076
AXPZ20 KNHC 161526
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sun Jun 16 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
1500 UTC.

...SPECIAL FEATURES...

Central America and southern Mexico Heavy Rainfall Event: A
broad area of low pressure has developed over northern Central
America and southern Mexico. This weather pattern, known as a
Central American Gyre (CAG), enhances moist SW flow off the
Pacific and into the coastal terrain of Central America and
southern Mexico. This moist flow can persist for several days,
resulting in 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. This pattern is expected to persist through at least
the middle of the week across northern Central America and
southern Mexico. This will increase the threat to life and
property as the event persists. The main areas impacted by the
heavy rainfall will be northwest Nicaragua, southwest Honduras
northwest Nicaragua, and coastal sections of Honduras, El
Salvador, Guatemala, and the Mexican state of Chiapas. Farther
south, the moist southwest flow was also causing persistent heavy
rainfall across Costa Rica and Panama, although this will be
diminishing today as the focus shifts northward to northern
Central America. Additionally, dangerous surf could impact
Chiapas, Guatemala and El Salvador today through the next few
days.

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

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

The monsoon trough is displaced farther north than usual due to
the ongoing Central American Gyre. It now extends off the coast
of Mexico near a 1003 mb low pressure at 15N95W, and continues to
07N125W. The ITCZ extends from 07N125W 06N140W. Numerous
moderate to isolated strong convection is noted from 10N to 15N
between 85W and 105W.

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

Refer to the section above for details on the Central American
Gyre.

A large cluster of showers and thunderstorms is active off
Chiapas in southern Mexico, associated with a broad area of low
pressure over the region known as the Central American Gyre.
These thunderstorms are probably 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 1027 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, highest near the entrance of the Gulf. Mostly
gentle to moderate breezes and slight to moderate seas persist
elsewhere with 5 to 7 ft seas. Smoke from agricultural fires in
Mexico are causing haze particularly off Colima, Jalisco and
Nayarit.

For the forecast, fresh to strong SW winds, rough seas, and
numerous showers and thunderstorms will impact the offshore
waters of southern Mexico through Thu, primarily off Chiapas and
Oaxaca. This weather is associated with a broad area of low
pressure over the region known as the Central American Gyre.
Dangerous surf is also possible today through the next few days
in this region. Farther north, fresh to strong winds and rough
seas will persist off Baja California Norte through Mon,
primarily beyond 120 nm offshore. Large swell of 8 to 12 ft will
move into the waters off Baja California today, and persist
mainly north of Cabo San Lazaro before subsiding by Tue night.

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

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 7 to 10 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 winds, rough seas and
numerous showers and thunderstorms will persist through Thu
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 possible today through the
next few days in this region. Farther south, seas to 8 ft in S
swell will continue around the Galapagos Islands through Tue.

...REMAINDER OF THE AREA...

Broad ridging dominates the waters north of the ITCZ and monsoon
trough, anchored by a 1027 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.

$$
Christensen