[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131559
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Jul 13 2023

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
1550 UTC.

...SPECIAL FEATURES...

Atlantic Gale Warning: As of 1200 UTC Invest Area AL94 was
located just north of the discussion area at 31.1N 48.2W. The
minimum central pressure is 1004 mb and maximum sustained winds
are near 35 kts. While the Ocean Prediction Center has an active
gale warning for this system, a recent scatterometer pass found
evidence that gale force winds extend south of 31N on the SE
quadrant of the low. Maximum sustained winds are currently 35 kts
with seas to 13 ft. Seas in excess of 8 ft extend as far south as
27N. Scattered moderate convection is observed from 26N to north
of 31N, between 42W and 46W. Strong southerly winds extend as far
south as 26N, between 43W and 47W. This invest area currently has
a medium chance of developing into a tropical cyclone over the
next 48 hours, however the gale warning is set to expire at 21 UTC
as the system slowly moves off to the north. Please read the
latest NWS High Seas Forecast issued by the National Hurricane
Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml
for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave extends along 33W from 16N to
02N, moving west at 15-20 kt. Scattered moderate convection is
observed from 08N to 11N between 31W and 35W.

A central Atlantic tropical wave extends along 48W from 16N to
02N, moving west at 15-20 kt. Scattered moderate convection is
observed from 10N to 12N between 45W and 49W.

A central Caribbean tropical wave extends from the coast of Haiti
near 18N73W to the coast of Colombia near 11N74W. Scattered
moderate convection is observed from 16N to 19N between 71W and
77W. Isolated convective activity is noted in both the Windward
and Mona Passages.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 16N17W to
09N33W to 12N41W. The ITCZ continues in segments from 12N41W to
11N46W, and from 10N51W to 09N60W. In addition to the convection
associated with the tropical waves, scattered moderate convection
is observed along the monsoon trough from 09N to 13N between 23W
and 29W. Similar convection is observed along the western segment
of the ITCZ from 08N to 10N between 53W and 58W.

GULF OF MEXICO...

A surface trough is moving NW across the Bay of Campeche,
supporting a few showers and thunderstorms offshore Veracruz,
Mexico. Otherwise, high pressure continues to dominate the Gulf of
Mexico. In the western Gulf, winds are moderate from the SE-S
with 3-5 ft seas. In the eastern Gulf, anticyclonic winds are
gentle around a 1017 mb high centered near 28N84W. Seas are 1-3 ft
east of 90W.

For the forecast, a ridge will continue to dominate the Gulf
waters, through early next week, while a trough will develop over
the Yucatan Peninsula each evening and move offshore. This pattern
will maintain moderate to fresh winds pulsing north and west of
the Yucatan peninsula during the late afternoon and evening hours.
Elsewhere, gentle to moderate winds and slight seas will prevail.

CARIBBEAN SEA...

For details about convection in the Caribbean Sea, please see the
Tropical Wave section above.

The standard gradient between subtropical high pressure and lower
pressure over the SW Caribbean Sea is supporting moderate to fresh
easterly trade winds across the majority of the basin. Fresh NE
winds are funneling through the Windward Passage, enhanced by the
approaching tropical wave. Strong winds are noted in the south-
central Caribbean and south of Hispaniola. Seas are 5-7 ft in the
eastern and central basin, and 3-5 ft in the NW basin.

For the forecast, a tropical wave that extends from the
southeastern Bahamas to 15N73W and to NW Colombia will move across
the rest of the central Caribbean through early this afternoon,
then across the remainder of the Caribbean through Sun. Another
tropical wave will move across the Windward Islands Sat afternoon,
and enter the southeastern Caribbean that afternoon. It will move
across the rest of the southeastern Caribbean through Sun night
and across the western Caribbean Mon and Mon night. The passage of
the tropical waves will modulate fresh to strong winds across
mainly the central Caribbean through the period. Winds may reach
gale-force in the Gulf of Venezuela Fri night.

ATLANTIC OCEAN...

Please refer to the special features section for information
Invest area AL94 and the associated gale warning in the central
subtropical Atlantic.

A surface trough east of Florida is supporting scattered moderate
convection from 27N to 28N between 77W and 80W. Otherwise weak
ridging along 22-27N is the dominate feature in the western and
central Atlantic. Winds are generally moderate or less, except
for fresh easterlies near the Greater Antilles and the strong to
gale winds associated with Invest Area AL94. Seas are generally
3-5 ft outside of the direct impacts from this system. In the
eastern Atlantic, the gradient between the Azores high and lower
pressure over NW Africa is supporting moderate to fresh NE winds,
with strong funneling between the Canary Islands. Seas are in the
5-7 ft range.

For the forecast west of 55W, high pressure will persist
northeast of the Bahamas through Sun. Farther south, the northern
end of a tropical wave will move westward across the waters south
of 22N through Fri. Expect fresh to strong NE to E winds and rough
seas south of 22N both ahead of and following the tropical wave.
Looking ahead, the ridge will shift northward early next week
ahead of another tropical wave that will be approaching the area.

$$
Flynn
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