[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201036
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Jan 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 32N. 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.

...SPECIAL FEATURES...

Caribbean Gale Warning: High pressure north of the area will
continue to support strong to near gale force winds over the
south-central Caribbean through the latter part of the week.
Nocturnal pressure fluctuations will cause these winds to pulse to
gale force within 90 nm off the coast of Colombia this morning,
and again tonight. Please read the latest NWS High Seas Forecast
issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Sierra
Leone near 08N13W to 07N17W to 06N20W. The ITCZ continues from
06N20W, to 02N30W and 02N40W. A few showers are possible form 03N
to 05N between 15W and 20W.

GULF OF MEXICO...

A surface ridge extends 1029 mb high pressure over Apalachicola,
Florida, across the northern Gulf to the Texas coast. This is
supporting moderate to locally fresh E winds south of 25N, with 4
to 6 ft seas, and gentle to moderate E to SE winds north of 25N
with 1 to 3 ft seas. Relatively warm, moist SE flow over cooler
shelf waters along the north Texas coast are supporting the
potential for sea fog this morning. Elsewhere, no significant
weather is observed.

For the forecast, the ridge will persist across the northern Gulf
through Fri. A trough will form off the west coast of the Yucatan
Peninsula tonight, supporting brief pulses of fresh to strong
winds. A cold front will move over the northern Gulf Sat and
become stationary into Sat night. The western part of the front
will begin to lift north as a warm front late Sat night through
Sun, while the rest of the front dissipates as Atlantic high
pressure builds westward across the area through Sun night.

CARIBBEAN SEA...

A tight gradient due to high pressure north of the area is
supporting fresh to strong NW winds in the lee of Cuba, Windward
Passage, off Cabo Beata on the southern coast of Hispaniola, and
over much of the south central and southwest Caribbean, to include
the winds to gale force off Colombia. Fresh trade winds persist
over the eastern Caribbean, and moderate to fresh NE winds are
noted elsewhere in the northwest Caribbean. Seas are 8 to 13 ft
over the southwest Caribbean due in part to NE to E swell. Seas
are reaching 8 ft off Belize and Quintana Roo due to the long
fetch of fresh NE winds from the Cuban coast. 5 to 7 ft seas are
noted elsewhere. Regional radar suggests scattered showers persist
in the trade wind flow across the eastern Caribbean.

For the forecast, little change in the pattern through tonight.
Winds and seas diminish Thu through Sat as the high pressure
weakens, although strong winds will persist off Colombia through
Sat night.

ATLANTIC OCEAN...

West of 60W: A cold front reaches from 31N45W to 26N60W, then is
stationary to the Turks and Caicos Islands. Farther west, a
surface ridge extending west to east along roughly 28N/29N is
supporting moderate to fresh NE winds with 5 to 7 ft seas in open
waters south of 25N, and gentle to moderate winds and 4 to 6 ft
seas north of 25N, except 2 to 5 ft north of the northern Bahamas
and off the northeast Florida coast. No significant shower
activity is evident.

For the forecast, the front will dissipate through tonight, as a
new cold front moves southward into waters between northeastern
Florida and Bermuda. The main portion of this new front will lift
to the northeast of the area Thu, leaving a trailing stationary
segment to dissipate along 27N by Thu evening. This front will be
followed by yet another cold front that will move southward across
the waters between Bermuda and NE Florida late Fri, reach from
near 31N60W to 27N70W and to West Palm Beach, Florida Sat night,
then begin to weaken as it reaches the far southern waters late
Sun. High pressure will build over the area in the wake of this
front.

Farther east, a ridge extends along 27N/28N supporting moderate
to fresh NE to E trade winds south of 25N where seas are 8 to 9 ft
in a mix of N swell and shorter period wind waves. NW swell is
reaching as far south as 30N between 45W and 65W, but 4 to 6 ft
seas are noted elsewhere north of 25N. A sharp upper trough
reaches from the Canary Islands to near 10N40W. Upper divergence
southeast of the upper trough is supporting moderate showers
within 480 nm to the southeast of the upper trough.

$$
Christensen
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