[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131804
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 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 1200 UTC surface analysis and satellite imagery through
1740 UTC.

...SPECIAL FEATURES...

Gale-force winds are being included in the Meteo-France high
seas forecast, for the area that is called AGADIR, during the
next 12 hours or so. The surface pressure gradient has been
increasing, between a 1032 mb high pressure center that is near
41N24W, and lower surface pressures in NW Africa. The sea
heights range from 8 feet to 9 feet from 27N northward from 32W
eastward. Please, refer to the following website,
http://www.gmdss.org/II.html for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 21W/22W, from 13N
southward, moving westward from 10 knots to 15 knots.
Precipitation: monsoon trough-related precipitation surrounds
this tropical wave.

An Atlantic Ocean tropical wave is along 51W/52W, from 13N
southward, moving westward from 10 knots to 15 knots.
Precipitation: ITCZ-related precipitation surrounds this
tropical wave.

A Caribbean Sea tropical wave is along 80W from Cuba southward,
moving westward from 10 knots to 15 knots. Precipitation:
scattered to numerous moderate-to-strong is 210 nm to 310 nm to
the west of the tropical wave, from Honduras to 20N. Some
precipitation also is reaching the coast of the Yucatan
Peninsula from 19N to 20N. Similar scattered to numerous
moderate-strong precipitation is in the coastal plains/coastal
waters from NE Costa Rica to east central Nicaragua.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of Guinea
near 11N15W, to 09N20W, and 09N30W. The ITCZ continues from
09N30W, to 09N36W, 08N46W, 09N50W, and 08N58W. Precipitation:
widely scattered moderate to isolated strong is within 250 nm to
the north of the monsoon trough/ITCZ, and within 330 nm to the
south of the monsoon trough/ITCZ.

GULF OF MEXICO...

Broad upper level cyclonic wind flow spans the Gulf of Mexico,
from the Texas Big Bend and the Deep South of Texas, into the
southwest corner of the Gulf of Mexico and to the central Gulf
waters. Precipitation: scattered moderate to strong is in the SW
corner of the Gulf of Mexico. Isolated moderate to locally
strong is elsewhere in the Gulf of Mexico, mostly from 86W
westward.

A surface ridge is to the north of the area, from central
Georgia to NE Texas. Broad surface anticyclonic wind flow covers
the Gulf of Mexico. A surface ridge extends from the NE corner
of Florida, toward southern Mississippi and SE Louisiana, to
south central Texas.

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

CARIBBEAN SEA...

A Caribbean Sea tropical wave is along 80W from Cuba southward,
moving westward from 10 knots to 15 knots. Precipitation:
scattered to numerous moderate-to-strong is 210 nm to 310 nm to
the west of the tropical wave, from Honduras to 20N. Some
precipitation also is reaching the coast of the Yucatan
Peninsula from 19N to 20N. Similar scattered to numerous
moderate-strong precipitation is in the coastal plains/coastal
waters from NE Costa Rica to east central Nicaragua.

Expect strong-to-near gale force east winds, and sea heights
ranging from 9 feet to 13 feet, from 18N southward between 69W
and 82W, now and for the next 24 hours or so.

A tropical wave, that extends from western Cuba to eastern Costa
Rica, will move to the west of the basin by Wednesday. High
pressure centered to the north of the region will support strong
to near-gale force trade winds and building seas into Wednesday
in the central Caribbean Sea, including strong nocturnal NE
winds across the Windward Passage from tonight into Wednesday.
The winds and the seas will diminish from Wednesday through
Friday. The trade winds and related seas will increase in the
south central Caribbean Sea and around the Leeward Islands, on
Saturday and Saturday night, as another tropical wave approaches
the eastern Caribbean Sea.

ATLANTIC OCEAN...

A middle level to upper level trough extends from South Carolina
to SE Florida. Deep tropical moisture is in the same area. Some
atmospheric instability to the northern end of the 80W tropical
wave also is involved. Precipitation: scattered moderate to
widely scattered strong covers the land areas and the waters
that are from the Atlantic Ocean coast of Cuba to 28N in Florida
between the eastern coastal waters of the Bahamas to 83W in
Florida and in the Gulf of Mexico. Isolated moderate is
elsewhere from 28N northward from 75W westward to Florida.

One upper level cyclonic circulation center is near 27N57W.
Upper level cyclonic wind flow covers the Atlantic Ocean from
12N northward between 43W and the Bahamas. Comparatively drier
air in subsidence is apparent in water vapor imagery from 360 nm
to 760 nm from the center in the E semicircle. A surface trough
is along 29N52W 23N56W, curving to 19N58W. Precipitation: widely
scattered moderate to isolated strong is within 900 nm to the
west of the surface trough. Isolated moderate is elsewhere from
20N northward between 50W and 73W.

A second upper level cyclonic circulation center is near 34N33W.
Upper level cyclonic wind flow covers the Atlantic Ocean from
20N northward from 40W eastward. Comparatively drier air in
subsidence is apparent in water vapor imagery within 900 nm of
the center in the S semicircle. A surface trough is along 31N44W
24N46W 18N47W. Precipitation: isolated moderate rainshowers are
within 240 nm on either side of the surface trough.

A ridge extends just to the north of the area from roughly
Bermuda to Georgia. This pattern will maintain gentle to
moderate E winds across the basin, with fresh to strong winds
pulsing off the coast of Hispaniola tonight. The winds and the
seas will build on Saturday, to the south of 22N and to the
north of the Leeward Islands, as a tropical wave approaches the
region from the east. Expect fresh to strong winds to pulse off
Hispaniola by Saturday, again.

$$
mt/ah
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