000
AXPZ20 KNHC 132112
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Showers and thunderstorms associated with a broad area of low 
pressure (EP94) located near 10N130W or well to the southwest of
the southern tip of the Baja California Peninsula are showing 
some signs of organization. The low pressure is along a tropical 
wave with axis along 130W from 04N to 16N. Scattered moderate to
isolated strong convection is within 180 nm SE and 120 nm NW
semicircles of low center. Environmental conditions appear 
conducive for development of this system, and a tropical 
depression is likely to form during the next couple of days or so
while it moves west- northwestward to northwestward at 10 to 15 
mph. By the weekend, upper-level winds are forecast to become 
less favorable for additional development while the system moves 
slowly westward. There is a high 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
08N95W to 11N118W. The ITCZ continues from 11N118W to 1009 mb low
pressure located near 10N130W to to beyond 04N140W. Aside from 
the convection mentioned above in the Special Features section, 
scattered moderate isolated strong convection is noted from 05N 
to 08N between 80W and 97W, from 06N to 15N between 97W and 123W,
and from 01N to 05N W of 136W. 

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

A ridge dominates the offshore forecast waters of Baja California
producing gentle to moderate NW to N winds and seas of 4-6 ft. In
the Gulf of California, mainly light and variable winds are noted,
except N of 29N where scatterometer data provide observations of
gentle to moderate southerly winds. Seas are 1-3 ft, except 3-4
ft near to the entrance of the Gulf. Fresh N winds are in the 
Gulf of Tehuantepec with seas 6-7 ft downstream to about 13N. 
Light westerly winds and seas of 4-6 ft in S to SW swell prevail 
elsewhere across the Mexican offshore waters.

For the forecast, a ridge will remain in control of the weather
pattern across the region over the next several days. 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 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, and gentle to moderate northerly winds in the Gulf of
Panama, and near the Azuero Peninsula. South of 04N, moderate to
locally fresh southerly winds are seen. Seas are 7-9 ft in 
between Ecuador and the Galapagos Islands, and 5-7 ft elsewhere.

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. 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 138W from 18N to 24N. An area of fresh
to strong NE winds remains between the northern end of the 
trough axis and a ridge to the N covering roughly the waters 
from 22N to 26N W of 135W. Seas are 8 to 10 ft within these 
winds. Moderate to locally fresh SE to S winds are south of 06N 
between 110W and 130W, where seas are 6-8 ft in long period S 
swell. S swell is reaching 8 ft as far north as 09N between 110W
and 120W. Elsewhere, winds are moderate or weaker, with seas of 
5-7 ft.

For the forecast, the surface trough near 138W will drift westward
crossing 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. As the trough moves W of the area,
high pressure will build across most of the northern forecast 
region, particularly N of 20N and W of 110W. Under the influence
of this system, mainly gentle to moderate anticyclonic flow is 
expected with seas generally in the 4-6 ft range.

$$
GR