[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131804
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Wed Dec 13 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
1500 UTC.

...SPECIAL FEATURES...

Central Atlantic Gale Warning:
A newly developed 1014 mb low is centered along a stationary front
near 24N43W. Near-gale to gale-force NE to ENE winds along with 14
to 16 ft seas are occurring northeast of the low from 26N to 29N
between 38W and 43W. As this low gradually tracks west-
northwestward through Thursday, these gale winds and even higher
seas at 16 to 19 ft will shift westward. Please read the latest
High Seas Forecast issued by the National Hurricane Center at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

Atlantic Significant North Swell:
Large north swell continues to sustain 12 to 15 ft seas from the
Virgin and northern Leeward Islands northeastward to near 45W
between 18N and 30N. As this swell starts to decay this evening,
both sea heights and coverage area will gradually decrease
overnight. Seas are expected drop below 12 ft by late Thursday
morning.

Western Atlantic and Florida Offshore Gale Warning:
A stationary front extends southwestward from near Bermuda across
31N68W and the central Bahamas and Florida Straits to beyond
western Cuba. A strong high pressure is forecast to move offshore
from the Carolinas early Thursday morning. Tight pressure gradient
between these two features will cause fresh to strong NE winds
currently across the offshore waters of southeast Florida and
north of the Bahamas to become near-gale to gale-force by mid
Thursday morning. Seas of 8 to 10 ft in these waters will also
build further to between 11 and 15 ft by Thursday afternoon. Once
the high has moved farther eastward toward the north-central
Atlantic on Saturday, both winds and seas at these waters should
gradually subside. Meanwhile, a low pressure system is anticipated
to form near the stationary front at the southeastern Gulf of
Mexico on Saturday, then moves northeastward across central and
northern Florida into the western Atlantic through Sunday. This
system might cause southerly gales and very rough seas in the
central and northeast Florida offshore waters on Sunday, and
western Atlantic waters Sunday night through Monday.

For the Significant North Swell and Western Atlantic/Florida
Offshore Gales, please read the latest High Seas and Offshore
Waters Forecasts issued by the National Hurricane Center, at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and
https://www.nhc.noaa.gov/marine/offshore.php for more details.

...MONSOON TROUGH/ITCZ...

A monsoon trough stays mostly east of 10W along the central Africa
coast. An ITCZ meanders west-northwestward from offshore of
Liberia at 05N12W across 06N40W to just southeast of Trinidad and
Tobago at 10N59W. Widely scattered to scattered moderate
convection is seen up to 200 nm south, and 150 nm north of the
ITCZ.

...GULF OF MEXICO...

The stationary front mentioned in the Special Features section
continues southwestward from the Florida Straits across western
Cuba to just south of the Yucatan Channel. Convergent ENE winds to
its north are causing widely scattered showers and isolated
thunderstorms across the south-central and southeastern Gulf, and
the Florida Straits and Yucatan Channel. Otherwise, a broad
surface ridge extends southwestward from a strong 1037 mb high
over northern Alabama to near Veracruz, Mexico. Fresh to strong
ENE winds and seas of 6 to 9 ft are present across the eastern
Gulf. Moderate to fresh ENE to ESE winds and 5 to 8 ft seas exist
at the central and northwestern Gulf. Gentle to moderate NE to E
winds and seas at 3 to 6 ft prevail for the rest of the Gulf.

For the forecast, strong high pressure building across the eastern
United States will continue to support fresh to strong winds over
the eastern Gulf. Areal coverage of the fresh to strong winds
will increase to the northwestern Gulf by early Thursday. A large
area of near gale-force winds will develop over the north-central
and eastern Gulf Thu through Fri night with the potential to
reach gale force. Low pressure will develop north of the Yucatan
Peninsula Fri night into Sat and then track northeastward across
central Florida Sat night into Sun morning. A cold front will move
into the western Gulf Sat, with strong to near-gale force winds
and rough seas. The front will merge with the area of low pressure
by Sat night and exit the Gulf Sun morning.

...CARIBBEAN SEA...

A surface trough curves northeastward from a 1014 mb low at the
western Gulf of Honduras to the southwestern end of a stationary
front just south of the Yucatan Channel. Another surface trough is
seen at the southwestern basin near the San Andres and Providencia
Islands. Widely scattered moderate convection is occurring near
these features over the northwestern basin and along the coast of
Nicaragua and Costa Rica. Up to 8 inches of rain was reported at
Havana, Cuba which caused some river flooding. Strong to near-
gale ENE trade winds and seas of 11 to 13 ft are evident at the
southwestern basin north of eastern Panama and northwestern
Colombia. Fresh to strong ENE trades and 8 to 10 ft seas are found
at the central and northeastern basin, and near the Windward
Passage. Gentle to moderate NE to E winds and seas at 5 to 7 ft
are noted at the Gulf of Honduras and waters near Costa Rica and
western Panama. Moderate to fresh NE to ENE winds and 6 to 8 ft
seas prevail elsewhere in the basin.

For the forecast, strong high pressure north of the region will
support fresh to strong trade winds across the central and eastern
basin through tonight. Fresh to strong NE winds and rough seas
over the northwestern basin will diminish to between moderate and
fresh by this evening. Fresh to strong NE winds in the Windward
Passage will diminish Fri night.

...ATLANTIC OCEAN...

Please read the Special Features section at the beginning on
Significant North Swell and multiple Gale Warnings.

A stationary front extends southwestward from near Bermuda across
31N68W and the central Bahamas and Florida Straits to beyond
western Cuba. Scattered showers and isolated thunderstorms are
seen near and up to 200 nm northwest of this boundary. Another
stationary front curves southwestward from south of the Azores
across 31N30W and a 1014 mb low near 24N43W to east of the
northern Leeward Islands at 18N57W. Scattered moderate convection
is evident north 18N between 32W and 48W. Farther south, a surface
trough is triggering scattered showers from 12N to 18N between 43W
and 50W. Refer to the Monsoon Trough/ITCZ section for additional
convection in the Atlantic Basin.

Fresh to strong NE to ENE winds and seas of 7 to 10 ft are noted
behind the first stationary front, including the northwest Bahamas
and Florida offshore waters. Outside the winds and seas mentioned
in the Special Features section, fresh to strong NE to E winds and
8 to 11 ft seas are exist from 16N to 30N between the second
stationary front and the southeast Bahamas/Puerto Rico. Gentle to
moderate E to SE winds and seas at 6 to 8 ft dominate the area
in between these two areas, including the central Bahamas. To the
south, gentle to moderate NE to SE winds and 6 to 8 ft seas are
present from 04N to 16N/20N between 30W and the Lesser Antilles.
Near the Canary and Cabo Verde Islands, gentle with locally
moderate with locally fresh NE to SE winds and seas of 4 to 7 ft
in moderate NW swell are found north of 07N between the Africa
coast and 30W/second stationary front. Light to gentle winds and 4
to 6 ft seas in mixed moderate swells prevail for the remainder of
the Atlantic Basin.

For the forecast W of 55W, the first stationary front is forecast
to lift northward towards the northwest Bahamas and the Straits
of Florida today. Strong high pressure building north of the area
will lead to the development of strong to near-gale force NE to E
winds and building seas over the northern Bahamas and Straits of
Florida today, with these winds spreading northward and eastward
through Fri. Gale-force winds are expected east of Florida by the
end of the week. An area of low pressure is forecast to move from
the Gulf of Mexico, across Florida, and into the Atlantic waters
this weekend. A large area of gale force winds are possible east
of the low.

$$

Chan
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