359
AXNT20 KNHC 170908
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

Heavy Rainfall over Central America and Mexico, and gale warning
over the Gulf of Mexico:

A broad area of low pressure is centered over northern Central
America and southern Mexico. This area of low pressure will shift
W to WNW toward the western Gulf coast over the next few days.
Environmental conditions appear conducive for a tropical cyclone
to develop from this broad circulation, and a tropical depression
or tropical storm is likely to form by midweek while it moves
toward the western Gulf coast. There is currently a medium chance
for TC genesis in the next 48 hours and a high chance for TC
genesis in the next 7 days.

This broad area of low pressure is known as a Central American
Gyre (CAG), and often persists for several days. Regardless of
tropical cyclone development, this weather pattern will cause
life- threatening conditions that include flooding and mudslides.
With the current CAG, the circulation is producing strong SW
monsoonal flow in the eastern north Pacific, advecting abundant
tropical moisture northward into the coastal terrain of Central
America and southern Mexico. The pattern is expected to persist
through at least the middle of this week across northern Central
America and southern Mexico, with the threat to life and property
increasing as the event persists. The main areas impacted by the
heavy rainfall will be northwest Nicaragua, southwest Honduras,
and coastal sections of Honduras, El Salvador, Guatemala, and the
Mexican states of Chiapas and Oaxaca. Heavy rainfall is also
possible across Quintana Roo, Yucatan, Tabasco, Veracruz,
northeast Queretaro, northeast Hidalgo, and San Luis Potosi this
week.

The persistence of the moist pattern will create very hazardous
conditions in the region that could be life-threatening. Please
refer to your local meteorological office bulletins for more
detailed information.

For mariners in the Gulf of Mexico: Overnight ASCAT pass suggests
gale force winds are ongoing N of the Yucatan peninsula and a
gale warning has been issued. Expect building seas in excess of
15 ft with this system by later tonight.

...TROPICAL WAVES...

The axis of an Atlantic Ocean tropical wave is near 27W, from 16N
southward, moving westward 10 knots to 15 knots. Scattered
moderate to isolated strong convection is where the wave is
interacting with the monsoon trough.

The axis of an Atlantic Ocean tropical wave is near 60W/61W, from
16N southward, moving westward 10 knots to 15 knots. Scattered
moderate convection is east of the wave axis from 06N to 16N
between 52W and 60W.

...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. Convection is noted in the tropical
waves section above.

GULF OF MEXICO...

Please read the SPECIAL FEATURES section for information on the
possibility of heavy rainfall across the Yucatan Peninsula,
Tabasco, Veracruz, and parts of Queretaro, Hidalgo, and San Luis
Potosi this week.

A Central American Gyre is currently over southern Mexico and
Central America. High pressure ridge is along the Gulf coast
states. The pressure gradient between these features is supporting
minimal gale force winds N of the Yucatan peninsula (discussed in
the special features section above). Elsewhere, fresh to strong
winds cover the central Gulf, with moderate to fresh winds
elsewhere. Seas are in the 8-10 ft range in the area of gale force
winds, 5-8 ft elsewhere over the central Gulf, and 4-6 ft
elsewhere.

For the forecast, The gyre center is expected to persist through
the middle of this week, while shifting W to WNW into the SW Gulf
of Mexico. Showers and thunderstorms across the SE Gulf, along
with increasing winds to gale- force and rough seas, are expected
to shift over the W Gulf with this system. Environmental
conditions appear conducive for a tropical cyclone to develop from
this broad circulation, and a tropical depression or tropical
storm is likely to form by midweek while it moves toward the
western Gulf coast.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for information on the
potential for heavy rainfall across the Yucatan Peninsula this
week.

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.

For the forecast, the gyre center is expected to persist through
the middle of this week, while shifting W to WNW into the Gulf of
Mexico. 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.
Scattered showers and thunderstorm are active along this trough.
Moderate 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
1024 mb high pressure near 34N39W. 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 will shift eastward
early this week. Gentle to moderate NE to E winds will reach fresh
speeds N of 25N and west of 60W later this morning as high
pressure builds in the wake of the trough. A new trough, or an
area of low pressure, is forecast to form a few hundred miles
northeast of the central Bahamas in a day or two. Environmental
conditions could be conducive for some development of this system
thereafter while it moves westward or west- northwestward. The
system is forecast to approach the coast of the southeast United
States on Thursday or Friday. Regardless of development, fresh to
strong winds and rough seas will develop across the waters N of
25N tonight through Thu.

$$
AL