841 
AXPZ20 KNHC 271531
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Sep 27 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
1420 UTC.

...TROPICAL WAVES...

A tropical wave is along 86W north of 06N to across the Gulf of
Papagayo, moving west at 5 to 10 kt. Scattered moderate isolated
strong convection is noted from 04N to 13N between 81W and 90W.

A tropical wave is analyzed along 127W/128W from 03N to 17N, 
moving W at around 10 kt. Scattered moderate isolated strong
convection is noted from 10N to 17N between 123W and 130W.

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

The monsoon trough extends from 09N90W to 10N110W to 09N117W. 
Segments of the ITCZ extend from 09N117W to 09N126W, and from
09N131W to 08N139W. Scattered moderate isolated strong convection
is noted from 04N to 08N between 90W and 94W, and from 03N to 09N
between 118W and 140W.

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

A ridge extends across the offshore waters W of 110W with a
trough extending along the Gulf of California. Fresh NW-N winds
are offshore Baja California from near Cabo San Lazaro northward,
with seas of 7-11 ft in NW swell. A plume of fresh to strong N-NE
winds is in the Gulf of Tehuantepec, along with 5-7 ft seas.
Winds are mainly light to gentle elsewhere, along with 4-6 ft
seas in typical mixed S and NW swell. In the Gulf of California,
seas are 1-3 ft, except 3-4 ft near the entrance.

For the forecast, moderate to fresh NW winds will persist off 
Baja California north of Cabo San Lazaro through the evening 
between high pressure north of the area and a trough over the 
Gulf of California. Winds will then gradually diminish through 
Fri as the ridge shifts NW. Seas of 8 to 12 ft in NW swell will 
persist through Thu offshore Baja California before slowly 
subsiding Fri through Sat. Farther south, moderate to fresh N gap
winds will pulse to strong across the Gulf of Tehuantepec 
at night. Looking ahead, fresh to strong westerly gap winds over
the northern Gulf of California will start Fri afternoon, ahead 
of an approaching cold front, possibly reaching near-gale force 
by Sat evening. 

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

A tropical wave is moving across the Papagayo region as described
above. Light and variable breezes are evident off northern 
Central America, north of the monsoon trough, along with combined
seas of 3-5 ft in southerly swell. Gentle S to SW breezes are 
noted farther south, except moderate winds S of 05N. Combined 
seas are 4-7 ft there, except 5-8 ft offshore Ecuador, highest S
of the Galapagos Islands.

For the forecast, gentle to moderate winds will prevail to the north
of 05N with seas 5 ft or less through Sun night, with moderate SW
winds farther south. Seas south of 05N will build to 6-9 ft in 
southerly swell through Fri evening, with seas highest to the SW 
of the Galapagos. 

...REMAINDER OF THE AREA...

The remnant trough that was T.C. Fourteen-E has passed W of the 
area. A tropical wave described above along 127W/128W combined
with high pressure N of the monsoon trough/ITCZ is supporting a
growing area of fresh to strong winds roughly from 13N to 23N
between 124W and 135W. Moderate to fresh trades cover the
remainder of the waters N of the monsoon trough/ITCZ and W of 
120W. A large area of northerly swell of 7-11 ft roughly N of 13N
and W of 114W, up to around 12 ft along 30N to the E of 135W. To
the south, mainly moderate southerly winds are S of the monsoon
trough/ITCZ. Southerly swell of 7-10 are S of 05N and W of 110W.
Mainly gentle winds and 4-7 ft seas cover the remainder of the
open waters.

For the forecast, the tropical wave will continue westward,
approaching 140W Fri morning. Some development of this system is
possible over the next couple of days while it moves generally 
westward at about 10 to 15 kt. By this weekend, upper-level winds
are forecast to become unfavorable for further development 
before the system moves into the Central Pacific basin. At a 
minimum, fresh to strong seas and seas of 8-12 ft will accompany 
this feature. High pressure will dominate the waters elsewhere N
of the monsoon trough/ITCZ. The pressure gradient will weaken by
the end of the week into the weekend as the wave departs and the
high weakens leading to improving conditions. Meanwhile, for
seas, the northerly swell of 8 ft or greater will reach to the
Equator and W of 115W by the end of the week, while the southerly
swell of 8 ft or greater lingers near the Equator and southward.
Both large areas of swell should gradually decay this weekend.

$$
Lewitsky