[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051032
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sat Aug 5 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is near 36W from 06N to 20N,
moving west at 15 to 20 kt. Scattered moderate convection is seen
within 210 nm W and 60 nm E of the wave axis from 08N to 11N.

The northern portion of a central Atlantic tropical wave, near
54W from 15N to 22N, has broken off and shot out well ahead of
the southern portion of the tropical wave, which is near 47W from
06N to 15N. The northern portion of the wave is moving W at 20 kt.
The southern portion of the wave is moving W at 10 to 15 kt. The
northern portion shows up well as a surface trough in ASCAT
satellite data from Fri evening. Scattered moderate convection is
present from 07N to 10N between 47W and 56W, and from 16N to 21.5N
between 54W and 59W.

An eastern Caribbean tropical wave is near 68/69W from 23N
southward through the Mona Passage to western Venezuela. It is
moving west at 15 kt. Scattered showers and isolated tstorms are
located near and just W of the wave axis, near the S coast of the
Dominican Republic. Similar activity is seen within 240 nm E of
the wave axis from 13N-18N.

A tropical wave along 95W extends from the Bay of Campeche near
20N southward through southern Mexico to the Pacific Ocean. The
tropical wave is moving W around 10 kt, in tandem with an upper-
level trough. Numerous moderate scattered strong convection is
occurring over the SW Bay of Campeche from 18N to 21N between 93W
and 96.5W.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic along the coast of
Mauritania near 18N16W to 13N26W to 12N37W to 09N47W to 09N54W.
Other than the convection mentioned in the Tropical Waves section
above, isolated moderate convection is occurring south of the
trough from 05N to 11N between 11W and 28W.

The eastern end of the East Pacific monsoon trough is causing
scattered thunderstorms just north of western Panama, south of 10N
between 81W and 82.5W.

...GULF OF MEXICO...

See the Tropical Waves section above for information on
thunderstorms in the Bay of Campeche. Surface ridging prevails
across the Gulf of Mexico, anchored by a 1015 mb high pressure
centered near 27N85W. Deep-layered ridging is also present across
the northern and central Gulf. As a result of subsidence from the
deep-layered ridging, no precipitation is occurring north of 23N.
Light to gentle winds and seas of 1 to 2 ft prevail over the
eastern Gulf. Gentle to moderate with locally fresh E to SSE winds
and 2 to 4 ft seas prevail across the western Gulf, including the
Bay of Campeche.

For the forecast, weak high pressure centered over the NE Gulf
will support gentle to moderate winds over most of the basin.
Moderate return flow across the far western Gulf will continue
through early next week. A thermal trough will move off the
Yucatan Peninsula each night, and will produce moderate to fresh
winds to the northwest of the Yucatan Peninsula.

...CARIBBEAN SEA...

A broad upper-level low over the NW Caribbean is inducing isolated
showers and tstorms north of 18N and west of 80W. Convection
elsewhere in the basin is mentioned above in the Tropical Waves
and Monsoon Trough sections. Fresh to strong ENE winds and seas
of 6 to 9 ft are occurring in the south-central Caribbean,
offshore Colombia. Elsewhere in the eastern and central Caribbean,
fresh trades with seas 3-6 ft prevail. In the northwest Caribbean,
gentle trades and 1-3 ft seas prevail, except in the Gulf of
Honduras, where winds are moderate to locally fresh with 3 to 4 ft
seas.

For the forecast, fresh to strong trades will prevail in the S
central Caribbean with moderate to fresh trades elsewhere in the
central and eastern Caribbean. Gentle to moderate trades are
expected in the western Caribbean.

...ATLANTIC OCEAN...

A weak surface trough runs northeastward through the NW Bahamas,
with isolated showers and tstorms near Andros Island and the Old
Bahama Channel. More significant convection is north of 30N
between 75W and 79W. Scattered showers and isolated tstorms seen
from 28N to 31N between 59W and 69W are being enhanced by upper-
level diffluence. Scattered showers and isolated tstorms
approaching the Turks and Caicos Islands from the east are
associated with a tropical wave, mentioned above.

A surface ridge extends WSW from 1026 mb high pressure near 31N46W
to 29N65W to 27N75W. Mainly moderate southerly winds and seas of
3-5 ft prevail near the ridge axis from 26N to 31N, west of 55W.
To the south, fresh trade winds and 7 to 9 ft seas are noted from
14N to 26N between Africa and 61W. South of 25N, between 61W and
70W, fresh SE winds and 5 to 6 ft seas prevail.

For the forecast W of 55W, moderate to locally fresh SW winds
off NE Florida will gradually diminish this morning. Ridging will
dominate the basin this weekend into early next week. Expect ESE
trade winds to increase to fresh speeds this weekend S of 25N and
E of 75W. Winds off the N coast of Hispaniola will pulse to
locally strong speeds during the afternoons and evenings today
through Mon.

$$
Hagen
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