[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131021
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Tue Jul 13 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
1000 UTC.

...SPECIAL FEATURES...

Due to tightening pressure gradient between a 1031 mb high over
the NE Atlantic and a pronounced surface trough across NW Africa,
gale winds and rising seas are expected off the coast of Morocco for
the next couple of days. Meteo-France at Agadir has issued a Gale
Warning valid until 00 UTC on Jul 14 for N to NE winds of Force 8
on the Beaufort Wind Scale.

For more details, refer to the Meteo-France High Seas Forecast
listed on their website:
www.meteofrance.com/previsions-meteo-marine/bulletin/grandlarge/
metarea2

...TROPICAL WAVES...

An Atlantic tropical wave is near 24W from 15N southward and
moving W at 10 to 15 kt. Scattered showers and a few thunderstorms
are seen from 06N to 12N between 23W and 27W.

Another Atlantic tropical wave is along 47W from 13N southward
and moving W at 15 to 20 kt. Scattered moderate to isolated strong
convection is noted from 07N to 10N between 50W and 53W.

A Caribbean tropical wave extends from central Cuba central
Panama, and moving W at 15 to 20 kt. Scattered moderate convection
is noted off Honduras south of 18N and west of 80W.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Senegal at 13N16W to
08N25W to 08N37W. Segments of the ITCZ continue from 08N37W to
07N47W, and from 07N50W to the coast of Guyana near 06N57W. In
addition to the areas of convection mentioned in the Tropical
Waves section above, scattered moderate convection is observed
from 06N to 13N east of 19W to the African coast, and from 05N to
08N between 35W and 40W.

...GULF OF MEXICO...

A surface ridge extends east to west along the northern Gulf
coast. A trough is analyzed south of this ridge over the northeast
Gulf, from 26N88W to near Panama City, Florida. Another trough is
evident over the west-central Gulf off Tampico, Mexico. This
pattern is supporting moderate to fresh E winds and seas to 5 ft
across the Straits of Florida, and over the eastern Bay of
Campeche. Elsewhere, gentle to moderate E to SE winds and slight
to moderate seas are noted. A few showers and thunderstorms are
active off the coast of Tamaulipas in northeast Mexico, near the
surface trough in that area. No significant shower or thunderstorm
activity is noted elsewhere.

For the forecast, the surface ridge just north of the area will
maintain gentle to moderate winds and slight to moderate seas
across much of the Gulf through Fri. A surface trough will develop
each day over the Yucatan and shift westward into the SW Gulf.
This will support fresh to occasionally strong winds off the
northwest Yucatan Peninsula and eastern Bay of Campeche during the
overnight hours through mid week.

...CARIBBEAN SEA...

An earlier scatterometer satellite pass indicated near-gale force
winds across the Gulf of Venezuela, and a large area of fresh to strong
tradewinds elsewhere across the southeast and south-central parts
of the basin. Seas in these areas are estimated to be 8 to 11 ft.
The enhanced wind flow is occurring as high pressure builds in the
wake of the tropical wave moving across the basin. Fresh to
strong NE winds are evident along the Windward Passage, with seas
likely reaching 8 ft near the northern entrance to the Passage.
The scatterometer pass also showed fresh to locally strong E winds
off eastern Honduras and northeast Nicaragua, just ahead of the
wave axis. The convergent wind flow was supporting scattered
showers and thunderstorms in this same area as well. A few
thunderstorms are active across the Corn Islands of Nicaragua,
ahead of the tropical wave. Farther south, the interaction of the
tropical wave with the monsoon trough is supporting a cluster of
strong thunderstorms over the Gulf of Uraba along western part of
the Caribbean coast of Colombia.

For the forecast, the tropical wave from central Cuba to central
Panama will move west of the basin by tonight into early Wed.
High pressure centered north of the region will continue to support
strong to near- gale force tradewinds and building seas into Wed
over the central Caribbean, including strong nocturnal NE winds
across the Windward Passage tonight into Wed. Winds and seas will
diminish Wed through Fri. Looking ahead, tradewinds and related
seas will increase over the south-central Caribbean and around the
Leeward Islands Sat and Sat night as another tropical wave
approaches the eastern Caribbean.

...ATLANTIC OCEAN...

Please see the Tropical Waves and Monsoon Trough/ITCZ sections
above for additional convection across the basin. Also refer to
the Special Feature section for gale winds and rough seas off the
coast of Morocco.

An upper-level low over the Georgia-S Carolina border at 32N81W
is helping to trigger scattered showers and isolated
thunderstorms north of the northern Bahamas and east of east-
central Florida, and off northeast Florida. A few showers and
thunderstorms are noted in the Cay Sal area of the Bahamas as
well, just north of where a tropical wave is situated. Meanwhile,
a ridge extends north of the area from roughly Bermuda to the
Carolinas. This pattern will maintaining gentle to moderate E
winds across the basin, with fresh to strong winds pulsing off the
coast of Hispaniola. Seas are 5 to 7 ft in open waters, although
reaching 8 ft near the northern approaches to the Windward
Passage. Farther east, fresh NE winds and seas to 8 ft are ongoing
over the tropical Atlantic waters east of the Caribbean, between
the ridge axis and a complex of troughs analyzed roughly north of
20N between 40W and 50W. This trough is being enhanced by an upper
low centered near 27N56W. Scattered showers and thunderstorms are
noted directly beneath this upper low. Fresh to strong NE winds
are noted east of 25N, with reaching gale force of Morocco, with 7
to 10 ft seas. Elsewhere over the eastern Atlantic, gentle to
moderate NE winds and 5 to 7 ft seas persist.

For the forecast, winds and seas over the tropical Atlantic west
of 35W will diminish through tonight. Fresh to strong winds will
pulse off Hispaniola again tonight, but overall little change is
expected through Fri. Looking ahead, winds and seas will build Sat
south of 22N and north of of Leeward Islands as a tropical wave
approaches the region from the east. Expect fresh to strong winds
to again pulse off Hispaniola by Sat as well.

$$
Christensen
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