[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040317
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Thu Mar 4 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 0000 UTC surface analysis and satellite imagery through
0330 UTC.

...SPECIAL FEATURES...

Atlantic Gale Warning: A deepening low pressure system of 1004
mb is analyzed northeast of the northern Bahamas near 30N75W. An
occluded front wraps around the low to north of 31N and then
enters back south of 31N as a cold front near 31N72W to across the
northern Bahamas and to the Straits of Florida. A trialing
reinforcing trough extends approximately 30-60 nm behind the
front. Vigorous showers and thunderstorms are occurring north of
26N and ahead of the cold front. A gale warning remains in effect
for the waters north of 30N and ahead of the front, with fresh to
strong winds elsewhere north of 26N between 60W-80W. Seas of 8-14
ft accompany these winds, and will peak at around 16 ft along 31N
Thu. The gale warning will remain in effect through early Thu
afternoon with winds diminishing to fresh to strong ahead of the
front thereafter. Please read the latest NWS High Seas Forecast
from the National Hurricane Center at the website:
www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details on the
Gale Warning.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea-Bissau near
12N16W to 23N16W. The ITCZ continues from 23N16W to 00N38W to the
coast of Brazil near 03N44W. Scattered moderate and isolated
strong convection is noted from 00N-03N between 15W-31W, from
02S-07N between 27W-37W and from 04N-07N between 38W-42W.

GULF OF MEXICO...

A cold front is in the process of exiting the basin, extending
from the Straits of Florida to the northeast tip of the Yucatan
Peninsula near 21N87W and continuing inland to 17N93W just east of
the Chivela Pass. A pair of 1021 mb high pressure areas are
analyzed in the western Gulf, one near the Texas/Louisiana border
at 29N94W and the other near Tampico, Mexico at 21.5N97.5W. Areas
of low-level clouds dominate the basin in the wake of the front
with cool dense air in place. Winds behind the front are
diminishing with mainly moderate to locally fresh northerly
winds, except fresh to strong in the eastern Bay of Campeche. Seas
are 3-6 ft behind the front, and 3 ft or less ahead of the front.

The cold front will completely exit the basin overnight. A low
pressure system will develop in the northwest Gulf on Fri night,
then deepen and move rapidly eastward across the Gulf through Sat
night. High pressure building behind the front will support strong
E winds across the eastern Gulf Sun night through Mon night. Seas
will build with the increasing winds by the end of the weekend
into early next week.

CARIBBEAN SEA...

A cold front is in the process of moving southeast across the
Yucatan Channel. Weak 1017 mb high pressure is ahead of the front
southwest of central Cuba near 21N81W. Low pressure is analyzed
over northern Colombia near 08N74W. Fresh to strong winds are in
the south-central Caribbean where the pressure gradient is tight,
with moderate to fresh trades elsewhere south of 16N, and gentle
to moderate winds north of 16N. Seas are 7-10 ft in the south-
central and southwest Caribbean, and 4-7 ft elsewhere south of 16N
and east of 82W. Seas of 2-4 ft cover the remainder of the basin.
As it is normal for this time of the year, shallow moisture
embedded in the trade wind flow is moving across the area
producing isolated to scattered passing showers.

The cold front moving through the Yucatan Channel will stall and
weaken across the NW Caribbean Thu and Fri. Fresh to occasionally
strong winds will prevail in the southern Caribbean near the
coasts of Venezuela and Colombia through Sun, with gentle to
moderate winds expected elsewhere. Looking ahead, another front
may move into the northwest Gulf Sat night and Sun, stall from the
Windward Passage to Belize by Sun night, then dissipate Mon. Winds
are forecast to increase to fresh to strong across the majority of
the central and western Caribbean by the end of the weekend into
early next week as the pressure gradient in the wake of the next
cold front significantly tightens due to building high pressure
north of the area. Seas will also build significantly across
those portions of the basin with the increasing winds.

ATLANTIC OCEAN...

Attention remains focused on the deepening low pressure located
northeast of the northern Bahamas. See the Special Features
Section above for details on the ongoing Gale Warning associated
with this low.

A cold front extends into the area near 32N40W to 30N50W, then
continues west-northwest as warm front through 32N63W to the gale
force low mentioned above. Areas of showers and thunderstorms are
spreading across the waters north of 26N and west of 55W. A pre-
frontal trough is analyzed front 32N36W to 28N47W, with a frontal
trough analyzed to the east from 31N24W to 28N33W. The remainder
of the Atlantic forecast waters south of these features is
dominated by ridging anchored by a 1025 mb high pressure located
26N37W. Strong mid-upper westerly winds are transporting abundant
moisture from NE South America all the way to western Africa,
including the Cabo Verde Islands.

Looking ahead, another developing low pressure system will move
rapidly from central Florida to Bermuda Sat night and Sun,
possibly accompanied by winds to gale force, and dragging a cold
front across the region through Sun night and Mon. High pressure
building in the wake of the front will produce a large area of
fresh to strong N-NE winds across the waters south of 27N and west
of 60W by the end of the weekend into early next week. As a
result, seas will build across the waters west of 60W.

$$
Lewitsky
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