704 
AXPZ20 KNHC 310219
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Thu Aug 31 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
0100 UTC.

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

The monsoon trough axis extends from Panama near 09N78W to
12N102W to 08N126W. The ITCZ extends from 11N140W westward. 
Scattered moderate convection is evident from 02N to 06N between 
92W and 97W, and within 180 nm either side of monsoon trough 
between 101W and 116W. Similar convection is from 11N to 14N 
between 128W and 130W.

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

Broad surface troughing extends from near Punta Eugenia to
17N114W. Gentle to moderate winds dominate the offshore waters of
Mexico. Seas are 3-5 ft from Cabo San Lazaro southward, and 5-8
ft north of there. In the Gulf of California, convection over
mainland Mexico is pushing toward the coast with the potential
for increasing winds and building seas. Similar convection is
along the coast from near the Gulf of Tehuantepec to near Cabo
Corrientes.

For the forecast, a surge of fresh to near gale force winds is
anticipated in the northern Gulf of California later this
evening, with moderate to fresh winds across the Gulf of
California thereafter through Thu night. Fresh to strong winds
will pulse in the northern Gulf of California through Fri night.
Fresh to strong northerly winds will pulse in the Gulf of
Tehuantepec Fri night through Sat night. Winds will be moderate
or weaker elsewhere through Sat. Winds will increase to moderate
to fresh nearshore Baja California Sun night as the pressure
gradient tightens along the peninsula. Meanwhile NW swell of
around 8 ft offshore Baja California Norte will subside Thu, with
seas possibly building back to around 8 offshore all of Baja
California early next week.

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

Light to gentle southwest winds prevail across the offshore 
waters N of 04N along with seas of 4-5 ft, except 4-6 ft offshore
Panama and Colombia in long-period south to southwest swell. To
the south of 04N, including the waters offshore southern Colombia
and in between Ecuador and the Galapagos Islands, moderate to
locally fresh S winds with seas of 7-9 ft are present due to 
long-period S to SW swell. Scattered tstms are noted along the
coast of Colombia, as well as El Salvador and Guatemala.

For the forecast, moderate to locally fresh south to southwest 
winds will continue between the coast of Ecuador and the 
Galapagos Islands most of the time through the weekend. Southerly
swell will keep seas around 7-9 ft there through Thu before 
subsiding slightly, then renewed long period S to SW swell will 
move through those waters Fri, increasing seas back to 7-9 ft 
through Sat through the weekend. Swell of 6-8 ft will reach the 
waters offshore Panama and Costa Rica. Elsewhere, light to gentle
variable winds will prevail through most of the the forecast,
locally and occasionally moderate to fresh near Gulfs, along
with slight to moderate seas in long-period SW swell.

...REMAINDER OF THE AREA...

The post-tropical remnant low of former Tropical Cyclone Irwin 
is centered near 19N135.5W with an estimated central pressure of
1006 mb. It is moving westward at around 10 kt. A tight pressure
gradient between the low and strong high pressure to its north 
is keeping strong to near gale force winds in the northwest 
semicircle from the low to 26N between 132W and 140W. Seas are 
10-13 ft in this area. Scattered moderate convection is present 
within 90 nm in the N quadrant. Elsewhere north of 21N and west 
of 120W, fresh N to NE winds and 7 to 10 ft seas prevail, with
locally strong winds N of 28N. Gentle to moderate winds and seas
of 5-8 ft prevail across the remainder of the waters N of 05N, 
with moderate to locally fresh southerly winds and 6-9 ft seas in
southerly swell S of 05N.

For the forecast, the post-tropical remnant low of Irwin will 
continue moving westward, with a slightly slower motion expected,
reaching 140W Fri evening. Fresh to strong winds and elevated
seas will continue to accompany the low, mainly in the NW
semicircle. Elsewhere, northerly swell will propagate through 
the open waters well W of Baja California through Fri, keeping 
seas of 6-10 ft N of 20N and W of 120W. Southerly swell in the 
far southern waters to the south of 06N will keep seas 7-10 ft 
through Thu before subsiding slightly. Another long period S 
swell event will push northward across the Equator Thu night and
Fri with seas of 8-9 ft south of 05N and east of 120W into Sat 
before subsiding late in the weekend. A broad north-south 
oriented surface trough is expected to move from along 112W to
120W by the weekend, resulting in shifting winds.

$$
Lewitsky