[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120544
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sat Aug 12 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 0000 UTC surface analysis and satellite imagery through
0530 UTC.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 25W/26W, from 16N
southward, moving westward from 5 knots to 10 knots.
Precipitation: isolated moderate to locally strong is within
300 nm to the southeast of the monsoon trough between 20W and
31W.

An Atlantic Ocean tropical wave is along 50W, from 17N southward,
moving westward about 10 knots. Precipitation: widely scattered
moderate to isolated strong is from 06N to 10N between 47W and
53W.

A Caribbean Sea tropical wave is along 78W, from 20N southward,
moving westward from 15 knots to 20 knots. The tropical wave is
moving through the westernmost sections of Jamaica. The monsoon
trough is along 10N from 74W in Colombia beyond Costa Rica.
Precipitation: numerous strong is within 90 nm to 180 nm to the
south of the monsoon trough between 76W and 82W, and within 180 nm
to the south of the monsoon trough between 83W and 86W. Isolated
moderate to locally strong is within 520 nm to the west of the
tropical wave from 14N northward.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal areas of SW Senegal,
to 12N20W, 09N30W, 08N39W, and 08N42W. The ITCZ continues from
08N42W, to 06N53W at the coast of French Guiana. Precipitation:
scattered moderate to strong from 10N to 15N between the coast of
Africa and 20W. Isolated moderate to locally strong is elsewhere
from 14N southward from 60W eastward.

...GULF OF MEXICO...

A surface ridge passes through the NW Bahamas and Lake Okeechobee
in south Florida, toward the upper Texas Gulf coast and SW
Louisiana.

Upper level cyclonic wind flow covers the Gulf of Mexico from the
east central sections into the SW corner. Precipitation: widely
scattered moderate to isolated strong is in the Isthmus of
Tehuantepec of southern Mexico.

Mostly moderate anticyclonic wind flow covers the western half of
the Gulf of Mexico. Some fresh SE winds are from 26N southward
from 90W westward. Gentle or slower winds are elsewhere. The sea
heights are reaching 4 feet off the coast of NE Mexico; 3 feet
from the coastal waters of the middle Texas Gulf coast into the
west central Gulf; 1 foot in the NE corner of the area; and 2 feet
elsewhere.

Expect moderate to fresh SE winds overnight across the west-
central Gulf between high pressure over the northeast Gulf and
lower pressure over central Mexico. A trough will move off the
Yucatan Peninsula each night supporting fresh to occasionally
strong winds off northwest Yucatan. Elsewhere, the ridge over the
northern Gulf will support mostly gentle to moderate winds and
slight seas across the basin into mid week.

...CARIBBEAN SEA...

Please, read the SPECIAL FEATURES section, for details about the
78W tropical wave and the nearby precipitation.

Upper level cyclonic wind flow covers the area that is from 10N
northward between 60W and 70W. Precipitation: isolated moderate is
in the area of the upper level cyclonic wind flow.

The sea heights range from 6 feet to 9 feet from Hispaniola and
Jamaica southward between the Mona Passage and 78W. The
comparatively highest sea height of 9 feet is along 74W in the
coastal waters/offshore waters of Colombia. The sea heights:
range from 3 feet to 4 feet in the Venezuela coastal
waters/offshore waters; 5 feet in the coastal waters/offshore
waters of Puerto Rico; range from 3 feet to 4 feet from Jamaica
southward between 78W and 80W; 2 feet elsewhere in the western
Caribbean Sea waters. The exception is for 1 foot in the eastern
coastal waters/offshore waters of Honduras. Strong easterly winds
are from 18N southward between 72W and 78W. Moderate and fresh NE
winds are in the eastern one-third of the area. Moderate or slower
winds have been in the western one-third of the area.

Fresh to strong winds over the south-central Caribbean will
expand across much of the central and southwest Caribbean through
late Sat as high pressure builds north of the area. Except for
fresh to strong winds over the Gulf of Honduras Sun night, these
winds and seas will diminish slightly into early next week over
most of the basin as a trough moving into the Bahamas weakens the
high pressure. Looking ahead, winds and seas will increase again
over the south-central Caribbean as high pressure builds over the
western Atlantic.

...ATLANTIC OCEAN...

The GFS model for 500 mb and for 700 mb shows that an inverted
trough and cyclonic wind flow cover the area that is from Cuba
northward between 70W and 80W. Precipitation: scattered moderate
to widely scattered strong is from Cuba to 28N between 70W and
80W, and on the Caribbean Sea side of Cuba for 300 nm to the south
of Cuba. A Caribbean Sea tropical wave is moving through the
westernmost sections of Jamaica.

A surface trough passes through 31N42W, to 23N57W. Precipitation:
widely scattered moderate to isolated strong is from 19N northward
between 50W and 62W. Upper level cyclonic wind flow covers the
area that is from 20N northward between 50W and 62W.

A surface ridge extends from a 1023 mb high pressure center that
is near 30N59W, through 28N66W, across the NW Bahamas and Lake
Okeechobee in south Florida, toward the upper Texas Gulf coast and
SW Louisiana.

Strong NE winds are within 240 nm on either side of 24N33W 31N13W.
Fresh NE winds are within 240 nm to 360 nm on either side of the
rest of the line 32N13W 27N27W 19N38W 14N49W 16N60W. Mostly fresh
to moderate southerly winds are from the monsoon trough/ITCZ
southward. Moderate or slower winds are in the remainder of the
Atlantic Ocean. The sea heights range from 7 feet to 11 feet from
30W eastward. The comparatively highest sea heights range from
9 feet to 11 feet from 18N northward. The sea heights range from
3 feet to 6 feet in the remainder of the Atlantic Ocean.

A new outbreak of Saharan dust was in the eastern Atlantic Ocean
on Friday. The Saharan Air Layer tracking product from CIMSS was
indicating that African dust was reaching the eastern Caribbean
Sea.

The subtropical ridge extends along 28N and will lift northward
through Sat ahead of a surface trough moving westward toward the
Bahamas through early next week. Expect moderate to fresh easterly
winds south of 24N following the trough Sun to Tue. Fresh to
strong winds will pulse off Hispaniola during the late afternoons
and early evenings through Tue.

$$
mt/al
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