635
AXPZ20 KNHC 181604
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Jun 18 2024

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1545 UTC.

...SPECIAL FEATURES...

Central America and southern Mexico Heavy Rainfall Event:
Potential Tropical Cyclone One (PTC One) over the southwestern
Gulf of Mexico as of 15Z continues to sustain convergent
monsoonal winds and draw abundant moisture from the Pacific Ocean
into the coastal terrain of Central America and southern Mexico.
This pattern will linger at least through late week, enhancing
heavy rainfall and strong thunderstorms. This can cause life-
threatening conditions that include flooding and mudslides.
Numerous heavy showers and thunderstorms have persisted near the
coasts of Oaxaca and Chiapas States in Mexican overnight. Areas
expecting the heaviest rainfall through Sat continue to be the
northwest portion of Nicaragua, eastern and central Honduras, El
Salvador, coastal sections of Guatemala and the Mexican state of
Chiapas. Additionally, dangerous surf conditions will impact
these coastal areas through the next few days. Please refer to
your local meteorological and emergency management office
bulletins for more detailed information.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough axis extends southwestward from the offshore
waters of the state of Guerrero near 15N104W southwestward to
09N120W to 06N130W to 05N136W, where it transitions to the
ITCZ and continues westward to beyond 06N140W. Scattered
moderate to strong convection is within 120 nm south of the
trough between 121W and 124W. Scattered moderate convection
is within 60 nm south of the trough between 119W and 124W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Refer to the Special Features section above for details on a
heavy rainfall event.

Refer to the ITCZ/Monsoon Trough section for convection in the
region. Potential Tropical Cyclone One mentioned in the Special
Features section is sustaining fresh to strong with locally
near-gale SW to W winds and 8 to 11 ft seas over the offshore
waters of Oaxaca and Chiapas States in southern Mexico.
Meanwhile, moderate to fresh NW winds and seas of 7 to 9 ft in
residual NW swell linger west of Baja California Norte. Gentle to
moderate W to NW winds with 5 to 7 ft seas exist near Baja
California Sur and central Mexico. Gentle to moderate southerly
winds along with seas of 1 to 3 ft are present over the Gulf of
California.

For the forecast, fresh to strong SW to W winds, rough to very
rough seas, and numerous heavy showers and strong thunderstorms
will impact the offshore waters of southern Mexico through Fri
morning, primarily off Chiapas, Oaxaca and southeastern Guerrero
States. Dangerous surf is also anticipated along the coastal
areas of this region until Fri evening. Farther north, fresh NW
winds and rough seas will persist off Baja California Norte until
late this morning, primarily beyond 120 nm offshore. Residual NW
swell in these waters mainly north of Cabo San Lazaro will
gradually subside through tonight. From Wed evening through Fri
morning, fresh to strong NW winds and rough seas should develop
near Baja California Sur, including waters near Cabo San Lucas as
pressure gradient increases.

...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...

Refer to the Special Features section above for details on a
heavy rainfall event.

Potential Tropical Cyclone One mentioned in the Special
Features section is sustaining moderate to fresh with locally
strong SW to W winds and 7 to 9 ft seas across the offshore
waters of Guatemala and El Salvador. For the rest of the Central
America, and Colombia offshore waters, gentle to moderate WSW to
W winds and seas of 4 to 6 ft exist. These convergent monsoonal
winds are triggering scattered showers and isolated thunderstorms
near the coast of Guatemala, El Salvador, Panama and Colombia.
Near the Galapagos Islands and off Ecuador, gentle to moderate
southerly winds and seas at 6 to 8 ft in moderate southerly swell
prevail.

For the forecast, fresh to strong SW to W winds, rough to very
rough seas and numerous heavy showers and strong thunderstorms
will persist across the offshore waters of northern Central
America through Fri. Dangerous surf is also anticipated along the
coastal areas of this region until Fri evening. Farther south,
rough seas in moderate to large southerly swell will continue
near the Galapagos Islands and offshore of Ecuador through Wed.

...REMAINDER OF THE AREA...

Refer to the ITCZ/Monsoon Trough section for convection in the
region.

A broad surface ridge extends southeastward from a 1025 mb high
that is northeast of Hawaii to west of Baja California Sur near
20N119W. The associated gradient is supporting moderate to fresh
NNW to NE winds and seas of 6 to 8 ft in northerly long-period
swell north of 18N and west of 120W. Gentle to moderate NE winds
and 5 to 7 ft seas in generally moderate northerly swell are
evident farther southwest from 08N to 18N and west of 127W. Light
to gentle winds and seas of 4 to 6 ft due to mixed moderate
swell are over the waters near the ITCZ and monsoonal trough west
of 118W. South of the monsoon trough from 07N to 14N and east of
118W, fresh to locally strong SW to W winds and 7 to 9 ft seas
are noted. For the remainder of the region, gentle to moderate
southerly winds and seas at 6 to 8 ft in moderate to large
southerly swell prevail.

For the forecast, the high pressure and related ridge will
gradually weaken starting this afternoon, which should allow
winds and seas north of 18N and west of 120W to subside through
Thu morning. South of the monsoon trough from 07N to 12N and east
of 118W, fresh to strong SW to W winds will become more
widespread with seas building to between 8 and 10 ft by Wed.
Scattered moderate convection in this same general area is
anticipated to persist through at least Thu. Seas of 6 to 8 ft
will shift west of the Galapagos Islands by Wed.

$$
Aguirre