647 
AXPZ20 KNHC 122159
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu Oct 12 2023

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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...TROPICAL WAVES...

A tropical wave has an axis along 97W north of 02N to the 
southern Mexico coast, moving westward at 10 to 15 kt. Scattered 
moderate convection is noted from 03N to 12N between 94W and 
103W. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough axis extends from the coast of Costa
Rica/Nicaragua border near 11N86W to 15N105W to 10N125W to 
beyond 09N140W. Scattered moderate convection is noted from 05N 
to 13N between 86W and 119W and from 06N to 11N W of 135W. 
 
...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A ridge continues to extend across the Baja California offshore
waters. The pressure gradient between this feature and lower
pressure over Mexico has weakened. As a result, gentle to 
moderate NW winds prevail with locally fresh winds noted N of 
27N. The northwesterly swell continues to propagate across the 
Baja California Norte offshore waters, bringing seas 8 to 12 ft 
to waters N of 25N. The highest seas are noted in the far 
northwest corner of the forecast waters. South of 25N, seas range
5 to 7 ft within mostly NW swell. The latest scatterometer data 
noted moderate to fresh winds across the Gulf of California. 
Seas range 2 to 4 ft. In southern Mexico, moderate to fresh winds
are noted to the west of the Gulf of Tehuantepec, otherwise 
gentle to moderate winds prevail over the area. Seas are 6 to 8 
ft within mixed swell. Scattered thunderstorms are noted around 
and south of the Gulf of Tehuantepec. Otherwise, no significant 
convection is noted across the rest of the Mexico offshore waters
at this time.

For the forecast, the northwesterly swell impacting the Baja 
California offshore waters will slowly subside by Sat. Winds 
across the Baja California and Gulf of California offshore waters
will become light to gentle Fri and Sat. Winds could become 
moderate once again later in the weekend. The first Gulf of 
Tehuantepec gap wind event of this fall season is expected to 
begin later this weekend. Fresh to strong N to NE winds with 
fresh to strong N to NE winds will begin Sun morning, and 
possibly becoming gale-force by Sun night. The gale-force winds 
will end by Tue, with the strong winds continuing through most of
the week. October marks the beginning of the Tehuantepec wind 
events.

Looking ahead, an area of low pressure is expected to form 
several hundred miles to the south of the southwestern coast of 
Mexico during the early to middle part of next week. Thereafter, 
some gradual development is possible while the system moves 
generally north-northwestward. The latest Tropical Weather 
Outlook gives this system a low chance of tropical cyclone 
formation through 7 days.

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

Light to gentle W to SW winds prevail across the Central and
South American offshore waters. Southerly swell is bringing 8 ft
seas across the Ecuador and Galapagos Islands offshore waters, in
addition to parts of the Guatemala/El Salvador offshore waters.
Otherwise, seas range 5 to 7 ft. Scattered thunderstorms are
noted across the Central American offshore waters. 

For the forecast, winds are expected to increase to moderate 
across the Ecuador and Galapagos Islands offshore waters by Sat. 
Moderate winds is also expected across the Central American 
waters by Sun. Gentle to moderate winds will continue across 
these waters through early next week. The long- period southerly 
swell will slowly subside across the area through the weekend. 

...REMAINDER OF THE AREA...

A ridge extends across the waters, N of 15N and W of 120W.
Moderate to locally fresh winds are noted to the west of the Baja
California offshore waters, N of 23N and E of 124W. Northwesterly
swell bringing rough seas up to 12 ft is also noted across this 
area. Otherwise, scatterometer shows gentle to moderate winds 
across the rest of the waters N of the monsoon trough. Seas range
6 to 7 ft. South of the monsoon trough, gentle to moderate winds
mostly prevailing across the area. Fresh to locally strong winds
are noted near 10N114W. Long-period south to southwesterly swell
is propagating in the waters E of 115W and bringing seas to 8 
ft. Otherwise, seas range 5 to 7 ft. 

For the forecast, the NW swell bringing rough seas to the NW
portion of the waters will subside by Fri night. Meanwhile, high
pressure over the area will gradually shift eastward and weaken 
through Fri as a cold front enters the northwest part of the area
while weakening. Northwest swell will follow in behind this 
front, bringing seas of 8 to 9 ft to the far northwest waters 
from Fri through Sat night. Another cold front is forecast to 
reach 30N140W on Mon, bringing another set of swell to the area 
early next week. The southerly swell impacting the waters west of
the Galapagos Islands is also expected to subside by Fri. 

$$
AReinhart