313
AXNT20 KNHC 171752
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Mon Jun 17 2024

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
1700 UTC.

...SPECIAL FEATURES...

Heavy Rainfall over Central America and Mexico, and Gale Warning
over the Gulf of Mexico:

Satellite imagery and surface observations indicate that a broad area
of low pressure is forming over the Bay of Campeche. This system
is known as a Central American Gyre (CAG), and often persists for
several days, with the threat to life and property increasing as
the event continues. Environmental conditions appear conducive
for additional gradual development, and a tropical depression or
tropical storm is likely to form by midweek while it moves slowly
westward or west-northwestward toward the western Gulf coast.
Regardless of development, several days of heavy rainfall are
expected across portions of southern Mexico and Central America,
and these rains are likely to cause life-threatening flooding and
flash flooding. Locally heavy rainfall is also expected to spread
over portions of the northwestern coast of the Gulf of Mexico by
the middle of the week. In addition, gale warnings have been
issued for portions of the Gulf of Mexico, and more information on
those warnings is available in the High Seas Forecasts issued by
the National Weather Service. Interests along the western and
northwestern Gulf coasts should monitor the progress of this
system. Increasing winds and building seas are expected. An Air
Force Reserve Hurricane Hunter aircraft is scheduled to
investigate the system later today. Currently, this system has a
high chance of tropical cyclone formation over the next 48 hours.

Refer to the latest NHC Tropical Weather Outlook at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

The axis of an Atlantic Ocean tropical wave is near 28W, from 16N
southward, moving westward at 10 to 15 knots. Scattered moderate
to isolated strong convection is where the wave is interacting
with the monsoon trough.

The axis of a Caribbean tropical wave is near 62W, from 16N
southward, moving westward at 10 to 15 knots. Scattered moderate
convection is east of the wave axis from 07N to 11N between 52W
and 62W.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of Guinea
Bissau near 12N16W, then continues westward to 06N35W. The ITCZ
extends from 06N35W to 07N50W. Aside from the convection
associated with the tropical waves, scattered moderate to isolated
strong convection is noted from )5n to 11N and E of 22W to the
coast of W Africa. Scattered moderate convection is within about
270 nm S of the monsoon trough between 30W and 41W.

GULF OF MEXICO...

Please read the SPECIAL FEATURES section for information on the
possibility of heavy rainfall across portions of southern Mexico
and Central America.

A Central American Gyre is currently over southern Mexico and
Central America while a ridge dominates Florida and the eastern
Gulf. The pressure gradient between these features is supporting
strong to minimal gale force winds E winds across most of the
eastern Gulf, including the Yucatan Channel. Similar wind speeds
are over the western Gulf N of 22N. Seas are 8 to 11 ft within
these winds, with the highest seas across the waters from 22N to
25N between 91W and 94W. Moderate to fresh winds are noted over
the NE Gulf and in the Bay of Campeche with seas of 4 to 7 ft.
Clusters of moderate to strong convection are noted over the
Yucatan Peninsula and in the Bay of Campeche. Scattered showers
with embedded thunderstorms are also seen across the remainder of
the Gulf region, particularly over the western half of it.

For the forecast, the gyre center is expected to persist through
the middle of this week. Showers and thunderstorms, along with
winds to gale-force and rough seas, are expected to continue over
the western Gulf with this system. Environmental conditions appear
conducive for additional gradual development, and a tropical
depression or tropical storm is likely to form by midweek while it
moves slowly westward or west-northwestward toward the western
Gulf coast.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for information on the
possibility of heavy rainfall across portions of southern Mexico
and Central America.

A Central American Gyre is currently over southern Mexico and
Central America. The circulation around the gyre is supporting
strong to near-gale force SE winds over the northwest Caribbean,
where combined seas are 8-11 ft. Gentle to moderate winds are
noted elsewhere, with 4-6 ft seas W of 70W and 2-4 ft E of 70W.
Band of showers and thunderstorms are observed over the NW
Caribbean under a SE wind flow. One of these bands is affecting
western Cuba and the Isle of Youth. Showers and thunderstorms are
also near the coast of Nicaragua and regional waters.

For the forecast, the gyre center is expected to persist through
the middle of this week. The resultant pattern will continue to
produce fresh to near gale-force SE winds and scattered showers
and thunderstorms across the NW Caribbean today, then shift across
the Gulf of Mexico through Wed. Otherwise, gentle to moderate
trades over the central and E Caribbean will reach moderate to
fresh speeds on Wed and prevail through Fri evening.

ATLANTIC OCEAN...

A surface trough extends from 31N60W toward the Windward Passage.
A weak 1014 mb low is analyzed along the trough axis near 28N64W.
Scattered showers and thunderstorm are active along, and ahead
this trough. Moderate to fresh NE winds and 3 to 5 ft seas are
noted west of the trough, with light breezes and 3 to 5 ft seas
elsewhere west of 55W. The remainder of the Atlantic discussion
area is dominated by 1025 mb high pressure located near 34N38W.
This pattern is supporting gentle to moderate winds over much of
the waters E of 55W, with seas in the 4-7 ft range.

For the forecast west of 55W, the trough and associated low pressure
will shift eastward through at least mid-week. The pressure gradient
between these systems and a ridge over the western Atlantic will
support moderate to fresh NE winds W of the trough/low through
tonight, with winds increasing to fresh to strong speeds by early
Tue morning. An area of cloudiness and thunderstorms located
several hundred miles east of the Bahamas is associated with the
aforementioned trough and an upper-level area of low pressure.
Environmental conditions could be conducive for some development
of this system during the next few days while it moves westward or
west- northwestward. The system is forecast to approach the coast
of the southeast United States on Thursday or Friday.

$$
GR