772
AXPZ20 KNHC 151525
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sat Jun 15 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 Heavy Rainfall Event: Moist onshore flow
associated with a Central American Gyre (CAG) has been delivering
periods of heavy rainfall across Panama and Costa Rica. This
activity will likely continue through at least early Sun then
gradually diminish. Meanwhile, the focus will be shifting
farther north to northern Central America, where moderate to
fresh onshore flow is already bringing clusters of showers and
thunderstorms to the coastal regions of El Salvador. This onshore
flow will increase Sun and continue into mid week as the CAG
intensifies and persists. This pattern will bring the threat of
heavy rainfall, flooding and mudslides to primarily coastal
regions of northern Central America from northwest Nicaragua,
Honduras, El Salvador, Guatemala, and into the Mexican state of
Chiapas.

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 extends from 13N88W to 18N105W to 06N125W.
The ITCZ extends from 06N125W to beyond 08N140W. Scattered
moderate convection from 06N to 08N between 77W and 87W. Numerous
moderate to isolated strong from 11N to 14N between 97W and 98W.

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

A ridge extends from 1029 mb high pressure well to the northwest
near 35N140W, southeastward to the Revillagigedo Islands. Recent
scatterometer satellite passes indicate moderate NW flow off Baja
California on the eastern edge of the ridge, but concurrent
altimeter passes show 6 to 8 ft seas to the west of Guadalupe
Island, primarily due to NW swell approaching the region. Light
to gentle breezes are noted elsewhere, with 4 to 6 ft seas in
mixed swell, except for slight seas over the Gulf of California.
Hazy conditions were noticed yesterday off Jalisco and Colima,
but recent observations indicate visibility may have improved.

For the forecast, fresh to locally 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 into mid week before subsiding. Meanwhile, off
southern Mexico, expect fresh SW winds and building seas starting
tonight off Chiapas as a Central American Gyre develops over the
region. Winds and seas will increase further off Chiapas and
Oaxaca through the early part of the week as the gyre intensifies
and persists.

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

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

With the monsoon trough displaced farther north than usual, this
is bringing fresh winds across the Colombia and Panama offshore
waters with seas 7 to 9 ft, with the maximum seas noted off the
southern Azuero Peninsula of Panama. Across the rest of the
Central American offshore waters, winds are moderate to fresh
with 6 to 8 ft seas. Strong thunderstorms continue to impact
Central America, bringing heavy rain and frequent lightning.
These storms could cause hazardous marine conditions. In the
Ecuador and Galapagos Island offshore waters, winds are gentle to
moderate. Seas are 6 to 8 ft within S swell.

For the forecast, the developing Central American Gyre will cause
an increase in winds, rough seas and widespread showers and
thunderstorms across much of offshore waters through mid week.
Fresh to strong winds and rough seas in the Gulf of Panama will
diminish by early Sun, as the focus of strong SW winds and rough
seas shifts farther north from Nicaragua to Guatemala. 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 1029 mb high pressure near 35N140W.
Moderate to fresh winds prevail across waters north of the
monsoon trough and west of 115W with seas 6 to 9 ft. East of
115W, gentle to moderate winds are noted south of the monsoon
trough to 05N. Seas are 5 to 7 ft across the rest of the Pacific
waters.

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 early next week.
Seas will build to 8 to 12 ft by Sun night into Mon. SW flow
south of the monsoon trough is forecast to continue tonight
between 90W and 115W, supporting seas of 6 to 8 ft. Similar winds
and seas are likely to return there by the end of the weekend
into early next week. 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