[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281009
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Tue Dec 28 2021

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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

...Atlantic Gale Warning...

A deepening low pressure system located over the central
Atlantic is producing hurricane force winds N of the forecast
area, with gale force winds that extend into the discussion area
south of 31N. A cold front associated with the deepening low
enters the Atlantic forecast region near 31N40W and extends
westward to near 23N60W and then to 25N70W east of the Bahamas.
SW winds to gale force are occurring north of 29n and east of the
front to 35W. Very large seas are accompanying the front with NW
swell. An altimeter satellite pass from around 0830 UTC indicated
seas as high as 20 ft along 31N following the front. Scattered
showers and thunderstorms are evident within 90 nm east of the
front. The front will move southwest through Wed, with gale
force winds lifting NE of the area midday today. Seas will subside
accordingly, although 8 to 14 ft seas will persist north of 20N
and east of 60W through tonight. Please read the latest NWS High
Seas Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more
information.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Sierra Leone near
08N13W to 06N20W. The ITCZ continues from 06N20W to the coast of
NE Brazil near 00N47W. No significant convection is evident at
this time.

...GULF OF MEXICO...

The extension of a ridge that is centered near Abaco Island,
Bahamas near 27N77W reaches westward across the Gulf waters.
Gentle to moderate SE to S flow and seas of 1-3 ft prevail over
the eastern half of the Gulf while moderate to fresh SE to S
winds with seas of 3-6 ft are noted over the western half of the
Gulf.

For the forecast, the ridge extending from the western Atlantic
into the Gulf will continue support moderate to fresh winds
across the central and western Gulf through Wed. The ridge will
shift eastward, allowing gentle to moderate winds and slight to
moderate seas across the entire basin Thu as a weak frontal
boundary stalls and dissipates along the Texas coast. Looking
ahead, southeast to south winds are expected to increase over the
western Gulf by late Fri as low pressure moves into the Central
Plains. A strong cold front associated with this low pressure may
reach the Texas coast late Sat night.

...CARIBBEAN SEA...

Weak high pressure centered north of the area over the northern
Bahamas dominates the pattern across the Caribbean Sea. Earlier
scatterometer and altimeter passes confirmed the presence of fresh
to strong northeast winds and seas of 7 to 9 ft off the coast of
Colombia with moderate to locally fresh trades and 5-7 ft
prevalent across the remainder of the south- central Caribbean,
including the Windward Passage. Elsewhere, seas of 3-5 ft are
noted, with the exception of the far eastern part of the basin
where gentle to moderate trades are observed.

For the forecast, winds and seas will increase through mid week across
the central Caribbean and the Gulf of Honduras as high pressure
near the Bahamas builds.

...ATLANTIC OCEAN...

Please see the Special Features section above for details about
the gale warning in the Atlantic.

High pressure is building over the waters west of 65W in the wake
of the cold front moving through the region. This is supporting
gentle to moderate winds and 3 to 5 ft seas over open waters.
Farther east, the Atlantic ridge extends from 1025 mb high
pressure over Morocco, southeastward to 20N50W, supporting light
to gentle winds along the ridge axis. Moderate to fresh trade
winds and seas of 4 to 7 ft prevail across the tropical Atlantic
south of the ridge axis.

For the forecast west of 65W, the cold front will move southeast
of the region through Wed. High pressure currently over the
northern Bahamas will shift eastward following the front, and
strengthen northeast of the Bahamas through Sat.

$$
Christensen
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