000
AXPZ20 KNHC 230356
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Wed Aug 23 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 0000 UTC surface analysis and satellite imagery through
0300 UTC.

...TROPICAL WAVES...

A tropical wave axis is near 100W north of 05N, moving westward 
around 10 kt. Scattered moderate convection is within 30 nm of
the coast of eastern Guerrero.

A tropical wave extends from 03N-16N with axis near 115W, moving
westward at 10 to 15 kt. No significant convection is noted near
this tropical wave.

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

The monsoon trough axis extends from 10N84W to 14N115W to 
10N132W. The ITCZ extends from 10N132W to beyond 07N140W. 
Scattered moderate and isolated strong convection is from 11N to
13N between 87W and 89W. Scattered moderate convection is noted
from 10N to 12N between 105W and 107W.

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

Fresh northerly gap winds persist across the Gulf of Tehuantepec,
due in part to lower pressure over the tropical eastern Pacific
as the monsoon trough becomes active. The short duration of the
gap winds is keeping seas to 6 ft or less for now across the Gulf
of Tehuantepec. Farther north, A recent ship observation a 
little south of Punta Eugenia showed NW winds at 20 kt, part of a
larger area of fresh NW winds off Baja California Sur north of 
Cabo San Lazaro. These winds are funneling along the coast on 
the eastern edge of the subtropical ridge centered west of the 
area. A weak pressure gradient is supporting gentle breezes 
elsewhere, with moderate combined seas primarily in SW swell. 
Scattered showers and thunderstorms are active along the coast of
eastern Guerrero state, following a tropical wave moving through
the area.

For the forecast, the northerly gap winds will continue to pulse
mainly at night across the Gulf of Tehuantepec through Thu 
night. Looking ahead, a broad area of low pressure is expected to
form offshore of the coast of Central America or southern Mexico
during the next few days. Environmental conditions appear 
generally favorable for gradual development of this system. A 
tropical depression could form late this week while it moves 
slowly northwest to north- northwest, possibly supporting strong 
winds and rough seas off western Oaxaca Fri, and off Guerrero and
Michoacan Fri night through Sat night.

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

Earlier scatterometer satellite data confirmed fresh to strong SW
to W winds along and south of the monsoon trough off the coast
from western Panama to northwest Costa Rica. A concurrent
altimeter satellite pass at 95W indicated 8 to 9 ft seas in the
areas of stronger winds, likely indicative of wave heights off 
Costa Rica. Scattered showers and thunderstorms are active from
northwest Nicaragua to eastern El Salvador, to include the Gulf
of Fonseca. This activity is due in part to enhanced easterly 
wind convergence north of the monsoon trough. A small low
pressure area may be starting to develop off Nicaragua and
northern Costa Rica along the monsoon trough. Gentle to moderate
winds and moderate combined seas in SW swell are noted elsewhere.

For the forecast, regardless of whether a small low pressure area
develops overnight, the active monsoon trough will support fresh
to strong SW winds and rough seas off Costa Rica and Nicaragua 
through Thu. These winds and seas will diminish Fri as the 
monsoon trough lifts north of the area. Gentle breezes and
moderate SW swell will persist across the region thereafter
through Sun.

...REMAINDER OF THE AREA...

Recent altimeter data confirmed 8 to 9 ft seas as part of a
larger area extending south of 10N and east of 110W, due in part
to enhanced fresh to strong SW monsoon flow along with a
component of SW swell. Broad ridging dominates the pattern north
of 20N, supporting gentle to moderate breezes and moderate
combined seas in a mix of SW and NW swell. 

For the forecast, fresh to strong SW winds will persist south of
the monsoon trough and east of 120W through Thu. The surface 
ridge should strengthen on Fri into Sun, forcing fresh NE trades 
and seas 6 to 8 ft west of 120W from 10N to 20N.

$$
Christensen