[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180936
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Jun 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 0600 UTC surface analysis and satellite imagery through
0800 UTC.

...SPECIAL FEATURES...

Gale Warning Eastern Tropical Atlantic Low (AL92): A tropical
wave located several hundred miles SW of the Cabo Verde Islands
with axis near 31W and with a 1010 mb low near 09.5N30.5W. The
wave axis extends from 04N to 13N, and is moving W at around 15
kt. Scattered moderate convection is observed from 06N to 12N
between 30W and 36W. This activity is gradually becoming better
organized and environmental conditions appear conducive for
additional development. A tropical depression is likely to form
over the next couple of days. This system is expected to move
westward at 15-20 kt across the eastern and central tropical
Atlantic through the middle part of this week, with associated
winds and seas spreading W of 35W by this evening. Winds are
forecast to reach 35 kt or greater by late Mon night and a gale
warning has been issued. There is a high (70%) chance of tropical
cyclone development through the next 48 hours, and a high (90%)
chance of development through the next seven days. Please refer to
the latest Tropical Weather Outlook at www.hurricanes.gov, for
more details.

...TROPICAL WAVES...

Please refer to the Special Features section for information on
the tropical wave (with AL92) in the eastern Atlantic.

A central Atlantic tropical wave extends along 45W from 01N to
10N, moving W at 15-20 kt. Only isolated showers and thunderstorms
are observed in the vicinity of the tropical wave.

A tropical wave is mainly inland S of Trinidad and Tobago along
61W/62W across far eastern Venezuela and into northern Brazil from
01N to 10N, moving W at around 15 kt. Associated convection is
confined to inland locations.

A SW Caribbean Sea tropical wave extends along 82W/83W from 14N
southward into the tropical eastern Pacific Ocean, moving W at
around 20 kt. Scattered moderate convection is observed from 11N
to 15N between 82W and 84W.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 17N16W
to 05N46W. No ITCZ is currently present. In addition to the
convection associated with the tropical waves, scattered moderate
to strong convection is observed from 05N to 14N east of 23W,
likely associated with the next tropical wave.

GULF OF MEXICO...

Weak surface ridging prevails across the majority of the basin,
supporting gentle to moderate S-SW winds across the Gulf. A
surface trough extends just NW and offshore the Yucatan
Peninsula, with moderate to fresh winds on either side of it.
Seas are 3-5 ft W of 91W, and 2-4 ft E of 91W, except 1-3 ft in
the SE Gulf through the Straits of Florida. In the NE Gulf,
middle to upper level diffluence is supporting thunderstorms in
the coastal waters off the Florida Peninsula. Smoke due to
agricultural fires over Mexico may be reducing visibilities in
coastal waters from the Yucatan Peninsula westward.

For the forecast, high pressure extending from the Atlantic
through the Straits of Florida and to the upper Texas coast will
generally persist through the next several days. 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, except locally
fresh in the NW and W central Gulf today through Thu night. A weak
front may sink into the far northern Gulf by mid-week. 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 see the Tropical Waves section for information on a
tropical wave in the SW Caribbean and another tropical wave over
eastern Venezuela.

The gradient between subtropical high pressure and lower
pressure over the SW Caribbean is supporting fresh to strong
easterly trade winds in the central Caribbean and Gulf of
Honduras as noted by earlier ASCAT scatterometer data. Trade
winds are gentle to moderate elsewhere across the basin. Seas are
8-10 ft in the central and SW Caribbean per a recent altimeter
pass, and 4-7 ft across the remainder of the basin. Smoke due to
agricultural fires over portions of Central America may be
reducing visibilities in the NW Caribbean to the Yucatan
Peninsula.

For the forecast, the pressure gradient between the Bermuda High
and the Colombian Low will support fresh to strong E trades from
the central Caribbean to Nicaragua through this morning, then
again across the central Caribbean tonight through early Wed.
Fresh to strong E winds are expected in the Gulf of Honduras
before sunrise today, then moderate to fresh through at least Thu.
Scattered to numerous thunderstorms are expected across SW
portions to the west of 76W through tonight. A strong tropical
wave, and possible tropical cyclone, will move across 55W and into
the Tropical Atlantic waters Thu and Thu night.

ATLANTIC OCEAN...

Please refer to the Special Features section for information on
a gale warning and associated area of low pressure (AL92) in the
eastern Atlantic which has a high tropical cyclone development
potential.

High pressure of 1025 mb centered near 32N47W extends a ridge
WSW to the central Bahamas and ESE to the Canary Islands. This is
supporting mainly moderate to locally fresh winds across the
subtropical Atlantic waters, except gentle to moderate right under
the ridge axis. Seas are 3-5 ft W of 70W, 3-4 ft N of 24N between
35W and 55W, and 4-7 ft elsewhere. In the far western Atlantic, a
mid to upper level trough is generating heavy showers and
thunderstorms N of 24N and W of 64W, including the northern and
central Bahamas. Winds and seas may be higher in and near any
convection.

For the forecast W of 55W, Bermuda high pressure extends a ridge
N of the area which will continue to dominate through mid-week. A
weak cold front or trough may shift offshore N Florida and stall
early in the week before dissipating. Mainly gentle to moderate
anticyclonic winds will prevail the next several days, locally
fresh offshore N Hispaniola and offshore N Florida. A strong
tropical wave, and possible tropical cyclone, will move across 55W
and into the Tropical Atlantic waters Thu.

$$
Lewitsky
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