderate to
locally strong is from 11N southward from 60W eastward.

...GULF OF MEXICO...

A surface ridge passes through SE Louisiana, to the coastal
plains of Mexico near 22N97W. An upper level trough is moving
through the eastern half of the Gulf of Mexico. Precipitation:
broken to overcast multilayered clouds, and isolated moderate
to locally strong, are to the north of the line that runs
from the upper Texas Gulf coast, toward the Yucatan Channel.
Shallow patches of moisture are supporting isolated showers
throughout the rest of the area.

Mostly fresh to some strong NE winds are in the eastern
one-third of the area. Mostly moderate to some fresh easterly
winds are in the rest of the Gulf of Mexico. Moderate seas
are in the SE corner and into the Straits of Florida. Slight
seas cover the rest of the Gulf of Mexico.

Strong high pressure of 1033 mb over the Ohio Valley will
shift slowly eastward into the eastern U.S. through Fri.
This system will support fresh to locally strong easterly
winds over the SE Gulf, including the Straits of Florida
through at least Thu night. SE return flow is expected
to develop Sat, becoming fresh to strong across N portions
Sat night through Sun.

...CARIBBEAN SEA...

A cold front passes through the Atlantic Ocean, to the
SE Bahamas near 21N71W. A stationary front continues
from 21N71W, curving through Haiti, to 16N76W in the
Caribbean Sea, to the coast of Colombia near 10N76W.
Precipitation: isolated moderate to locally strong is
from 16N southward between 64W and 80W. Shallow patches
of moisture are supporting isolated showers throughout
the rest of the area.

Moderate to rough seas cover the open waters and the
offshore waters of the Caribbean Sea from 72W westward.
Slight seas cover the rest of the area that is from 72W
eastward, and in the coastal waters from 72W westward.
Mostly strong to some fresh northerly winds are from
the stationary front westward. Moderate easterly winds
are from the stationary front eastward.

A stationary front extends from Haiti to near eastern
Panama. Fresh to strong N to NE winds and seas to 11 ft
follow the front. High pressure will build SE across the
western Atlantic through Fri. This will force the N part
of the front to drift SE across Hispaniola through early
Thu while gradually dissipating. Fresh to strong N to NE
winds behind the front will veer NE tonight through early
Fri, with strongest winds in the lee of Cuba and through
the Windward Passage. At the same time, fresh trades are
expected in the south-central Caribbean, including the
Gulf of Venezuela, pulsing to strong each night. High
pressure will move N of the region Sat through Sun to
bring a return to more typical E trade winds.

...ATLANTIC OCEAN...

Please, read the SPECIAL FEATURES section, for details
about the Central Atlantic Ocean Significant Swell Event.
Rough seas, in general, are to the north of the line
11N60W 10N50W 07N34W 08N27W 16N22W, to the coast of
Africa along 16N; and to the north of the line that runs
from the NE Caribbean Sea islands beyond the northern
coasts of the Bahamas Islands. Moderate seas are in
the remainder of the Atlantic Ocean, except for slight
seas from the Bahamas southward.

A cold front passes through 31N64W to 24N65W, curving
to the SE Bahamas near 21N71W. A stationary front
continues from 21N71W, curving through Haiti, to
16N76W in the Caribbean Sea, to the coast of Colombia
near 10N76W. Mostly strong to some fresh northerly wind
flow is from the cold front northwestward. A surface
trough is along 27N59W 20N58W. Precipitation: widely
scattered moderate to isolated strong is within 30 nm
to 60 nm on either side of the line 24N60W beyond 31N62W.
Isolated moderate is elsewhere from 19N northward
between 54W and 65W, and within 60 nm to the south of
the cold front between 69W and 71W.

A north central Atlantic Ocean cold front curves through
31N37W to 29N40W and 29N45W. A stationary front continues
from 29N45W to 31N51W. Precipitation: isolated moderate
is from 28N northward between 30W and 52W.

A surface trough is along 22N44W 18N46W 15N54W 14N60W.
Precipitation: scattered moderate to isolated strong is
from 19N to 25N between 38W and 50W.

Strong NE winds are from 11N to 25N from the Cabo Verde
Islands eastward. Strong anticyclonic wind flow covers
the area that is from 16N northward between the Cabo
Verde Islands and 36W. Fresh to strong NE winds are from
05N to 16N between the Cabo Verde Islands and 36W. Strong
E to SE winds are from 25N northward between 45W and 58W.

A cold front extends from near Bermuda to Haiti. Fresh
to strong northerly winds prevail between the front and
75W. Strong high pressure will build into the western
Atlantic behind the front through early Thu and maintain
the fresh to strong N to NE winds, before gradually
diminishing to moderate to fresh Thu night through
Fri. The front will move SE and reach from 31N61W to
central Hispaniola this evening, from 28N55W to the
N Mona Passage Thu evening, then gradually dissipate
through Fri. Winds will slowly subside Fri night
and Sat as high pressure weakens, with seas subsiding
modestly.

$$
mt/gr
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