000
AXPZ20 KNHC 121544
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Sep 12 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.

...TROPICAL WAVES...

A tropical wave has its axis along 126W from 04N to 15N, moving 
westward at 10-15 kt. Clusters of moderate to strong convection
are noted behind the wave axis from 05.5N to 09N between 117W 
and 126W. Scattered moderate to isolated strong convection is seen
elsewhere from 05N to 15N between 115W and 130W. A broad area of
low pressure is along the wave axis. Some slow development of 
this system is expected during the next few days, and a tropical 
depression could form while it moves generally west-northwestward
across the western portion of the eastern Pacific basin. Strong 
winds and seas to 10 ft could develop with this system by Wed 
night into Thu. There is a low chance of tropical cyclone formation
within the next 48 hours.

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

The monsoon trough extends from northern Colombia near 10N75W to
09N90W to 08N98W. The ITCZ continues from 08N98W to 12N110W to
11n124w to 02N140W. Aside from the convection associated with
tropical wave, scattered moderate convection is from 03N to 07N E
of 90W to the coast of Colombia. Similar convective activity is
observed from 11N to 14N between 102W and 106W. 

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

A ridge is building across the offshore forecast waters of Baja
California, bringing moderate NW to N winds offshore Baja 
California Norte and gentle NW winds offshore Baja California 
Sur. Seas are 5-7 ft off Baja California Norte and 4-6 ft off 
Baja California Sur. In the Gulf of California, gentle to 
moderate S winds prevail along with 1-3 ft seas. In the Gulf of 
Tehuantepec, fresh N gap winds are occurring along with seas to 
6-7 ft. Gentle and variable winds prevail elsewhere with 4-6 ft 
seas in long-period S to SW swell.

For the forecast, fresh N gap winds will prevail in the Gulf of 
Tehuantepec through Wed morning. Mainly gentle to moderate NW to
N winds are forecast over the waters west of Baja California 
through today, increasing to moderate to fresh from tonight 
through the end of the week. Seas will build 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. South of 04N, gentle to moderate southerly 
winds prevail. Seas are 7-9 ft in between Ecuador and the 
Galapagos Islands. Seas are 4-6 ft offshore Central America and 
Colombia, except up to 7 ft off southern Colombia, in long period
S to SW swell.

For the forecast, gentle to moderate south winds will continue
over the waters between Ecuador and the Galapagos Islands through
today, increasing to moderate to fresh tonight through Thu, with
seas of 7-9 ft in long period S to SW swell through Thu night. 
Elsewhere, light to gentle winds will prevail through Fri night, 
except for moderate NE to E winds in the Gulf of Papagayo pulsing
through tonight. Long-period southerly swell, with seas of 6-7 
ft, will propagate across the Central America and Colombia 
offshore forecast waters through Thu before subsiding Fri.

...REMAINDER OF THE AREA...

The remnant low of Jova has dissipated into an open trough. The 
trough extends along 130W/131W from 21N to 28N. 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 9 ft within these winds. 
Fresh NE winds and seas 7 to 8 ft are occurring to the west of 
the aforementioned tropical wave along 126W. Fresh SE to S winds
are south of 06N between 120W and 126W, where seas are 8-9 ft in
long period S swell. S swell of 8-9 ft is occurring east of 120W
and south of 06N. Elsewhere, winds are moderate or weaker, with 
seas of 5-7 ft.

For the forecast, the surface trough near 130W/131W will drift 
west-southwestward through tonight. An area of fresh to strong 
winds between the trough and a high pressure to the N is forecast
to persist through early Wed morning. Elsewhere north of the 
ITCZ and E of 125W, mainly gentle to moderate NE to E winds will 
prevail. To the south of 06N and east of 120W, seas of 8 to 9 ft
in long-period southerly swell will continue through tonight 
before gradually subsiding Wed.

$$
GR