000
AXPZ20 KNHC 022157
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sat Sep 2 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 is along 95W, moving west at 10 kt. Numerous 
moderate to scattered strong convection is noted within 180 nm
west of the axis from 11N to 14N. 

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

The monsoon trough axis extends from Costa Rica near 09N84W to
07N95W to 14N110W to 05N135W. The ITCZ continues from 05N135W to
beyond 03N140W. Scattered moderate convection is active from 04N
to 07N between 78W and 82W.

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

See Tropical Waves section above for information on a tropical
wave that is likely to induce low pressure development next week
offshore SW Mexico. 

A recent scatterometer satellite pass confirmed fresh to strong 
northerly gap winds across the Gulf of Tehuantepec offshore up 
to 180 nm offshore. Combined seas in this plume are likely reaching
near 8 ft with the assistance of SW swell moving into the 
region. Clusters of showers and thunderstorms are active ahead of
the tropical wave farther offshore. Gentle breezes are evident 
elsewhere, with 4 to 6 ft in combined seas. 

For the forecast, fresh to strong northerly winds will pulse in 
the Gulf of Tehuantepec into Sun. Expect fresh to strong winds 
along the Baja California coast and parts of the Gulf of 
California through the early part of the week as the pressure 
gradient tightens along the peninsula. Looking ahead, 
environmental conditions will be conducive for gradual 
development of low pressure off southern Mexico during the next 
several days, and a tropical depression is expected to form by 
the middle of next week. The system is forecast to move westward 
to west- northwestward, passing well south of mainland Mexico but
may bring near-gale force winds and very rough seas to the 
Revillagigedo Islands by late Thu. There is a low chance of 
tropical formation within 48 hours, but a high chance within in 
the next 7 days. 

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

Moderate gap winds were confirmed over the Gulf of Papagayo by a
recent scatterometer satellite pass. Moderate SW winds are likely
ongoing elsewhere south of the monsoon trough, extending from off
Ecuador to the coast of western Panama and Costa Rica. An earlier
altimeter satellite pass verified there was 8 to 10 ft seas off
Ecuador and southern Colombia, likely due to SW swell. Combined
seas are 6 to 8 ft elsewhere. A line of showers and 
thunderstorms extends from off the southern coast of Colombia to 
off the coast of western Panama. 

For the forecast, moderate to locally fresh south to southwest winds
will continue south of 10N through Mon, along with long period S
to SW swell. Elsewhere, light to gentle variable winds will 
prevail, except locally moderate to fresh near the Gulf of 
Papagayo Mon tonight.

...REMAINDER OF THE AREA...

Long period SW swell of 7 to 8 ft is present mainly south of 10N
and east of 125W, along with moderate southerly swell. Elsewhere,
gentle breezes persist with 5 to 7 ft combined seas in mixed
swell. 

For the forecast, the main issue east of 125W for next week will
be the development and movement of the low pressure off southern
Mexico discussed in Mexican waters section above. Longer period
SW swell will persist as well. Farther west, building high 
pressure farther north of the area will support moderate to fresh
trade winds from 10N to 20N west of 125W starting early next 
week. 

$$
Christensen