000
AXPZ20 KNHC 120908
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...TROPICAL WAVES...

A tropical wave has its axis along 95W north of 04N to across 
the Gulf of Tehuantepec. It is moving westward at 10 to 15 kt. 
Scattered moderate convection is along the wave axis from 08N to 
12N. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough axis extends from the Costa Rica/Nicaragua
border near 11N85W to 12N90W to 14N105W to 11N120W to 09N140W. 
Scattered moderate to isolated strong convection can be found
from 08N to 12N between 86W and 96W, from 04N to 09N between 97W
and 102W, from 08N to 10N between 111W and 117W, and from 06N to
10N W of 138W.
 
...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

The pressure gradient between a ridge across the offshore forecast
waters of Baja California and a meandering trough over the Gulf 
of California supports moderate to fresh NW to N winds just W of
the Baja California Peninsula, and moderate to fresh SW to W winds
in the Gulf of California, where isolated wind barbs of 25 kt 
are observed based on recent scatterometer data. Seas are 8 to 
10 ft in NW swell N of Punta Eugenia, and 5 to 7 ft between Punta
Eugenia and Los Cabos. Seas of 2 to 4 ft are noted in the Gulf 
of California, with seas in the 3 to 5 ft range near the entrance
to the Gulf. Farther south, seas continue to subside, with an 
area of 8 to 9 ft seas in a westerly wind flow from 13N to 15N 
between 98W and 104W. Fresh to strong W winds are noted along 
the coast of Oaxaca, including the west part of the Gulf of 
Tehuantepec, particularly N of 15N between 95W and 98W. These 
winds could be associated with a broad area of low pressure over 
SE Mexico. Seas are 8 to 10 ft within these winds based on
altimeter data.

For the forecast, a ridge will continue to build eastward across
the offshore waters of Baja California the remainder of the week.
A swell event, with seas in the 8 to 11 ft range will continue 
to propagate across the offshore waters of Baja California N of 
Cabo San Lazaro through Fri. In the Gulf of California, moderate
to fresh south to southwest winds are expected through tonight,
then gentle to moderate W to NW winds will prevail through the
upcoming weekend. Fresh to strong west winds that are just south
and southwest of the Gulf of Tehuantepec will diminish to 20 kt 
by early this afternoon. The first Gulf of Tehuantepec gap wind 
event of this fall season is expected to begin on Sun morning, 
with fresh to strong north to northeast winds lasting well into 
next week as winds gradually increase. There is a possibility for
these winds to reach gale-force Mon and Mon night. 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. Currently, the latest Tropical Weather Outlook
gives this system a low chance of tropical cyclone formation
through7 days.

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

Mostly light and variable winds are north of about 07N, and 
gentle to moderate south winds south of 07N. Seas are generally 
4 to 6 ft across the region due a southerly swell. 

For the forecast, mainly light to gentle winds will continue 
north of of the monsoon trough, with gentle to moderate winds 
south of it. Long-period southerly swell will continue to 
propagate across the offshore forecast waters with seas of 
5 to 7 ft through at least Fri.

...REMAINDER OF THE AREA...

A ridge dominates the forecast waters N of 15N and W of 120W. 
The associated pressure gradient is allowing for generally gentle
to moderate northeast to east trade winds and seas of 5 to 6 ft 
per recent altimeter data. Elsewhere, north of the monsoon trough
and ITCZ light to gentle northeast to east winds are present 
with seas of 4 to 5 ft. Gentle to moderate south to southwest 
winds are south of the monsoon trough. Seas there are 5 to 6 ft 
due to southerly long-period swell. 

For the forecast, 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. A rather extensive set of northwest
swell will follow in behind this front bringing seas of 8 to 10 ft
to the far northwest waters starting Fri. Another cold front is
forecast to reach 30N140W on Mon.

$$
GR