[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 050757 CCA
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Sep 5 2023

Updated to indicate the development chances of Invest 95L

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
0535 UTC.

...SPECIAL FEATURES...

Invest 95L: A central Atlantic tropical wave has its axis along
36W. Low pressure of 1011 mb is along the tropical wave near 11N.
Satellite imagery shows scattered moderate to isolated strong
convection from 07N to 15N and between 31W and 42W. Fresh to
locally strong winds are noted with the strongest convection. Seas
in the area described are 5-7 ft. Showers and thunderstorms
associated with the area of low pressure have become a little
better organized over the past several hours. Environmental
conditions are conducive for further development, and a tropical
depression or tropical storm is expected to form over the next day
or so while the low moves toward the west-northwest at 15 to 20
mph across the central tropical Atlantic. Additional
strengthening, possibly to a hurricane, is likely later this week
while the system moves over western portions of the tropical
Atlantic, near or to the northeast of the northern Leeward
Islands. The disturbance has a high chance of development over
the next 48 hours.

Please refer to the latest NHC Tropical Weather Outlook
at www.hurricanes.gov for more details.

...TROPICAL WAVES...

A strong tropical wave is along 15W, south of 19N, moving westward
at 15 kt. The wave axis remains over western Africa producing a
large area of showers and thunderstorms, mainly east of 21W and
from 06N to 15N. Moderate to strong northerly winds are evident
east of 25W and south of 27N. Seas in these waters are 4-7 ft.
Environmental conditions appear conducive for development once
the wave moves offshore, and a tropical depression could form over
the far eastern tropical Atlantic during the middle to latter
part of the week while the system moves to the west or west-
northwest at 10 to 15 mph. This system is expected to move across
the Cabo Verde Islands Wednesday night and Thursday, and interests
there should monitor its progress. The disturbance has a low
chance of development in the next 48 hours and a high chance of
development in the next 7 days. For more details, please visit
hurricanes.gov

A central Caribbean Sea tropical wave has its axis along 78W,
south of 19N, moving westward at 10-15 kt. A few showers are noted
near the trof axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of
Mauritania near 17N16W and continues westward to Invest 95L near
11N35W and to 12N53W. The ITCZ extends from 12N53W to 12N62W.
Aside from the convection discussed in the Special Features and
Tropical Waves section, isolated to scattered moderate convection
is observed near the monsoon trough and ITCZ between 44W and the
Windward Islands.

...GULF OF MEXICO...

A weak surface trough extends from 26N90W to NW Yucatan producing
a few showers. In the rest of the Gulf, patches of low-level
moisture are seen across the eastern Gulf waters sustaining
shallow convection and it is generally dry everywhere else. A
weak pressure pattern supports mainly moderate or weaker winds and
seas of 2-4 ft across the Gulf. However, moderate to locally fresh
S-SE winds and seas building to 5 ft are noted in the
southeastern and northwestern Gulf waters, especially near the
southern Texas coast and the Florida Straits.

For the forecast, high pressure over the SE US will support moderate E
to SE winds across most of the basin through tonight, and gentle
to moderate winds thereafter through mid-week. Afterward, a weak
pressure gradient will result in light to gentle winds and
slight seas the remainder of the forecast period, with the
exception of gentle to moderate winds just W of the Yucatan
Peninsula.

...CARIBBEAN SEA...

A surface trough in the NW Caribbean Sea, diurnal heating and
divergence aloft result in a few showers in the nearshore waters
of Cuba, the Gulf of Gonave and the Bay Islands. The remainder of
the Caribbean Sea experiences a dry airmass that suppresses the
development of deep convection.

The pressure gradient between the subtropical ridge in the central
Atlantic and lower pressures in northern South AMerica support
moderate to locally strong easterly trade winds in the eastern and
central Caribbean. Seas in these waters are 4-7 ft. Light to
gentle winds and seas of 1-4 ft prevail elsewhere.

For the forecast, moderate to fresh trade winds and moderate seas will
continue in the central and eastern Caribbean the entire forecast
period, except for developing fresh to strong winds in the south-
central waters Tue night into Wed. Gentle to locally moderate
winds and slight seas will prevail elsewhere. Looking ahead, an
area of low pressure located several hundred nm WSW of the Cabo
Verde Islands is expected to become a tropical depression or
tropical storm within a day or two, and should cross 55W by Fri.

...ATLANTIC OCEAN...

Please read the SPECIAL FEATURES section for details on Invest 95L.

The remnants of Tropical Depression Katia are located near 28N34W
producing a small area of convection to the west of the center. A
recent scatterometer satellite pass captured fresh to strong
easterly winds north of the center. Seas of 8-10 ft are found
north of 27N and between 30W and 41W.

A surface trough extends from 25N67W to Hispaniola and along with
plenty of tropical moisture and divergence aloft support scattered
moderate convection south of 25N and between 65W and 75W. Farther
east, a stationary front enters the central Atlantic near 31N50W
and extends southward to 25N51W. Water vapor satellite imagery
depict a strong upper level low near 30N43W. The interaction of
these weather systems sustain scattered moderate to isolated
strong convection from 23N to 28N and between 47W and 53W.
The remainder of the Atlantic is under pressure pattern supporting
moderate or weaker winds and slight to moderate seas.

For the forecast, seas of 8 to 10 ft in N to NE swell are occurring
over much of the area N of 26N E of 65W. The swell will gradually
subside through Tue. Looking ahead, an area of low pressure
located several hundred nm WSW of the Cabo Verde Islands is
expected to become a tropical depression or tropical storm within
a day or two, and should cross 55W by Fri.

$$
DELGADO
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