[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292315
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Thu Dec 30 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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

...Atlantic Gale Warning...

A cold front reaching from the eastern Azores to the central
Atlantic near 20N45W will stall and dissipate west of 35W through
tonight. A second, reinforcing cold front moving across the north
central Atlantic will move across the waters north of 25N and
east of 50W through Thu night, accompanied by winds to minimal
gale force near 31N35W Thu afternoon. Very rough seas to 18 ft
will also accompany the front in NW swell, with swell to 8 ft
reaching as far south as 22N east of 55W through Thu night. Winds
will diminish through Fri as the front stalls along 27N. Seas to
12 ft will linger through Fri north of 22N between 35W and 55W.

...Caribbean Gale Warning...

High pressure centered northeast of the Bahamas will build
through Fri, supporting fresh to strong trade winds across the
central Caribbean Sea through Sun, with winds pulsing to minimal
gale force off Colombia Thu night, with seas to 14 ft. Gale force
winds are expected to pulse once again on Fri night.

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 remains inland over Africa. The ITCZ extends from
06N11W to 03N33W to 02N50W near the coast of NE Brazil. Scattered
moderate convection with embedded thunderstorms is noted from 01N
to 06N along the length of the ITCZ.

...GULF OF MEXICO...

The gradient between high pressure in the western Atlantic and
lower pressure over eastern Mexico is generating moderate to fresh
SE to S winds across the majority of the Gulf. Seas are
predominately 5 to 7 ft over most of the basin, with seas 2-4 ft
in the SE Gulf.

For the forecast, surface high pressure centered NE of the
central Bahamas will remain nearly stationary through Sun and
support moderate to locally fresh return flow across the central
and western basin, increasing to fresh to strong Fri night as the
pressure gradient increases ahead of a strong cold front forecast
to come off the coast of Texas Sat evening. Strong to near gale
force northerly winds will follow this front, with gale conditions
affecting the NW and SW basin Sun and Sun evening. The front is
forecast to move east of the gulf Mon morning. Winds and seas
associated with the front will gradually subside through Mon
night.

...CARIBBEAN SEA...

Please see the Special Features section for details about the
gale warning in effect for the Caribbean.

A 1021 mb high pressure centered north of the area is supporting
fresh to strong trade winds across the central Caribbean. Seas are
5 to 8 ft across this area. Fresh E to SE winds are noted across
the Gulf of Honduras and the eastern Caribbean with seas 4 to 6
ft. Elsewhere, moderate E to SE winds and 3 to 5 ft seas are
observed. No significant shower or thunderstorm activity is
evident at this time with waver vapor satellite imagery confirming
very dry air dominates the basin.

For the forecast, the high pressure centered NE of the central
Bahamas will remain nearly-stationary through Sun, supporting
moderate to fresh trade winds across the Caribbean, except for
locally strong winds in the Gulf of Honduras, central Caribbean
and portions of the SW basin. Gale force winds are expected off
Colombia Thu night and Fri night.

...ATLANTIC OCEAN...

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

A 1021 mb high pressure NE of the Bahamas near 27N67W dominates
the weather in the Western Atlantic. This is generating mostly
light to gentle anticyclonic flow and 3 to 5 ft seas west of 65W.
Moderate SW winds are noted off the northeast Florida coast and
moderate E winds extending 180nm north of the Greater Antilles.

Farther east, a cold front extends from 31N28W to 19N47W in the
central and eastern Atlantic. Scatterometer data confirms a fresh
westerly breeze behind the front with strong SW winds extending
300 nm ahead of the front north of 24N. Scattered moderate
convection is observed east of the front within 120 nm N of 23N.
Near gale force winds expected in the vicinity of thunderstorms.
Significant wave heights of 12-14 ft area noted from 26N to 31N
between 30W and 50W with 8 ft seas extending as far south as 17N
in the central Atlantic. The subtropical ridge extends from high
pressure over the Iberian Peninsula to 20N35W. Gentle to moderate
NE winds and 5 to 7 ft seas are observed south of the ridge.

For the forecast west of 65W, high pressure centered NE of the
central Bahamas will remain nearly-stationary through early Sun.
The high pressure will weaken and move east Sun ahead of a strong
cold front moving off the northeast Florida coast late Sun night.
Strong to near gale force winds and building seas associated with
the front will affect the offshore waters N of 26N Sun and Mon.

$$
AReinhart
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