[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211756
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Wed Jun 21 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
1500 UTC.

...SPECIAL FEATURES...

Tropical Storm Bret: Tropical Storm Bret is centered near
13.0N 52.5W at 21/1500 UTC or 408 nm E of Barbados, and moving W
at 12 kt. Estimated minimum central pressure is 1001 mb. Maximum
sustained wind speed is 50 kt with gusts to 60 kt. Seas 12 ft or
greater are observed within 120 NM NE quadrant, 60 NM SE quadrant,
30 NM SW quadrant, and 90 NM NW quadrant with seas to 16 ft.
Scattered to numerous moderate convection is noted from 11N-16N
between 50W and 54W. Bret is expected to continue moving west for
the next several days. On the forecast track, the center of Bret
is expected to approach the Lesser Antilles on Thursday, move
across the Lesser Antilles late Thursday and Thursday night, and
then move westward across the eastern and central Caribbean Sea
Friday and Saturday. Through Saturday, storm total rainfall
amounts of 3 to 6 inches with maximum amounts of 10 inches are
possible across portions of the Lesser Antilles from Guadeloupe
south to St. Vincent and the Grenadines, including Barbados. The
heavy rainfall could lead to flash flooding, especially across
areas of higher terrain. Urban flooding is also possible.

Please read the latest HIGH SEAS FORECAST issued by National
Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, the latest NHC
Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml
and Forecast/ Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details.

Invest Area (AL93): A tropical wave extends along 37W from 03N to
15N, moving west at about 15 kt. A 1010 mb low is analyzed along
the wave near 10.4N37.9W. Scattered showers and isolated thunderstorms
are noted up to 165 nm west of the wave axis. Strong winds are
noted in the northern semicircle of the low, where seas are in the
6-8 ft range. Environmental conditions appear conducive for
further development of this system, and a tropical depression
will likely form during the next couple of days. The latest
Tropical Weather Outlook assigns a high chance of tropical
cyclone formation in the next 48 hours, and over the next seven
days. Refer to the latest NHC Tropical Weather Outlook at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A new tropical wave just emerged off the coast of west Africa.
This tropical wave extends along 16W from 02N to near the Gambia
coast, moving west at 5 to 10 kt. Scattered moderate to isolated
strong convection is from 02N to 11N between Sierra Leone/Liberia
and 23W.

A Caribbean tropical wave extends from east-central Venezuela
through the northern Windwards Islands along 62W, and is moving
west at 10-15 kt. Widely scattered showers are observed from 10N
to 15N between 57W and 65W.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near the city
of Banjul in Gambia, through Invest Area AL93 to 10N43W. No ITCZ
is currently present in the Atlantic. Scattered moderate
convection is depicted from 11N-13N between 30W and 36W.

The eastern end of the east Pacific Monsoon Trough is producing
scattered showers and thunderstorms near the Panama coast in the
Carribbean Sea.

...GULF OF MEXICO...

Cluster of showers and thunderstorms associated with a surface
trough are moving southeast in the northeastern Gulf. Fresh to
strong localized winds and 4 to 6 ft seas are present near this
activity. Fresh southerly winds with seas at 3 to 5 ft are
located at the south-central Gulf north of the Yucatan Peninsula.
Elsewhere, a high pressure ridge continues to dominate the basin.
Anticyclonic winds are mostly gentle to moderate. Seas are
generally 3 to 4 ft across the basin.

For the forecast, the high pressure ridge will generally persist
into the upcoming weekend. Fresh winds will pulse north of the
Yucatan Peninsula each night through the forecast period as a
diurnal trough develops and moves offshore. Elsewhere, gentle to
moderate southerly winds will prevail, locally fresh at times.
Smoke from agricultural fires in Mexico will produce hazy skies
over the central and western Gulf for at least the next day or
two.

...CARIBBEAN SEA...

Please refer to the sections above for information on Tropical
Storm Bret and the tropical waves moving across the basin.

Scattered showers and isolated thunderstorms are currently
affecting the coasts of Honduras and Nicaragua due to an upper
level trough. The pressure gradient between the subtropical high
pressure and lower pressure over northern Colombia is supporting
fresh to strong trade winds in the central Caribbean, where seas
are in the 7-9 ft range. Winds are gentle to moderate elsewhere,
with 3-6 ft seas.

For the forecast, Tropical Storm Bret will strengthen a little as
it moves to near 13.2N 54.4W this evening with maximum sustained
winds 55 kt gusts 65W and maintain intensity as it nears 13.5N
57.1W early Thu, then approaches the Lesser Antilles near 13.9N
60.1W early Thu evening as it tracks west-northwest. Bret will
move into the eastern Caribbean Sea Thu night reaching near 14.3N
63.5W early on Fri as it begins to weaken. Bret is forecast to
reach near 14.6N 67.1W Fri evening with maximum sustained winds 45
kt gusts 55 kt and to near 14.7N 70.7W early Sat and dissipate by
early Sun. The low pressure (AL93), that is currently over the
eastern Atlantic may move across the tropical N Atlantic waters
this weekend as a possible tropical cyclone. Otherwise, fresh to
strong E trades will persist across the central Caribbean through
early Thu. Moderate to fresh E to SE winds are expected in the
Gulf of Honduras through late tonight, increase to fresh to strong
through Thu, then to near gale Thu night and diminish back to
fresh to strong Fri into early Sat.

...ATLANTIC OCEAN...

Please refer to the Special Features section for information on
Tropical Storm Bret and Invest Area AL93.

Clusters of showers and thunderstorms are depicted from central
Bahamas through southwest of Bermuda in association with low-level
convergence and mid-level divergence. Moderate to fresh southerly
winds and seas of 4 to 6 ft are depicted north of 29N between 74W
and the Florida/Georgia coasts. Otherwise, a large 1022 mb high
pressure in the central Atlantic continues to support gentle to
moderate winds N of 24N and moderate to fresh winds south of 24N.
Seas are 2 to 5 ft outside from Tropical Storm Bret and Invest
AL93.

For the forecast W of 55W, the aforementioned large high pressure
will continue to control the weather regime throughout the rest
of the forecast period. Moderate to fresh S to SW winds north of
27N and west of 70W will change little through the end of the
week. Otherwise, mainly gentle to moderate anticyclonic winds will
prevail the next several days, except locally fresh offshore N
Hispaniola and offshore N Florida. AL93 may move across the
tropical N Atlantic waters this weekend as a possible tropical
cyclone.

$$

Forecaster KRV/Chan
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