[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121759
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is near 29W from west of the
Cabo Verde Islands at 16N southward, and moving west around 15
kt. Scattered moderate convection is noted from 07N to 10N
between 24W and 33W.

A western Atlantic tropical wave is relocated to 59W near Barbados
from 20N southward, based on 12Z sounding data from Guadeloupe
and Barbados. It is moving west around 15 kt. Widely scattered
showers and isolated thunderstorms are noted near the Lesser
Antilles.

A western Caribbean tropical wave is near 82W from near the Cayman
Islands southward, and moving west around 20 kt. Scattered showers
and isolated thunderstorms are occurring over southern Cuba and
nearby waters, and across the southwestern Caribbean Sea.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic through the coast of Gambia,
then extends southwestward across 10N27W to 07N34W. Besides the
convection related to the tropical wave mentioned in the above
section, scattered to numerous moderate convection is seen from
07N to 13N between the Guinea/Sierra Leone coast and 24W. An ITCZ
continues westward from 07N34W to 07N46W. Widely scattered showers
are found near and up to 90 nm south of the ITCZ.

...GULF OF MEXICO...

A surface trough is triggering widely scattered showers at the
Bay of Campeche. Otherwise, a broad surface ridge along with a
1017 mb high at the northeastern Gulf are dominating much of the
region. Light to gentle winds and seas of 1 to 2 ft are present
over the eastern and north-central Gulf, including the Florida
Straits. Gentle to moderate E to SSE winds and 2 to 4 ft seas
prevail elsewhere in the Gulf, including the Bay of Campeche.

For the forecast, a trough will move off the Yucatan Peninsula
each night, supporting fresh winds off northwest Yucatan.
Elsewhere, the high and related ridge over the northern Gulf will
support mostly gentle to moderate winds and slight seas across the
region into mid week.

...CARIBBEAN SEA...

An upper-level low in the eastern basin near 16N68W is producing
widely scattered showers and isolated thunderstorms from Curacao
northward to Puerto Rico. Refer to the Tropical Waves section
above for additional weather in the Caribbean Basin. The Atlantic
Ridge to the north near 28N continues to sustain a trade-wind
regime across much of the basin, except near Costa Rica and
Panama. Fresh to strong ENE to E winds and seas of 6 to 9 ft exist
across the central basin. Gentle to moderate E to ESE winds and 2
to 4 ft seas are noted at the northwestern basin, including the
Gulf of Honduras. Light to gentle monsoonal winds and seas at 3 to
6 ft in moderate easterly swell are present near Costa Rica and
Panama. Moderate to fresh easterly winds and 4 to 7 ft seas
prevail for the rest of the basin.

For the forecast, fresh to strong winds and rough seas over the
south-central Caribbean will expand across much of the central
and southwest Caribbean through late today as the Atlantic Ridge
strengthens. 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 ridge. Looking ahead, winds and seas
will increase again over the south-central Caribbean as the
Atlantic Ridge strengthens again.

...ATLANTIC OCEAN...

A surface trough is causing scattered showers and isolated
thunderstorms at the Great Bahama Bank, and the central and
northwest Bahamas. An upper-level trough runs northward from near
the Windward Passage to south of Bermuda. Interaction with
convergent southerly winds is causing scattered moderate
convection north of 27N between 67W and the Georgia-Florida coast.
Another surface trough extends southwestward from the north-
central Atlantic across 31N44W to northeast of Puerto Rico near
22N63W. This feature is generating widely scattered moderate
convection from 21N to 28N between 57W and 65W. Refer to the
Monsoon Trough/ITCZ and Tropical Waves sections at the beginning
for additional convection in the Atlantic Basin.

An Atlantic Ridge extends southwestward from a 1026 mb high near
35N35W across 31N60W to near the central Bahamas. This ridge is
supporting light to gentle winds and seas of 4 to 6 ft in moderate
northerly swell north of 27N between 45W and the Georgia-Florida
coast. For the eastern Atlantic, moderate to fresh with locally
strong NNE to NE trades and seas of 7 to 10 ft dominate north of
21N between the Africa coast and 45W, including the Canary Islands.
For the tropical Atlantic, gentle to moderate with locally fresh
NE to E trades and 5 to 7 ft seas are evident from 10N to 20N
between 32W and the Lesser Antilles. Near the Cabo Verde Islands,
light to gentle monsoonal winds with seas at 4 to 6 ft are noted
from 10N to 21N between the central Africa coast and 32W. Gentle
to moderate southerly winds and seas of 6 to 8 ft in moderate
southerly swell prevail for the remainder of the Atlantic Basin.

For the forecast W of 55W, the Atlantic Ridge will lift northward
today ahead of the 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.

$$

Forecaster Chan
This weather bulletin was brought to you by:
www.nashvilleweather.net