[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202322
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

Tropical Storm Bret: Tropical Storm Bret is centered near 12.2N
48.6W at 20/2100 UTC or about 725 nm E of the Windward Islands
moving W or 280 degrees at 15 kt. Estimated minimum central
pressure is 1006 mb. Maximum sustained wind speed is 40 kt with
gusts to 50 kt. Seas 12 ft or greater are observed within 60 nm
N semicircle and 30 nm SE quadrant of center with seas to 15 ft.
A burst of deep convection developed over Bret's center during the
past several hours, with a convective band wrapping around the
east side of the circulation. On the forecast track, the center
of Bret is expected to move across portions of the Lesser Antilles
Thursday afternoon and Thursday night, and then move across the
eastern Caribbean Sea on Friday. Bret is a little stronger. Additional
strengthening is forecast during the next day or so, and Bret is
expected to be a tropical storm when it reaches the Lesser Antilles,
bringing a risk of flooding from heavy rainfall, strong winds,
and dangerous waves along the coast. Given the uncertainty in the
track and intensity forecasts, it is too early to specify the
location and magnitude of where Bret's associated hazards could
occur. A Tropical Storm Watch has been issued for Barbados, and
additional watches are likely for other islands within the Lesser
Antilles later tonight. Please read the latest HIGH SEAS FORECAST
issued by National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest T.S.
Bret Forecast/Advisory and Public Advisory at www.hurricanes.gov
for more details.

Invest Area (AL93): Shower and thunderstorm activity has diminished
during the past several hours in association with a tropical wave
located several hundred miles southwest of the Cabo Verde Islands.
Its axis is along 34W S of 15N moving W at 10 to 15 kt. A 1011
mb low pressure is analyzed along the wave axis near 09.5N34W.
Currently, convection is limited. However, environmental conditions
appear conducive for further development of this system, and a
tropical depression will likely form during the next couple of
days while the system moves westward at 10 to 15 kt across the
eastern and central tropical Atlantic. The latest Tropical
Weather Outlook gives this system a high chance of tropical
cyclone formation in the next 48 hours, as well as over the next
seven days. Refer to the latest NHC Tropical Weather Outlook at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave is approaching the Lesser Antilles. Its axis is
along 58W extending southward into Guyana, and moving W at 15 to
20 kt. Scattered moderate convection is near the northern end of
the wave axis from 12N-16N between 56W and 60W.

A tropical wave is near 80W from 14N southward across Panama
into the East Pacific region, moving W at 15 to 20 kt. The wave
appears to enhance convection over parts of Panama.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends SW from the coast of Senegal near 15N17W
to a 1011 mb low pressure located 09.5N34W. A large cluster of
moderate to strong convection is noted along the W coast of Africa
likely associated with the next tropical wave. This strong convective
activity is affecting mainly Sierra Leone, and covers the area from
05N-11N between 10W-15.5W. No ITCZ is present based on the latest
analysis.

...GULF OF MEXICO...

A cold front is over the NE Gulf, and extends from northern Florida
near 30N82.5W to SE Louisiana. Numerous showers and thunderstorms
are occurring near the frontal boundary, and over much of the
State of Florida. S of the front to about 27N moderate to fresh
SW winds and seas of 5-7 ft are noted, with higher winds near
thunderstorms. Elsewhere, the Atlantic ridge extends across
south-central Florida into the Gulf waters. The pressure gradient
between the ridge and lower pressure inland Mexico supports
moderate to fresh southerly winds across the western half of the
Gulf, and a gentle to moderate anticyclonic flow across the
eastern half of the Gulf S of 27N. Seas are generally 4-6 ft based
on altimeter data, except 1-3 ft over the SE Gulf.

For the forecast, high pressure extending from the Straits of
Florida to the upper Texas coast will generally persist through
the week and 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 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 Special Features section for information on
Tropical Storm Bret, which is forecast to move across portions
of the Lesser Antilles Thursday afternoon and Thursday night.

The most recent satellite derived wind data provide observations
of fresh to strong trade winds across the central Caribbean.
Seas are 8-11 ft within these winds based on altimeter data.
Moderate to fresh trades dominate the eastern Caribbean with
seas of 4-6 ft. Moderate to locally fresh E winds are noted in
the Gulf of Honduras with seas of 3-5 ft. Gentle to moderate
winds prevail elsewhere, except in the lee of Cuba where light to
gentle winds are seen. Scattered showers and thunderstorms are
noted over parts of Central America and the Greater Antilles.

For the forecast, Tropical Storm Bret will begin to gradually
strengthen as it moves to near 12.3N 49.2W this evening, to near
12.7N 51.9W Wed morning with maximum sustained winds 45 kt gusts
50 kt, to near 13.2N 54.5W Wed evening, to near 13.6N 57.3W
early Thu with maximum sustained winds 55 kt gusts 65 kt. Bret is
forecast to maintain its intensity as it approaches the Lesser
Antilles Thu evening and move into the eastern Caribbean Sea near
14.2N 63.6W early on Fri. Bret is forecast to begin to weaken as
it nears 14.4N 70.4W early Sat with maximum sustained winds 45
kt gusts 55 kt and dissipate by early on Mon. Otherwise, the
pressure gradient between the Bermuda High and the Colombian Low
will support fresh to strong E trades across the central Caribbean
through early Thu. Moderate to fresh E winds are expected in the
Gulf of Honduras.

...ATLANTIC OCEAN...

Please refer to the Special Features section for information on
Tropical Storm Bret and Invest Area AL93 located in the eastern
Atlantic Ocean.

A surface trough is an analyzed E of Florida and runs from 31N78W
to near Lake Okeechobee, Florida. Showers and thunderstorms are
near the trough axis and over much of Florida. Gentle to moderate
S winds are noted on the E side of the trough to about 70W.
The Bermuda-Azores high dominates the remainder of the Atlantic
forecast waters with a 1025 mb high center near 31N44W. The
pressure gradient between the high pressure and T.S. Bret is
resulting in an area of moderate to fresh NE to E winds roughly
from 12N-21N between 38W and 55W with seas of 6-8 ft. Gentle to
moderate anticyclonic flow is noted elsewhere, with light to
gentle winds near the high pressure center. Outside of Bret, and
E of 70W, seas are generally 4-6 ft, and 2-4 ft W of 70W and E of
the Bahamas.

For the forecast W of 55W, broad high pressure ridging extending
southwest across the area will continue to control the weather
regime during the rest of the forecast period. Moderate to fresh
south to southwest winds N of 27N and W of 70W will change little
through the end of the week. Otherwise, mainly gentle to moderate
anticyclonic winds will prevail the next several days, locally
fresh offshore N Hispaniola and offshore N Florida.

$$
GR
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