[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292310
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sun Jul 30 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 1800 UTC surface analysis and satellite imagery through
2310 UTC.

...TROPICAL WAVES...

A tropical wave is being analyzed in the eastern Atlantic
extending along 20W from the equator to 19N, moving westward at
an uncertain 10-15 kt. Scattered moderate convection is observed
from 10N to 17N east of 18W, enhanced by the monsoon trough.

A central Atlantic tropical wave extends along 20N47W to 04N54W
in French Guiana, moving westward at 15-20 kts. Strong E winds are
in the vicinity of the northern terminus of the wave axis with
seas of 8-9 ft. While this feature is only producing disorganized
cloudiness and showers, environmental conditions are expected to
be favorable for gradual development during the next few days, and
a tropical depression is likely to form early next week. The
disturbance is forecast to move west- northwestward to
northwestward at about 15 kt during the next day or so, and then
turn north-northwestward to northward over the central subtropical
Atlantic Monday and Tuesday. This feature has a low chance of
tropical cyclone development through 48 hours and a high chance
over the next seven days. The tropical wave is expected to
continue westward after the disturbance moves northwest and breaks
away.

A Caribbean tropical wave extends along 69W from the Mona Passage
to Venezuela, moving west at 10-15 kt. Outside of some showers
and tstorms impacting Puerto Rico and Hispaniola, no other
convection is noted at this time.

The far northern extent of a tropical wave is over the Bay of
Campeche, SE Mexico, and central America along 92W south of 20N,
moving west at 15 kt. Scattered moderate convection is in the Bay
of Campeche south of 22N east of 92W, including inland over the
Yucatan Peninsula.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 15N17W
to 07N28W to 18N45W to 12N57W. In addition to the convection in
the eastern Atlantic described in the tropical wave section,
scattered moderate convection is observed from 12N to 16N between
55W and 60W.

The eastern extent of the Pacific monsoon trough is supporting
scattered showers and thunderstorms in the SW Caribbean along the
coast of Panama and Costa Rica.

GULF OF MEXICO...

Please refer to the TROPICAL WAVES section above for information
about the Bay of Campeche tropical wave.

1020 mb high pressure is centered near south-central Louisiana.
Scattered moderate convection is in the SW Gulf of Mexico from 18N
to 23N west of 95W. Easterly winds are light to gentle across the
majority of the basin, increasing to moderate speeds in the Bay
of Campeche. Seas are 1-3 ft in the northern Gulf and 2-4 ft in
the southern Gulf.

For the forecast, a weak surface ridge will remain the dominant
feature across the basin through early next week. This will
support gentle to moderate winds, except over the eastern Bay of
Campeche, where winds will be enhanced by a thermal trough that
will emerge off the Yucatan Peninsula each night. A weak surface
trough currently extending from northern Florida to western
Florida Keys will meander across the eastern Gulf tonight and
remain the focus for scattered showers and isolated thunderstorms.
Weak high pressure will shift SE into the east central Gulf Tue
and Wed and allow for moderate return flow to develop across the W
Gulf.

CARIBBEAN SEA...

Please refer to the TROPICAL WAVES and MONSOON TROUGH/ITCZ section
above for convection in the Caribbean Sea.

The gradient between the expansive subtropical high and lower
pressure over Colombia is supporting enhanced easterly trades
winds across the basin. Trades are strong in the south-central
Caribbean with 8-10 ft seas, and fresh in the remainder of the
central basin with 7-8 ft seas, and moderate to fresh in the
eastern and NW Caribbean with 5-7 ft seas. Isolated showers and
tstorms are noted in the lee of Cuba.

For the forecast, the pressure gradient between the Bermuda High
and lower pressure over Colombia will induce pulsing fresh to
strong trades across the entire central Caribbean through the
weekend, then become confined to the south central Caribbean
through early next week. A strong tropical wave over Central
America will continue to produce scattered showers and
thunderstorms across the SW Caribbean tonight and Sun. A strong
tropical wave is expected to move across the Tropical Atlantic and
reach 55W by late Sun. A broad area of low pressure has developed
in the vicinity of the wave and is expected to move NW into the
open Atlantic through Wed.

ATLANTIC OCEAN...

The weather pattern is dominated by a subtropical high pressure
ridge with its axis oriented E-W along 32N. In the western
Atlantic winds are gentle to moderate from the S-SE with 4-6 ft
seas. In the central Atlantic, winds are gentle to moderate from
the E. Seas are generally 4-6 ft in the central Atlantic. Higher
winds and seas are near the tropical disturbance. In the eastern
Atlantic, the gradient between the subtropical high pressure and
lower pressure over Africa is supporting moderate to fresh NE
winds and 6-8 ft seas. An area of Saharan Air is observed east of
40W and north of 12N. Lower visibility and hazy skies may be
possible within this area.

For the forecast west of 55W, high pressure centered over the
central Atlantic will gradually shift eastward through Tue, and
will maintain moderate to locally fresh trade winds S of 23N
through early Mon. Fresh trades will pulse each late afternoon
through evening N of Hispaniola and over the Windward Passage.
Developing surface low pressure across the central Atlantic near
17.5N45.5W will move NW then N across the NE offshore zones Mon
through early Wed before exiting the region to the N.

$$
Mahoney
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