AXPZ20 KNHC 230253
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sat Sep 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
Central East Pacific Invest 97E: Showers and thunderstorms
continue to become better organized associated with a tropical
wave with axis along 115W from 06N to 19N, moving W at 10-15 kt.
Scattered moderate isolated strong convection is noted from 09N
to 18N between 114W and 119W. Winds are currently around 20 kt in
this area, and seas to around 7 ft. Further development of the
disturbance is likely, and a tropical depression is expected to
form this weekend or early next week while the system moves
generally westward across the central and western parts of the
eastern Pacific basin. This area has a medium chance of tropical
cyclone formation through 48 hours and a high chance through the
next 7 days.
Please read the latest NHC Tropical Weather Outlook at
www.hurricanes.gov for more details.
Please read the Special Features section for details.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 10N86W to 14N112W to 10N140W.
Scattered to numerous moderate convection is noted from 00N to
16N between 90W and 129W. Scattered showers are noted along the
trough and W of 136W.
...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A surface ridge dominates the offshore forecast waters of Baja
California supporting gentle to moderate NW winds and seas of
5-7 ft per recent altimeter data. In the Gulf of California,
winds are mainly gentle with seas of 1-3 ft, except 3-4 ft near
the entrance. Fresh to locally strong N-NE winds are noted in
and downwind of the Gulf of Tehuantepec with seas of 4-6 ft.
Elsewhere over the Mexico offshore waters, light to gentle winds
with seas of 4-6 ft in mixed SW and NW swell prevail.
For the forecast, the surface ridge will remain in control of
the weather pattern across the region into the start of next
week. Moderate NW to N winds over waters W of Baja California
will increase to fresh to locally strong from near Cabo San
Lazaro northward, starting early Sat as the parent high pressure
strengthens and builds SE into the area. Seas W of Baja
California will remain 5-7 ft through Mon night, then may build
to 7-11 ft thereafter in NW swell. Fresh to locally strong winds
in the Gulf of Tehuantepec will pulse through early Sat, and then
again starting early Tue. Winds will be mainly moderate or
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA,
COLOMBIA, AND WITHIN 750 NM OF ECUADOR...
Moderate to fresh offshore winds are noted over and downstream
the Gulf of Papagayo, with 4-6 ft seas. Seas are 3-5 ft
elsewhere. Light to gentle winds prevail elsewhere north of the
monsoon trough, except moderate in the Gulf of Panama. South of
the monsoon trough, gentle to moderate winds prevail.
For the forecast, moderate to fresh gap winds will prevail in
the Gulf of Papagayo through Sat. Elsewhere, winds will be
moderate or weaker through the next several days. Slight to
moderate seas will prevail, highest offshore Ecuador to the
Galapagos Islands, where they may build slightly in S-SW swell by
the middle of next week.
...REMAINDER OF THE AREA...
Refer to the Special Features section above for details on a
broad area of low pressure along a tropical wave near 115W.
The remnants of Kenneth are analyzed as a trough along 125W from
21N-26N. Associated winds are 15-20 kt along with 8-10 ft seas,
mainly near 23N126W. Elsewhere, winds are mainly moderate or
weaker, except fresh S of the monsoon trough between 110W and
122W. NW-N swell extends from offshore California to S of 30N
between 119W and 127W with seas to around 8 ft. Easterly swell is
supporting seas to around 8 ft in the W-central waters from
about 13N to 17N and W of 138W. Seas are 5-7 across the remainder
of the waters W of 108W, and 3-6 ft E of 108W, lowest in the lee
of the Galapagos Islands.
For the forecast, other than the broad area of low pressure
along the tropical wave near 115W, weak high pressure will
prevail N of the monsoon trough through the weekend with mainly
moderate or weaker winds. Meanwhile, the areas of seas of around
8 ft will decay later tonight, with seas of 4-7 ft across the
remainder of the waters. Looking ahead, a weakening cold front
may push just SE of 30N140W for the start of next week with
strong high pressure building in across the waters N of the
monsoon trough/ITCZ behind it. This will result in moderate to
fresh trades N of 10N and W of 120W by the middle of next week. A
set of southerly swell will build seas to around 8 ft NE of
03.4S120W by early next week, with seas of 7-9 ft S of 04N and W
of 115W by the middle of next week. Meanwhile, NW swell
associated with the frontal system N of the area will push into
the northern waters early next week building seas to 7-10 ft N of
10N and W of 118W by the middle of next week.