[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181755
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Aug 18 2022

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
1730 UTC.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 23W/24W, from 19N
southward, moving westward from 10 knots to 15 knots.
Precipitation: the precipitation that is close to the tropical
wave also is close to the monsoon trough.

An Atlantic Ocean tropical wave is along 53W, from 19N
southward, moving westward from 15 knots to 20 knots.
Precipitation: isolated moderate to locally strong is within 420
nm to the west of the tropical wave from 11N southward. A weak
surface trough has been in Suriname during the last 24 hours,
before the arrival of the tropical wave.

A tropical wave is along 88W/89W, from 20N southward, moving
westward 10 knots. The wave is passing through the Yucatan
Peninsula, to parts of Guatemala, Honduras, and El Salvador,
into the eastern Pacific Ocean. Precipitation: scattered to
numerous moderate to strong is from 17N to 20N between 87W and
91W, in the Yucatan Peninsula and in Belize, and in parts of
northern Guatemala. Broken to overcast multilayered clouds, and
other rainshowers, are elsewhere in the Caribbean Sea and in the
Gulf of Mexico, from 12N to 23N between Jamaica and the SW Gulf
of Mexico. This weather system is forecast to move through
Central America and southeastern Mexico through tonight, before
emerging into the SW Gulf of Mexico on Friday. It is possible
that a low pressure center may form in the SW Gulf of Mexico on
Friday. Additional slow development of this system is possible,
while it moves northwestward in the southwestern Gulf of Mexico,
through the weekend.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal areas of Senegal
near 15N17W, to 12N20W 11N30W 11N37W. The ITCZ continues from
11N37W, to 12N44W 10N50W. Precipitation: disorganized isolated
moderate to locally strong is from 13N southward from 60W
eastward.

GULF OF MEXICO...

A cold front/stationary front passes through NE Florida, to the
Florida coastal waters in the NE Gulf of Mexico, beyond central
Louisiana. Precipitation: widely scattered moderate to isolated
strong is from 25N northward, and in the coastal plains and
coastal waters of U.S.A. Gulf coast states.

Broad and weak surface anticyclonic wind flow spans the area. A
1014 mb high pressure center is near 27N89W. The surface
pressure gradient is flat and weak.

Expect light to gentle winds, and sea heights that range from 1
foot to 2 feet in the east central, the southeastern part, and
in the north central Gulf of Mexico. Gentle to moderate winds,
and sea heights that range from 1 foot to 3 feet, are in the
northwestern, the west central, and in the northeastern Gulf of
Mexico. Moderate to fresh ENE winds, and sea heights that range
from 2 feet to 4 feet, are in the SW corner of the Gulf of
Mexico.

An upper level cyclonic circulation center is inland near
22N99W, in Mexico.

A 1014 mb high pressure center, that is in the SE Louisiana
offshore waters near 27N88W, will drift ESE and dissipate
tonight. A cold front extending from Horseshoe Beach in Florida,
NW to the coast of Mississippi, will exit the NE Gulf this
evening. Rainshower activity that is associated with it will
linger through Fri. A tropical wave that is in Guatemala is
forecast to move across southeastern Mexico through tonight,
before emerging into the Bay of Campeche on Friday, where an
area of low pressure may form. Additional slow development of
this system is possible, while the system moves NW, into the SW
Gulf of Mexico through the weekend. Moderate to fresh E to SE
winds are expected in the SW and west central Gulf of Mexico
from this evening through Sat night.

CARIBBEAN SEA...

Broad upper level anticyclonic wind flow covers the areas that
are from Jamaica westward. Comparatively drier air in subsidence
in water vapor imagery covers the remainder of the area.

The surface pressure gradient, based on the Atlantic Ocean
surface ridge, is sustaining gentle to moderate trade winds in
most of the basin. The exceptions are strong winds offshore NE
Colombia and the Gulf of Venezuela, and fresh winds in the
interior sections of the Gulf of Honduras. The sea heights range
from 6 feet to 8 feet in the south central parts of the
Caribbean Sea just to the north of Colombia. The sea heights
range from 4 feet to 6 feet in the central parts of the area,
and in the Gulf of Honduras. A surface trough is along 28N66W
23N67W 17N67W from the Atlantic Ocean to the Caribbean Sea.
Precipitation: isolated moderate to locally strong is from 14N
to 22N between 65W and 73W.

A weak pressure gradient supports moderate or weaker easterly
trade winds, in most of the Caribbean Sea. The exceptions are:
locally fresh to strong trade winds off N Colombia and in the
Gulf of Venezuela, and fresh to local strong winds in the Gulf
of Honduras. The sea heights range from 3 feet to 5 feet in the
south central Caribbean Sea and in the Gulf of Honduras. The sea
heights range from 1 foot to 3 feet in the remainder of the area.

The monsoon trough is along 10N/11N, between 74W in Colombia,
and beyond the border of Costa Rica/Nicaragua, into the eastern
Pacific Ocean. No significant deep convective precipitation is
related directly to the monsoon trough.

A tropical wave that is moving through Guatemala continues to
generate numerous showers and thunderstorms in the Honduras
offshore waters, and scattered showers elsewhere west of 82W.
This active weather is expected to shift westward gradually
through tonight, as the wave moves through  southeastern Mexico,
before emerging into the Bay of Campeche on Friday. Surface
ridging that is  building N of the region will support fresh to
strong winds in the south central and parts of the SW Caribbean
Sea, from today through Sat, then weaken gradually through Mon.
A broad tropical wave will move through the Tropical Atlantic
waters tonight, to the eastern Caribbean Sea on Fri, and to the
central Caribbean Fri night and Saturday.

ATLANTIC OCEAN...

An upper level trough is along 63W. Cyclonic wind flow from a
Bahamas inverted trough covers much of the area that is between
70W and 80W. A surface trough is along 28N66W 23N67W 17N67W from
the Atlantic Ocean to the Caribbean Sea. Precipitation: isolated
moderate to locally strong is from 14N to 22N between 65W and
73W, and from 28N northward between 64W and 67W. A frontal
boundary is along 31N and northward between 70W and 80W.
Precipitation: widely scattered moderate to isolated strong is
to the northwest of the line that runs from Bermuda to Andros
Island in the Bahamas. Broad surface anticyclonic wind flow
covers the Atlantic Ocean from 20N northward from 60W eastward.

The sea heights range from 7 feet to 9 feet from 10N northward
within 400 nm of the coast of Africa. Fresh to strong NE winds
are from 12N northward from 40W eastward. Moderate to fresh
winds are from 13N to 27N between 40W and 60W. Gentle to
moderate wind speeds are in the remainder of the Atlantic Ocean.
The sea heights range from 4 feet to 6 feet elsewhere from 40W
eastward, from 27N southward between 40W and 50W, and from 23N
southward between 50W and 60W. The sea heights range from 2 feet
to 4 feet in the remainder of the Atlantic Ocean.

Surface ridging, that is building from the Azores high to the
Bahamas, is expected to shift northward gradually to be along
30N through Sat, then N of the area by Mon night. A frontal
boundary in the NE Florida offshore waters will linger across
the region today, then move northward. Active weather N of 27N
between Florida and 68W will persist through tonight. Moderate
to fresh easterly winds are forecast S of 25N from Thu through
Sun, as a tropical wave moves through the eastern and central
Caribbean Sea.

$$
mt
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