000
AXPZ20 KNHC 131546
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Sep 13 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

A broad area of low pressure (EP94) located well to the southwest
of the southern tip of the Baja California Peninsula is producing
a large area of disorganized showers and thunderstorms. The low
pressure is along a tropical wave with axis along 129W from 04N
to 16N. Numerous moderate to isolated strong convection is within
about 150 nm S semicircle of the low center. Scattered moderate
to isolated strong convection is elsewhere from 06N to 16N
between 122W and 135W. Environmental conditions appear conducive
for development of this system, and a tropical depression is 
likely to form during the next two or three days while it moves 
west-northwestward to northwestward at 10 to 15 kt. By the 
weekend, upper-level winds are forecast to become less favorable 
for additional development while the system moves slowly 
westward. There is a medium chance of tropical cyclone formation 
within the next 48 hours. Currently, fresh to strong winds and 
seas in the 8 to 11 ft range are expected with this system over 
the next 48 hours. Refer to the latest NHC Tropical Weather 
Outlook at www.hurricanes.gov for more details.

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

The monsoon trough extends from northern Colombia near 10N74W to
07N100W to 10.5N 117W. The ITCZ continues from 10.5N117W to 
09.5n129w to to beyond 05N140W. Aside from the convection 
mentioned above in the Special Features section, scattered 
moderate isolated strong convection is noted from 05N to 12N 
between 80W and 92W, from 06N to 14N between 97W and 120W, and
from 02N to 07N W of 135W. 

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

A ridge dominates the offshore forecast waters of Baja California
producing mainly moderate NW to N winds to the west of Baja 
California, north of Cabo San Lazaro. To the south of Cabo San 
Lazaro, gentle NW winds prevail. Seas are 5-7 ft to the west of 
Baja California Norte and 5-6 ft west of Baja California Sur. 
Mainly gentle S to SW winds and 1-3 ft seas are in the Gulf of 
California. Fresh to strong N winds are in the Gulf of Tehuantepec
with seas 6 to 8 ft. Light to gentle and variable winds prevail 
elsewhere with seas of 5-7 ft in long period S swell.

For the forecast, fresh N gap winds will prevail in the Gulf of 
Tehuantepec through late this morning. Mainly moderate to locally
fresh NW to N winds are forecast over the waters west of Baja 
California through the upcoming weekend. Seas are expected to 
build to 6 to 7 ft off Baja California Sur with these winds. 

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

Long period S to SW swell is affecting the waters offshore
Central America and northern South America. N of 04N, winds are 
light to gentle, except for moderate E winds in the Papagayo
region. South of 04N, moderate to locally fresh southerly winds
are seen. Seas are 8-9 ft in between Ecuador and the Galapagos 
Islands based on altimeter data. Seas are 5-7 ft offshore Central
America and Colombia, except up to 8 ft off southern Colombia, 
in long period S to SW swell.

For the forecast, moderate to fresh southerly winds will prevail 
over the waters between Ecuador and the Galapagos Islands through
Thu before diminishing late in the week. Seas of 8 to 9 ft in 
long period S to SW swell will continue over these waters through
Thu or Thu night before subsiding. Elsewhere, light to gentle 
winds will prevail through Fri night, except for moderate NE to E
winds in the Gulf of Papagayo through late this morning. Long-
period southerly swell, with seas of 6-7 ft, will continue to 
propagate across the offshore waters of Central America through 
tonight before gradually subsiding Thu and Thu night.

...REMAINDER OF THE AREA...

A surface trough is along 136W from 20N to 26N. An area of fresh
to strong NE winds remains between the northern end of the 
trough axis and a ridge to the N. Seas are 8 to 10 ft within 
these winds. Moderate to locally fresh SE to S winds are south 
of 06N between 100W and 130W, where seas are 8-9 ft in long 
period S swell. S swell is reaching 8 ft as far north as 08N. 
Elsewhere, winds are moderate or weaker, with seas of 5-7 ft.

For the forecast, the surface trough near 136W will drift
westward and cross 140W this evening. An area of fresh to strong
winds between the trough and a high pressure to the N is forecast
to persist through this evening. Elsewhere north of the ITCZ and
E of 125W, mainly gentle to moderate NE to E winds will prevail.
To the south of 09N and east of 128W, seas of 8 to 9 ft in long-
period southerly swell will continue through late this morning 
before gradually subsiding this afternoon through Thu night.

$$
GR