[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 101010
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Fri Dec 10 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
1000 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough remains mostly confined to the African
continent, reaching the coast of Guinea near 09N13W and extending
to 07N17W. The ITCZ then continues from 07N17W to 01S46W.
Scattered moderate convection is noted from 04N to 07N between
16W and 42W.

GULF OF MEXICO...

A broad surface ridge extends from the Mid-Atlantic states to the
Gulf of Mexico. A dry continental airmass continues to suppress
the development of showers and thunderstorms across the region,
allowing for tranquil weather conditions. Recent scatterometer
satellite data and surface observations indicate that moderate to
locally fresh SE-S winds prevail W of 90W, while weaker winds are
noted elsewhere in the basin. Seas of 2-4 ft are occurring in the
Gulf, with the highest seas prevailing in its northwestern
waters.

For the forecast, the high pressure ridge will gradually shift
eastward through Sat afternoon in response to a strong cold front
that will move over the NW Gulf on Sat. Moderate to fresh
southerly return flow will set-up across the western and central
Gulf beginning late Fri ahead of the front. Fresh to strong
northerly winds and building seas are expected in the wake of the
front through Sat night. The front will weaken as it reaches from
central Florida to the SW Gulf Sun and dissipate by Mon. Fresh to
strong east winds will spread westward through the Straits of
Florida and to the eastern Gulf S of 26N Mon through Tue night
along with building seas.

CARIBBEAN SEA...

The tight pressure gradient as a result of the strong ridge north
of the Greater Antilles and lower pressures over northern South
America is causing strong to near gale-force trades in the south-
central Caribbean, with the strongest winds occurring off the
coast of NW Colombia. Fresh to locally strong trades are noted in
the north-central Caribbean and moderate to fresh trades
elsewhere in the basin. Seas of 5-8 ft are prevalent in the
central Caribbean, with the highest seas occurring off NW
Colombia. Seas of 2-5 ft prevail in the rest of the basin.
Tranquil weather conditions continue across the Caribbean due to
very dry atmospheric conditions limiting the formation of
convection.

For the forecast, the aforementioned pressure gradient between
a ridge across the northern Caribbean Sea and the
Colombian/Panamanian low will continue to support fresh to strong
trades over the south- central Caribbean through the weekend.
Moderate to fresh trades will prevail elsewhere. High pressure
will continue to strengthen over the western Atlantic today
resulting in fresh to locally strong northeast winds in the
Windward Passage, the lee of Cuba and south of Hispaniola through
Tue night.

ATLANTIC OCEAN...

A weak stationary front extends from 31N62W to the Space Coast of
Florida near 28N80W. A recent scatterometer satellite pass show
moderate to locally fresh NE winds behind the frontal boundary. In
general, winds W of 60W are moderate or weaker. Seas of 4-7 ft
prevail W of 60W.

A broad surface trough is located along 51W from 15N to 26N with
scattered showers. The rest of the tropical Atlantic is dominated
by the robust Azores high, resulting a fairly tranquil weather
conditions. Satellite-derived wind data depict fresh to strong
easterly winds N of 05N and E of 55W. The strongest winds are
confined to E of 33W and N of 16N. Seas of 8-11 ft are found E of
48W, while seas of 5-8 ft are found elsewhere in the basin.

For the forecast west of 65W, the weakening stationary front
will dissipate through the next 18 hours. High pressure will
continue building in the wake of the front, supporting moderate
to fresh NE to E winds S of 22N, and mainly gentle to moderate
winds N of 22N through Sat night. The next cold front will move
off the northeast Florida coast early on Sun, and reach from near
31N65W to South florida by Sun night. This front is forecast to
dissipate over the southeastern waters on Mon. High pressure
behind the front will bring fresh to strong northeast to east
winds mainly across the waters south of 27N by Mon night. These
conditions are expected to last through Tue night.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Marine and
aviation interests should monitor this ongoing situation by
reading the Volcanic Ash Advisory issued by Meteo-France, at
http://vaac.meteo.fr/volcanoes/la-palma/.

$$
ERA
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