[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 150422
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sat Jul 15 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
0415 UTC.

...SPECIAL FEATURES...

Subtropical Storm Don is centered near 34.7N 47.2W at 15/0300 UTC
or 995 nm W of the Azores moving N at 8 kt. Estimated minimum
central pressure is 1004 mb. Maximum sustained wind speed is 40 kt
with gusts to 50 kt. Tropical storm-force winds extend within 150
nm NE and 80 nm SE quadrants of center. Seas in excess of 12 ft
seas extend within 240 nm NE, 150 nm SE, and 180 nm NW quadrants
of center. A band of showers and thunderstorms is found over the
northern and eastern quadrants, mainly within 300 nm from the
center. On the forecast track, a turn toward the east at a
similar forward speed is expected by Sunday night, followed by a
turn to the southeast by Monday. Some slight weakening is forecast
during the next couple of days, and Don could possibly become a
post- tropical cyclone or remnant low at any time.

Please read the latest HIGH SEAS FORECAST issued by Ocean
Prediction Center at web-site
https://www.opc.noaa.gov/text/MIAHSFAT1.shtml and the latest
Subtropical Storm Don Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A new tropical wave has been introduced off the coast of Africa
based on satellite imagery, recent scatterometer satellite and
wave model data. The wave axis is along 19W, south of 17N, moving
westward at 15 kt. Scattered moderate to isolated strong convection
is observed from 06N and 12N and between 18W and 28W. A recent
scatterometer pass show fresh to strong southerly winds associated
with the strongest convection.

A central Atlantic tropical wave extends along 43W, south of 19N,
moving westward at 15-20 kt. A dry Saharan airmass has enveloped
the wave and no deep convection is associated with this feature.

Another central Atlantic tropical wave extends along 58W, south
of 19N, moving westward at 15-20 kt. No deep convection is
noted with this feature. Moisture associated with this wave will
spread across the Windward Islands to night and Sat increasing the
chance of showers and isolated thunderstorms.

A western Caribbean Sea tropical wave extends along 81W, south of
20N, moving westward at 10-15 kt. The wave axis stretches from
western Cuba to western Panama. The wave is enhancing the
scattered showers and thunderstorms affecting western Cuba and the
SW Caribbean.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of
Senegal near 15N17W and continues to 14N27W, 10N39W and 11N40W.
The ITCZ extends from 11N40W to 09N57W. Aside from the convection
described in the TROPICAL WAVES section, no deep convection is
present in the rest of the monsoon trough or ITCZ.

GULF OF MEXICO...

A few showers and isolated thunderstorms are noted off SW Florida
while the rest of the Gulf of Mexico is under the influence of a
dry airmass that suppresses the development of showers and
thunderstorms. The pressure gradient between the persistent ridge
south of Louisiana and lower pressures across Mexico sustain
moderate to fresh E-SE winds in the Bay of Campeche and western
Gulf. Locally strong NE winds are occurring in the eastern Bay of
Campeche. Seas of 3-5 ft are present in the Bay of Campeche and
western Gulf. Light to gentle anticyclonic winds and 1-3 ft seas
prevail elsewhere.

For the forecast, a ridge will continue to dominate the Gulf waters,
through the next several days, while a trough will develop over
the Yucatan Peninsula each evening and move offshore. This
pattern will maintain moderate to fresh winds pulsing north and
west of the Yucatan peninsula during the late afternoon and
evening hours. Elsewhere, gentle to moderate winds and slight
seas will prevail.

CARIBBEAN SEA...

Aside from the convection described in the TROPICAL WAVES section,
only isolated showers are seen across the Caribbean Sea associated
with patches of shallow moisture. A recent scatterometer satellite
pass captured strong to near gale-force easterly trade winds in
the south-central Caribbean Sea, with the strongest winds
occurring within 90 nm of NW Colombia and the Gulf of Venezuela.
Seas in these waters are 8-12 ft. Fresh to strong easterly winds
and seas of 5-8 ft are noted in the north-central Caribbean
waters. Moderate to fresh easterly winds and seas of 4-7 ft are
evident in the eastern Caribbean. Moderate or weaker winds and
seas of 2-5 ft prevail elsewhere in the basin.

For the forecast, a tropical wave between central Cuba and western
Panama will move across the remainder of the Caribbean through
late Sat. Another tropical wave will move across the Windward
Islands and through the southeastern Caribbean Sat, then weaken as
it moves across the central Caribbean through late Sun and across
the western Caribbean late Mon. The passage of the tropical waves
will modulate fresh to strong winds across mainly the central
Caribbean through the period.

ATLANTIC OCEAN...

Please refer to the SPECIAL FEATURES section for information
regarding Subtropical Storm Don in the central Atlantic.

A weak surface trough over the NW Bahamas is producing scattered
moderate convection, mainly south of 26N and west of 76W. The
remainder of the western Atlantic is dominated by a 1021 mb high
pressure system located just NW of Bermuda. The pressure gradient
between the ridge and lower pressures in the Caribbean Sea sustain
fresh to strong easterly winds south of 23N and between 70W and
74W. Seas in these waters are 4-8 ft. Elsewhere west of 55W, moderate
or weaker winds and slight to moderate seas prevail.

In the eastern Atlantic, a 1030 mb high pressure system centered
near the Azores supports fresh to near gale-force NE-E winds north
of 22N and east of 35W. The strongest winds are occurring off Western
Sahara and in the water passages between the Canary Islands. Seas
in the region described are 8-12 ft. Moderate or weaker winds and
moderate seas are prevalent in the remainder of the tropical
Atlantic.

For the forecast west of 55W, high pressure will persist northeast
of the Bahamas through Sun, supporting pulses of fresh to strong
NE to E winds and rough seas off Hispaniola. The ridge will shift
northward into Mon ahead of a tropical wave that will be
approaching the area from the east. Looking ahead, the northern
portion of the tropical wave will move westward south of 22N into
mid week.

$$
DELGADO
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