[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 080517
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Fri Dec 8 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 0000 UTC surface analysis and satellite imagery through
0505 UTC.

...SPECIAL FEATURE...

Atlantic Significant Swell Event: A cold front extends from
31N47W to 24N57W, where it becomes a stationary front to the
Dominican Republic. A recent scatterometer satellite pass captured
fresh to strong winds are found north of 27N and between 40W and
60W. Seas of 12-17 ft are present north of 26N and between the
front and 65W. Seas of 8-12 ft are noted between 65W and 75W, and
also east of the front to 37W and north of 25N. These seas will
diminish gradually and decay below 12 ft by late Sat.

Please, read the latest 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 details.

...MONSOON TROUGH/ITCZ...

The monsoon trough is confined to the African continent. The ITCZ
extends from 09N17W to 04N33W to 00N50W. Scattered moderate
convection is observed from 02N to 07N and between 25W and 49W.

...GULF OF MEXICO...

High pressure dominates the Gulf of Mexico. Stratocumulus clouds
cover most of the basin due to the dry continental airmass
filtering southward from the United States. A moderate pressure
gradient support moderate to fresh southerly winds and seas of 3-5
ft west of 95W and north of 22N. Moderate to fresh easterly winds
and seas of 3-5 ft are found in the Florida Straits. Elsewhere, moderate
or weaker winds and seas of 2-4 ft prevail.

For the forecast, high pressure of 1023 mb centered near Jacksonville,
FL is spreading surface ridging over the Gulf of Mexico,
producing a gentle to moderate anticyclonic flow. The high
pressure will shift eastward into the Atlantic tonight, inducing
moderate to locally fresh return flow across most of the basin Fri
through Sat. A strong cold front is forecast to enter the NW Gulf
Sat evening. The front will reach from Mobile, AL to Tuxpan,
Mexico Sun morning, from Cedar Key, FL to the central Yucatan
Peninsula Sun evening, and exit the basin Mon morning. Strong to
gale force winds are expected behind the front, with gale force
winds possible across the western Gulf, from offshore southern
Texas southward to the Bay of Campeche Sat night through Sun
evening. Strong NW gales to near storm-force are possible
offshore Veracruz Sun afternoon. A line of strong thunderstorms is
likely to accompany the cold front as it moves across the Gulf of
Mexico. Winds and seas will gradually subside across the basin
late Mon.

...CARIBBEAN SEA...

A weak stationary front stretches from Haiti to the Bay Islands of
Honduras. A few showers are noted near the boundary. High pressure
north of the islands sustain fresh to strong trade easterly winds
in the south-central Caribbean Sea. These winds were confirmed by
a recent scatterometer satellite pass. Seas in these waters are
8-10 ft. The strongest winds and highest seas are found offshore
NW Colombia. Fresh to locally strong easterly winds and seas of
5-8 ft are evident in the north-central Caribbean, including the
Windward Passage. Moderate to fresh easterly breezes and seas of
4-7 ft are prevalent in the remainder of the basin.

For the forecast, the aforementioned front will remain nearly
stationary through Fri while gradually weakening. Fresh NE winds
will continue Fri to the NW of the front across the northwest
Caribbean, including the Gulf of Honduras. Fresh to strong NE
winds in the Windward Passage will continue through Sat night.
Strengthening high pressure N of the area will bring an increase
in the aerial extent of the fresh to strong trade winds across the
central Caribbean during the upcoming weekend, with the strongest
winds near the coast of Colombia. Looking ahead, the next cold
front will enter the northwest Caribbean late Sun night or early
Mon, followed by fresh N to NE winds.

...ATLANTIC OCEAN...

Please see the Special Features section above for details about
very rough seas in the central Atlantic.

The cold front entering the tropical Atlantic near 31N47W is the
only feature of interest across the basin, outside of the deep
tropics. The front stretches from 31N47W to 24N58W, where it
becomes a stationary front to the Dominican Republic. Latest
satellite imagery depict shallow convection within 120 nm on both
sides of the boundary. For information on the winds and seas
associated with this feature, please read the Special Features
section. The remainder of the SW North Atlantic (west of 55W) is
dominated by a broad subtropical ridge positioned near NE Florida.
Moderate to fresh NE winds and seas of 7-10 ft are present south
of 24N and west of the front.

The rest of the central and eastern tropical Atlantic is dominated
by a 1027 mb high pressure system positioned near Madeira island.
The pressure gradient between this ridge and lower pressures in
the deep tropics support a broad area of moderate to fresh
easterly winds south of 20N and west of 35W. Seas in these waters
are 6-9 ft. Similar winds and seas are evident from 17N to 27N and
east of 35W. Elsewhere, moderate or weaker winds and slight to
moderate seas prevail.

For the forecast W of 55W, the aforementioned front will become
stationary on Fri, stretching from 22N55W to the N coast of
Hispaniola by Fri afternoon, then will remain nearly stationary
along 21N on Sat. Strengthening high pressure N of the area will
push the front farther south on Sun reaching the northern Leeward
Islands as a dissipating front. The gradient between the strong
high pressure along 31N and lower pressure associated with the
stalled front will induce fresh to strong NE to E trade winds
south of 23N Fri afternoon through Sun. On Sun, fresh to strong
southerly flow will set up over the waters east of northeast
Florida to about 70W in advance of the next cold front. This cold
front is expected to move into the NW forecast waters late Sun,
followed by strong northwest winds. Brief winds to gale force
appear possible north of 30N near this front, east of northern
Florida. Seas will build both east and west of this cold front.

$$
Delgado
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