[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181818
TWDAT

Tropical Weather Discussion...Update
NWS National Hurricane Center Miami FL
1805 UTC Sat Dec 18 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 1200 UTC surface analysis and satellite imagery through
1630 UTC.

...SPECIAL FEATURES...

Updated webpage for METEO-FRANCE forecast

A cold front curves west-southwestward from S of the Azores
Islands through 31N27W to 30N31W, then continues northwestward as
a warm front to beyond 31N at 35W. Fresh to near-gale winds and
seas of 13 to 16 ft associated with these features are present
N of 28N between 24W and 50W. Scattered moderate convection is
seen N of 30N between 26W and 42W. Near-gale to gale-force winds
are forecast by the METEO-FRANCE near Madeira and Irving through
Sun 21z. Refer to the website:
http://www.weather.gmdss.org/bulletins/METAREA2.HIGH_SEAS_FORECAST.1001.
18100130565.html, for more details.

...MONSOON TROUGH/ITCZ...

The ITCZ extends west-northwestward from SW of Sierra Leone at
05N19W to 09N36W, then continues westward from 10N39W to near the
Venezuela-Guyana border. A surface trough is situated between the
ITCZs near 09N30W. Scattered showers and isolated thunderstorms
are seen the first ITCZ from 03N to 10N between 22W and 32W.
Scattered showers are found near the surface trough and second
ITCZ from 05N to 12N between 32W and Venezuela-Guyana border.

...GULF OF MEXICO...

An upper-level trough near 27N86W is triggering scattered showers
and isolated thunderstorms over the E central Gulf. Otherwise, a
surface ridge stretching southwestward from northern Florida to
central Mexico is dominating the entire Gulf with gentle to
moderate SE to SSW winds, and seas of 3 to 5 ft.

For the forecast, a cold front will move off the Texas coast this
evening, bringing strong to near gale-force winds to the NW Gulf
and along the coast of Mexico Sun into Mon. The front will move
slowly until low pressure forms along the front in the central
Gulf late Mon, then moves northeastward into the SE U.S. Tue,
dragging the cold front across the Gulf as it does. Winds and seas
will subside Tue night into Wed in the wake of the front.

...CARIBBEAN SEA...

Two surface troughs are producing scattered showers and isolated
thunderstorms over the NW basin, near the Mexico-Belize and
Honduras-Nicaragua borders and nearby waters. Moderate ESE trades
and seas of 4 to 6 ft are present across the NW basin. Moderate
to fresh E trades and seas at 6 to 8 ft are noted over the SW
basin. Fresh to strong with locally near-gale ENE to E trades with
seas of 8 to 12 ft are evident over the central basin. Fresh ENE
to E trades and seas at 7 to 9 ft prevail for the E basin.

For the forecast, the Bermuda High building southward through the
Atlantic will support fresh to strong trades over the central and
E Caribbean and tropical N Atlantic this weekend. The high will
move east for the start of next week, leading to weaker trades.
Large N to NE swell will continue in the tropical N Atlantic as
well as Mona and Anegada Passages through Mon. Looking ahead, a
cold front should move through the Yucatan Channel Tue.

...ATLANTIC OCEAN...

A weak cold front curves southwestward from just W of the Canary
Islands through 31N20W to well NW of the Cabo Verde Islands at
20N36W, then continues west-southwestward as a shear line to E of
the Leeward Islands at 18N59W. Scattered moderate convection is
noted up to 60 nm along either side of the cold front. Scattered
showers are occurring near and up to 80 nm N of the shear line. to
the N of 27N. Converging surface winds farther S of this cold
front are coupling with strong mid to upper-level winds to trigger
scattered moderate convection and widespread cloudiness near Cabo
Verde Islands from 12N to 31N between the Mauritania coast and
35W.

A 1026 mb high S of Bermuda near 29N64W is providing light to
gentle winds and seas of 4 to 6 ft N of 26N between 55W and
George-Florida coast. Moderate to fresh with locally near-gale
W to SW winds with seas of 5 to 8 ft are found N of 26N between
the NW African coast and 24W. Gentle to moderate N to NE trades
and seas of 4 to 6 ft are seen near the Cabo Verde Islands from
08N to 26N between the Mauritania coast and 26W. Moderate to fresh
NE trades and seas at 9 to 11 ft are evident from 07N to 26N
between 26W and the Greater/Lesser Antilles. Refer to the Special
Features Section for additional information on winds and seas over
the central Atlantic. Gentle to moderate ENE to SE trades and
seas of 5 to 6 ft prevail for the remainder of the Atlantic Basin.

For the forecast W of 60W, the Bermuda High is inducing fresh to
strong trades near the Greater Antilles and mainly gentle winds
elsewhere. These conditions will prevail through early Sun, before
the high moves to the E and winds relax. A cold front will move
off the SE U.S. coast Sun night and continue eastward, bringing
strong to near-gale winds on both sides of the front mainly north
of 28N. Low pressure is likely to move northeastward off the SE
U.S. coast Tue, bringing another potential for strong to near-gale
winds on Wed. Large N swell impacting the Atlantic zone from 19N-
22N between 55W-65W will diminish on Sun.

$$

Chan
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