[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201004
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Dec 20 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
0930 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: A cold front stretches from South
Florida to near 24N92W to near Veracruz, Mexico. Gale force winds
are ongoing E of Tampico, Mexico. As low pressure forms in the
western Gulf today, these gale winds will move NE to the N and W
of the track of the low pressure, and into the north-central Gulf
of Mexico by this evening. The low will then move NE into northern
Gulf late tonight, and conditions will somewhat improve. Seas of
10 to 14 ft are expected in the area of gale-force winds,
especially offshore Tampico, Mexico, this morning. Please refer
to the latest High Seas Forecast that is issued by the National
Hurricane Center, at the following website:
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details.

Atlantic Gale Warning: Low pressure will track NE from the NE Gulf
of Mexico, across northern Florida, and into the Atlantic tonight
into Tue. This strengthening low will lead to gale force southerly
winds ahead of it late Tue, mainly N of 28N and W of 70W, with the
potential for more gale force W winds behind the trailing cold
front Tue night into early Wed. Seas of 9 to 14 ft are also likely
in the area of gale force winds. As the low moves well NE of the
area and in the wake of the cold front, conditions will slowly
improve by Wed night. Please refer to the latest High Seas
Forecast that is issued by the National Hurricane Center, at the
following website:
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details.

Eastern Atlantic Gale Warning from 35W eastward: Gale-force winds
are forecast in the area that is called IRVING. An Azores low
pressure center and two frontal boundaries are to the north of 25N
from 31W eastward. These conditions are expected to continue
until 21 December at 00 UTC. Please refer to the Meteo-France High
Seas Forecast on the following website,
http://www.gmdss.org/bulletins/METAREA2.HIGH_SEAS_WARNING.1956.19
1956225601.html, for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of Liberia
near 06N11W to 05N19W. The ITCZ continues from 05N19W to 04N25W
and 04N36W. A surface trough is along 39W/40W from 06N toward the
Equator. Scattered moderate convection noted within 150 nm both
sides of the monsoon trough, and within 150 nm to the N of the
ITCZ.

...GULF OF MEXICO...

Please see Special Features section above for details on gale
conditions being induced by a cold front and developing low
pressure moving eastward across the Gulf of Mexico today and
tonight.

The stalling cold front stretches early this morning from South
Florida to near 24N92W, with an accelerating southern portion of
the front extending S from 24N92W to the western Bay of Campeche.
Strong N winds are noted behind this front W of 94W, with fresh NE
winds elsewhere N of the boundary. To the south and east of the
front, mainly gentle to moderate easterly winds prevail. Seas in
the area of strong winds in the western Gulf range from 8 to 12
ft, with seas elsewhere behind the front ranging from 4 to 7 ft.
Seas are 2 to 4 ft ahead of the front in the SE Gulf.

For areas within 180 nm behind the front, N of 22N and W of 85W,
numerous moderate to isolated strong convection is occurring. A
cluster of numerous strong convection is noted from 24N to 28N
between 89W and 93W.

Low pressure will form well E of Tampico, Mexico today, along the
frontal boundary, then track NE into Tue. The portion of the
front to the east of the low will retreat north as a warm front,
while the cold front will continue to the south of the low. Gales
offshore Veracruz early this morning will propagate NE through the
day, to the N and W of the center of the low, and into the north-
central Gulf of Mexico. The low and cold front will move east and
through the basin by later on Tue, with strong winds and high
seas impacting most of the basin, before conditions improve Wed,
as weak high pressure builds into the area.

...CARIBBEAN SEA...

Strong winds are ongoing within 120 nm N of the Caribbean coast
of Colombia, with moderate to fresh trades dominating the much of
the rest of the basin, except for gentle to moderate E winds in
the NW Caribbean. Seas are 5 to 7 ft, except 8 to 10 ft offshore
Colombia and 2 to 4 ft in the NW basin. No significant convection
is ongoing this morning.

The gradient between retreating high pressure to the northeast
and lower pressure over South America will lead to fresh to strong
winds across waters offshore Colombia into tonight, with moderate
to fresh winds elsewhere across the basin. Large N to NE swell
will continue in the tropical N Atlantic into Tue. A cold front
will move through the Yucatan Channel late Tue, then reach an
eastern Cuba to Nicaragua line by Wed night, before stalling.
Fresh N winds can be expected behind this front.

...ATLANTIC OCEAN...

Please see Special Features section above for gale conditions that
will develop offshore northern Florida Tue in association with low
pressure and a cold front, as well as low pressure that is
inducing gale conditions in the far eastern Atlantic, to the S of
the Azores.

High pressure of 1020 mb centered near 28N58W is dominating much
of the basin early this morning, causing generally gentle winds to
between 24N and 32N. Farther south, fresh to locally strong trades
are ongoing, highest between 40W an 50W. Off the SE U.S. coast, an
eastward moving cold front stretches from W of Bermuda through the
NW Bahamas and into South Florida. Fresh to strong NW winds are
occurring behind this front, with some fresh to locally strong S
winds ahead of it, N of 28N and W of 50W.

A large area of NE swell combined with wind waves exists across
the width of the basin S of 23N, translating to seas of 8 to 11
ft. Farther N and E, closer to the strong low pressure over the
Azores, northerly swell is leading to seas N of 27N and E of 45W
of 9 to 13 ft. Elsewhere, seas are 4 to 6 ft, except seas are now
increasing behind the aforementioned cold front offshore Florida,
with waves of 7 to 10 ft occurring.

Most of the basin is convection-free, but a band of moderate
thunderstorms is occurring within 60 nm ahead of the cold front SW
of Bermuda. This activity is confined to areas N of 28N.

A cold front from west of Bermuda through the NW
Bahamas to South Florida will track east today, with little
additional southward progress. Strong W winds are likely N of 29N
in association with it. Low pressure developing in the Gulf of
Mexico and moving NE to offshore northern Florida and Georgia
today into Tue will cause the western portions of the front to
retreat northward as a warm front. Near the low, strong to gale
force winds are expected over northwest waters late Tue into Thu.

$$
KONARIK
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