[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180535
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Jul 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
0500 UTC.

...SPECIAL FEATURES...

Newly upgraded Tropical Storm Don is centered near 37.4N 40.4W at 18/0300 UTC
or 640 nm W of the Azores moving SE at 11 kt. Estimated minimum central
pressure is 1007 mb. Maximum sustained wind speed is 35 kt with gusts
to 45 kt. Seas in excess of 12 ft extend out 120 nm in the
southeast quadrant and 90 nm in the southwest quadrant of the
storm. Scattered moderate convection extends out to 120 nm in the
northeast quadrant of the partially exposed center, with cooling
tops. A recent scatterometer satellite pass showed gale force
winds in the area of the strongest convection. Don is expected to
move in a clockwise pattern over the next couple of days then
start moving northward, and gradually intensifying.

Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more
details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave was relocated to 48W south of 13N based
on Hovmoller satellite analysis, and consistent diagnostic model
inputs from both the GFS and ECMWF. The wave is be moving west at
15-20 kt. Scattered moderate convection is noted within 90 nm
either side of the wave axis from 07N to 10N.

A Caribbean Sea tropical wave is along 71W from 19N southward,
moving west at 15-20 kt. Scattered moderate convection is noted
along the coast the Dominican Republic.

A Caribbean Sea tropical Wave is along 85W from 18N off the coast
of Belize southward to through Honduras and Nicaragua, moving west
at 15-20 kt. Scattered moderate to isolated strong convection is
noted in the far western Gulf of Honduras near Puerto Barrios.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends off the coast of Senegal near 15N17W
to 11N25W to 12N35W. The ITCZ continues from 12N35W to 12N45W, and
from 11N50W to 10N65W. Scattered moderate to isolated strong
convection is along the monsoon trough from 09N to 13N east of
25W. Scattered moderate convection is noted within 180 nm north
and 120 nm south of the ITCZ between 52W and 57W.

GULF OF MEXICO...

1018 mb high pressure is centered over the northwest Gulf of
Mexico near 27N91W, with weak troughs over the northeast Gulf and
the southwest Gulf. Fresh NW winds are starting to pulse off the
western coast of the Yucatan peninsula, but elsewhere the pattern
is maintaining light to gentle breezes and slight seas.

For the forecast, the high pressure will prevail through the
forecast period supporting mainly gentle to moderate winds. A
trough will develop over the Yucatan Peninsula each evening and
move offshore. This pattern will maintain pulsing of moderate to
fresh winds north and west of the Yucatan peninsula during the
late afternoon and evening hours.

CARIBBEAN SEA...

Please read the TROPICAL WAVES section for details on two tropical
waves in the Caribbean Sea.

Fresh to strong winds are active across the south-central
Caribbean, as well as in the Windward Passage and off Cabo Beata
on the south coast of Hispaniola. Seas are 6 to 9 ft over the
southwest Caribbean, and 5 to 8 ft elsewhere over the central
Caribbean. Gentle to moderate breezes and 3 to 5 ft seas are noted
elsewhere. Trade wind convergence is supporting clusters of
showers and thunderstorms along coast of Nicaragua, and near the
Gulf of Uraba along the Colombia/Panama border. Showers and
thunderstorms are also noted off the coast of western Cuba.

For the forecast, the pressure gradient between high pressure
over the Atlantic and the Colombian low will maintain fresh to
strong winds across the central Caribbean through Sat night. High
pressure N of the area will build further westward, producing an
increase in areal coverage of the fresh to strong winds from the
middle to end of the week. Moderate to locally fresh winds in the
Gulf of Honduras are forecast to reach fresh to strong speeds Sat
night.

ATLANTIC OCEAN...

Please read the SPECIAL FEATURES section for information about
Tropical Depression Don in the central Atlantic Ocean.

Divergent flow aloft on the east side of an upper low centered off
northeast Florida is supporting scattered showers and a few
thunderstorms from 28N to 30N between 67W and 70W, and isolated
showers and thunderstorms over the northern Bahamas. A surface
ridge extends from 1027 mb high pressure near 32N56W to east-
central Florida. A scatterometer satellite pass indicated fresh
winds funneling off the north coast of Hispaniola south of the
ridge, and just north of the Mona Passage. Gentle to moderate
winds are evident elsewhere west of 50W. Buoy and altimeter
satellite data indicate seas are mostly 4 to 6 ft in this area.
Farther east, light to gentle NE winds prevail north of 22N under
the influence of the high pressure. South of 22N to the ITCZ from
the coast of Africa to the Bahamas, easterly moderate to locally
fresh winds prevail with seas 5-8 ft. South of the ITCZ, light to
gentle winds with 4-5 ft seas are noted.

For the forecast west of 55W, surface high pressure will prevail across the
forecast waters this week. This will support mainly moderate to
fresh E to SE winds, except for fresh to strong winds and rough
seas N of Hispaniola at night through early Fri.

$$
Christensen
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