947
AXPZ20 KNHC 170357
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Mon Jun 17 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 0000 UTC surface analysis and satellite imagery through
0300 UTC.

...SPECIAL FEATURES...

Central America and southern Mexico Heavy Rainfall Event:
A broad area of low pressure persists over northern Central
America and southern Mexico. This weather pattern, known as a
Central American Gyre (CAG), directs moist SW flow from the
Pacific Ocean into the coastal terrain of Central America and
southern Mexico. This pattern will persist at least through
midweek, enhancing heavy rainfall and strong thunderstorms. This
can cause life-threatening conditions that include flooding and
mudslides. Numerous heavy showers and thunderstorms have already
impacted the coasts of Guatemala and the Mexican state of
Chiapas. The main areas impacted by the heavy rainfall will be
northwest Nicaragua, southwest 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...

A monsoon trough extends southwestward from the coast of
Guerrero State in Mexico through 13N114W to 08N128W. An ITCZ
continues westward from 08N128W to beyond 07N140W. Numerous
moderate to scattered strong convection is noted south of the
monsoon trough from 13N to 16N between 91W and 97W. Scattered
moderated convection is seen farther south from 08N to 12N
between 87W and 111W...and near the ITCZ from 06N to 08N west of
134W.

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

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

A large cluster of showers and thunderstorms is active off
Chiapas and Oaxaca in southern Mexico, associated with a broad
area of low pressure over the region known as the Central
American Gyre. These thunderstorms are causing widespread
lightning, gusty winds and locally rough seas off Chiapas and
Oaxaca. Fresh to strong NE to E winds are noted in this region
with seas 7 to 10 ft.

Meanwhile, a 1028 mb high pressure is located well NW of the
region near 34N140W. Pressure gradient between this high
pressure and lower pressure over the Colorado River Valley is
creating gale force winds off the California coast. Because of
that, this is driving fresh to locally strong winds across the
waters just west of Guadalupe Island off Baja California Norte.
This is also sending NW swell across the Baja California offshore
water, with combined seas are 8 to 12 ft north of Punta Eugenia.
In the Gulf of California, light to gentle winds are noted with
seas 2 to 4 ft. Mostly gentle to moderate breezes and slight to
moderate seas persist elsewhere with 5 to 7 ft seas.

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 Thu,
primarily off Chiapas, Oaxaca and southeastern Guerrero. This
inclement weather is associated with a broad area of low pressure
over the region known as the Central American Gyre. Dangerous
surf is also anticipated through Thu along the coastal areas of
this region. Farther north, fresh to strong NW winds and very
rough seas will persist off Baja California Norte through Tue
morning, primarily beyond 120 nm offshore. Large swell of 8 to 10
ft will linger in these waters mainly north of Cabo San Lazaro
through Mon evening before gradually subsiding through Tue night.


...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 heavy
rainfall.

With the monsoon trough displaced farther north than usual, this
is bringing fresh to strong winds across the Guatemala, El
Salvador and Nicaragua offshore waters. Seas are 8 to 11 ft in
this area within S to SW swell. Across the rest of the Central
American offshore waters, winds are gentle to moderate with 5 to
7 ft seas within S to SW swell. Strong thunderstorms continue to
impact mainly northern Central America off Guatemala, El Salvador
and Nicaragua which is bringing heavy rain and frequent
lightning. These storms could cause hazardous marine conditions.
In the Ecuador and Galapagos Island offshore waters, winds are
moderate with seas 5 to 8 ft within S to SW swell.

For the forecast, fresh to strong SW to W winds, rough to very
rough seas and numerous heavy showers and strong thunderstorms
will persist through Fri across the offshore waters of northern
Central America, associated with a broad area of low pressure
known as a Central American Gyre. Dangerous surf is also
anticipated through Thu along the coastal areas of this region.
Farther south, rough seas in moderate to large southerly swell
will continue near the Galapagos Islands and offshore of Ecuador
through Tue.

...REMAINDER OF THE AREA...

Broad ridging dominates the waters north of the ITCZ and monsoon
trough, anchored by a 1028 mb high pressure centered near
34N140W. Across waters north of 20N, winds are moderate to fresh
with NW swell propagating into the area bringing seas 8 to 12 ft
north of 25N between 115W and 130W. From the ITCZ and monsoon
trough to 20N and west of 120W, winds are gentle to moderate
with 6 to 8 ft seas in mixed swell. East of 120W, winds are
light to gentle with 5 to 6 ft seas within SW swell. South of the
monsoon trough and ITCZ, winds are mostly gentle to moderate
with 6 to 8 ft seas in SW to S swell.

For the forecast, strengthening high pressure centered NW of the
area will dominate waters west of 120W into the weekend. Fresh to
strong winds from the California Channel Islands southward are
likely to dip south of 30N at times through Tue. Seas will build
to 8 to 12 ft by Sun night into Mon, mainly north of 20N between
120W and 130W, and subside below 8 ft by Tue night into Wed. SW
flow south of the monsoon trough is forecast to continue this
morning between 90W and 115W, supporting seas of 6 to 8 ft.
Thunderstorms will persist near the monsoon trough and east of
110W or so through the next couple of days. Seas to 8 ft will
hover around 03S near the Galapagos Islands through the weekend.

$$

Chan