[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191834
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat Aug 19 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
1750 UTC.

...SPECIAL FEATURES...

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

...in the Eastern Tropical Atlantic Ocean (AL98):

Shower and thunderstorm activity continues in association
with a tropical wave, and a 1006 mb broad area of low pressure
center, that is near 16N35W. This position is several hundred
miles to the west of the Cabo Verde Islands. The environmental
conditions appear to be generally favorable for more development
of this system. It is likely for a short-lived tropical
depression to form this weekend. It will move west-northwestward
or northwestward 10 mph across the eastern tropical Atlantic
Ocean. The upper level winds that will be over the system are
forecast to increase by early next week. More development is
not expected. The chance of formation into a tropical cyclone
during the next 48 hours is high.

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

...to the East-Southeast of the Lesser Antilles (AL90):

A 1007 mb low pressure center is near 12N59W. This low
pressure center is along a tropical wave, that is just
to the east of the Windward Islands. The precipitation
pattern that is surrounding this weather feature has
become comparatively better organized during the last
24 hours. More development of this system is likely.
It is possible that a tropical depression may
form early next week. It will be moving westward
to west-northwestward 10 to 15 mph, across the Lesser
Antilles and into the eastern and the central Caribbean Sea.
Heavy rainfall is possible in parts of the Windward
Islands during the next couple of days. Anyone who has
interests in the eastern and the central Caribbean should
monitor the progress of this system. The chance of
formation into a tropical cyclone during the next 48 hours
is medium.

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

...in the Central Tropical Atlantic Ocean (AL99):

A 1007 mb low pressure center is near 16N49W, roughly halfway
between the Cabo Verde Islands and the Lesser Antilles. This
weather system is producing disorganized rainshowers and
thunderstorms to the east of its center. The environmental
conditions are only marginally conducive. It is possible that
a short-lived tropical depression may form during the next
day or two. The weather feature will be moving
est-northwestward 10 to 15 mph, through the tropical Atlantic
Ocean. More development is not anticipated, since the upper
level winds are expected to become increasingly unfavorable.
The chance of formation into a tropical cyclone during the
next 48 hours is medium.

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

...TROPICAL WAVES...

A Caribbean Sea tropical wave is along 80W/81W,
from 28N southward, moving westward 10 knots to
15 knots. Precipitation: isolated moderate to
locally strong is within 240 nm on either side
of the tropical wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal border areas
Senegal and Guinea-Bissau, to the 16N35W low pressure center,
to the 16N49W low pressure center. The ITCZ is along 15N51W
12N57W. Precipitation: widely scattered moderate to isolated
strong is from 05N to 16N from 30W eastward.

...GULF OF MEXICO...

for the Western Gulf of Mexico:
An area of disturbed weather, that is near the northwestern
and central Bahamas now, is expected to move into the Gulf
of Mexico by early next week. A broad area of low pressure
is expected to form there. Some slow development of this
system is possible. It is possible that a tropical depression
may form. The weather system will westward, approaching the
western Gulf of Mexico coastline by the middle of next week.
Please, refer to the latest NHC Tropical Weather Outlook, at
www.hurricanes.gov, for more details.

A broad east-to-west oriented surface ridge is in the
middle of the Gulf of Mexico. The weak surface pressure
gradient is sustaining mainly light to gentle
anticyclonic winds. The sea heights are reaching:
3 feet off the NW coast of the Yucatan Peninsula;
2 feet from the coastal waters of the middle Texas
Gulf coast southward into the SW corner of the area,
and in the SE Gulf/Straits of Florida;
and 1 foot elsewhere.

A surface ridge over the Gulf waters will support mostly
gentle to moderate winds and slight seas across the basin
through tonight. Looking ahead, an area of disturbed
weather located near the northwestern and central Bahamas
is expected to move into the Gulf of Mexico by early next
week, where a broad area of low pressure is expected
to form. Some slow development of this system is possible
thereafter, and a tropical depression could form as it
moves westward and approaches the western Gulf of Mexico
coastline by the middle of next week. This system has
a low chance of development in 48 hours and a medium
chance in the next 7 days.

...CARIBBEAN SEA...

Please, refer to the TROPICAL WAVES section, for details
about the 80W/81W tropical wave.

The pressure gradient between the ridge to the north of
the islands and lower pressures in northern South America
continue to support moderate to fresh easterly winds in
the eastern and central Caribbean. Seas in these waters
are 4-7 ft. Moderate or weaker winds, and seas
of 2-5 ft, are elsewhere.

The monsoon trough is along 08N/10N between 74W in
Colombia, beyond Costa Rica, and into the Pacific Ocean.
Precipitation: isolated moderate to locally strong is
within 240 nm to the north and to the south of the
monsoon trough.

The 24-hour rainfall totals in inches, according to the
Pan American Temperature and Precipitation Tables,
MIATPTPAN, for the period that ended at 19/1200 UTC,
are: 0.64 in Montego Bay in Jamaica; and 0.09 in Freeport
in the Bahamas, and in Trinidad.

Moderate to fresh trade winds will prevail over the
eastern and central Caribbean through today. Winds will
increase to fresh to strong over the eastern and central
basin tonight through late Mon as a strong tropical wave
moves across the region. Looking ahead, a low pressure,
AL99, will move NE of Puerto Rico early next week,
supporting moderate to fresh SE winds in the far
E Caribbean Mon night through mid-week. Environmental
conditions are forecast to become increasingly unfavorable
for more development of this system during the next day
or two while it moves west-northwestward 10 to 15 kt
across the central tropical Atlantic. This system has
a low chance of development in the next 7 days.

...ATLANTIC OCEAN...

...Near the coast of Africa:

A tropical wave located near the western coast of Africa is
producing a large area of disorganized showers and
thunderstorms.
Some slow development is possible while it moves generally
west-northwestward across the tropical eastern Atlantic during
the
next several days. Please, refer to the latest NHC Tropical
Weather Outlook, at www.hurricanes.gov, for more details.

An expansive central Atlantic Ocean subtropical ridge covers the
tropical Atlantic Ocean. The ridge is maintaining fairly dry
weather conditions outside of the deep tropics. Fresh easterly
trade winds are found south of 25N and west of 45W. The seas
in these waters are 5-9 ft, with the highest seas occurring
near 17N58W. Fresh to locally strong SE winds are south of 10N
and west of 45W. Seas are 4-7 ft.

Fresh to strong N-NE winds have been off Morocco and Western
Sahara, with the comparatively fastest winds in the water
passages of the Canary Islands. Meteo-France has been advising
that gusts to near gale-force are going to be expected in those
waters. Seas of 4-7 ft are north of 22N and east of 20W.
Moderate or weaker winds, and slight to moderate seas,
are elsewhere.

Fresh to strong tradewinds will pulse off Hispaniola
and the Windward Passage each evening into early next
week. Fresh tradewinds south of 25N will persist through
the weekend. A strong tropical wave will enhance winds
and seas near the Leeward and Virgin Islands over the
weekend, and north of Puerto Rico early next week.
Environmental conditions are forecast to become
increasingly unfavorable for further development of this
system during the next day or two while it moves
west-northwestward 10 to 15 kt across the central
tropical Atlantic. This system has a low chance of
development during the next 7 days.

$$
MT
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