000
AXPZ20 KNHC 251609
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Mon Sep 25 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 is analyzed along 116W from 04N to 17N, moving W
at around 10 kt. Scattered moderate to strong convection is from
05N to 14.5N between 114.5W and 124W.

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

The monsoon trough extends from 10.5N74.5W to 10N82W to 08N92W to
12N102W to 06.5N119W to 08N122W. The ITCZ extends from 10.5N128W
to beyond 08.5N140W. Scattered moderate to strong convection is 
noted from 03.5N to 09N E of 99W, and from 05.5N to 10N between 
103W and 111W. Scattered moderate isolated strong convection is 
noted from 10N to 14N between 125W and 128W, and within 240 nm S 
of ITCZ between 128W and 135W.

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

A modest surface ridge continues to dominate the offshore 
forecast waters of Baja California, centered on a 1020 mb high 
near 30N124W. This pressure pattern is supporting moderate to 
fresh NW-N winds from near Cabo San Lazaro northward. Seas are 
4-7 ft in NW swell offshore Baja California. Winds are moderate 
or weaker elsewhere, with seas of 4-5 ft, except 1-3 ft in the 
northern Gulf of California. Scattered moderate to strong
nocturnal convection persists across the coastal waters within
200 nm of the coast between the Gulf of Tehuantepec and Puerto
Vallarta.

For the forecast, the surface ridge will continue to extend
southeastward across the offshore waters through Tue. Moderate 
to fresh NW-N winds offshore Baja California from near Cabo San 
Lazaro northward will increase to fresh to strong today and
continue through early Wed. Winds will then diminish to moderate
Wed through Fri as the Pacific ridge shifts NW. Moderate N winds
will pulse to strong across the Gulf of Tehuantepec on Tue  
and then again Thu night. Seas will gradually build 8 to 12 ft 
in new NW swell offshore Baja California Tue through Fri.

Looking ahead, low pressure is expected to develop across the 
northern Gulf of California by the end of the upcoming week, and 
induce strong SW winds across a large portion of the Gulf. 

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

Winds are generally gentle to moderate elsewhere to the north of
05N, where seas are 3-5 ft. Moderate S to SW winds prevail 
elsewhere to the south of 05N, from offshore Ecuador to the 
Galapagos Islands. Seas there are 5 to 6 ft. 

For the forecast, gentle to moderate winds prevail to the north 
of 05N, with seas of 3-5 ft. Moderate to fresh SW monsoonal 
winds will prevail to the S of 07N through mid week. Slight to 
moderate seas will prevail, highest offshore Ecuador to the 
Galapagos Islands, before seas build slightly region-wide in S-SW
swell beginning Wed. 

...REMAINDER OF THE AREA...

The remnants of T.C. Fourteen-E are centered near 16N128W. Fresh
to strong winds are noted across the northern semicircle with 
the low, with seas to 10 ft. Widely scattered moderate convection
lingers within 150 nm across the eastern semicircle.

A surface trough prevails along 131W from 22N to 26N. Scattered
shallow convection is near the trough. Associated winds are 
moderate with remnant 5 ft seas in mixed swell across the N side.
Elsewhere N of 20N, anticyclonic winds are moderate or weaker, 
and seas are 4-6 ft. S of 20N and to the west of the remnants of 
Fourteen, the modest pressure gradient between a weak high 
pressure ridge along 28N and lower pressure near the ITCZ is 
yielding moderate ENE trade winds and seas of 5 to 7 ft in mixed 
N and SE swell.

New southerly swell is building seas to around 8 ft S of the 
Equator and W of 110W and will propagate northwestward over the
next 48 hours.

For the forecast, the remnants of T.C. Fourteen-E will gradually 
dissipate during the next 48 hours while moving westward. The 
surface trough near 131W will gradually shift W-SW and dissipate 
through Tue. Elsewhere, weak high pressure will prevail N of the 
monsoon trough and E of 120W through Wed and yield moderate or 
weaker winds. 

Looking ahead, a cold front will push SE of 30N140W on Tue with 
strong high pressure centered north of the Hawaiian Islands 
building SE across the waters N of the ITCZ late Tue through Thu.
This will freshen the trade wind flow south of 25N Tue night 
through Thu. NW swell associated with the front will push into 
the northern waters this afternoon, building seas to 7-11 ft N 
of 10N and W of 115W by the middle of the week. Meanwhile, the 
southerly swell will continue to build seas to around 8 ft NE of
03.4S120W through late Tue. Another set of SE swell will enter
the area S of the equator by mid week and spread N through Fri.

$$
Stripling