Tropical Weather Discussion

- as issued by NHC/TPC -

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Tropical Weather Discussion (NHC/TPC):
NWS National Hurricane Center Miami FL
1805 UTC Fri Jan 22 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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200|UTC surface analysis and satellite imagery through=20
1710 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: High pressure north of the area and
low pressure over northern Colombia will combine for a tight
pressure gradient offshore of northwest Colombia where winds will
pulse to gale force during the overnight into the early morning
hours for the next several days. Seas will build to 6-10 ft=20
during the gale force winds. Please read the latest NWS High=20
Seas Forecast issued by the National Hurricane Center at the=20
website https://urldefense.com/v3/__https://www.nhc.noaa.gov/text/MIAHSFAT2=
.shtml__;!!DZ3fjg!rSRmK7ZXJT8QPwMMVW9iajf5k9MuZ3uvHpxRYSQZ2k5ecm1StQWXa2JyU=
HlbVgelJP1qZGYG$  for more=20
details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Liberia near 05N09W
to 03N24W. The ITCZ then extends from 03N24W to 04N41W to the
coast of northern Brazil near 03N51W. An area of scattered
moderate convection is noted along the monsoon trough from
00N to 05N between 15W and 23W. Scattered showers to isolated
moderate convection persist along the ITCZ.

GULF OF MEXICO...

Onshore flow along the Texas coast is producing patchy
dense fog that should lift by this afternoon. A surface
trough extends across the northwestern Gulf of Mexico from
SW Louisiana to Tampico, Mexico, where an interesting mesoscale
low is observed on satellite imagery. The remainder of the Gulf
is under the influence of a receding ridge of high pressure that
is centered northeast of the Bahamas. The latest ASCAT pass
shows gentle SW winds in the eastern Gulf, with gentle to=20
moderate S winds in the western Gulf. 2-4 ft seas are found
over the entirety of the Gulf of Mexico. Except for the patchy
fog in the western Gulf, no significant weather is observed
at this time.

A weak cold front will move into the N Gulf later today,
becoming stationary tonight, and dissipating by Sat night.
High pressure building north of the front over the SE United
States will support a gradual increase of SE winds and building
seas across W Gulf Sat into Sun, with strong SE winds possible
in NW Gulf by Sun night. Winds and seas diminish across the
Gulf Mon as the high shifts farther east with a weak cold=20
front moving into NW Gulf Mon afternoon. The front should
stall over NW and W Gulf on Tue.

CARIBBEAN SEA...

Please refer to the Special Features section for information
on a Gale Warning in the south central Caribbean off the
coast of Colombia.

Elsewhere across the Caribbean, fresh to strong trades are
noted in the south central Caribbean, with mainly moderate
to fresh trades elsewhere. Seas are mainly 3-6 ft across
the basin outside of the stronger winds near the coast of
Colombia. Mainly fair conditions are noted on satellite
imagery with isolated trade wind showers possible.

The Bermuda High displaced to near the Bahamas will
continue to support fresh to strong winds over the=20
south central Caribbean, with winds pulsing to gale force
during the overnight hours off the coast of Colombia through
the next several nights. Mainly moderate to fresh trades
will prevail elsewhere, pulsing to fresh to strong near
the Gulf of Honduras on Monday and Tuesday. No significant
cold fronts are expected to reach these waters for at least
the next several days. N swell will propagate into the
Tropical N Atlantic waters on Monday and Tuesday.

ATLANTIC OCEAN...

West of 60W, a 1019 mb high pressure near 25N72W extends
a ridge from the Gulf of Mexico, across the Straits of
Florida and the Bahamas. A cold front extends from=20
31N70W to the FL/GA border. Light to gentle winds are
noted underneath the ridge from 20N to 27N, with moderate
to locally fresh WNW winds observed north of 27N in
association with the cold front. Strong winds are noted
north of 30N between 65W and 71W. NW swell of 7-11 ft
prevails north of 23N and east of 68W, with 3-6 ft seas
in mainly E to NE swell elsewhere outside of the Bahamas.
Seas are 2-4 ft west of the Bahamas.

East of 60W, a cold front enters our area near 31N48W,
continuing SW to 27N53W where it becomes stationary to
25N61W. An area of scattered moderate to strong=20
convection is noted north of 25N between 40W and 48W.
Over the eastern Atlantic, 1029 mb high pressure is=20
centered near 32N24W. Moderate to fresh NE flow was=20
observed by scatterometer over most of the basin. NW swell
of 8-14 ft covers the majority of the area north of 24N/25N
with 6-9 ft seas south of 24N/25N. Scattered moderate=20
convection, enhanced by an upper-level trough, is observed
from the monsoon trough north to 23N between 08W and 23W.

For the forecast, a cold front will move into the waters
between Bermuda and NE Florida today, reaching along 28N
by Sat afternoon, then merging with a reinforcing front
along 24N east of the Bahamas by Sun afternoon, and finally
stalling along 20N off the coast of the Dominican Republic
by Mon afternoon. A strong Bermuda High will build over
the area in the wake of this front. A new cold front may
emerge off of the SE United States coast and move across
the basin beginning on Tue night.

$$
Graphical representation of waves, etc. on this image (NCEP/OPC) [more].
Various tropical satellite imagery available here

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