[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200606
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Jun 20 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
0350 UTC.

...SPECIAL FEATURES...

Tropical Storm Bret: As of 03 UTC, Tropical Storm Bret is
centered near 11.4N 43.5W, or about 1050 nm E of the southern
Windward Islands, moving W at 16 kt. The estimated minimum
central pressure is 1008 mb. Maximum sustained winds are 35 kt
with gusts to 45 kt. Seas 12 ft or greater extend up to 60 nm in
the N semicircle. As Bret interacts with subtropical high
pressure to the north, strong winds and rough seas in excess of
8 ft reach as far north as 18N. Satellite imagery continues to
become better defined. A central dense overcast is developing
near the center of Bret, with outer rain bands extending up to
180 nm. On the forecast track, Bret is forecast to initially
strengthen before moving across the Lesser Antilles near
hurricane intensity on Thursday and Friday bringing a risk of
flooding from heavy rainfall, hurricane-force winds, and
dangerous storm surge and waves. Given the larger than usual
uncertainty in the track forecast, it is too early to specify
the location and magnitude of where these hazards could occur.
However, everyone in the Lesser Antilles, Puerto Rico, and the
Virgin Islands should closely monitor updates to the forecast
for Bret and have their hurricane plan in place. Please read the
latest HIGH SEAS FORECAST issued by National Hurricane Center at
wed-site 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): A tropical wave in the Eastern Atlantic
extends along 30W from 03N to 15N, moving W at around 15 kt. A
1012 mb low pressure is analyzed along the wave axis near
08N30W. Winds are currently strong north of the low-pressure
center, generating 6-9 ft seas. Scattered moderate with isolated
strong convection is observed from 07N to 11N between 29W and
36W. Environmental conditions appear favorable for further
development, and a tropical depression could form in the next
couple days while the system moves westward at 10-15 kt across
the eastern and central tropical Atlantic. The current tropical
weather outlook assigns a medium (60%) probability of formation
through the next 48 hours, and a high (70%) probability over the
next seven days. Please refer to the latest Tropical Weather
Outlook at www.hurricanes.gov, for more details.

...TROPICAL WAVES...

A central Atlantic tropical wave extends along 53W from 01N to
15N, moving west at 10-15 kt. The northern portion of the wave
is approaching NDBC buoy 41040, which is currently reporting 15
kt ENE winds and 6 ft seas. Associated convection remains
isolated and weak.

A central Caribbean Sea tropical wave extends along 75W from 03N
to 14N, moving west at around 10 kt. The northern portion of the
wave is approaching NDBC buoy 42058, which is reporting 20 kt
ENE winds and 8 ft seas. No significant convection is occurring
near this wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 16N16W
to Invest Area 93L near 08N30W to 10N36W. No ITCZ is currently
present. All significant convection is described in the Special
Features section.

GULF OF MEXICO...

The subtropical Atlantic ridge extends across Florida into the
Gulf waters. Scattered showers and thunderstorms are noted in
the north-central and NE Gulf, particularly within 180 nm of the
coast. The pressure gradient between the ridge and lower
pressure over Mexico and the southern US is supporting moderate
to fresh S-SW winds in the western and northern Gulf, where seas
are 4-6 ft. A surface trough across the Yucatan Peninsula is
supporting moderate to fresh NE-E winds in the south-central
Gulf. Elsewhere, winds are gentle to moderate and seas are in
the 2-4 ft range. Smoke due to agriculture fires over Mexico may
be reducing visibilities along the coast of Mexico and the
western Bay of Campeche where the latest SAB analysis indicates
a medium concentration.

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 approach the Lesser
Antilles late this week.

The gradient between subtropical high pressure and lower
pressure over the SW Caribbean is supporting strong easterly
trade winds in the central Caribbean, where seas are in the 6-9
ft range. Fresh SE winds are noted in the Gulf of Honduras.
Gentle winds are noted in the lee of Cuba and Windward Passage,
where seas are 1-3 ft. Winds are moderate elsewhere, with 4-6 ft
seas.

For the forecast, Tropical Storm Bret near 11.4N 43.5W 1008 mb
at 11 PM EDT moving W at 16 kt. Maximum sustained winds 35 kt
gusts 45 kt. Bret will move to 11.8N 45.8W Tue morning, 12.3N
48.7W Tue evening, 12.8N 51.4W Wed morning, strengthen to a
hurricane near 13.3N 53.9W Wed evening, 13.8N 56.7W Thu morning,
and weaken to a tropical storm near 14.3N 59.4W Thu evening.
Bret will change little in intensity as it moves to 15.0N 64.5W
late Fri. 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.

A surface trough extends across the western Atlantic from 31N74W
to 26N80W. Numerous moderate with isolated strong convection is
observed from 24N to 31N west of 78W, with widely isolated
thunderstorms throughout the remainder of the western
subtropical Atlantic. A 1027 mb high pressure centered near
31N47W is the dominate feature across the basin. North of 20N,
anticyclonic winds are gentle to moderate with 3-6 ft seas.
South of 20N and outside of the immediate impacts from Tropical
Storm Bret, fresh NE-E winds and 5-7 ft seas are observed.

For the forecast W of 55W, Bermuda high pressure extends a ridge
SW through the central Bahamas to the SE Gulf of Mexico, and
will continue to dominate through mid-week. A weak cold front
off the SE US coast will linger and gradually dissipate through
the early part of the week with locally fresh winds E of it
tonight. Mainly gentle to moderate anticyclonic winds will
prevail the next several days, locally fresh offshore N
Hispaniola and offshore N Florida.

$$
Flynn
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