[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180529
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Wed Oct 18 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
0515 UTC.

...SPECIAL FEATURES...

Central Tropical Atlantic (AL94) Gale Warning: A 1008 mb low
pressure system is located several hundred miles east of the
Lesser Antilles, near 12N45W. Numerous moderate to isolated strong
convection is evident on satellite imagery from 05N to 19N and
between 41W and 50W. Strong to near gale-force winds are occurring
in the northern and eastern quadrants. Seas of 8-11 ft are found
from 09N to 21N and between 42W and 52W. A recent altimeter
satellite pass captured seas to 11 ft in the northern quadrant.
Environmental conditions are expected to remain conducive for
gradual development, and a tropical depression is likely to form
during the next day or so while the system moves westward to west-
northwestward across the central and western tropical Atlantic.
Interests in the Lesser Antilles should monitor the progress of
this system. Additional information, including gale warnings, can
be found in High Seas Forecasts issued by the National Weather
Service. Regardless of development, this system has the potential
to bring gusty winds, heavy rainfall, and flooding to portions of
the Lesser Antilles beginning Friday. This disturbance has a high
chance of tropical cyclone formation through the next 48 hours.
Please refer to the latest NHC Tropical Weather Outlook at
www.hurricanes.gov for more details. Additional information,
regarding the Gale Warning, can be found in the latest HIGH SEAS
FORECAST issued by the National Hurricane Center at website
- https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Mauritania near 17N15W and continues southwestward to 02N30W and
then to 03N35W. The ITCZ extends from 03N35W to 08N44W. Scattered
moderate to isolated strong convection is observed south of 08N
and between 16W and 41W.

...GULF OF MEXICO...

A 1019 mb high pressure system near the coast of Louisiana
continues to dominate the Gulf of Mexico. A dry continental
airmass enveloping the basin is suppressing the development of
deep convection. However, a weak surface trough in the Bay of
Campeche allows for shallow showers in the area. Moderate
northerly winds and seas of 3-6 ft are found in the SE Gulf and
Bay of Campeche. Meanwhile, slight to gentle winds and slight
seas prevail elsewhere.

For the forecast, high pressure will continue to dominate the Gulf
waters the remainder of the work-week. As the high pressure moves
toward the SE of the United States, winds will veer to NE and E
over the E and central Gulf, and to the SE and S over the western
Gulf. Under this pattern, expect mainly gentle to moderate winds
and slight to moderate seas. A frontal system will bring moderate
to fresh westerly winds for the NE Gulf on Fri.

...CARIBBEAN SEA...

A stationary front stretches from eastern Cuba to the Gulf of
Honduras and Belize. A few showers and isolated thunderstorms are
seen near the frontal boundary. Similar convection is also
evident within 100 nm of the coasts of Nicaragua, Costa Rica and
northern Colombia. A recent scatterometer satellite pass depicted
fresh to strong northerly winds behind the aforementioned front.
These winds are sustaining wave heights of 4-7 ft. Moderate to
fresh easterly trade winds and seas of 3-5 ft are noted in the
south- central Caribbean Sea. In the remainder of the basin,
moderate or weaker winds and seas of 1-3 ft are prevalent.

For the forecast, a stationary front extends from eastern Cuba to
the Gulf of Honduras. The front should remain in place through
Wed before dissipating Wed night. Fresh to locally strong NE winds
and moderate seas will persist over the northwest Caribbean
through Wed as high pressure builds over the area. Looking ahead,
a broad area of low pressure (AL94) located about 900 nautical
miles east of the Windward Islands continues to show signs of
organization. It has a high chance of tropical cyclone formation
trough 48 hours. Regardless of development, this system has the
potential to bring gusty winds, heavy rainfall, and flooding to
portions of the Lesser Antilles beginning Friday.

...ATLANTIC OCEAN...

Please see the Special Features section above for more details on
Invest 94L located well east of the Lesser Antilles.

A stationary front remains draped across the southwestern
tropical Atlantic, extending from 31N63W to the SE Bahamas and NE
Cuba. Scattered moderate convection is present near the frontal
boundary, especially south of 27N. Moderate or weaker winds and
moderate seas are present behind the frontal boundary. Farther
east, a surface trough is analyzed along 60W, extending from 25N
to 18N. A few showers are observed on satellite imagery within 200
nm of this feature. Moderate to locally fresh easterly winds and
seas of 5-7 ft are occurring in the area described.

The remainder of the tropical Atlantic is dominated by a 1023 mb
subtropical ridge positioned near 28N45W, suppressing the
development of deep convection across the central and eastern
Atlantic outside of the deep tropics. A weak cold front enters the
northeast corner of the basin near 31N18W and continues to near
the eastern Canary Islands and then continues as a surface trough
to 21N34W. Decaying northerly swell supports seas of 6-9 ft north
of the cold front and surface trough. Elsewhere outside of the
influence of Invest 94L, moderate or weaker winds and moderate
seas prevail.

For the forecast W of 55W, a stationary front extends from 31N64W
to eastern Cuba. The front will remain in place before
dissipating Wed night or Thu. High pressure will build over the
area in the wake of the front. Looking ahead, the next frontal
system will move offshore the southeastern United States Fri
night. Fresh to strong winds and rough seas are forecast north of
27N Fri night through Sat night with this system. A broad area of
low pressure (AL94) located about 900 nautical miles east of the
Windward Islands continues to show signs of organization. It has a
high chance of tropical cyclone formation trough 48 hours.
Interests in the Lesser Antilles should monitor the progress of
this system.

$$
DELGADO
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